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14fe5a98 |
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07-Mar-2024 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Fix types of the last chip select storage variables First of all, last_cs_index_mask should be aligned with the original cs_index_mask, which is 16-bit (for now) wide. Use the same pattern for the last_cs_index_mask. Second, last_cs can be negative and since 'char' is equal to 'unsigned char' in the kernel, it's incorrect, strictly speaking, to assign signed number to it. Use s8 type as it's done for *_native_cs ones. With this change, regroup a bit the ordering to avoid too much memory space to be wasted due to paddings. Shuffle kernel documentation accordignly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://msgid.link/r/20240307150256.3789138-3-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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7b1d87af |
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19-Feb-2024 |
David Lechner <dlechner@baylibre.com> |
spi: add spi_optimize_message() APIs This adds a new spi_optimize_message() function that can be used to optimize SPI messages that are used more than once. Peripheral drivers that use the same message multiple times can use this API to perform SPI message validation and controller-specific optimizations once and then reuse the message while avoiding the overhead of revalidating the message on each spi_(a)sync() call. Internally, the SPI core will also call this function for each message if the peripheral driver did not explicitly call it. This is done to so that controller drivers don't have to have multiple code paths for optimized and non-optimized messages. A hook is provided for controller drivers to perform controller-specific optimizations. Suggested-by: Martin Sperl <kernel@martin.sperl.org> Link: https://lore.kernel.org/linux-spi/39DEC004-10A1-47EF-9D77-276188D2580C@martin.sperl.org/ Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://msgid.link/r/20240219-mainline-spi-precook-message-v2-1-4a762c6701b9@baylibre.com Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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620d269f |
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07-Feb-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
spi: Drop compat layer from renaming "master" to "controller" Now that all in-tree users followed the rename, the compat stuff can go away. This completes the renaming started with commit 8caab75fd2c2 ("spi: Generalize SPI "master" to "controller"") Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/ad1d949325b61a4682e8d6ecf9d05da751e6a99f.1707324794.git.u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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c0c0293c |
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06-Feb-2024 |
David Lechner <dlechner@baylibre.com> |
spi: drop gpf arg from __spi_split_transfer_maxsize() The __spi_split_transfer_maxsize() function has a gpf argument to allow callers to specify the type of memory allocation that needs to be used. However, this function only allocates struct spi_transfer and is not intended to be used from atomic contexts so this type should always be GFP_KERNEL, so we can just drop the argument. Some callers of these functions also passed GFP_DMA, but since only struct spi_transfer is allocated and not any tx/rx buffers, this is not actually necessary and is removed in this commit. Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://lore.kernel.org/r/20240206200648.1782234-1-dlechner@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
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c5d74fe6 |
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04-Feb-2024 |
R SUNDAR <prosunofficial@gmail.com> |
spi: Remove the @multi_cs_cap to prevent kernel-doc warnings ./include/linux/spi/spi.h:778: warning: Excess struct member 'multi_cs_cap' description in 'spi_controller' Signed-off-by: R SUNDAR <prosunofficial@gmail.com> Link: https://lore.kernel.org/r/20240204154506.3561-1-prosunofficial@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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e6c5812d |
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31-Jan-2024 |
David Lechner <dlechner@baylibre.com> |
spi: reorder spi_message struct member doc comments The members of `struct spi_message` were reordered in commit ae2ade4ba581 ("spi: Reorder fields in 'struct spi_message'") but the documentation comments were not updated to match. This commit updates the comments to match the new order. Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://msgid.link/r/20240131170732.1665105-1-dlechner@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org>
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6df534cc |
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05-Jan-2024 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
spi: make spi_bus_type const Now that the driver core can properly handle constant struct bus_type, move the spi_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Mark Brown <broonie@kernel.org> Cc: <linux-spi@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://msgid.link/r/2024010549-erasure-swoop-1cc6@gregkh Signed-off-by: Mark Brown <broonie@kernel.org>
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2f8c7c37 |
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24-Jan-2024 |
Mark Brown <broonie@kernel.org> |
spi: Raise limit on number of chip selects As reported by Guenter the limit we've got on the number of chip selects is set too low for some systems, raise the limit. We should really remove the hard coded limit but this is needed as a fix so let's do the simple thing and raise the limit for now. Fixes: 4d8ff6b0991d ("spi: Add multi-cs memories support in SPI core") Reported-by: Guenter Roeck <linux@roeck-us.net> Suggested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://msgid.link/r/20240124-spi-multi-cs-max-v2-1-df6fc5ab1abc@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
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4d8ff6b0 |
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25-Nov-2023 |
Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com> |
spi: Add multi-cs memories support in SPI core AMD-Xilinx GQSPI controller has two advanced mode that allows the controller to consider two flashes as one single device. One of these two mode is the parallel mode in which each byte of data is stored in both devices, the even bits in the lower flash & the odd bits in the upper flash. The byte split is automatically handled by the QSPI controller. The other mode is the stacked mode in which both the flashes share the same SPI bus but each of the device contain half of the data. In this mode, the controller does not follow CS requests but instead internally wires the two CS levels with the value of the most significant address bit. For supporting both these modes SPI core need to be updated for providing multiple CS for a single SPI device. For adding multi CS support the SPI device need to be aware of all the CS values. So, the "chip_select" member in the spi_device structure is now an array that holds all the CS values. spi_device structure now has a "cs_index_mask" member. This acts as an index to the chip_select array. If nth bit of spi->cs_index_mask is set then the driver would assert spi->chip_select[n]. In parallel mode all the chip selects are asserted/de-asserted simultaneously and each byte of data is stored in both devices, the even bits in one, the odd bits in the other. The split is automatically handled by the GQSPI controller. The GQSPI controller supports a maximum of two flashes connected in parallel mode. A SPI_CONTROLLER_MULTI_CS flag bit is added in the spi controller flags, through ctlr->flags the spi core will make sure that the controller is capable of handling multiple chip selects at once. For supporting multiple CS via GPIO the cs_gpiod member of the spi_device structure is now an array that holds the gpio descriptor for each chipselect. CS GPIO is not tested on our hardware, but it has been tested by @Stefan https://lore.kernel.org/all/005001da1efc$619ad5a0$24d080e0$@opensource.cirrus.com/ Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com> Tested-by: Stefan Binding <sbinding@opensource.cirrus.com> Link: https://lore.kernel.org/r/20231125092137.2948-4-amit.kumar-mahapatra@amd.com Signed-off-by: Mark Brown <broonie@kernel.org>
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39cefd85 |
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29-Nov-2023 |
Nam Cao <namcao@linutronix.de> |
spi: introduce SPI_TRANS_FAIL_IO for error reporting The default message transfer implementation - spi_transfer_one_message - invokes the specific device driver's transfer_one(), then waits for completion. However, there is no mechanism for the device driver to report failure in the middle of the transfer. Introduce SPI_TRANS_FAIL_IO for drivers to report transfer failure. Signed-off-by: Nam Cao <namcao@linutronix.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/4b420dac528e60f122adde16851da88e4798c1ea.1701274975.git.namcao@linutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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3fc6350f |
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13-Nov-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
treewide, spi: Get rid of SPI_MASTER_HALF_DUPLEX The SPI_MASTER_HALF_DUPLEX is the legacy name of a definition for a half duplex flag. Since all others had been replaced with the respective SPI_CONTROLLER prefix get rid of the last one as well. There is no functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # for input Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20231113111249.3982461-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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bef4a48f |
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07-Nov-2023 |
Mark Hasemeyer <markhas@chromium.org> |
spi: Fix null dereference on suspend A race condition exists where a synchronous (noqueue) transfer can be active during a system suspend. This can cause a null pointer dereference exception to occur when the system resumes. Example order of events leading to the exception: 1. spi_sync() calls __spi_transfer_message_noqueue() which sets ctlr->cur_msg 2. Spi transfer begins via spi_transfer_one_message() 3. System is suspended interrupting the transfer context 4. System is resumed 6. spi_controller_resume() calls spi_start_queue() which resets cur_msg to NULL 7. Spi transfer context resumes and spi_finalize_current_message() is called which dereferences cur_msg (which is now NULL) Wait for synchronous transfers to complete before suspending by acquiring the bus mutex and setting/checking a suspend flag. Signed-off-by: Mark Hasemeyer <markhas@chromium.org> Link: https://lore.kernel.org/r/20231107144743.v1.1.I7987f05f61901f567f7661763646cb7d7919b528@changeid Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@kernel.org
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a8ecbc54 |
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14-Oct-2023 |
Hans de Goede <hdegoede@redhat.com> |
spi: Export acpi_spi_find_controller_by_adev() Export acpi_spi_find_controller_by_adev() so that ACPI glue code which wants to dynamically create a spi_device using acpi_spi_device_alloc() or spi_new_device() on a controller, to which the code does not already have a reference, can find the controller. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20231014205314.59333-2-hdegoede@redhat.com Signed-off-by: Mark Brown <broonie@kernel.org>
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f6d7f050 |
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10-Oct-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Don't use flexible array in struct spi_message definition The struct spi_message can be embedded into another structures. With that the flexible array might be problematic as sparse complains about it, although there is no real issue in the code because when the message is embedded it doesn't use flexible array member. That memeber is a private to spi_message_alloc() API, so move it to that API in a form of an inherited data type. Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Fixes: 75e308ffc4f0 ("spi: Use struct_size() helper")) Closes: https://lore.kernel.org/r/20231009-onshore-underage-c58415adfd92-mkl@pengutronix.de Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de> Link: https://lore.kernel.org/r/20231010163100.89734-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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75e308ff |
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13-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Use struct_size() helper The Documentation/process/deprecated.rst suggests to use flexible array members to provide a way to declare having a dynamically sized set of trailing elements in a structure.This makes code robust agains bunch of the issues described in the documentation, main of which is about the correctness of the sizeof() calculation for this data structure. Due to above, prefer struct_size() over open-coded versions. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230714091748.89681-5-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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702ca026 |
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10-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Fix spelling typos and acronyms capitalization Fix - spelling typos - capitalization of acronyms in the comments. While at it, fix the multi-line comment style. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230710154932.68377-16-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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82238d2c |
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10-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Rename SPI_MASTER_GPIO_SS to SPI_CONTROLLER_GPIO_SS Rename SPI_MASTER_GPIO_SS to SPI_CONTROLLER_GPIO_SS and convert the users to SPI_CONTROLLER_GPIO_SS to follow the new naming shema. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230710154932.68377-14-andriy.shevchenko@linux.intel.com Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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90366cd6 |
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10-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Get rid of old SPI_MASTER_MUST_TX & SPI_MASTER_MUST_RX Convert the users from SPI_MASTER_MUST_TX and/or SPI_MASTER_MUST_RX to SPI_CONTROLLER_MUST_TX and/or SPI_CONTROLLER_MUST_RX respectively and kill the not used anymore definitions. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230710154932.68377-13-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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c397f09e |
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10-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Get rid of old SPI_MASTER_NO_TX & SPI_MASTER_NO_RX Convert the users from SPI_MASTER_NO_TX and/or SPI_MASTER_NO_RX to SPI_CONTROLLER_NO_TX and/or SPI_CONTROLLER_NO_RX respectively and kill the not used anymore definitions. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230710154932.68377-12-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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edf6a864 |
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10-Jul-2023 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Sort headers alphabetically Sorting headers alphabetically helps locating duplicates, and make it easier to figure out where to insert new headers. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20230710154932.68377-8-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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d8e4ebf87 |
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22-Jun-2023 |
Miquel Raynal <miquel.raynal@bootlin.com> |
spi: Create a helper to derive adaptive timeouts Big transfers might take a bit of time, too constraining timeouts might lead to false positives. In order to simplify the drivers work and with the goal of factorizing code in mind, let's add a helper that can be used by any spi controller driver to derive a relevant per-transfer timeout value. The logic is simple: we know how much time it would take to transfer a byte, we can easily derive the total theoretical amount of time involved for each transfer. We multiply it by two to have a bit of margin and enforce a minimum of 500ms. Suggested-by: Mark Brown <broonie@kernel.org> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/Message-Id: <20230622090634.3411468-2-miquel.raynal@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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67a142dc |
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21-Apr-2023 |
Krishna Yarlagadda <kyarlagadda@nvidia.com> |
spi: Add TPM HW flow flag TPM specification [1] defines flow control over SPI. Client device can insert a wait state on MISO when address is transmitted by controller on MOSI. Detecting the wait state in software is only possible for full duplex controllers. For controllers that support only half- duplex, the wait state detection needs to be implemented in hardware. Add a flag SPI_TPM_HW_FLOW for TPM device to set when software flow control is not possible and hardware flow control is expected from SPI controller. Reference: [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm -profile-ptp-specification/ Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Link: https://lore.kernel.org/r/20230421091309.2672-2-kyarlagadda@nvidia.com Signed-off-by: Mark Brown <broonie@kernel.org>
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027781f3 |
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10-Mar-2023 |
Leonard Göhrs <l.goehrs@pengutronix.de> |
spi: core: add spi_split_transfers_maxwords Add spi_split_transfers_maxwords() function that splits spi_transfers transparently into multiple transfers that are below a given number of SPI words. This function reuses most of its code from spi_split_transfers_maxsize() and for transfers with eight or less bits per word actually behaves the same. Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de> Link: https://lore.kernel.org/r/20230310092053.1006459-1-l.goehrs@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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d2f19eec |
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13-Mar-2023 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Constify spi parameters of chip select APIs The "spi" parameters of spi_get_chipselect() and spi_get_csgpiod() can be const. Fixes: 303feb3cc06ac066 ("spi: Add APIs in spi core to set/get spi->chip_select and spi->cs_gpiod") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/b112de79e7a1e9095a3b6ff22b639f39e39d7748.1678704562.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
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38dca04d |
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13-Mar-2023 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Constify spi_get_drvdata()'s spi parameter The "spi" parameter of spi_get_drvdata() can be const. dev_get_drvdata() has been taking a const pointer since commit 7d1d8999b4bec0ba ("i2c: Constify i2c_get_clientdata's parameter"). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/0f1700ade27a8f3935d04480ff7bef8a887331eb.1678704562.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
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cc4b1567 |
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13-Mar-2023 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Constify spi_get_ctldata()'s spi parameter The "spi" parameter of spi_get_ctldata() can be const. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/8960e07adaad8d92d2c3aa045af9ee3c5d2130a8.1678704562.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
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ae2ade4b |
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01-Mar-2023 |
Christophe JAILLET <christophe.jaillet@wanadoo.fr> |
spi: Reorder fields in 'struct spi_message' Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size from 112 to 96 bytes. This should have no real impact on memory allocation because 'struct spi_message' is mostly used on stack, but it can save a few cycles when the structure is initialized with spi_message_init() and co. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/c112aad16eb47808e1ec10abd87b3d273c969a68.1677704283.git.christophe.jaillet@wanadoo.fr Signed-off-by: Mark Brown <broonie@kernel.org>
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2a81ada3 |
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10-Jan-2023 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
driver core: make struct bus_type.uevent() take a const * The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9d77522b |
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14-Feb-2023 |
Christophe JAILLET <christophe.jaillet@wanadoo.fr> |
spi: Reorder fields in 'struct spi_transfer' Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size from 144 to 128 bytes. Turn 'timestamped' into a bitfield so that it can be easily merged with some other bifields and move 'error'. This should have no real impact on memory allocation because 'struct spi_transfer' is mostly used on stack, but it can save a few cycles when the structure is initialized or copied. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/93a051da85a895bc6003aedfb00a13e1c2fc6338.1676370870.git.christophe.jaillet@wanadoo.fr Signed-off-by: Mark Brown <broonie@kernel.org>
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6e80133a |
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09-Feb-2023 |
William Zhang <william.zhang@broadcom.com> |
spi: export spi_transfer_cs_change_delay_exec function For SPI controller that implements transfer_one_message, it needs to insert the delay that required by cs change event between the transfers. Add a wrapper for the local function _spi_transfer_cs_change_delay_exec and export it for SPI controller driver to use. Signed-off-by: William Zhang <william.zhang@broadcom.com> Link: https://lore.kernel.org/r/20230209200246.141520-9-william.zhang@broadcom.com Signed-off-by: Mark Brown <broonie@kernel.org>
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303feb3c |
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19-Jan-2023 |
Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com> |
spi: Add APIs in spi core to set/get spi->chip_select and spi->cs_gpiod Supporting multi-cs in spi core and spi controller drivers would require the chip_select & cs_gpiod members of struct spi_device to be an array. But changing the type of these members to array would break the spi driver functionality. To make the transition smoother introduced four new APIs to get/set the spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and spi->cs_gpiod references in spi core with the API calls. While adding multi-cs support in further patches the chip_select & cs_gpiod members of the spi_device structure would be converted to arrays & the "idx" parameter of the APIs would be used as array index i.e., spi->chip_select[idx] & spi->cs_gpiod[idx] respectively. Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com> Reviewed-by: Michal Simek <michal.simek@amd.com> Link: https://lore.kernel.org/r/20230119185342.2093323-2-amit.kumar-mahapatra@amd.com Signed-off-by: Mark Brown <broonie@kernel.org>
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6c6871cd |
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04-Nov-2022 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Merge spi_controller.{slave,target}_abort() Mixing SPI slave/target handlers and SPI slave/target controllers using legacy and modern naming does not work well: there are now two different callbacks for aborting a slave/target operation, of which only one is populated, while spi_{slave,target}_abort() check and use only one, which may be the unpopulated one. Fix this by merging the slave/target abort callbacks into a single callback using a union, like is already done for the slave/target flags. Fixes: b8d3b056a78dcc94 ("spi: introduce new helpers with using modern naming") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/809c82d54b85dd87ef7ee69fc93016085be85cec.1667555967.git.geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
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b8d3b056 |
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11-Oct-2022 |
Yang Yingliang <yangyingliang@huawei.com> |
spi: introduce new helpers with using modern naming For using modern names host/target to instead of all the legacy names, I think it takes 3 steps: - step1: introduce new helpers with modern naming. - step2: switch to use these new helpers in all drivers. - step3: remove all legacy helpers and update all legacy names. This patch is for step1, it introduces new helpers with host/target naming for drivers using. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20221011092204.950288-1-yangyingliang@huawei.com Signed-off-by: Mark Brown <broonie@kernel.org>
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aea672d0 |
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20-Oct-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Introduce spi_get_device_match_data() helper The proposed spi_get_device_match_data() helper is for retrieving a driver data associated with the ID in an ID table. First, it tries to get driver data of the device enumerated by firmware interface (usually Device Tree or ACPI). If none is found it falls back to the SPI ID table matching. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221020195421.10482-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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f25723dc |
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27-Sep-2022 |
Vincent Whitchurch <vincent.whitchurch@axis.com> |
spi: Save current RX and TX DMA devices Save the current RX and TX DMA devices to avoid having to duplicate the logic to pick them, since we'll need access to them in some more functions to fix a bug in the cache handling. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Link: https://lore.kernel.org/r/20220927112117.77599-2-vincent.whitchurch@axis.com Signed-off-by: Mark Brown <broonie@kernel.org>
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86432b7f |
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08-Sep-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Group cs_change and cs_off flags together in struct spi_transfer The commit 5e0531f6b90a ("spi: Add capability to perform some transfer with chipselect off") added a new flag but squeezed it into a wrong group of struct spi_transfer members (note that SPI_NBITS_* are macros for easier interpretation of the tx_nbits and rx_nbits bitfields). Group cs_change and cs_off flags together and their doc strings. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220908130518.32186-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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5e0531f6 |
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07-Sep-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
spi: Add capability to perform some transfer with chipselect off Some components require a few clock cycles with chipselect off before or/and after the data transfer done with CS on. Typically IDT 801034 QUAD PCM CODEC datasheet states "Note *: CCLK should have one cycle before CS goes low, and two cycles after CS goes high". The cycles "before" are implicitely provided by all previous activity on the SPI bus. But the cycles "after" must be provided in order to terminate the SPI transfer. In order to use that kind of component, add a cs_off flag to spi_transfer struct. When this flag is set, the transfer is performed with chipselect off. This allows consummer to add a dummy transfer at the end of the transfer list which is performed with chipselect OFF, providing the required additional clock cycles. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/r/434165c46f06d802690208a11e7ea2500e8da4c7.1662558898.git.christophe.leroy@csgroup.eu Signed-off-by: Mark Brown <broonie@kernel.org>
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b30f7c8e |
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01-Sep-2022 |
Mark Brown <broonie@kernel.org> |
spi: mux: Fix mux interaction with fast path optimisations The spi-mux driver is rather too clever and attempts to resubmit any message that is submitted to it to the parent controller with some adjusted callbacks. This does not play at all nicely with the fast path which now sets flags on the message indicating that it's being handled through the fast path, we see async messages flagged as being on the fast path. Ideally the spi-mux code would duplicate the message but that's rather invasive and a bit fragile in that it relies on the mux knowing which fields in the message to copy. Instead teach the core that there are controllers which can't cope with the fast path and have the mux flag itself as being such a controller, ensuring that messages going via the mux don't get partially handled via the fast path. This will reduce the performance of any spi-mux connected device since we'll now always use the thread for both the actual controller and the mux controller instead of just the actual controller but given that we were always hitting the slow path anyway it's hopefully not too much of an additional cost and it allows us to keep the fast path. Fixes: ae7d2346dc89 ("spi: Don't use the message queue if possible in spi_sync") Reported-by: Casper Andersson <casper.casan@gmail.com> Tested-by: Casper Andersson <casper.casan@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20220901120732.49245-1-broonie@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
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95c8222f |
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29-Jun-2022 |
David Jander <david@protonic.nl> |
spi: spi.c: Fix comment style Capitalize first word in comment where appropriate and add parentheses to function names. Reported-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220629142519.3985486-3-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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dc302905 |
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21-Jun-2022 |
David Jander <david@protonic.nl> |
spi: opportunistically skip ctlr->cur_msg_completion There are only a few drivers that do not call spi_finalize_current_message() in the context of transfer_one_message(), and even for those cases the completion ctlr->cur_msg_completion is not needed always. The calls to complete() and wait_for_completion() each take a spin-lock, which is costly. This patch makes it possible to avoid those calls in the big majority of cases, by introducing two flags that with the help of ordering via barriers can avoid using the completion safely. In case of a race with the context calling spi_finalize_current_message(), the scheme errs on the safe side and takes the completion. The impact of this patch is worth the effort: On a i.MX8MM SoC, the time the SPI bus is idle between two consecutive calls to spi_sync(), is reduced from 19.6us to 16.8us... roughly 15%. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-12-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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69fa9590 |
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21-Jun-2022 |
David Jander <david@protonic.nl> |
spi: Ensure the io_mutex is held until spi_finalize_current_message() This patch introduces a completion that is completed in spi_finalize_current_message() and waited for in __spi_pump_transfer_message(). This way all manipulation of ctlr->cur_msg is done with the io_mutex held and strictly ordered: __spi_pump_transfer_message() will not return until spi_finalize_current_message() is done using ctlr->cur_msg, and its calling context is only touching ctlr->cur_msg after returning. Due to this, we can safely drop the spin-locks around ctlr->cur_msg. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-11-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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66a22159 |
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21-Jun-2022 |
David Jander <david@protonic.nl> |
spi: Remove the now unused ctlr->idling flag The ctlr->idling flag is never checked now, so we don't need to set it either. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-8-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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ae7d2346 |
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21-Jun-2022 |
David Jander <david@protonic.nl> |
spi: Don't use the message queue if possible in spi_sync The interaction with the controller message queue and its corresponding auxiliary flags and variables requires the use of the queue_lock which is costly. Since spi_sync will transfer the complete message anyway, and not return until it is finished, there is no need to put the message into the queue if the queue is empty. This can save a lot of overhead. As an example of how significant this is, when using the MCP2518FD SPI CAN controller on a i.MX8MM SoC, the time during which the interrupt line stays active (during 3 relatively short spi_sync messages), is reduced from 98us to 72us by this patch. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-3-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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1714582a |
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21-Jun-2022 |
David Jander <david@protonic.nl> |
spi: Move ctlr->cur_msg_prepared to struct spi_message This enables the possibility to transfer a message that is not at the current tip of the async message queue. This is in preparation of the next patch(es) which enable spi_sync messages to skip the queue altogether. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-2-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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67b9d641 |
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09-Jun-2022 |
David Jander <david@protonic.nl> |
spi: Fix per-cpu stats access on 32 bit systems On 32 bit systems, the following kernel BUG is hit: BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 caller is debug_smp_processor_id+0x18/0x24 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc1-00001-g6ae0aec8a366 #181 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: dump_backtrace from show_stack+0x20/0x24 r7:81024ffd r6:00000000 r5:81024ffd r4:60000013 show_stack from dump_stack_lvl+0x60/0x78 dump_stack_lvl from dump_stack+0x14/0x1c r7:81024ffd r6:80f652de r5:80bec180 r4:819a2500 dump_stack from check_preemption_disabled+0xc8/0xf0 check_preemption_disabled from debug_smp_processor_id+0x18/0x24 r8:8119b7e0 r7:81205534 r6:819f5c00 r5:819f4c00 r4:c083d724 debug_smp_processor_id from __spi_sync+0x78/0x220 __spi_sync from spi_sync+0x34/0x4c r10:bb7bf4e0 r9:c083d724 r8:00000007 r7:81a068c0 r6:822a83c0 r5:c083d724 r4:819f4c00 spi_sync from spi_mem_exec_op+0x338/0x370 r5:000000b4 r4:c083d910 spi_mem_exec_op from spi_nor_read_id+0x98/0xdc r10:bb7bf4e0 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:82358040 r4:819f7c40 spi_nor_read_id from spi_nor_detect+0x38/0x114 r7:82358040 r6:00000000 r5:819f7c40 r4:819f7c40 spi_nor_detect from spi_nor_scan+0x11c/0xbec r10:bb7bf4e0 r9:00000000 r8:00000000 r7:c083da4c r6:00000000 r5:00010101 r4:819f7c40 spi_nor_scan from spi_nor_probe+0x10c/0x2d0 r10:bb7bf4e0 r9:bb7bf4d0 r8:00000000 r7:819f4c00 r6:00000000 r5:00000000 r4:819f7c40 per-cpu access needs to be guarded against preemption. Fixes: 6598b91b5ac3 ("spi: spi.c: Convert statistics to per-cpu u64_stats_t") Reported-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David Jander <david@protonic.nl> Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Link: https://lore.kernel.org/r/20220609121334.2984808-1-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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5dfac65b |
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08-Jun-2022 |
David Jander <david@protonic.nl> |
spi: <linux/spi/spi.h>: Add missing documentation for struct members Fixes these "make htmldocs" warnings: include/linux/spi/spi.h:82: warning: Function parameter or member 'syncp' not described in 'spi_statistics' include/linux/spi/spi.h:213: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_device' include/linux/spi/spi.h:676: warning: Function parameter or member 'pcpu_statistics' not described in 'spi_controller' Fixes: 6598b91b5ac3 ("spi: spi.c: Convert statistics to per-cpu u64_stats_t") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David Jander <david@protonic.nl> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20220608153309.2899565-1-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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6598b91b |
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24-May-2022 |
David Jander <david@protonic.nl> |
spi: spi.c: Convert statistics to per-cpu u64_stats_t This change gives a dramatic performance improvement in the hot path, since many costly spin_lock_irqsave() calls can be avoided. On an i.MX8MM system with a MCP2518FD CAN controller connected via SPI, the time the driver takes to handle interrupts, or in other words the time the IRQ line of the CAN controller stays low is mainly dominated by the time it takes to do 3 relatively short sync SPI transfers. The effect of this patch is a reduction of this time from 136us down to only 98us. Suggested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220524091808.2269898-1-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>
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657f8bd8 |
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21-May-2022 |
Julia Lawall <Julia.Lawall@inria.fr> |
spi: fix typo in comment Spelling mistake (triple letters) in comment. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Link: https://lore.kernel.org/r/20220521111145.81697-13-Julia.Lawall@inria.fr Signed-off-by: Mark Brown <broonie@kernel.org>
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19368f0f |
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19-Apr-2022 |
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> |
spi: Use helper for safer setting of driver_override Use a helper to set driver_override to the reduce amount of duplicated code. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20220419113435.246203-8-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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75d6fe48 |
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12-May-2022 |
Siddh Raman Pant <siddhpant.gh@gmail.com> |
spi: Doc fix - Describe add_lock and dma_map_dev in spi_controller This fixes the corresponding warnings during building the docs. Signed-off-by: Siddh Raman Pant <siddhpant.gh@gmail.com> Link: https://lore.kernel.org/r/4e6187a4-d0f8-4750-e407-e09cc1c91789@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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4a3cc7fb |
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27-Jan-2022 |
Miquel Raynal <miquel.raynal@bootlin.com> |
spi: spi-mem: Introduce a capability structure Create a spi_controller_mem_caps structure and put it within the spi_controller structure close to the spi_controller_mem_ops strucure. So far the only field in this structure is the support for dtr operations, but soon we will add another parameter. Also create a helper to parse the capabilities and check if the requested capability has been set or not. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Reviewed-by: Pratyush Yadav <p.yadav@ti.com> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-2-miquel.raynal@bootlin.com
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6bb477df |
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17-Feb-2022 |
Yun Zhou <yun.zhou@windriver.com> |
spi: use specific last_cs instead of last_cs_enable Commit d40f0b6f2e21 instroduced last_cs_enable to avoid setting chipselect if it's not necessary, but it also introduces a bug. The chipselect may not be set correctly on multi-device SPI busses. The reason is that we can't judge the chipselect by bool last_cs_enable, since chipselect may be modified after other devices were accessed. So we should record the specific state of chipselect in case of confusion. Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Link: https://lore.kernel.org/r/20220217141234.72737-1-yun.zhou@windriver.com Signed-off-by: Mark Brown <broonie@kernel.org>
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f48dc6b9 |
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10-Feb-2022 |
Linus Walleij <linus.walleij@linaro.org> |
spi: Retire legacy GPIO handling All drivers using GPIOs as chip select have been rewritten to use GPIO descriptors passing the ->use_gpio_descriptors flag. Retire the code and fields used by the legacy GPIO API. Do not drop the ->use_gpio_descriptors flag: it now only indicates that we want to use GPIOs in addition to native chip selects. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20220210231954.807904-1-linus.walleij@linaro.org Signed-off-by: Mark Brown <broonie@kernel.org>
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a0386bba |
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23-Jan-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
spi: make remove callback a void function The value returned by an spi driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Claudius Heine <ch@denx.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com> Acked-by: Łukasz Stelmach <l.stelmach@samsung.com> Acked-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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e612af7a |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Add API to count spi acpi resources Some ACPI nodes may have more than one Spi Resource. To be able to handle these case, its necessary to have a way of counting these resources. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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87e59b36 |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Support selection of the index of the ACPI Spi Resource before alloc If a node contains more than one SPI resource it may be necessary to use an index to select which one you want to allocate a spi device for. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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000bee0e |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Create helper API to lookup ACPI info for spi device This can then be used to find a spi resource inside an ACPI node, and allocate a spi device. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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e3dc1399 |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Make spi_alloc_device and spi_add_device public again This functions were previously made private since they were not used. However, these functions will be needed again. Partial revert of commit da21fde0fdb3 ("spi: Make several public functions private to spi.c") Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-2-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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11396230 |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Add API to count spi acpi resources Some ACPI nodes may have more than one Spi Resource. To be able to handle these case, its necessary to have a way of counting these resources. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-5-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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92640f98 |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Support selection of the index of the ACPI Spi Resource before alloc If a node contains more than one SPI resource it may be necessary to use an index to select which one you want to allocate a spi device for. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-4-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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70dd264b |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Create helper API to lookup ACPI info for spi device This can then be used to find a spi resource inside an ACPI node, and allocate a spi device. Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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941bffd7 |
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21-Jan-2022 |
Stefan Binding <sbinding@opensource.cirrus.com> |
spi: Make spi_alloc_device and spi_add_device public again This functions were previously made private since they were not used. However, these functions will be needed again. Partial revert of commit da21fde0fdb3 ("spi: Make several public functions private to spi.c") Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20220121172431.6876-2-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
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44ea6281 |
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03-Sep-2021 |
Jakub Kicinski <kuba@kernel.org> |
spi: don't include ptp_clock_kernel.h in spi.h Commit b42faeee718c ("spi: Add a PTP system timestamp to the transfer structure") added an include of ptp_clock_kernel.h to spi.h for struct ptp_system_timestamp but a forward declaration is enough. Let's use that to limit the number of objects we have to rebuild every time we touch networking headers. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20210904013140.2377609-1-kuba@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
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#
da21fde0 |
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07-Oct-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
spi: Make several public functions private to spi.c All these functions have no callers apart from drivers/spi/spi.c. So drop their declarations in include/linux/spi/spi.h and don't export them. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20211007121415.2401638-5-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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#
bdc7ca00 |
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07-Oct-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
spi: Remove unused function spi_busnum_to_master() The last user is gone since commit 2962db71c703 ("staging/fbtft: Remove fbtft_device") in 2019. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20211007121415.2401638-3-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6098475d |
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08-Oct-2021 |
Mark Brown <broonie@kernel.org> |
spi: Fix deadlock when adding SPI controllers on SPI buses Currently we have a global spi_add_lock which we take when adding new devices so that we can check that we're not trying to reuse a chip select that's already controlled. This means that if the SPI device is itself a SPI controller and triggers the instantiation of further SPI devices we trigger a deadlock as we try to register and instantiate those devices while in the process of doing so for the parent controller and hence already holding the global spi_add_lock. Since we only care about concurrency within a single SPI bus move the lock to be per controller, avoiding the deadlock. This can be easily triggered in the case of spi-mux. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
04e6bb0d |
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04-Aug-2021 |
Mason Zhang <Mason.Zhang@mediatek.com> |
spi: modify set_cs_timing parameter This patch modified set_cs_timing parameter, no need pass in spi_delay to set_cs_timing callback. By the way, we modified the mediatek and tegra114 spi driver to fix build err. In mediatek spi driver, We have support set absolute time not clk_count, and call this function in prepare_message not user's API. Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com> Link: https://lore.kernel.org/r/20210804133746.6742-1-Mason.Zhang@mediatek.com Signed-off-by: Mark Brown <broonie@kernel.org>
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8c33ebfe |
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04-Aug-2021 |
Mason Zhang <Mason.Zhang@mediatek.com> |
spi: move cs spi_delay to spi_device As we know, spi core layer has removed spi_set_cs_timing() API. So this patch moved spi_delay for cs_timing from spi_controller to spi_device, because cs timing should be set by spi_device but not controller. Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com> Link: https://lore.kernel.org/r/20210804133716.32040-1-Mason.Zhang@mediatek.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
8dd591ad |
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28-Jun-2021 |
Randy Dunlap <rdunlap@infradead.org> |
spi: <linux/spi/spi.h>: add missing struct kernel-doc entry Fix kernel-doc warning in spi.h by adding the missing kernel-doc entry and also correct the original comment so that they both indicate the correct polarity of the flag. ../include/linux/spi/spi.h:673: warning: Function parameter or member 'devm_allocated' not described in 'spi_controller' Fixes: 794aaf01444d ("spi: Fix use-after-free with devm_spi_alloc_*") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: William A. Kennington III <wak@google.com> Cc: Mark Brown <broonie@kernel.org> Cc: linux-spi@vger.kernel.org Cc: Lukas Wunner <lukas@wunner.de> Reviewed-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/20210628210520.5712-1-rdunlap@infradead.org Signed-off-by: Mark Brown <broonie@kernel.org>
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#
b470e10e |
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24-Jun-2021 |
Vinod Koul <vkoul@kernel.org> |
spi: core: add dma_map_dev for dma device Some controllers like qcom geni need the parent device to be used for dma mapping, so add a dma_map_dev field and let drivers fill this to be used as mapping device Signed-off-by: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
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#
0c79378c |
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21-Jun-2021 |
Sebastian Reichel <sebastian.reichel@collabora.com> |
spi: add ancillary device support Introduce support for ancillary devices, similar to existing implementation for I2C. This is useful for devices having multiple chip-selects, for example some microcontrollers provide a normal SPI interface and a flashing SPI interface. Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Link: https://lore.kernel.org/r/20210621175359.126729-2-sebastian.reichel@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
4ccf3598 |
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09-Jun-2021 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
spi: remove spi_set_cs_timing() No one seems to be using this global and exported function, so remove it as it is no longer needed. Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210609071918.2852069-1-gregkh@linuxfoundation.org Signed-off-by: Mark Brown <broonie@kernel.org>
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#
35f3f850 |
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10-May-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Switch to signed types for *_native_cs SPI controller fields While fixing undefined behaviour the commit f60d7270c8a3 ("spi: Avoid undefined behaviour when counting unused native CSs") missed the case when all CSs are GPIOs and thus unused_native_cs will be evaluated to -1 in unsigned representation. This will falsely trigger a condition in the spi_get_gpio_descs(). Switch to signed types for *_native_cs SPI controller fields to fix above. Fixes: f60d7270c8a3 ("spi: Avoid undefined behaviour when counting unused native CSs") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20210510131242.49455-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
794aaf01 |
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07-Apr-2021 |
William A. Kennington III <wak@google.com> |
spi: Fix use-after-free with devm_spi_alloc_* We can't rely on the contents of the devres list during spi_unregister_controller(), as the list is already torn down at the time we perform devres_find() for devm_spi_release_controller. This causes devices registered with devm_spi_alloc_{master,slave}() to be mistakenly identified as legacy, non-devm managed devices and have their reference counters decremented below 0. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174 [<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98) [<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24) r4:b6700140 [<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40) [<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4) r5:b6700180 r4:b6700100 [<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60) r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10 [<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec) r5:b117ad94 r4:b163dc10 [<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0) r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10 [<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8) Instead, determine the devm allocation state as a flag on the controller which is guaranteed to be stable during cleanup. Fixes: 5e844cc37a5c ("spi: Introduce device-managed SPI controller allocation") Signed-off-by: William A. Kennington III <wak@google.com> Link: https://lore.kernel.org/r/20210407095527.2771582-1-wak@google.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d6644a1c |
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01-Apr-2021 |
Wan Jiabing <wanjiabing@vivo.com> |
spi: Remove repeated struct declaration struct spi_transfer is declared twice. One is declared at 24th line. The blew one is not needed though. Remove the duplicate. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20210401065904.994121-1-wanjiabing@vivo.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
df41a5da |
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03-Mar-2021 |
Heikki Krogerus <heikki.krogerus@linux.intel.com> |
spi: Remove support for dangling device properties >From now on only accepting complete software nodes. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20210303152814.35070-5-heikki.krogerus@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
47afc77b |
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03-Mar-2021 |
Heikki Krogerus <heikki.krogerus@linux.intel.com> |
spi: Add support for software nodes Making it possible for the drivers to assign complete software fwnodes to the devices instead of only the device properties in those nodes. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20210303152814.35070-2-heikki.krogerus@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
3ab1cce5 |
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08-Mar-2021 |
Alexandru Ardelean <aardelean@deviqon.com> |
spi: core: remove 'delay_usecs' field from spi_transfer The 'delay' field in the spi_transfer struct is meant to replace the 'delay_usecs' field. However some cleanup was required to remove the uses of 'delay_usecs'. Now that it's been cleaned up, we can remove it from the kernel tree. Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com> Link: https://lore.kernel.org/r/20210308145502.1075689-10-aardelean@deviqon.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
883c36a3 |
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08-Feb-2021 |
Bhaskar Chowdhury <unixbhaskar@gmail.com> |
spi: Change provied to provided in the file spi.h s/provied/provided/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Link: https://lore.kernel.org/r/20210208114928.32241-1-unixbhaskar@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
98621ed0 |
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21-Dec-2020 |
Sowjanya Komatineni <skomatineni@nvidia.com> |
spi: spi-mem: Mark dummy transfers by setting dummy_data bit This patch marks dummy transfer by setting dummy_data bit to 1. Controllers supporting dummy transfer by hardware use this bit field to skip software transfer of dummy bytes and use hardware dummy bytes transfer. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Link: https://lore.kernel.org/r/1608585459-17250-6-git-send-email-skomatineni@nvidia.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d962608c |
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21-Dec-2020 |
Dragos Bogdan <dragos.bogdan@analog.com> |
spi: Add SPI_NO_TX/RX support Transmit/receive only is a valid SPI mode. For example, the MOSI/TX line might be missing from an ADC while for a DAC the MISO/RX line may be optional. This patch adds these two new modes: SPI_NO_TX and SPI_NO_RX. This way, the drivers will be able to identify if any of these two lines is missing and to adjust the transfers accordingly. Signed-off-by: Dragos Bogdan <dragos.bogdan@analog.com> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20201221152936.53873-2-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
f7005142 |
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21-Dec-2020 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: uapi: unify SPI modes into a single spi.h header This change moves all the SPI mode bits into a separate 'spi.h' header in uAPI. This is meant to re-use these definitions inside the kernel as well as export them to userspace (via uAPI). The SPI mode definitions have usually been duplicated between between 'include/linux/spi/spi.h' and 'include/uapi/linux/spi/spidev.h', so whenever adding a new entry, this would need to be put in both headers. They've been moved from 'include/linux/spi/spi.h', since that seems a bit more complete; the bits have descriptions and there is the SPI_MODE_X_MASK. This change also does a conversion of these bitfields to _BITUL() macro. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20201221152936.53873-1-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
5e844cc3 |
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11-Nov-2020 |
Lukas Wunner <lukas@wunner.de> |
spi: Introduce device-managed SPI controller allocation SPI driver probing currently comprises two steps, whereas removal comprises only one step: spi_alloc_master() spi_register_controller() spi_unregister_controller() That's because spi_unregister_controller() calls device_unregister() instead of device_del(), thereby releasing the reference on the spi_controller which was obtained by spi_alloc_master(). An SPI driver's private data is contained in the same memory allocation as the spi_controller struct. Thus, once spi_unregister_controller() has been called, the private data is inaccessible. But some drivers need to access it after spi_unregister_controller() to perform further teardown steps. Introduce devm_spi_alloc_master() and devm_spi_alloc_slave(), which release a reference on the spi_controller struct only after the driver has unbound, thereby keeping the memory allocation accessible. Change spi_unregister_controller() to not release a reference if the spi_controller was allocated by one of these new devm functions. The present commit is small enough to be backportable to stable. It allows fixing drivers which use the private data in their ->remove() hook after it's been freed. It also allows fixing drivers which neglect to release a reference on the spi_controller in the probe error path. Long-term, most SPI drivers shall be moved over to the devm functions introduced herein. The few that can't shall be changed in a treewide commit to explicitly release the last reference on the controller. That commit shall amend spi_unregister_controller() to no longer release a reference, thereby completing the migration. As a result, the behaviour will be less surprising and more consistent with subsystems such as IIO, which also includes the private data in the allocation of the generic iio_dev struct, but calls device_del() in iio_device_unregister(). Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org>
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#
029b42d8 |
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27-Oct-2020 |
Oleksij Rempel <linux@rempel-privat.de> |
spi: introduce SPI_MODE_X_MASK macro Provide a macro to filter all SPI_MODE_0,1,2,3 mode in one run. The latest SPI framework will parse the devicetree in following call sequence: of_register_spi_device() -> of_spi_parse_dt() So, driver do not need to pars the devicetree and will get prepared flags in the probe. On one hand it is good far most drivers. On other hand some drivers need to filter flags provide by SPI framework and apply know to work flags. This drivers may use SPI_MODE_X_MASK to filter MODE flags and set own, known flags: spi->flags &= ~SPI_MODE_X_MASK; spi->flags |= SPI_MODE_0; Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20201027095724.18654-2-o.rempel@pengutronix.de Signed-off-by: Mark Brown <broonie@kernel.org>
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#
cfd97f94 |
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24-Jul-2020 |
Colton Lewis <colton.w.lewis@protonmail.com> |
spi: correct kernel-doc inconsistency Silence documentation build warnings by correcting kernel-doc comment for spi_transfer struct. Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com> Link: https://lore.kernel.org/r/20200725050242.279548-1-colton.w.lewis@protonmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
2ae3de10 |
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15-Jul-2020 |
Randy Dunlap <rdunlap@infradead.org> |
spi: fix duplicated word in <linux/spi/spi.h> Change doubled word "as" to "as a". Change "Return: Return:" in kernel-doc notation to have only one "Return:". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Mark Brown <broonie@kernel.org> Cc: linux-spi@vger.kernel.org Link: https://lore.kernel.org/r/40354d64-be71-3952-a980-63a76a278145@infradead.org Signed-off-by: Mark Brown <broonie@kernel.org>
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#
60a883d1 |
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09-Jul-2020 |
Marek Szyprowski <m.szyprowski@samsung.com> |
spi: use kthread_create_worker() helper Use kthread_create_worker() helper to simplify the code. It uses the kthread worker API the right way. It will eventually allow to remove the FIXME in kthread_worker_fn() and add more consistency checks in the future. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20200709065007.26896-1-m.szyprowski@samsung.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d40f0b6f |
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29-Jun-2020 |
Douglas Anderson <dianders@chromium.org> |
spi: Avoid setting the chip select if we don't need to On some SPI controllers (like spi-geni-qcom) setting the chip select is a heavy operation. For instance on spi-geni-qcom, with the current code, is was measured as taking upwards of 20 us. Even on SPI controllers that aren't as heavy, setting the chip select is at least something like a MMIO operation over some peripheral bus which isn't as fast as a RAM access. While it would be good to find ways to mitigate problems like this in the drivers for those SPI controllers, it can also be noted that the SPI framework could also help out. Specifically, in some situations, we can see the SPI framework calling the driver's set_cs() with the same parameter several times in a row. This is specifically observed when looking at the way the Chrome OS EC SPI driver (cros_ec_spi) works but other drivers likely trip it to some extent. Let's solve this by caching the chip select state in the core and only calling into the controller if there was a change. We check not only the "enable" state but also the chip select mode (active high or active low) since controllers may care about both the mode and the enable flag in their callback. Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20200629164103.1.Ied8e8ad8bbb2df7f947e3bc5ea1c315e041785a2@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
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#
809b1b04 |
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16-Jun-2020 |
Robin Gong <yibin.gong@nxp.com> |
spi: introduce fallback to pio Add fallback to pio mode in case dma transfer failed with error status SPI_TRANS_FAIL_NO_START. If spi client driver want to enable this feature please set xfer->error in the proper place such as dmaengine_prep_slave_sg() failure detect(but no any data put into spi bus yet). Besides, add master->fallback checking in its can_dma() so that spi core could switch to pio next time. Please refer to spi-imx.c. Signed-off-by: Robin Gong <yibin.gong@nxp.com> Link: https://lore.kernel.org/r/1592347329-28363-2-git-send-email-yibin.gong@nxp.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ad89c885 |
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14-Apr-2020 |
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
docs: spi: spi.h: fix a doc building warning We need to add a blank line to avoid this warning: ./include/linux/spi/spi.h:401: WARNING: Unexpected indentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/1c701b3ac903dc0bc304dca958fbdee53bd38dc3.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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#
7a86a419 |
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09-Mar-2020 |
Qiujun Huang <hqjagain@gmail.com> |
spi: update the structure documentation some members were not described in documentation. Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Link: https://lore.kernel.org/r/1583774179-30736-1-git-send-email-hqjagain@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6a726824 |
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04-Mar-2020 |
Vladimir Oltean <vladimir.oltean@nxp.com> |
spi: Do spi_take_timestamp_pre for as many times as necessary When dealing with a SPI controller driver that is sending more than 1 byte at once (or the entire buffer at once), and the SPI peripheral driver has requested timestamping for a byte in the middle of the buffer, we find that spi_take_timestamp_pre never records a "pre" timestamp. This happens because the function currently expects to be called with the "progress" argument >= to what the peripheral has requested to be timestamped. But clearly there are cases when that isn't going to fly. And since we can't change the past when we realize that the opportunity to take a "pre" timestamp has just passed and there isn't going to be another one, the approach taken is to keep recording the "pre" timestamp on each call, overwriting the previously recorded one until the "post" timestamp is also taken. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20200304220044.11193-8-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ea235786 |
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28-Feb-2020 |
John Garry <john.garry@huawei.com> |
spi: Allow SPI controller override device buswidth Currently ACPI firmware description for a SPI device does not have any method to describe the data buswidth on the board. So even through the controller and device may support higher modes than standard SPI, it cannot be assumed that the board does - as such, that device is limited to standard SPI in such a circumstance. As a workaround, allow the controller driver supply buswidth override bits, which are used inform the core code that the controller driver knows the buswidth supported on that board for that device. A host controller driver might know this info from DMI tables, for example. Signed-off-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/1582903131-160033-2-git-send-email-john.garry@huawei.com Signed-off-by: Mark Brown <broonie@kernel.org>
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#
7d93aecd |
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02-Jan-2020 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Add generic support for unused native cs with cs-gpios Some SPI master controllers always drive a native chip select when performing a transfer. Hence when using both native and GPIO chip selects, at least one native chip select must be left unused, to be driven when performing transfers with slave devices using GPIO chip selects. Currently, to find an unused native chip select, SPI controller drivers need to parse and process cs-gpios theirselves. This is not only duplicated in each driver that needs it, but also duplicates part of the work done later at SPI controller registration time. Note that this cannot be done after spi_register_controller() returns, as at that time, slave devices may have been probed already. Hence add generic support to the SPI subsystem for finding an unused native chip select. Optionally, this unused native chip select, and all other in-use native chip selects, can be validated against the maximum number of native chip selects available on the controller hardware. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/20200102133822.29346-2-geert+renesas@glider.be Signed-off-by: Mark Brown <broonie@kernel.org>
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#
862dd2a9 |
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26-Dec-2019 |
Vladimir Oltean <olteanv@gmail.com> |
spi: Don't look at TX buffer for PTP system timestamping The API for PTP system timestamping (associating a SPI transaction with the system time at which it was transferred) is flawed: it assumes that the xfer->tx_buf pointer will always be present. This is, of course, not always the case. So introduce a "progress" variable that denotes how many word have been transferred. Fix the Freescale DSPI driver, the only user of the API so far, in the same patch. Fixes: b42faeee718c ("spi: Add a PTP system timestamp to the transfer structure") Fixes: d6b71dfaeeba ("spi: spi-fsl-dspi: Implement the PTP system timestamping for TCFQ mode") Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Link: https://lore.kernel.org/r/20191227012417.1057-1-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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a3470c18 |
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23-Oct-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: document CS setup, hold & inactive times in header This change documents the CS setup, host & inactive times. They were omitted when the fields were added, and were caught by one of the build bots. Fixes: 25093bdeb6bc ("spi: implement SW control for CS times") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20191023070046.12478-1-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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3984d39b |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: spi-fsl-espi: convert transfer delay to `spi_delay` format The way the max delay is computed for this controller, it looks like it is searching for the max delay from an SPI message a using that. No idea if this is valid. But this change should support both `delay_usecs` and the new `delay` data which is of `spi_delay` type. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-17-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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25093bde |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: implement SW control for CS times This change implements CS control for setup, hold & inactive delays. The `cs_setup` delay is completely new, and can help with cases where asserting the CS, also brings the device out of power-sleep, where there needs to be a longer (than usual), before transferring data. The `cs_hold` time can overlap with the `delay` (or `delay_usecs`) from an SPI transfer. The main difference is that `cs_hold` implies that CS will be de-asserted. The `cs_inactive` delay does not have a clear use-case yet. It has been implemented mostly because the `spi_set_cs_timing()` function implements it. To some degree, this could overlap or replace `cs_change_delay`, but this will require more consideration/investigation in the future. All these delays have been added to the `spi_controller` struct, as they would typically be configured by calling `spi_set_cs_timing()` after an `spi_setup()` call. Software-mode for CS control, implies that the `set_cs_timing()` hook has not been provided for the `spi_controller` object. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-16-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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81059366 |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: tegra114: change format for `spi_set_cs_timing()` function The initial version of `spi_set_cs_timing()` was implemented with consideration only for clock-cycles as delay. For cases like `CS setup` time, it's sometimes needed that micro-seconds (or nano-seconds) are required, or sometimes even longer delays, for cases where the device needs a little longer to start transferring that after CS is asserted. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-15-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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bebcfd27 |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: introduce `delay` field for `spi_transfer` + spi_transfer_delay_exec() The change introduces the `delay` field to the `spi_transfer` struct as an `struct spi_delay` type. This intends to eventually replace `delay_usecs`. But, since there are many users of `delay_usecs`, this needs some intermediate work. A helper called `spi_transfer_delay_exec()` is also added, which maintains backwards compatibility with `delay_usecs`, by assigning the value to `delay` if non-zero. This should maintain backwards compatibility with current users of `udelay_usecs`. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-9-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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6c613f68 |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: core,atmel: convert `word_delay_usecs` -> `word_delay` for spi_device This change does a conversion from the `word_delay_usecs` -> `word_delay` for the `spi_device` struct. This allows users to specify inter-word delays in other unit types (nano-seconds or clock cycles), depending on how users want. The Atmel SPI driver is the only current user of the `word_delay_usecs` field (from the `spi_device` struct). So, it needed a slight conversion to use the `word_delay` as an `spi_delay` struct. In SPI core, the only required mechanism is to update the `word_delay` information per `spi_transfer`. This requires a bit more logic than before, because it needs that both delays be converted to a common unit (nano-seconds) for comparison. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-8-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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84593a13 |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: sprd: convert transfer word delay to spi_delay struct The Spreadtrum SPI driver is the only user of the `word_delay` field in the `spi_transfer` struct. This change converts the field to use the `spi_delay` struct. This also enforces the users to specify the delay unit to be `SPI_DELAY_UNIT_SCK`. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-5-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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329f0dac |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: make `cs_change_delay` the first user of the `spi_delay` logic Since the logic for `spi_delay` struct + `spi_delay_exec()` has been copied from the `cs_change_delay` logic, it's natural to make this delay, the first user. The `cs_change_delay` logic requires that the default remain 10 uS, in case it is unspecified/unconfigured. So, there is some special handling needed to do that. The ADIS library is one of the few users of the new `cs_change_delay` parameter for an spi_transfer. The introduction of the `spi_delay` struct, requires that the users of of `cs_change_delay` get an update. This change also updates the ADIS library. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-4-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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b2c98153 |
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26-Sep-2019 |
Alexandru Ardelean <alexandru.ardelean@analog.com> |
spi: introduce spi_delay struct as "value + unit" & spi_delay_exec() There are plenty of delays that have been introduced in SPI core. Most of them are in micro-seconds, some need to be in nano-seconds, and some in clock-cycles. For some of these delays (related to transfers & CS timing) it may make sense to have a `spi_delay` struct that abstracts these a bit. The important element of these delays [for unification] seems to be the `unit` of the delay. It looks like micro-seconds is good enough for most people, but every-once in a while, some delays seem to require other units of measurement. This change adds the `spi_delay` struct & a `spi_delay_exec()` function that processes a `spi_delay` object/struct to execute the delay. It's a copy of the `cs_change_delay` mechanism, but without the default for 10 uS. The clock-cycle delay unit is a bit special, as it needs to be bound to an `spi_transfer` object to execute. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Link: https://lore.kernel.org/r/20190926105147.7839-3-alexandru.ardelean@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
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79591b7d |
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04-Sep-2019 |
Vladimir Oltean <olteanv@gmail.com> |
spi: Add a PTP system timestamp to the transfer structure SPI is one of the interfaces used to access devices which have a POSIX clock driver (real time clocks, 1588 timers etc). The fact that the SPI bus is slow is not what the main problem is, but rather the fact that drivers don't take a constant amount of time in transferring data over SPI. When there is a high delay in the readout of time, there will be uncertainty in the value that has been read out of the peripheral. When that delay is constant, the uncertainty can at least be approximated with a certain accuracy which is fine more often than not. Timing jitter occurs all over in the kernel code, and is mainly caused by having to let go of the CPU for various reasons such as preemption, servicing interrupts, going to sleep, etc. Another major reason is CPU dynamic frequency scaling. It turns out that the problem of retrieving time from a SPI peripheral with high accuracy can be solved by the use of "PTP system timestamping" - a mechanism to correlate the time when the device has snapshotted its internal time counter with the Linux system time at that same moment. This is sufficient for having a precise time measurement - it is not necessary for the whole SPI transfer to be transmitted "as fast as possible", or "as low-jitter as possible". The system has to be low-jitter for a very short amount of time to be effective. This patch introduces a PTP system timestamping mechanism in struct spi_transfer. This is to be used by SPI device drivers when they need to know the exact time at which the underlying device's time was snapshotted. More often than not, SPI peripherals have a very exact timing for when their SPI-to-interconnect bridge issues a transaction for snapshotting and reading the time register, and that will be dependent on when the SPI-to-interconnect bridge figures out that this is what it should do, aka as soon as it sees byte N of the SPI transfer. Since spi_device drivers are the ones who'd know best how the peripheral behaves in this regard, expose a mechanism in spi_transfer which allows them to specify which word (or word range) from the transfer should be timestamped. Add a default implementation of the PTP system timestamping in the SPI core. This is not going to be satisfactory performance-wise, but should at least increase the likelihood that SPI device drivers will use PTP system timestamping in the future. There are 3 entry points from the core towards the SPI controller drivers: - transfer_one: The driver is passed individual spi_transfers to execute. This is the easiest to timestamp. - transfer_one_message: The core passes the driver an entire spi_message (a potential batch of spi_transfers). The core puts the same pre and post timestamp to all transfers within a message. This is not ideal, but nothing better can be done by default anyway, since the core has no insight into how the driver batches the transfers. - transfer: Like transfer_one_message, but for unqueued drivers (i.e. the driver implements its own queue scheduling). Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Link: https://lore.kernel.org/r/20190905010114.26718-3-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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b42faeee |
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04-Sep-2019 |
Vladimir Oltean <olteanv@gmail.com> |
spi: Add a PTP system timestamp to the transfer structure SPI is one of the interfaces used to access devices which have a POSIX clock driver (real time clocks, 1588 timers etc). The fact that the SPI bus is slow is not what the main problem is, but rather the fact that drivers don't take a constant amount of time in transferring data over SPI. When there is a high delay in the readout of time, there will be uncertainty in the value that has been read out of the peripheral. When that delay is constant, the uncertainty can at least be approximated with a certain accuracy which is fine more often than not. Timing jitter occurs all over in the kernel code, and is mainly caused by having to let go of the CPU for various reasons such as preemption, servicing interrupts, going to sleep, etc. Another major reason is CPU dynamic frequency scaling. It turns out that the problem of retrieving time from a SPI peripheral with high accuracy can be solved by the use of "PTP system timestamping" - a mechanism to correlate the time when the device has snapshotted its internal time counter with the Linux system time at that same moment. This is sufficient for having a precise time measurement - it is not necessary for the whole SPI transfer to be transmitted "as fast as possible", or "as low-jitter as possible". The system has to be low-jitter for a very short amount of time to be effective. This patch introduces a PTP system timestamping mechanism in struct spi_transfer. This is to be used by SPI device drivers when they need to know the exact time at which the underlying device's time was snapshotted. More often than not, SPI peripherals have a very exact timing for when their SPI-to-interconnect bridge issues a transaction for snapshotting and reading the time register, and that will be dependent on when the SPI-to-interconnect bridge figures out that this is what it should do, aka as soon as it sees byte N of the SPI transfer. Since spi_device drivers are the ones who'd know best how the peripheral behaves in this regard, expose a mechanism in spi_transfer which allows them to specify which word (or word range) from the transfer should be timestamped. Add a default implementation of the PTP system timestamping in the SPI core. This is not going to be satisfactory performance-wise, but should at least increase the likelihood that SPI device drivers will use PTP system timestamping in the future. There are 3 entry points from the core towards the SPI controller drivers: - transfer_one: The driver is passed individual spi_transfers to execute. This is the easiest to timestamp. - transfer_one_message: The core passes the driver an entire spi_message (a potential batch of spi_transfers). The core puts the same pre and post timestamp to all transfers within a message. This is not ideal, but nothing better can be done by default anyway, since the core has no insight into how the driver batches the transfers. - transfer: Like transfer_one_message, but for unqueued drivers (i.e. the driver implements its own queue scheduling). Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Link: https://lore.kernel.org/r/20190905010114.26718-3-olteanv@gmail.com Signed-off-by: Mark Brown <broonie@kernel.org>
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36f34737 |
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15-Jun-2019 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: Add a prototype for exported spi_set_cs_timing() Compiler is not happy about spi_set_cs_timing() prototype. drivers/spi/spi.c:3016:6: warning: no previous prototype for ‘spi_set_cs_timing’ [-Wmissing-prototypes] void spi_set_cs_timing(struct spi_device *spi, u8 setup, u8 hold, ^~~~~~~~~~~~~~~~~ Let's add it to the header. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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924b5867 |
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15-May-2019 |
Douglas Anderson <dianders@chromium.org> |
spi: Allow SPI devices to request the pumping thread be realtime Right now the only way to get the SPI pumping thread bumped up to realtime priority is for the controller to request it. However it may be that the controller works fine with the normal priority but communication to a particular SPI device on the bus needs realtime priority. Let's add a way for devices to request realtime priority when they set themselves up. NOTE: this will just affect the priority of transfers that end up on the SPI core's pumping thread. In many cases transfers happen in the context of the caller so if you need realtime priority for all transfers you should ensure the calling context is also realtime priority. Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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5d7e2b5e |
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23-Feb-2019 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: allow reporting the effectivly used speed_hz for a transfer Provide a means for the spi bus driver to report the effectively used spi clock frequency used for each spi_transfer. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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d5864e5b |
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23-Feb-2019 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: allow defining time that cs is deasserted as a multiple of SCK Support setting a delay between cs assert and deassert as a multiple of spi clock length. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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0ff2de8b |
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23-Feb-2019 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: allow defining time that cs is deasserted For some SPI devices that support speed_hz > 1MHz the default 10 us delay when cs_change = 1 is typically way to long and may result in poor spi bus utilization. This patch makes it possible to control the delay at micro or nano second resolution on a per spi_transfer basis. It even allows an "as fast as possible" mode with: xfer.cs_change_delay_unit = SPI_DELAY_UNIT_NSECS; xfer.cs_change_delay = 0; The delay code is shared between delay_usecs and cs_change_delay for consistency and reuse, so in the future this change_delay_unit could also apply to delay_usec as well. Note that on slower SOCs/CPU actually reaching ns deasserts on cs is not realistic as the gpio overhead alone (without any delays added ) may already leave cs deasserted for more than 1us - at least on a raspberry pi. But at the very least this way we can keep it as short as possible. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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937e6d75 |
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15-Apr-2019 |
Sowjanya Komatineni <skomatineni@nvidia.com> |
spi: expand mode support This patch changes mode and mode_bits from u16 to u32 to allow more mode configurations. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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e6f3f7e4 |
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12-Apr-2019 |
Noralf Trønnes <noralf@tronnes.org> |
spi: Add spi_is_bpw_supported() This let SPI clients check if the controller supports a particular word width. drivers/gpu/drm/tinydrm/mipi-dbi.c will use this to determine if the controller supports 16-bit for RGB565 pixels. If it doesn't it will swap the bytes before transfer on little endian machines. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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f1ca9992 |
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04-Apr-2019 |
Sowjanya Komatineni <skomatineni@nvidia.com> |
spi: add a method for configuring CS timing This patch creates set_cs_timing SPI master optional method for SPI masters to implement configuring CS timing if applicable. This patch also creates spi_cs_timing accessory for SPI clients to use for requesting SPI master controllers to configure device requested CS setup time, hold time and inactive delay. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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6d850281 |
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13-Mar-2019 |
Arnd Bergmann <arnd@arndb.de> |
spi: fix SPI_BPW_RANGE_MASK() regression Geert points out that I confused the min/max arguments that are reversed between SPI_BPW_RANGE_MASK() and GENMASK(). This time I have verified the result of the macro after fixing the arguments. Cc: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: eefffb42f665 ("spi: work around clang bug in SPI_BPW_RANGE_MASK()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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eefffb42 |
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07-Mar-2019 |
Arnd Bergmann <arnd@arndb.de> |
spi: work around clang bug in SPI_BPW_RANGE_MASK() Clang-8 evaluates both sides of a ?: expression to check for valid arithmetic even in the side that is never taken. This results in a build warning: drivers/spi/spi-sh-msiof.c:1052:24: error: shift count >= width of type [-Werror,-Wshift-count-overflow] .bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32), ^~~~~~~~~~~~~~~~~~~~~~~~~ Change the implementation to use the GENMASK() macro that does what we want here but does not have a problem with the shift count overflow. Link: https://bugs.llvm.org/show_bug.cgi?id=38789 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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b7bb367a |
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30-Jan-2019 |
Jonas Bonn <jonas@norrbonn.se> |
spi: support inter-word delay requirement for devices Some devices are slow and cannot keep up with the SPI bus and therefore require a short delay between words of the SPI transfer. The example of this that I'm looking at is a SAMA5D2 with a minimum SPI clock of 400kHz talking to an AVR-based SPI slave. The AVR cannot put bytes on the bus fast enough to keep up with the SoC's SPI controller even at the lowest bus speed. This patch introduces the ability to specify a required inter-word delay for SPI devices. It is up to the controller driver to configure itself accordingly in order to introduce the requested delay. Note that, for spi_transfer, there is already a field word_delay that provides similar functionality. This field, however, is specified in clock cycles (and worse, SPI controller cycles, not SCK cycles); that makes this value dependent on the master clock instead of the device clock for which the delay is intended to provide some relief. This patch leaves this old word_delay in place and provides a time-based word_delay_us alongside it; the new field fits in the struct padding so struct size is constant. There is only one in-kernel user of the word_delay field and presumably that driver could be reworked to use the time-based value instead. The time-based delay is limited to 8 bits as these delays are intended to be short. The SAMA5D2 that I've tested this on limits delays to a maximum of ~100us, which is already many word-transfer periods even at the minimum transfer speed supported by the controller. Signed-off-by: Jonas Bonn <jonas@norrbonn.se> CC: Mark Brown <broonie@kernel.org> CC: Rob Herring <robh+dt@kernel.org> CC: Mark Rutland <mark.rutland@arm.com> CC: linux-spi@vger.kernel.org CC: devicetree@vger.kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
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f0125f1a |
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23-Jan-2019 |
Mark Brown <broonie@kernel.org> |
spi: Go back to immediate teardown Commit 412e6037324 ("spi: core: avoid waking pump thread from spi_sync instead run teardown delayed") introduced regressions on some boards, apparently connected to spi_mem not triggering shutdown properly any more. Since we've thus far been unable to figure out exactly where the breakage is revert the optimisation for now. Reported-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: kernel@martin.sperl.org
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412e6037 |
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07-Jan-2019 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: avoid waking pump thread from spi_sync instead run teardown delayed When spi_sync is running alone with no other spi devices connected to the bus the worker thread is woken during spi_finalize_current_message to run the teardown code every time. This is totally unnecessary in the case that there is no message queued. On a multi-core system this results in one wakeup of the thread for each spi_message processed via spi_sync where in most cases the teardown does not happen as the hw is already in use. This patch now delays the teardown by 1 second by using a separate kthread_delayed_work for the teardown. This avoids waking the kthread too often. For spi_sync transfers in a tight loop (say 40k messages/s) this avoids the penalty of waking the worker thread 40k times/s. On a rasperry pi 3 with 4 cores the results in 32% of a single core only to find out that there is nothing in the queue and it can go back to sleep. With this patch applied the spi-worker is woken exactly once: after the load finishes and the spi bus is idle for 1 second. I believe I have also seen situations where during a spi_sync loop the worker thread (triggered by the last message finished) is slightly faster and _wins_ the race to process the message, so we are actually running the kthread and letting it do some work... This is also no longer observed with this patch applied as. Tested with a new CAN controller driver for the mcp2517fd which uses spi_sync for interrupt handling and spi_async for scheduling of can frames for transmission (in a different thread) Some statistics when receiving 100000 CAN frames with the mcp25xxfd driver on a Raspberry pi 3: without the patch: ------------------ root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done (spi0) 5 (irq/94-mcp25xxf) 0 root@raspcm3:~# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 821960 13592 50848 0 0 80 2 1986 105 1 2 97 0 0 0 0 0 821968 13592 50876 0 0 0 0 8046 30 0 0 100 0 0 0 0 0 821936 13592 50876 0 0 0 0 8032 24 0 0 100 0 0 0 0 0 821936 13592 50876 0 0 0 0 8035 30 0 0 100 0 0 0 0 0 821936 13592 50876 0 0 0 0 8033 22 0 0 100 0 0 2 0 0 821936 13592 50876 0 0 0 0 11598 7129 0 3 97 0 0 1 0 0 821872 13592 50876 0 0 0 0 37741 59003 0 31 69 0 0 2 0 0 821840 13592 50876 0 0 0 0 37762 59078 0 29 71 0 0 2 0 0 821776 13592 50876 0 0 0 0 37593 58792 0 28 72 0 0 1 0 0 821744 13592 50876 0 0 0 0 37642 58881 0 30 70 0 0 2 0 0 821680 13592 50876 0 0 0 0 37490 58602 0 27 73 0 0 1 0 0 821648 13592 50876 0 0 0 0 37412 58418 0 29 71 0 0 1 0 0 821584 13592 50876 0 0 0 0 37337 58288 0 27 73 0 0 1 0 0 821552 13592 50876 0 0 0 0 37584 58774 0 27 73 0 0 0 0 0 821520 13592 50876 0 0 0 0 18363 20566 0 9 91 0 0 0 0 0 821520 13592 50876 0 0 0 0 8037 32 0 0 100 0 0 0 0 0 821520 13592 50876 0 0 0 0 8031 23 0 0 100 0 0 0 0 0 821520 13592 50876 0 0 0 0 8034 26 0 0 100 0 0 0 0 0 821520 13592 50876 0 0 0 0 8033 24 0 0 100 0 0 ^C root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done (spi0) 228 (irq/94-mcp25xxf) 794 root@raspcm3:~# cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 17: 34 0 0 0 ARMCTRL-level 1 Edge 3f00b880.mailbox 27: 1 0 0 0 ARMCTRL-level 35 Edge timer 33: 1416870 0 0 0 ARMCTRL-level 41 Edge 3f980000.usb, dwc2_hsotg:usb1 34: 1 0 0 0 ARMCTRL-level 42 Edge vc4 35: 0 0 0 0 ARMCTRL-level 43 Edge 3f004000.txp 40: 1753 0 0 0 ARMCTRL-level 48 Edge DMA IRQ 42: 11 0 0 0 ARMCTRL-level 50 Edge DMA IRQ 44: 11 0 0 0 ARMCTRL-level 52 Edge DMA IRQ 45: 0 0 0 0 ARMCTRL-level 53 Edge DMA IRQ 66: 0 0 0 0 ARMCTRL-level 74 Edge vc4 crtc 69: 0 0 0 0 ARMCTRL-level 77 Edge vc4 crtc 70: 0 0 0 0 ARMCTRL-level 78 Edge vc4 crtc 77: 20 0 0 0 ARMCTRL-level 85 Edge 3f205000.i2c, 3f804000.i2c, 3f805000.i2c 78: 6346 0 0 0 ARMCTRL-level 86 Edge 3f204000.spi 80: 205 0 0 0 ARMCTRL-level 88 Edge mmc0 81: 493 0 0 0 ARMCTRL-level 89 Edge uart-pl011 89: 0 0 0 0 bcm2836-timer 0 Edge arch_timer 90: 4291 3821 2180 1649 bcm2836-timer 1 Edge arch_timer 94: 14289 0 0 0 pinctrl-bcm2835 16 Level mcp25xxfd IPI0: 0 0 0 0 CPU wakeup interrupts IPI1: 0 0 0 0 Timer broadcast interrupts IPI2: 3645 242371 7919 1328 Rescheduling interrupts IPI3: 112 543 273 194 Function call interrupts IPI4: 0 0 0 0 CPU stop interrupts IPI5: 1 0 0 0 IRQ work interrupts IPI6: 0 0 0 0 completion interrupts Err: 0 top shows 93% for the mcp25xxfd interrupt handler, 31% for spi0. with the patch: --------------- root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done (spi0) 0 (irq/94-mcp25xxf) 0 root@raspcm3:~# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- 0 0 0 804768 13584 62628 0 0 0 0 8038 24 0 0 100 0 0 0 0 0 804768 13584 62628 0 0 0 0 8042 25 0 0 100 0 0 1 0 0 804704 13584 62628 0 0 0 0 9603 2967 0 20 80 0 0 1 0 0 804672 13584 62628 0 0 0 0 9828 3380 0 24 76 0 0 1 0 0 804608 13584 62628 0 0 0 0 9823 3375 0 23 77 0 0 1 0 0 804608 13584 62628 0 0 0 12 9829 3394 0 23 77 0 0 1 0 0 804544 13584 62628 0 0 0 0 9816 3362 0 22 78 0 0 1 0 0 804512 13584 62628 0 0 0 0 9817 3367 0 23 77 0 0 1 0 0 804448 13584 62628 0 0 0 0 9822 3370 0 22 78 0 0 1 0 0 804416 13584 62628 0 0 0 0 9815 3367 0 23 77 0 0 0 0 0 804352 13584 62628 0 0 0 84 9222 2250 0 14 86 0 0 0 0 0 804352 13592 62620 0 0 0 24 8131 209 0 0 93 7 0 0 0 0 804320 13592 62628 0 0 0 0 8041 27 0 0 100 0 0 0 0 0 804352 13592 62628 0 0 0 0 8040 26 0 0 100 0 0 root@raspcm3:~# for x in $(pgrep spi0) $(pgrep irq/94-mcp25xxf) ; do awk '{printf "%-20s %6i\n", $2,$15}' /proc/$x/stat; done (spi0) 0 (irq/94-mcp25xxf) 767 root@raspcm3:~# cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 17: 29 0 0 0 ARMCTRL-level 1 Edge 3f00b880.mailbox 27: 1 0 0 0 ARMCTRL-level 35 Edge timer 33: 1024412 0 0 0 ARMCTRL-level 41 Edge 3f980000.usb, dwc2_hsotg:usb1 34: 1 0 0 0 ARMCTRL-level 42 Edge vc4 35: 0 0 0 0 ARMCTRL-level 43 Edge 3f004000.txp 40: 1773 0 0 0 ARMCTRL-level 48 Edge DMA IRQ 42: 11 0 0 0 ARMCTRL-level 50 Edge DMA IRQ 44: 11 0 0 0 ARMCTRL-level 52 Edge DMA IRQ 45: 0 0 0 0 ARMCTRL-level 53 Edge DMA IRQ 66: 0 0 0 0 ARMCTRL-level 74 Edge vc4 crtc 69: 0 0 0 0 ARMCTRL-level 77 Edge vc4 crtc 70: 0 0 0 0 ARMCTRL-level 78 Edge vc4 crtc 77: 20 0 0 0 ARMCTRL-level 85 Edge 3f205000.i2c, 3f804000.i2c, 3f805000.i2c 78: 6417 0 0 0 ARMCTRL-level 86 Edge 3f204000.spi 80: 237 0 0 0 ARMCTRL-level 88 Edge mmc0 81: 489 0 0 0 ARMCTRL-level 89 Edge uart-pl011 89: 0 0 0 0 bcm2836-timer 0 Edge arch_timer 90: 4048 3704 2383 1892 bcm2836-timer 1 Edge arch_timer 94: 14287 0 0 0 pinctrl-bcm2835 16 Level mcp25xxfd IPI0: 0 0 0 0 CPU wakeup interrupts IPI1: 0 0 0 0 Timer broadcast interrupts IPI2: 2361 2948 7890 1616 Rescheduling interrupts IPI3: 65 617 301 166 Function call interrupts IPI4: 0 0 0 0 CPU stop interrupts IPI5: 1 0 0 0 IRQ work interrupts IPI6: 0 0 0 0 completion interrupts Err: 0 top shows 91% for the mcp25xxfd interrupt handler, 0% for spi0 So we see that spi0 is no longer getting scheduled wasting CPU cycles There are a lot less context switches and corresponding Rescheduling interrupts All of these show that this improves efficiency of the system and reduces CPU utilization. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
f3186dd8 |
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07-Jan-2019 |
Linus Walleij <linus.walleij@linaro.org> |
spi: Optionally use GPIO descriptors for CS GPIOs This augments the SPI core to optionally use GPIO descriptors for chip select on a per-master-driver opt-in basis. Drivers using this will rely on the SPI core to look up GPIO descriptors associated with the device, such as when using device tree or board files with GPIO descriptor tables. When getting descriptors from the device tree, this will in turn activate the code in gpiolib that was added in commit 6953c57ab172 ("gpio: of: Handle SPI chipselect legacy bindings") which means that these descriptors are aware of the active low semantics that is the default for SPI CS GPIO lines and we can assume that all of these are "active high" and thus assign SPI_CS_HIGH to all CS lines on the DT path. The previously used gpio_set_value() would call down into gpiod_set_raw_value() and ignore the polarity inversion semantics. It seems like many drivers go to great lengths to set up the CS GPIO line as non-asserted, respecting SPI_CS_HIGH. We pull this out of the SPI drivers and into the core, and by simply requesting the line as GPIOD_OUT_LOW when retrieveing it from the device and relying on the gpiolib to handle any inversion semantics. This way a lot of code can be simplified and removed in each converted driver. The end goal after dealing with each driver in turn, is to delete the non-descriptor path (of_spi_register_master() for example) and let the core deal with only descriptors. The different SPI drivers have complex interactions with the core so we cannot simply change them all over, we need to use a stepwise, bisectable approach so that each driver can be converted and fixed in isolation. This patch has the intended side effect of adding support for ACPI GPIOs as it starts relying on gpiod_get_*() to get the GPIO handle associated with the device. Cc: Linuxarm <linuxarm@huawei.com> Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com> Tested-by: Fangjian (Turing) <f.fangjian@huawei.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6b03061f |
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03-Dec-2018 |
Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> |
spi: add support for octal mode I/O data transfer Add flags for Octal mode I/O data transfer Required for the SPI controller which can do the data transfer (TX/RX) on 8 data lines e.g. NXP FlexSPI controller. SPI_TX_OCTAL: transmit with 8 wires SPI_RX_OCTAL: receive with 8 wires Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com> Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
5132b3d2 |
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01-Nov-2018 |
Linus Walleij <linus.walleij@linaro.org> |
spi: gpio: Support 3WIRE high-impedance turn-around Some devices such as the TPO TPG110 display panel require a "high-impedance turn-around", in effect a clock cycle after switching the line from output to input mode. Support this in the GPIO driver to begin with. Other driver may implement it if they can, it is unclear if this can be achieved with anything else than GPIO bit-banging. Cc: Andrzej Hajda <a.hajda@samsung.com> Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
5039563e |
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20-Sep-2018 |
Trent Piepho <tpiepho@impinj.com> |
spi: Add driver_override SPI device attribute This attribute works the same was as the identically named attribute for PCI, AMBA, and platform devices. For reference, see: commit 3cf385713460 ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'") commit 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") commit 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") If the name of a driver is written to this attribute, then the device will bind to the named driver and only the named driver. The device will bind to the driver even if the driver does not list the device in its id table. This behavior is different than the driver's bind attribute, which only allows binding to devices that are listed as supported by the driver. It can be used to bind a generic driver, like spidev, to a device. Signed-off-by: Trent Piepho <tpiepho@impinj.com> Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz> Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
5f143af7 |
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25-Sep-2018 |
Marco Felsch <m.felsch@pengutronix.de> |
spi: make OF helper available for others The of_find_spi_device_by_node() helper function is useful for other modules too. Export the funciton as GPL like all other spi helper functions and make it available if CONFIG_OF is enabled, because it isn't related to the CONFIG_OF_DYNAMIC context. Finally add a stub if CONFIG_OF isn't enabled, so others must not care about it. Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
b445bfcb |
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25-Sep-2018 |
Marco Felsch <m.felsch@pengutronix.de> |
spi: switch to SPDX license identifier Use the appropriate SPDX license identifier and drop the previous license text. Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
0baf9eb2 |
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12-Sep-2018 |
David Lechner <david@lechnology.com> |
spi: add new SPI_CS_WORD flag This adds a new SPI mode flag, SPI_CS_WORD, that is used to indicate that a SPI device requires the chip select to be toggled after each word that is transferred. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
eeaceb8b |
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16-Aug-2018 |
Baolin Wang <baolin.wang@linaro.org> |
spi: Introduce one new field to set word delay For some SPI controllers, after each word size (specified by bits_per_word) transimission, the hardware need some delay to make sure the slave has enough time to receive the whole data. So introducing one new 'word_delay' field of struct spi_tansfer for slave devices to set this inter word delay time. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
c1f5ba70 |
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26-Apr-2018 |
Boris Brezillon <bbrezillon@kernel.org> |
spi: Get rid of the spi_flash_read() API This API has been replaced by the spi_mem_xx() one, its only user (spi-nor) has been converted to spi_mem_xx() and all SPI controller drivers that were implementing the ->spi_flash_xxx() hooks are also implementing the spi_mem ones. So we can safely get rid of this API. Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Frieder Schrempf <frieder.schrempf@exceet.de> Tested-by: Frieder Schrempf <frieder.schrempf@exceet.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
c36ff266 |
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26-Apr-2018 |
Boris Brezillon <bbrezillon@kernel.org> |
spi: Extend the core to ease integration of SPI memory controllers Some controllers are exposing high-level interfaces to access various kind of SPI memories. Unfortunately they do not fit in the current spi_controller model and usually have drivers placed in drivers/mtd/spi-nor which are only supporting SPI NORs and not SPI memories in general. This is an attempt at defining a SPI memory interface which works for all kinds of SPI memories (NORs, NANDs, SRAMs). Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Frieder Schrempf <frieder.schrempf@exceet.de> Tested-by: Frieder Schrempf <frieder.schrempf@exceet.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
8d26fdfc |
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30-Nov-2017 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Fix double "when" Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
8caab75f |
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13-Jun-2017 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Generalize SPI "master" to "controller" Now struct spi_master is used for both SPI master and slave controllers, it makes sense to rename it to struct spi_controller, and replace "master" by "controller" where appropriate. For now this conversion is done for SPI core infrastructure only. Wrappers are provided for backwards compatibility, until all SPI drivers have been converted. Noteworthy details: - SPI_MASTER_GPIO_SS is retained, as it only makes sense for SPI master controllers, - spi_busnum_to_master() is retained, as it looks up masters only, - A new field spi_device.controller is added, but spi_device.master is retained for compatibility (both are always initialized by spi_alloc_device()), - spi_flash_read() is used by SPI masters only. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6c364062 |
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22-May-2017 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: core: Add support for registering SPI slave controllers Add support for registering SPI slave controllers using the existing SPI master framework: - SPI slave controllers must use spi_alloc_slave() instead of spi_alloc_master(), and should provide an additional callback "slave_abort" to abort an ongoing SPI transfer request, - SPI slave controllers are added to a new "spi_slave" device class, - SPI slave handlers can be bound to the SPI slave device represented by an SPI slave controller using a DT child node named "slave", - Alternatively, (un)binding an SPI slave handler to the SPI slave device represented by an SPI slave controller can be done by (un)registering the slave device through a sysfs virtual file named "slave". From the point of view of an SPI slave protocol handler, an SPI slave controller looks almost like an ordinary SPI master controller. The only exception is that a transfer request will block on the remote SPI master, and may be cancelled using spi_slave_abort(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
2bca3445 |
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11-Apr-2017 |
Vignesh R <vigneshr@ti.com> |
spi: Add can_dma like interface for spi_flash_read Add an interface analogous to ->can_dma() for spi_flash_read() interface. This will enable SPI controller drivers to inform SPI core when not to do DMA mappings. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ed77d6bc |
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28-Mar-2017 |
Emiliano Ingrassia <ingrassia@epigenesys.com> |
spi: dynamycally allocated message initialization Invoke the proper function while initializing a dynamically allocated spi_message to avoid NULL pointer dereference during resources deallocation. Signed-off-by: Emiliano Ingrassia <ingrassia@epigenesys.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
826cf175 |
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28-Feb-2017 |
Dmitry Torokhov <dmitry.torokhov@gmail.com> |
spi: allow attaching device properties to SPI board info Generic device properties support statically defined property sets. For them to be usable, we need to attach these property sets before devices are registered and probed. Allowing to attach property list to spi_board_info structure will allow non-ACPI non-DT boards switch to using generic properties and get rid of custom platform data. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
8eee6b9d |
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10-Oct-2016 |
Thor Thayer <tthayer@opensource.altera.com> |
spi: Add Flag to Enable Slave Select with GPIO Chip Select. Some SPI masters require slave selection before the transfer can begin [1]. The SPI framework currently selects the chip using either 1) the internal CS mechanism or 2) the GPIO CS, but not both. This patch adds a new master->flags define to indicate both the GPIO CS and the internal chip select mechanism should be used. Tested On: Altera CycloneV development kit Compile tested for build errors on x86_64 (allyesconfigs) [1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39) Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6b1576aa |
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10-Oct-2016 |
Thor Thayer <tthayer@opensource.altera.com> |
spi: Add Flag to Enable Slave Select with GPIO Chip Select. Some SPI masters require slave selection before the transfer can begin [1]. The SPI framework currently selects the chip using either 1) the internal CS mechanism or 2) the GPIO CS, but not both. This patch adds a new master->flags define to indicate both the GPIO CS and the internal chip select mechanism should be used. Tested On: Altera CycloneV development kit Compile tested for build errors on x86_64 (allyesconfigs) [1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39) Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
323117ab |
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13-Sep-2016 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: core: Use spi_sync_transfer() in spi_write()/spi_read() Simplify spi_write() and spi_read() using the spi_sync_transfer() helper. This requires moving spi_sync_transfer() up. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
5090cc6a |
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17-Aug-2016 |
Heiner Kallweit <hkallweit1@gmail.com> |
spi: introduce max_message_size hook in spi_master Recently a maximum transfer size was was introduced in struct spi_master. However there are also spi controllers with a maximum message size, e.g. fsl-espi has a max message size of 64KB. Introduce a hook max_message_size to deal with such limitations. Also make sure that spi_max_transfer_size doesn't return greater values than spi_max_message_size, even if hook max_transfer_size is not set. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ef4d96ec |
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21-Jul-2016 |
Mark Brown <broonie@kernel.org> |
spi: Split bus and I/O locking The current SPI code attempts to use bus_lock_mutex for two purposes. One is to implement spi_bus_lock() which grants exclusive access to the bus. The other is to serialize access to the physical hardware. This duplicate purpose causes confusion which leads to cases where access is not locked when a caller holds the bus lock mutex. Fix this by splitting out the I/O functionality into a new io_mutex. This means taking both mutexes in the DMA path, replacing the existing mutex with the new I/O one in the message pump (the mutex now always being taken in the message pump) and taking the bus lock mutex in spi_sync(), allowing __spi_sync() to have no mutex handling. While we're at it hoist the mutex further up the message pump before we power up the device so that all power up/down of the block is covered by it and there are no races with in-line pumping of messages. Reported-by: Rich Felker <dalias@libc.org> Tested-by: Rich Felker <dalias@libc.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
f4502dd1 |
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07-Jun-2016 |
Vignesh R <vigneshr@ti.com> |
spi: Add DMA support for spi_flash_read() Few SPI devices provide accelerated read interfaces to read from SPI-NOR flash devices. These hardwares also support DMA to transfer data from flash to memory either via mem-to-mem DMA or dedicated slave DMA channels. Hence, add support for DMA in order to improve throughput and reduce CPU load. Use spi_map_buf() to get sg table for the buffer and pass it to SPI driver. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
7ba2f275 |
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23-Apr-2016 |
Heiner Kallweit <hkallweit1@gmail.com> |
spi: core: add hook flash_read_supported to spi_master If hook spi_flash_read is implemented the fast flash read feature is enabled for all devices attached to the respective master. In most cases there is just one flash chip, however there are also devices with more than one flash chip, namely some WiFi routers. Then the fast flash read feature can be used for the first chip only. OpenWRT implemented an own handling of this case, using controller_data element of spi_device to hold the information whether fast flash read can be used for a device. This patch adds hook flash_read_supported to spi_master which is used to extend spi_flash_read_supported() by checking whether the fast flash read feature can be used for a specific spi_device. If the hook is not implemented the default behavior is to allow fast flash read for all devices (if spi_flash_read is implemented). Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
c76d9ae4 |
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10-Mar-2016 |
Javier Martinez Canillas <javier@osg.samsung.com> |
spi: Fix htmldocs build error due struct spi_replaced_transfers The kernel-doc has to be just before the structure definition but the one for struct spi_replaced_transfers was before a structure declaration and that confuses kernel-doc which complains with the following build error: .//include/linux/spi/spi.h:933: error: Cannot parse struct or union! Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d6497816 |
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18-Feb-2016 |
Martin Sperl <kernel@martin.sperl.org> |
spi: docbook: fix parsing error Fixes docbook parsing error because documentation is not directly followed by the structure, but typedef used in structure. Reordering should solve that issue. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
556351f1 |
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10-Dec-2015 |
Vignesh R <vigneshr@ti.com> |
spi: introduce accelerated read support for spi flash devices In addition to providing direct access to SPI bus, some spi controller hardwares (like ti-qspi) provide special port (like memory mapped port) that are optimized to improve SPI flash read performance. This means the controller can automatically send the SPI signals required to read data from the SPI flash device. For this, SPI controller needs to know flash specific information like read command to use, dummy bytes and address width. Introduce spi_flash_read() interface to support accelerated read over SPI flash devices. SPI master drivers can implement this callback to support interfaces such as memory mapped read etc. m25p80 flash driver and other flash drivers can call this make use of such interfaces. The interface should only be used with SPI flashes and cannot be used with other SPI devices. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d9f12122 |
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14-Dec-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: add spi_split_transfers_maxsize Add spi_split_transfers_maxsize method that splits spi_transfers transparently into multiple transfers that are below the given max-size. This makes use of the spi_res framework via spi_replace_transfers to allocate/free the extra transfers as well as reverting back the changes applied while processing the spi_message. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
523baf5a |
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14-Dec-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: add spi_replace_transfers method Add the spi_replace_transfers method that can get used to replace some spi_transfers from a spi_message with other transfers. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
d780c371 |
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14-Dec-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: core: added spi_resource management SPI resource management framework used while processing a spi_message via the spi-core. The basic idea is taken from devres, but as the allocation may happen fairly frequently, some provisioning (in the form of an unused spi_device pointer argument to spi_res_alloc) has been made so that at a later stage we may implement reuse objects allocated earlier avoiding the repeated allocation by keeping a cache of objects that we can reuse. This framework can get used for: * rewriting spi_messages * to fullfill alignment requirements of the spi_master HW * to fullfill transfer length requirements (e.g: transfers need to be less than 64k) * consolidate spi_messages with multiple transfers into a single transfer when the total transfer length is below a threshold. * reimplement spi_unmap_buf without explicitly needing to check if it has been mapped Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
a0a90718 |
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08-Feb-2016 |
Mika Westerberg <mika.westerberg@linux.intel.com> |
spi: Let drivers translate ACPI DeviceSelection to suitable Linux chip select In Windows it is up to the SPI host controller driver to handle the ACPI DeviceSelection as it likes. The SPI core does not take any part in it. This is different in Linux because we always expect to have chip select in range of 0 .. master->num_chipselect - 1. In order to support this in Linux we need a way to allow the driver to translate between ACPI DeviceSelection field and Linux chip select number so provide a new optional hook ->fw_translate_cs() that can be used by a driver to handle translation and call this hook if set during SPI slave ACPI enumeration. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ee7683a3 |
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05-Feb-2016 |
Randy Dunlap <rdunlap@infradead.org> |
spi: Document max_transfer_size Fix kernel-doc warning for missing struct field notation. ..//include/linux/spi/spi.h:540: warning: No description found for parameter 'max_transfer_size' [Meaningful subject -- broonie] Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
4acad4aa |
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02-Dec-2015 |
Michal Suchanek <hramrach@gmail.com> |
spi: expose master transfer size limitation. On some SPI controllers it is not feasible to transfer arbitrary amount of data at once. When the limit on transfer size is a few kilobytes at least it makes sense to use the SPI hardware rather than reverting to gpio driver. The protocol drivers need a way to check that they do not sent overly long messages, though. Signed-off-by: Michal Suchanek <hramrach@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
49ddedf3 |
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27-Nov-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: add spi_message_init_no_memset to avoid zeroing the spi_message In the spi_loopback_test driver there is the need to initialize a spi_message that is filled with values from a static structure. Applying spi_message_init to such a prefilled structure results in all the settings getting reset to zero, which is not what we want. Copying each field of spi_message separately instead always includes the risk that some new fields have not been implemented in the copying code. So here we introduce a version of spi_message_init called spi_message_init_no_memset that does not fill the structure with zero first, but only initializes the relevant list_heads. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
3b1884c2 |
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30-Nov-2015 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Uninline spi_unregister_device() Uninline spi_unregister_device() in preparation of adding more code to it. Add kerneldoc documentation while we're at it. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ca5d2485 |
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23-Oct-2015 |
Andrew F. Davis <afd@ti.com> |
spi: Add THIS_MODULE to spi_driver in SPI core Add spi_register_driver helper macro that adds THIS_MODULE to spi_driver for the registering driver. We rename and modify the existing spi_register_driver to enable this. Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
a1fdeaa7 |
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22-Oct-2015 |
Javier Martinez Canillas <javier@osg.samsung.com> |
spi: fix kernel-doc warnings about missing return desc in spi.h When building docs with make htmldocs, warnings about not having a description for the return value are reported, i.e: warning: No description found for return value of 'spi_write' Fix these by following the kernel-doc conventions explained in Documentation/kernel-doc-nano-HOWTO.txt. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
6b7bc061 |
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22-Jun-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: add transfer histogram statistics via sysfs report transfer sizes as a histogram via the following files: /sys/class/spi_master/spi*/statistics/transfer_bytes_histo_* /sys/class/spi_master/spi*/spi*.*/statistics/transfer_bytes_histo_* Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
0243ed44 |
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15-Sep-2015 |
Geliang Tang <geliangtang@163.com> |
spi: fix kernel-doc warnings in spi.h Fix the following 'make htmldocs' warnings: .//include/linux/spi/spi.h:71: warning: No description found for parameter 'lock' .//include/linux/spi/spi.h:71: warning: Excess struct/union/enum/typedef member 'clock' description in 'spi_statistics' Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
eca2ebc7 |
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22-Jun-2015 |
Martin Sperl <kernel@martin.sperl.org> |
spi: expose spi_master and spi_device statistics via sysfs per spi-master statistics accessible as: /sys/class/spi_master/spi*/statistics/* per spi-device statistics accessible via: /sys/class/spi_master/spi*/spi*.*/statistics/* The following statistics are exposed as separate "files" inside these directories: * messages number of spi_messages * transfers number of spi_transfers * bytes number of bytes transferred * bytes_rx number of bytes transmitted * bytes_tx number of bytes received * errors number of errors encounterd * timedout number of messages that have timed out * spi_async number of spi_messages submitted using spi_async * spi_sync number of spi_messages submitted using spi_sync * spi_sync_immediate number of spi_messages submitted using spi_sync, that are handled immediately without a context switch to the spi_pump worker-thread Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ff61eb42 |
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07-Apr-2015 |
Geert Uytterhoeven <geert+renesas@glider.be> |
spi: Make master->handle_err() callback optional to avoid crashes If a driver doesn't implement the master->handle_err() callback and an SPI transfer fails, the kernel will crash with a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0003000 [00000000] *pgd=80000040004003, *pmd=00000000 Internal error: Oops: 80000206 [#1] SMP ARM Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.0.0-rc7-koelsch-05861-g1fc9fdd4add4f783 #1046 Hardware name: Generic R8A7791 (Flattened Device Tree) task: eec359c0 ti: eec54000 task.ti: eec54000 PC is at 0x0 LR is at spi_transfer_one_message+0x1cc/0x1f0 Make the master->handle_err() callback optional to avoid the crash. Also fix a spelling mistake in the callback documentation while we're at it. Fixes: b716c4ffc6a2b0bf ("spi: introduce master->handle_err() callback") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
ea022bbb |
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08-Mar-2015 |
Lars-Peter Clausen <lars@metafoo.de> |
spi: Remove support for legacy PM All SPI drivers have been converted from legacy suspend/resume callbacks to dev_pm_ops. So we can finally remove support for legacy PM from the SPI core. Since there aren't any special bus specific things to do during suspend/resume and since the PM core will automatically fallback directly to using the device's PM ops if no bus PM ops are specified there is no need to have any special SPI bus PM ops. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
b716c4ff |
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27-Feb-2015 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
spi: introduce master->handle_err() callback This callback would be useful to handle an error that occurs in the generic implementation of transfer_one_message(). The good candidate for this is to drain FIFO and / or to terminate DMA transfers when timeout happened. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
c6331ba3 |
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01-Mar-2015 |
Marcin Bis <marcin@bis.org.pl> |
spi: fix a typo in comment. alway -> always Signed-off-by: Marcin Bis <marcin@bis.org.pl> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
2c658e21 |
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18-Dec-2014 |
Jarkko Nikula <jarkko.nikula@linux.intel.com> |
spi: Remove FSF mailing addresses Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
0461a414 |
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09-Dec-2014 |
Mark Brown <broonie@kernel.org> |
spi: Pump transfers inside calling context for spi_sync() If we are using the standard SPI message pump (which all drivers should be transitioning over to) then special case the message enqueue and instead of starting the worker thread to push messages to the hardware do so in the context of the caller if the controller is idle. This avoids a context switch in the common case where the controller has a single user in a single thread, for short PIO transfers there may be no need to context switch away from the calling context to complete the transfer. The code is a bit more complex than is desirable in part due to the need to handle drivers not using the standard queue and in part due to handling the various combinations of bus locking and asynchronous submission in interrupt context. It is still suboptimal since it will still wake the message pump for each transfer in order to schedule idling of the hardware and if multiple contexts are using the controller simultaneously a caller may end up pumping a message for some random other thread rather than for itself, and if the thread ends up deferring due to another context idling the hardware then it will just busy wait. It can, however, have the benefit of aggregating power up and down of the hardware when a caller performs a series of transfers back to back without any need for the use of spi_async(). Signed-off-by: Mark Brown <broonie@kernel.org>
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#
b671358a |
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22-Nov-2014 |
Beniamino Galvani <b.galvani@gmail.com> |
spi: core: Add spi_transfer_is_last() helper This adds the function spi_transfer_is_last() which can be used by drivers to know whether a given transfer is the last one in the current message. Signed-off-by: Beniamino Galvani <b.galvani@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
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#
2c675689 |
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08-Aug-2014 |
Thierry Reding <treding@nvidia.com> |
spi: Add missing kerneldoc bits These are all arguments or fields that got added without updating the kerneldoc comments. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
e227867f |
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18-Feb-2014 |
Masanari Iida <standby24x7@gmail.com> |
treewide: Fix typo in Documentation/DocBook This patch fix spelling typo in Documentation/DocBook. It is because .html and .xml files are generated by make htmldocs, I have to fix a typo within the source files. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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#
6ad45a27 |
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02-Feb-2014 |
Mark Brown <broonie@linaro.org> |
spi: Make core DMA mapping functions generate scatterlists We cannot unconditionally use dma_map_single() to map data for use with SPI since transfers may exceed a page and virtual addresses may not be provided with physically contiguous pages. Further, addresses allocated using vmalloc() need to be mapped differently to other addresses. Currently only the MXS driver handles all this, a few drivers do handle the possibility that buffers may not be physically contiguous which is the main potential problem but many don't even do that. Factoring this out into the core will make it easier for drivers to do a good job so if the driver is using the core DMA code then generate a scatterlist instead of mapping to a single address so do that. This code is mainly based on a combination of the existing code in the MXS and PXA2xx drivers. In future we should be able to extend it to allow the core to concatenate adjacent transfers if they are compatible, improving performance. Currently for simplicity clients are not allowed to use the scatterlist when they do DMA mapping, in the future the existing single address mappings will be replaced with use of the scatterlist most likely as part of pre-verifying transfers. This change makes it mandatory to use scatterlists when using the core DMA mapping so update the s3c64xx driver to do this when used with dmaengine. Doing so makes the code more ugly but it is expected that the old s3c-dma code can be removed very soon. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
3a2eba9b |
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28-Jan-2014 |
Mark Brown <broonie@linaro.org> |
spi: Provide core support for full duplex devices It is fairly common for SPI devices to require that one or both transfer directions is always active. Currently drivers open code this in various ways with varying degrees of efficiency. Start factoring this out by providing flags SPI_MASTER_MUST_TX and SPI_MASTER_MUST_RX. These will cause the core to provide buffers for the requested direction if none are specified in the underlying transfer. Currently this is fairly inefficient since we actually allocate a data buffer which may get large, support for mapping transfers using a scatterlist will allow us to avoid this for DMA based transfers. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
99adef31 |
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15-Jan-2014 |
Mark Brown <broonie@linaro.org> |
spi: Provide core support for DMA mapping transfers The process of DMA mapping buffers for SPI transfers does not vary between devices so in order to save duplication of code in drivers this can be factored out into the core, allowing it to be integrated with the work that is being done on factoring out the common elements from the data path including more sharing of dmaengine code. In order to use this masters need to provide a can_dma() operation and while the hardware is prepared they should ensure that DMA channels are provided in tx_dma and rx_dma. The core will then ensure that the buffers are mapped for DMA prior to calling transfer_one_message(). Currently the cleanup on error is not complete, this needs to be improved. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
e9305331 |
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25-Jan-2014 |
Baruch Siach <baruch@tkos.co.il> |
spi: correct the transfer_one_message documentation wording The transfer_one_message callback handles messages, not transfers. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
6e5f5267 |
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25-Jan-2014 |
Baruch Siach <baruch@tkos.co.il> |
spi: spi.h: clarify the documentation of transfer_one Explicitly note the transfer_one and transfer_one_message are mutually exclusive, to make the text a little more newcomers friendly. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
bd6857a0 |
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21-Jan-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
spi: Correct set_cs() documentation The documentation for spi_master.set_cs() says: assert or deassert chip select, true to assert i.e. its "enable" parameter uses assertion-level logic. This does not match the implementation of spi_set_cs(), which calls spi_master.set_cs() with the wanted logic level of the chip select line, which depends on the polarity of the chip select signal. Correct the documentation to match the implementation. Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
0516712c |
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21-Jan-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
spi: Clarify transfer_one() w.r.t. spi_finalize_current_transfer() Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
269ccca8 |
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12-Jan-2014 |
Geert Uytterhoeven <geert+renesas@linux-m68k.org> |
spi: Kill superfluous cast in spi_w8r16() spi_write_then_read() takes a "void *" for rxbuf, so there's no need to cast the buffer pointer to "u8 *". Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
d3fbd457 |
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10-Jan-2014 |
Mark Brown <broonie@linaro.org> |
spi: Use bitfields for multiple data lines Trent Piepho observed that since the current realistic maximum number of data lines is four we can pack the spi_transfer struct more efficiently if we use a bitfield for the number of bits, allowing the fields to fit in a single byte along with cs_change. If space becomes an issue further optimiation is possible by only using the constants and packing the values chosen for them. Reported-by: Trent Piepho <tpiepho@gmail.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
89c1f6074 |
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13-Dec-2013 |
Trent Piepho <tpiepho@gmail.com> |
spi: Order fields in spi_device for better packing Now that spi_device->mode is a u16, the chip_select, bits_per_mode, and mode fields pack poorly, taking 8 bytes: four data and four padding. By moving (u8)bits_per_word up one position, to after (u8)chip_select, they pack better and only use 4 bytes. Signed-off-by: Trent Piepho <tpiepho@gmail.com> Reviewed-by: Sourav Poddar <sourav.poddar@ti.com> Tested-by: Sourav Poddar <sourav.poddar@ti.com>g Signed-off-by: Mark Brown <broonie@linaro.org>
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#
b158935f |
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05-Oct-2013 |
Mark Brown <broonie@linaro.org> |
spi: Provide common spi_message processing loop The loops which SPI controller drivers use to process the list of transfers in a spi_message are typically very similar and have some error prone areas such as the handling of /CS. Help simplify drivers by factoring this code out into the core - if drivers provide a transfer_one() function instead of a transfer_one_message() function the core will handle processing at the message level. /CS can be controlled by either setting cs_gpio or providing a set_cs function. If this is not possible for hardware reasons then both can be omitted and the driver should continue to implement manual /CS handling. This is a first step in refactoring and it is expected that there will be further enhancements, for example factoring out of the mapping of transfers for DMA and the initiation and completion of interrupt driven transfers. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
2841a5fc |
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04-Oct-2013 |
Mark Brown <broonie@linaro.org> |
spi: Provide per-message prepare and unprepare operations Many SPI drivers perform setup and tear down on every message, usually doing things like DMA mapping the message. Provide hooks for them to use to provide such operations. This is of limited value for drivers that implement transfer_one_message() but will be of much greater utility with future factoring out of standard implementations of that function. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
05071aa8 |
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27-Sep-2013 |
Lars-Peter Clausen <lars@metafoo.de> |
spi: Add a spi_w8r16be() helper This patch adds a new spi_w8r16be() helper, which is similar to spi_w8r16() except that it converts the read data word from big endian to native endianness before returning it. The reason for introducing this new helper is that for SPI slave devices it is quite common that the read 16 bit data word is in big endian. So users of spi_w8r16() have to convert the result to native endianness manually. A second reason is that in this case the endianness of the return value of spi_w8r16() depends on its sign. If it is negative (i.e. a error code) it is already in native endianness, if it is positive it is in big endian. The sparse code checker doesn't like this kind of mixed endianness and special annotations are necessary to keep it quiet (E.g. casting to be16 using __force). Doing the conversion to native endianness in the helper function does not require such annotations since we are not mixing different endiannesses in the same variable. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
666d5b4c |
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31-Aug-2013 |
Mark Brown <broonie@linaro.org> |
spi: core: Add devm_spi_register_master() Help simplify the cleanup code for SPI master drivers by providing a managed master registration function, ensuring that the master is automatically unregistered whenever the device is unbound. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
f477b7fb |
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11-Aug-2013 |
wangyuhang <wangyuhang2014@gmail.com> |
spi: DUAL and QUAD support fix the previous patch some mistake below: 1. DT in slave node, use "spi-tx-nbits = <1/2/4>" in place of using "spi-tx-dual, spi-tx-quad" directly, same to rx. So correct the previous way to get the property in @of_register_spi_devices(). 2. Change the value of transfer bit macro(SPI_NBITS_SINGLE, SPI_NBITS_DUAL SPI_NBITS_QUAD) to 0x01, 0x02 and 0x04 to match the actual wires. 3. Add the following check (1)keep the tx_nbits and rx_nbits in spi_transfer is not beyond the single, dual and quad. (2)keep tx_nbits and rx_nbits are contained by @spi_device->mode example: if @spi_device->mode = DUAL, then tx/rx_nbits can not be set to QUAD(SPI_NBITS_QUAD) (3)if "@spi_device->mode & SPI_3WIRE", then tx/rx_nbits should be in single(SPI_NBITS_SINGLE) Signed-off-by: wangyuhang <wangyuhang2014@gmail.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
b6aa23cc |
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01-Aug-2013 |
Stephen Warren <swarren@nvidia.com> |
spi: fix SPI_BIT_MASK so it always fits into 32-bits On a 64-bit platform, ~0UL fills 64-bits, which causes SPI_BIT_MASK(32) not to fit into 32 bits. This causes a warning when the result is assigned to a 32-bit variable. Use ~0U instead to prevent this. This fixes: drivers/spi/spi-gpio.c: In function 'spi_gpio_probe': drivers/spi/spi-gpio.c:446:2: warning: large integer implicitly truncated to unsigned type [-Woverflow] Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
49834de2 |
|
28-Jul-2013 |
Mark Brown <broonie@linaro.org> |
spi: Provide core support for runtime PM during transfers Most SPI drivers that implement runtime PM support use identical code to do so: they acquire a runtime PM lock in prepare_transfer_hardware() and then they release it in unprepare_transfer_hardware(). The variations in this are mostly missing error checking and the choice to use autosuspend. Since these runtime PM calls are normally the only thing in the prepare and unprepare callbacks and the autosuspend API transparently does the right thing on devices with autosuspend disabled factor all of this out into the core with a flag to enable the behaviour. Signed-off-by: Mark Brown <broonie@linaro.org> Reviewed-by: Stephen Warren <swarren@nvidia.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
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#
078726ce |
|
18-Jul-2013 |
Sourav Poddar <sourav.poddar@ti.com> |
driver: spi: Modify core to compute the message length Make spi core calculate the message length while populating the other transfer parameters. Usecase, driver can use it to populate framelength filed in their controller. Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
a2fd4f9f |
|
10-Jul-2013 |
Mark Brown <broonie@linaro.org> |
spi: Support transfer speed checking in the core Allow drivers to avoid implementing their own checks for simple rates by specifying the limits in the master structure. Signed-off-by: Mark Brown <broonie@linaro.org>
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#
eca8960a |
|
30-May-2013 |
Stephen Warren <swarren@nvidia.com> |
spi: fix incorrect handling of min param in SPI_BPW_RANGE_MASK SPI_BPW_RANGE_MASK is intended to work by calculating two masks; one representing support for all bits up-to-and-including the "max" supported value, and one representing support for all bits up-to-but-not-including the "min" supported value, and then taking the difference between the two, resulting in a mask representing support for all bits between (inclusive) the min and max values. However, the second mask ended up representing all bits up-to-and- including rather up-to-but-not-including. Fix this bug. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
4dd9572a |
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30-May-2013 |
Stephen Warren <swarren@nvidia.com> |
spi: fix undefined behaviour in SPI_BPW_RANGE_MASK The parameters to SPI_BPW_RANGE_MASK() are in the range 1..32. If 32 is used as a parameter, part of the expression is "1 << 32". Since 32 is >= the size of the type in use, such a shift is undefined behaviour. Add macro SPI_BIT_MASK to Implement a special case and thus avoid undefined behaviour. Use this new macro rather than BIT() when implementing SPI_BPW_RANGE_MASK(). This fixes build warnings such as: drivers/spi/spi-gpio.c:446:2: warning: left shift count >= width of type [enabled by default] SPI_BPW_MASK() already avoids this, since its parameter is also in range 1..32, yet it only shifts by up to one less than the input parameter. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Mark Brown <broonie@linaro.org>
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#
2922a8de |
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21-May-2013 |
Stephen Warren <swarren@wwwdotorg.org> |
spi: introduce macros to set bits_per_word_mask Introduce two macros to make setting up spi_master.bits_per_word_mask easier, and avoid mistakes like writing BIT(n) instead of BIT(n - 1). SPI_BPW_MASK is for a single supported value of bits_per_word_mask. SPI_BPW_RANGE_MASK represents a contiguous set of bit lengths. Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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#
446411e1 |
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13-Feb-2013 |
Andreas Larsson <andreas@gaisler.com> |
spi: Initialize cs_gpio and cs_gpios with -ENOENT The return value from of_get_named_gpio is -ENOENT when the given index matches a hole in the "cs-gpios" property phandle list. However, the default value of cs_gpio in struct spi_device and entries of cs_gpios in struct spi_master is -EINVAL, which is documented to indicate that a GPIO line should not be used for the given spi_device. This sets the default value of cs_gpio in struct spi_device and entries of cs_gpios in struct spi_master to -ENOENT. Thus, -ENOENT is the only value used to indicate that no GPIO line should be used. Signed-off-by: Andreas Larsson <andreas@gaisler.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
543bb255 |
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26-Mar-2013 |
Stephen Warren <swarren@wwwdotorg.org> |
spi: add ability to validate xfer->bits_per_word in SPI core Allow SPI masters to define the set of bits_per_word values they support. If they do this, then the SPI core will reject transfers that attempt to use an unsupported bits_per_word value. This eliminates the need for each SPI driver to implement this checking in most cases. Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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#
095c3752 |
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29-Jan-2013 |
Andreas Larsson <andreas@gaisler.com> |
spi: Document cs_gpios and cs_gpio in kernel-doc This adds missing kernel-doc entries for cs_gpios in struct spi_master and cs_gpio in struct spi_device. Signed-off-by: Andreas Larsson <andreas@gaisler.com> [grant.likely: tweaked the language of the descriptions] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
6d9eecd4 |
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09-Jan-2013 |
Lars-Peter Clausen <lars@metafoo.de> |
spi: Add helper functions for setting up transfers Quite often the pattern used for setting up and transferring a synchronous SPI transaction looks very much like the following: struct spi_message msg; struct spi_transfer xfers[] = { ... }; spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); ret = spi_sync(&msg); This patch adds two new helper functions for handling this case. The first helper function spi_message_init_with_transfers() takes a spi_message and an array of spi_transfers. It will initialize the message and then call spi_message_add_tail() for each transfer in the array. E.g. the following spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); can be rewritten as spi_message_init_with_transfers(&msg, xfers, ARRAY_SIZE(xfers)); The second function spi_sync_transfer() takes a SPI device and an array of spi_transfers. It will allocate a new spi_message (on the stack) and add all transfers in the array to the message. Finally it will call spi_sync() on the message. E.g. the follwing struct spi_message msg; struct spi_transfer xfers[] = { ... }; spi_message_init(&msg); spi_message_add_tail(&xfers[0], &msg); ... spi_message_add_tail(&xfers[ARRAY_SIZE(xfers) - 1], &msg); ret = spi_sync(spi, &msg); can be rewritten as struct spi_transfer xfers[] = { ... }; ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers)); A coccinelle script to find such instances will follow. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
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#
74317984 |
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15-Nov-2012 |
Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> |
of_spi: add generic binding support to specify cs gpio This will allow to use gpio for chip select with no modification in the driver binding When use the cs-gpios, the gpio number will be passed via the cs_gpio field and the number of chip select will automatically increased with max(hw cs, gpio cs). So if for example the controller has 2 CS lines, and the cs-gpios property looks like this: cs-gpios = <&gpio1 0 0> <0> <&gpio1 1 0> <&gpio1 2 0>; Then it should be configured so that num_chipselect = 4 with the following mapping: cs0 : &gpio1 0 0 cs1 : native cs2 : &gpio1 1 0 cs3 : &gpio1 2 0 Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: devicetree-discuss@lists.ozlabs.org Cc: spi-devel-general@lists.sourceforge.net Signed-off-by: Richard Genoud <richard.genoud@gmail.com> [grant.likely: fixed up type of cs count so min() can do type checking] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
dbabe0d6 |
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17-Apr-2012 |
Randy Dunlap <rdunlap@infradead.org> |
spi: fix spi.h kernel-doc warning Fix kernel-doc warning in spi.h (copy/paste): Warning(include/linux/spi/spi.h:365): No description found for parameter 'unprepare_transfer_hardware' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
8f53602b |
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27-Feb-2012 |
Shubhrajyoti D <shubhrajyoti@ti.com> |
spi: Trivial warning fix The loop count i traverses for ntrans which is unsigned so make the loop count i also unsigned. Fix the below warning In file included from drivers/spi/spi-omap2-mcspi.c:38: include/linux/spi/spi.h: In function 'spi_message_alloc': include/linux/spi/spi.h:556: warning: comparison between signed and unsigned integer expressions Cc: Vitaly Wool <vwool@ru.mvista.com> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
ffbbdd21 |
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22-Feb-2012 |
Linus Walleij <linus.walleij@linaro.org> |
spi: create a message queueing infrastructure This rips the message queue in the PL022 driver out and pushes it into (optional) common infrastructure. Drivers that want to use the message pumping thread will need to define the new per-messags transfer methods and leave the deprecated transfer() method as NULL. Most of the design is described in the documentation changes that are included in this patch. Since there is a queue that need to be stopped when the system is suspending/resuming, two new calls are implemented for the device drivers to call in their suspend()/resume() functions: spi_master_suspend() and spi_master_resume(). ChangeLog v1->v2: - Remove Kconfig entry and do not make the queue support optional at all, instead be more agressive and have it as part of the compulsory infrastructure. - If the .transfer() method is implemented, delete print a small deprecation notice and do not start the transfer pump. - Fix a bitrotted comment. ChangeLog v2->v3: - Fix up a problematic sequence courtesy of Chris Blair. - Stop rather than destroy the queue on suspend() courtesy of Chris Blair. Signed-off-by: Chris Blair <chris.blair@stericsson.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
3acbb014 |
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16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
SPI: Add helper macro for spi_driver boilerplate This patch introduces the module_spi_driver macro which is a convenience macro for SPI driver modules similar to module_platform_driver. It is intended to be used by drivers which init/exit section does nothing but register/unregister the SPI driver. By using this macro it is possible to eliminate a few lines of boilerplate code per SPI driver. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
0c4a1590 |
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10-May-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
spi: Use void pointers for data in simple SPI I/O operations Currently the simple SPI I/O operations all take pointers to u8 * buffers to operate on. This creates needless type compatibility issues and the underlying spi_transfer structure uses void pointers anyway so convert the API over to take void pointers too. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
2b9603a0 |
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02-Aug-2010 |
Feng Tang <feng.tang@intel.com> |
spi: enable spi_board_info to be registered after spi_master Currently spi_register_board_info() has to be called before its related spi_master be registered, otherwise these board info will be just ignored. This patch will remove this order limit, it adds a global spi master list like the existing global board info listr. Whenever a board info or a spi_master is registered, the spi master list or board info list will be scanned, and a new spi device will be created if there is a master-board info match. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
5c79a5ae |
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16-Aug-2010 |
Ernst Schwab <eschwab@online.de> |
spi.h: missing kernel-doc notation, please fix Added comments in kernel-doc notation for previously added struct fields. Signed-off-by: Ernst Schwab <eschwab@online.de> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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#
cf32b71e |
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28-Jun-2010 |
Ernst Schwab <eschwab@online.de> |
spi/mmc_spi: SPI bus locking API, using mutex SPI bus locking API to allow exclusive access to the SPI bus, especially, but not limited to, for the mmc_spi driver. Coded according to an outline from Grant Likely; here is his specification (accidentally swapped function names corrected): It requires 3 things to be added to struct spi_master. - 1 Mutex - 1 spin lock - 1 flag. The mutex protects spi_sync, and provides sleeping "for free" The spinlock protects the atomic spi_async call. The flag is set when the lock is obtained, and checked while holding the spinlock in spi_async(). If the flag is checked, then spi_async() must fail immediately. The current runtime API looks like this: spi_async(struct spi_device*, struct spi_message*); spi_sync(struct spi_device*, struct spi_message*); The API needs to be extended to this: spi_async(struct spi_device*, struct spi_message*) spi_sync(struct spi_device*, struct spi_message*) spi_bus_lock(struct spi_master*) /* although struct spi_device* might be easier */ spi_bus_unlock(struct spi_master*) spi_async_locked(struct spi_device*, struct spi_message*) spi_sync_locked(struct spi_device*, struct spi_message*) Drivers can only call the last two if they already hold the spi_master_lock(). spi_bus_lock() obtains the mutex, obtains the spin lock, sets the flag, and releases the spin lock before returning. It doesn't even need to sleep while waiting for "in-flight" spi_transactions to complete because its purpose is to guarantee no additional transactions are added. It does not guarantee that the bus is idle. spi_bus_unlock() clears the flag and releases the mutex, which will wake up any waiters. The difference between spi_async() and spi_async_locked() is that the locked version bypasses the check of the lock flag. Both versions need to obtain the spinlock. The difference between spi_sync() and spi_sync_locked() is that spi_sync() must hold the mutex while enqueuing a new transfer. spi_sync_locked() doesn't because the mutex is already held. Note however that spi_sync must *not* continue to hold the mutex while waiting for the transfer to complete, otherwise only one transfer could be queued up at a time! Almost no code needs to be written. The current spi_async() and spi_sync() can probably be renamed to __spi_async() and __spi_sync() so that spi_async(), spi_sync(), spi_async_locked() and spi_sync_locked() can just become wrappers around the common code. spi_sync() is protected by a mutex because it can sleep spi_async() needs to be protected with a flag and a spinlock because it can be called atomically and must not sleep Signed-off-by: Ernst Schwab <eschwab@online.de> [grant.likely@secretlab.ca: use spin_lock_irqsave()] Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Matt Fleming <matt@console-pimps.org> Tested-by: Antonio Ospite <ospite@studenti.unina.it>
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#
5a0e3ad6 |
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24-Mar-2010 |
Tejun Heo <tj@kernel.org> |
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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#
568d0697 |
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22-Sep-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: handle TX-only/RX-only Support two new half-duplex SPI implementation restrictions, for links that talk to TX-only or RX-only devices. (Existing half-duplex flavors support both transfer directions, just not at the same time.) Move spi_async() into the spi.c core, and stop inlining it. Then make that function perform error checks and reject messages that demand more than the underlying controller can support. Based on a patch from Marek Szyprowski which did this only for the bitbanged GPIO driver. Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
75368bf6 |
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22-Sep-2009 |
Anton Vorontsov <avorontsov@ru.mvista.com> |
spi: add support for device table matching With this patch spi drivers can use standard spi_driver.id_table and MODULE_DEVICE_TABLE() mechanisms to bind against the devices. Just like we do with I2C drivers. This is useful when a single driver supports several variants of devices but it is not possible to detect them in run-time (like non-JEDEC chips probing in drivers/mtd/devices/m25p80.c), and when platform_data usage is overkill. This patch also makes life a lot easier on OpenFirmware platforms, since with OF we extensively use proper device IDs in modaliases. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Jean Delvare <khali@linux-fr.org> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b73b2559 |
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22-Sep-2009 |
Randy Dunlap <randy.dunlap@oracle.com> |
spi.h: add missing kernel-doc for struct spi_master Add missing kernel-doc notation in spi.h for struct spi_master: Warning(include/linux/spi/spi.h:289): No description found for parameter 'mode_bits' Warning(include/linux/spi/spi.h:289): No description found for parameter 'flags' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
70d6027f |
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30-Jun-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: add spi_master flag word Add a new spi_master.flags word listing constraints relevant to that controller. Define the first constraint bit: a half duplex restriction. Include that constraint in the OMAP1 MicroWire controller driver. Have the mmc_spi host be the first customer of this flag. Its coding relies heavily on full duplex transfers, so it must fail when the underlying controller driver won't perform them. (The spi_write_then_read routine could use it too: use the temporarily-withdrawn full-duplex speedup unless this flag is set, in which case the existing code applies. Similarly, any spi_master implementing only SPI_3WIRE should set the flag.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b55f627f |
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30-Jun-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: new spi->mode bits Add two new spi_device.mode bits to accomodate more protocol options, and pass them through to usermode drivers: * SPI_NO_CS ... a second 3-wire variant, where the chipselect line is removed instead of a data line; transfers are still full duplex. This obviously has STRONG protocol implications since the chipselect transitions can't be used to synchronize state transitions with the SPI master. * SPI_READY ... defines open drain signal that's pulled low to pause the clock. This defines a 5-wire variant (normal 4-wire SPI plus READY) and two 4-wire variants (READY plus each of the 3-wire flavors). Such hardware flow control can be a big win. There are ADC converters and flash chips that expose READY signals, but not many host controllers support it today. The spi_bitbang code should be changed to use SPI_NO_CS instead of its current nonportable hack. That's a mode most hardware can easily support (unlike SPI_READY). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: "Paulraj, Sandeep" <s-paulraj@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
e7db06b5 |
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17-Jun-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: move more spi_setup() functionality into core Move some common spi_setup() error checks into the SPI framework from the spi_master controller drivers: - Add a new "mode_bits" field to spi_master - Use that in spi_setup to validate the spi->mode value being requested. Setting this new field is now mandatory for any controller supporting more than vanilla SPI_MODE_0. - Update all spi_master drivers to: * Initialize that field * Remove current spi_setup() checks using that value. This is a net minor code shrink. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7d077197 |
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17-Jun-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: move common spi_setup() functionality into core Start moving some spi_setup() functionality into the SPI core from the various spi_master controller drivers: - Make that function stop being an inline; - Move two common idioms from drivers into that new function: * Default bits_per_word to 8 if that field isn't set * Issue a standardized dev_dbg() message This is a net minor source code shrink, and supports enhancments found in some follow-up patches. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
6e538aaf |
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21-Apr-2009 |
David Brownell <dbrownell@users.sourceforge.net> |
spi: documentation: emphasise spi_master.setup() semantics This is a doc-only patch which I hope will reduce the number of spi_master controller driver patches starting out with a common implementation bug. (As in: almost every spi_master driver I see starts out with its version of this bug. Sigh.) It just re-emphasizes that the setup() method may be called for one device while a transfer is active on another ... which means that most driver implementations shouldn't touch any registers. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
fd5e191e |
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06-Apr-2009 |
Mike Rapoport <rppt@kernel.org> |
SPI: add dma_alignment field to spi_master Some SPI controllers have restrictions on DMAable buffers alignemt. Currently if the buffer supplied by protocol driver is not properly aligned, the controller silently performs transfer in PIO mode. Addition of dma_alignment field to spi_master allows protocol drivers to perform proper alignment. Signed-off-by: Mike Rapoport <mike@compulab.co.il> Cc: Bryan Wu <bryan.wu@analog.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
025dfdaf |
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16-Oct-2008 |
Frederik Schwarzer <schwarzerf@gmail.com> |
trivial: fix then -> than typos in comments and documentation - (better, more, bigger ...) then -> (...) than Signed-off-by: Frederik Schwarzer <schwarzerf@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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#
0a30c5ce |
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04-Jan-2009 |
Randy Dunlap <randy.dunlap@oracle.com> |
spi.h uses/needs device.h Include header files as used/needed: In file included from drivers/leds/leds-dac124s085.c:16: include/linux/spi/spi.h:66: error: field 'dev' has incomplete type include/linux/spi/spi.h: In function 'to_spi_device': include/linux/spi/spi.h:100: warning: type defaults to 'int' in declaration of '__mptr' ... Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
dc87c98e |
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15-May-2008 |
Grant Likely <grant.likely@secretlab.ca> |
spi: split up spi_new_device() to allow two stage registration. spi_new_device() allocates and registers an spi device all in one swoop. If the driver needs to add extra data to the spi_device before it is registered, then this causes problems. This is needed for OF device tree support so that the SPI device tree helper can add a pointer to the device node after the device is allocated, but before the device is registered. OF aware SPI devices can then retrieve data out of the device node to populate a platform data structure. This patch splits the allocation and registration portions of code out of spi_new_device() and creates two new functions; spi_alloc_device() and spi_register_device(). spi_new_device() is modified to use the new functions for allocation and registration. None of the existing users of spi_new_device() should be affected by this change. Drivers using the new API can forego the use of spi_board_info structure to describe the device layout and populate data into the spi_device structure directly. This change is in preparation for adding an OF device tree parser to generate spi_devices based on data in the device tree. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: David Brownell <dbrownell@users.sourceforge.net>
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102eb975 |
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23-Jul-2008 |
Grant Likely <grant.likely@secretlab.ca> |
spi: make spi_board_info.modalias a char array Currently, 'modalias' in the spi_device structure is a 'const char *'. The spi_new_device() function fills in the modalias value from a passed in spi_board_info data block. Since it is a pointer copy, the new spi_device remains dependent on the spi_board_info structure after the new spi_device is registered (no other fields in spi_device directly depend on the spi_board_info structure; all of the other data is copied). This causes a problem when dynamically propulating the list of attached SPI devices. For example, in arch/powerpc, the list of SPI devices can be populated from data in the device tree. With the current code, the device tree adapter must kmalloc() a new spi_board_info structure for each new SPI device it finds in the device tree, and there is no simple mechanism in place for keeping track of these allocations. This patch changes modalias from a 'const char *' to a fixed char array. By copying the modalias string instead of referencing it, the dependency on the spi_board_info structure is eliminated and an outside caller does not need to maintain a separate spi_board_info allocation for each device. If searched through the code to the best of my ability for any references to modalias which may be affected by this change and haven't found anything. It has been tested with the lite5200b platform in arch/powerpc. [dbrownell@users.sourceforge.net: cope with linux-next changes: KOBJ_NAME_LEN obliterated, etc] Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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aab0de24 |
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01-May-2008 |
Kay Sievers <kay.sievers@vrfy.org> |
driver core: remove KOBJ_NAME_LEN define Kobjects do not have a limit in name size since a while, so stop pretending that they do. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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49dce689 |
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16-Oct-2007 |
Tony Jones <tonyj@suse.de> |
spi doesn't need class_device Make the SPI framework and drivers stop using class_device. Update docs accordingly ... highlighting just which sysfs paths should be "safe"/stable. Signed-off-by: Tony Jones <tonyj@suse.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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2604288f |
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31-Jul-2007 |
David Brownell <david-b@pacbell.net> |
spi kerneldoc update This adds kerneldoc to the SPI framework. The "spi_driver" and "spi_board_info" structs were previously not described. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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4ef7af50 |
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31-Jul-2007 |
Anton Vorontsov <avorontsov@ru.mvista.com> |
SPI loopback mode definition Loopback mode is supported by various controllers. This mode can be useful for testing, especially in conjunction with spidev driver. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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c06e677a |
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17-Jul-2007 |
David Brownell <david-b@pacbell.net> |
SPI: add 3wire mode flag Add a new spi->mode bit: SPI_3WIRE, for chips where the SI and SO signals are shared (and which are thus only half duplex). Update the LM70 driver to require support for that hardware mode from the controller. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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f5a9c77d |
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16-Jun-2007 |
David Brownell <david-b@pacbell.net> |
spi doc updates Update two points in the SPI interface documentation: - Update description of the "chip stays selected after message ends" mode. In some cases it's required for correctness; it isn't just a performance tweak. (Yes: to use this mode on mult-device busses, another programming interface will be needed. One draft has been circulated already.) - Clarify spi_setup(), highlighting that callers must ensure that no requests are queued (can't change configuration except between I/Os), and that the device must be deselected when this returns (which is a key part of why it's called during device init). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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33e34dc6 |
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08-May-2007 |
David Brownell <david-b@pacbell.net> |
SPI kerneldoc Various documentation updates for the SPI infrastructure, to clarify things that may not have been clear, to cope with lack of editing, and fix omissions. Also, plug SPI into the kernel-api DocBook template, and fix all the resulting glitches in document generation. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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80224561 |
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12-Feb-2007 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI doc clarifications This clarifies some aspects of the SPI programming interface, based on feedback from Hans-Peter Nilsson. The in-memory representation of words is right-aligned, so for example a twelve bit word is stored using sixteen bits with four undefined bits in the MSB. And controller drivers must reject protocol tweaking modes they do not support. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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0ffa0285 |
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12-Feb-2007 |
Hans-Peter Nilsson <hans-peter.nilsson@axis.com> |
[PATCH] SPI cleanup() method param becomes non-const I'd like to assign NULL to kfree()d members of a structure. I can't do that without ugly casting (see the PXA patch) when the structure pointed to is const-qualified. I don't really see a reason why the cleanup method isn't allowed to alter the object it should clean up. :-) No, I didn't test the PXA patch, but I verified that the NULL-assignment doesn't stop me from doing rmmod/insmodding my own spi_bitbang-based driver. Signed-off-by: Hans-Peter Nilsson <hp@axis.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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ddc1e975 |
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12-Feb-2007 |
Ben Dooks <ben@fluff.org> |
[PATCH] spi: remove return in spi_unregister_driver() Make the spi_unregister_driver() code fit in with the rest of the header file, and only do the action if the driver passed is non-NULL. This also makes the code a line smaller. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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9b40ff4d |
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12-Feb-2007 |
Ben Dooks <ben@fluff.org> |
[PATCH] spi: add spi_set_drvdata() and spi_get_drvdata() Add wrappers for getting and setting the driver data using spi_device instead of using dev_{get|set}_drvdata with &spi->dev, to mirror the platform_{get|set}_drvdata. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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07b24630 |
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07-Feb-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Revert "Driver core: convert SPI code to use struct device" This reverts commit 2943ecf2ed32632473c06f1975db47a7aa98c10f. This should go through the SPI maintainer, it was my fault that it did not. Especially as it conflicts with other patches he has pending. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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2943ecf2 |
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22-Jan-2007 |
Greg Kroah-Hartman <gregkh@suse.de> |
Driver core: convert SPI code to use struct device Converts from using struct "class_device" to "struct device" making everything show up properly in /sys/devices/ with symlinks from the /sys/class directory. Cc: <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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4b1badf5 |
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29-Dec-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI: define null tx_buf to mean "shift out zeroes" Some issues were recently turned up with the current specification of what it means for spi_transfer.tx_buf to be null, as part of transfers which are (from the SPI protocol driver perspective) pure reads. Specifically, that it seems better to change the TX behaviour there from "undefined" to "will shift zeroes". This lets protocol drivers (like the ads7846 driver) depend on that behavior. It's what most controller drivers in the tree are already doing (with one exception and one case of driver wanting-to-oops), it's what Microwire hardware will necessarily be doing, and it removes an issue whereby certain security audits would need to define such a value anyway as part of removing covert channels. This patch changes the specification to require shifting zeroes, and updates all currently merged SPI controller drivers to do so. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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980a01c9 |
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28-Jun-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI: infrastructure to initialize spi_device.mode early This patch adds earlier initialization of spi_device.mode, as needed on boards using nondefault chipselect polarity. An example would be ones using the RS5C348 RTC without an external signal inverter between the RTC chipselect and the SPI controller. Without this mechanism, the first setup() call for that chip would wrongly enable chips, corrupting transfers to/from other chips sharing that SPI bus. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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a020ed75 |
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03-Apr-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI: busnum == 0 needs to work We need to be able to have a "SPI bus 0" matching chip numbering; but that number was wrongly used to flag dynamic allocation of a bus number. This patch resolves that issue; now negative numbers trigger dynamic alloc. It also updates the how-to-write-a-controller-driver overview to mention this stuff. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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ccf77cc4 |
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03-Apr-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI: devices can require LSB-first encodings Add spi_device hook for LSB-first word encoding, and update all the (in-tree) controller drivers to reject such devices. Eventually, some controller drivers will be updated to support lsb-first encodings on the wire; no current drivers need this. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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747d844e |
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02-Apr-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI: spi whitespace fixes This removes superfluous whitespace in the <linux/spi/spi.h> header. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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4cff33f9 |
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17-Feb-2006 |
Imre Deak <imre.deak@nokia.com> |
[PATCH] SPI: per-transfer overrides for wordsize and clocking Some protocols (like one for some bitmap displays) require different clock speed or word size settings for each transfer in an SPI message. This adds those parameters to struct spi_transfer. They are to be used when they are nonzero; otherwise the defaults from spi_device are to be used. The patch also adds a setup_transfer callback to spi_bitbang, uses it for messages that use those overrides, and implements it so that the pure bitbanging code can help resolve any questions about how it should work. Signed-off-by: Imre Deak <imre.deak@nokia.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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5d870c8e |
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11-Jan-2006 |
Andrew Morton <akpm@osdl.org> |
[PATCH] spi: remove fastcall crap gcc4 generates warnings when a non-FASTCALL function pointer is assigned to a FASTCALL one. Perhaps it has taste. Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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8275c642 |
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08-Jan-2006 |
Vitaly Wool <vwool@ru.mvista.com> |
[PATCH] spi: use linked lists rather than an array This makes the SPI core and its users access transfers in the SPI message structure as linked list not as an array, as discussed on LKML. From: David Brownell <dbrownell@users.sourceforge.net> Updates including doc, bugfixes to the list code, add spi_message_add_tail(). Plus, initialize things _before_ grabbing the locks in some cases (in case it grows more expensive). This also merges some bitbang updates of mine that didn't yet make it into the mm tree. Signed-off-by: Vitaly Wool <vwool@ru.mvista.com> Signed-off-by: Dmitry Pervushin <dpervushin@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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0c868461 |
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08-Jan-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] SPI core tweaks, bugfix This includes various updates to the SPI core: - Fixes a driver model refcount bug in spi_unregister_master() paths. - The spi_master structures now have wrappers which help keep drivers from needing class-level get/put for device data or for refcounts. - Check for a few setup errors that would cause oopsing later. - Docs say more about memory management. Highlights the use of DMA-safe i/o buffers, and zero-initializing spi_message and such metadata. - Provide a simple alloc/free for spi_message and its spi_transfer; this is only one of the possible memory management policies. Nothing to break code that already works. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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b885244e |
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08-Jan-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] spi: add spi_driver to SPI framework This is a refresh of the "Simple SPI Framework" found in 2.6.15-rc3-mm1 which makes the following changes: * There's now a "struct spi_driver". This increase the footprint of the core a bit, since it now includes code to do what the driver core was previously handling directly. Documentation and comments were updated to match. * spi_alloc_master() now does class_device_initialize(), so it can at least be refcounted before spi_register_master(). To match, spi_register_master() switched over to class_device_add(). * States explicitly that after transfer errors, spi_devices will be deselected. We want fault recovery procedures to work the same for all controller drivers. * Minor tweaks: controller_data no longer points to readonly data; prevent some potential cast-from-null bugs with container_of calls; clarifies some existing kerneldoc, And a few small cleanups. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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8ae12a0d |
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08-Jan-2006 |
David Brownell <david-b@pacbell.net> |
[PATCH] spi: simple SPI framework This is the core of a small SPI framework, implementing the model of a queue of messages which complete asynchronously (with thin synchronous wrappers on top). - It's still less than 2KB of ".text" (ARM). If there's got to be a mid-layer for something so simple, that's the right size budget. :) - The guts use board-specific SPI device tables to build the driver model tree. (Hardware probing is rarely an option.) - This version of Kconfig includes no drivers. At this writing there are two known master controller drivers (PXA/SSP, OMAP MicroWire) and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML mentions of other drivers in development. - No userspace API. There are several implementations to compare. Implement them like any other driver, and bind them with sysfs. The changes from last version posted to LKML (on 11-Nov-2005) are minor, and include: - One bugfix (removes a FIXME), with the visible effect of making device names be "spiB.C" where B is the bus number and C is the chipselect. - The "caller provides DMA mappings" mechanism now has kerneldoc, for DMA drivers that want to be fancy. - Hey, the framework init can be subsys_init. Even though board init logic fires earlier, at arch_init ... since the framework init is for driver support, and the board init support uses static init. - Various additional spec/doc clarifications based on discussions with other folk. It adds a brief "thank you" at the end, for folk who've helped nudge this framework into existence. As I've said before, I think that "protocol tweaking" is the main support that this driver framework will need to evolve. From: Mark Underwood <basicmark@yahoo.com> Update the SPI framework to remove a potential priority inversion case by reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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