#
73dfe970 |
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29-Mar-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Fix setting period with #pwm-cells = <1> and of_pwm_single_xlate() For drivers making use of of_pwm_single_xlate() (i.e. those that don't pass a hwpwm index) and also don't pass flags, setting period was wrongly skipped. This affects the pwm-pxa and ti-sn65dsi86 drivers. Reported-by: Karel Balej <balejk@matfyz.cz> Link: https://lore.kernel.org/r/D05IVTPYH35N.2CLDG6LSILRSN@matfyz.cz Fixes: 40ade0c2e794 ("pwm: Let the of_xlate callbacks accept references without period") Tested-by: Karel Balej <balejk@matfyz.cz> Link: https://lore.kernel.org/r/20240329103544.545290-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
024913db |
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14-Feb-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Provide pwmchip_alloc() function and a devm variant of it This function allocates a struct pwm_chip and driver data. Compared to the status quo the split into pwm_chip and driver data is new, otherwise it doesn't change anything relevant (yet). The intention is that after all drivers are switched to use this allocation function, its possible to add a struct device to struct pwm_chip to properly track the latter's lifetime without touching all drivers again. Proper lifetime tracking is a necessary precondition to introduce character device support for PWMs (that implements atomic setting and doesn't suffer from the sysfs overhead of the /sys/class/pwm userspace support). The new function pwmchip_priv() (obviously?) only works for chips allocated with pwmchip_alloc(). Link: https://lore.kernel.org/r/9577d6053a5a52536057dc8654ff567181c2da82.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
4e59267c |
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14-Feb-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Provide an inline function to get the parent device of a given chip Currently a pwm_chip stores in its struct device *dev member a pointer to the parent device. Preparing a change that embeds a full struct device in struct pwm_chip, this accessor function should be used in all drivers directly accessing chip->dev now. This way struct pwm_chip and this new function can be changed without having to touch all drivers in the same change set. Make use of this function in the framework's core sources. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/cc30090d2f9762bed9854a55612144bccc910781.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
62928315 |
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25-Jan-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Reorder symbols in core.c This moves the functions called by pwm consumers above the functions called by pwm providers. When character device support is added later this is hooked into the chip registration functions. As the needed callbacks are a kind of consumer and make use of the consumer functions, having this order is more natural and prevents having to add declarations for static functions. Also move the global variables for pwm tables to the respective functions to have them properly grouped. Link: https://lore.kernel.org/r/eed83de07bdfb69b5ceba0b9aed757ee612dea8f.1706182805.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
91bb2349 |
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09-Jan-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop duplicate check against chip->npwm in of_pwm_xlate_with_flags() args->args[0] is passed as parameter "index" to pwm_request_from_chip(). The latter function also checks for index >= npwm, so of_pwm_xlate_with_flags() doesn't need to do that. Link: https://lore.kernel.org/r/b06e445a6ed62a339add727eccb969a33d678386.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
40ade0c2 |
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09-Jan-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Let the of_xlate callbacks accept references without period With this extension of_pwm_xlate_with_flags() is suitable to replace the custom xlate function of the pwm-clps711x driver. While touching these very similar functions align their implementations. Link: https://lore.kernel.org/r/127622315d07d9d419ae8e6373c7e5be7fab7a62.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
4e77431c |
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09-Jan-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop useless member .of_pwm_n_cells of struct pwm_chip Apart from the two of_xlate implementations this member is write-only. In the of_xlate functions of_pwm_xlate_with_flags() and of_pwm_single_xlate() it's more sensible to check for args->args_count because this is what is actually used in the device tree. Acked-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/53d8c545aa8f79a920358be9e72e382b3981bdc4.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
a297d07b |
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09-Jan-2024 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Fix out-of-bounds access in of_pwm_single_xlate() With args->args_count == 2 args->args[2] is not defined. Actually the flags are contained in args->args[1]. Fixes: 3ab7b6ac5d82 ("pwm: Introduce single-PWM of_xlate function") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/243908750d306e018a3d4bf2eb745d53ab50f663.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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#
efb704ab |
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30-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Reduce number of pointer dereferences in pwm_device_request() pwm->chip and pwm->chip->ops are used several times in this function. Introduce local variables for these. There is no semantical change, but with ARCH=arm, allmodconfig and gcc-13 bloat-o-meter reports a slight improvement: add/remove: 1/1 grow/shrink: 1/1 up/down: 8/-36 (-28) Function old new delta pwm_apply_state 476 480 +4 __initcall__kmod_core__307_1092_pwm_debugfs_init4 - 4 +4 __initcall__kmod_core__307_1090_pwm_debugfs_init4 4 - -4 pwm_request_from_chip 628 596 -32 Total: Before=15091, After=15063, chg -0.19% Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
7170d3be |
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19-Dec-2023 |
Sean Young <sean@mess.org> |
pwm: Make it possible to apply PWM changes in atomic context Some PWM devices require sleeping, for example if the pwm device is connected over I2C. However, many PWM devices could be used from atomic context, e.g. memory mapped PWM. This is useful for, for example, the pwm-ir-tx driver which requires precise timing. Sleeping causes havoc with the generated IR signal. Since not all PWM devices can support atomic context, we also add a pwm_might_sleep() function to check if is not supported. Signed-off-by: Sean Young <sean@mess.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
c748a6d7 |
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19-Dec-2023 |
Sean Young <sean@mess.org> |
pwm: Rename pwm_apply_state() to pwm_apply_might_sleep() In order to introduce a pwm api which can be used from atomic context, we will need two functions for applying pwm changes: int pwm_apply_might_sleep(struct pwm *, struct pwm_state *); int pwm_apply_atomic(struct pwm *, struct pwm_state *); This commit just deals with renaming pwm_apply_state(), a following commit will introduce the pwm_apply_atomic() function. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # for input Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Lee Jones <lee@kernel.org> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b0445a18 |
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23-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Narrow scope of struct pwm_device pointer In the expression determining the size of the allocation for chip->pwms it's more natural to use sizeof(*chip->pwms) than sizeof(*pwm). With that changed, the variable pwm is only used in a for loop and its scope can be reduced accordingly. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
0360a487 |
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13-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Mention PWM chip ID in /sys/kernel/debug/pwm While it's not hard to match the entries from /sys/kernel/debug/pwm to the corresponding pwmchip in /sys/class/pwm, it's a bit simpler to have the number mentioned in /sys/kernel/debug/pwm. Link: https://lore.kernel.org/r/20230808165250.942396-3-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
54c86dd2 |
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13-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Replace PWM chip unique base by unique ID Traditionally each PWM device had a unique ID stored in the "pwm" member of struct pwm_device. However this number was hardly used and dropped in the previous commit. To identify a certain PWM you're supposed to use the chip's ID and the hwpwm of the PWM device now. With the PWM chip base gone PWM chips can get their IDs better and simpler using an idr. This is expected to change the numbering of PWM chips, but nothing should rely on the numbering anyhow. Other than that the side effects are: - The PWM chip IDs are smaller and in most cases consecutive. - The ordering in /sys/kernel/debug/pwm is ordered by ascending PWM chip ID. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
f3e25e68 |
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13-Nov-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop unused member "pwm" from struct pwm_device This member is only assigned to and never read. So drop it. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
a6e5654e |
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05-Jul-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop pwm_[sg]et_chip_data() The semantic of chip_data is a bit surprising as it's cleared when pwm_put() is called. Also there is a big overlap with the standard driver data. All drivers were adapted to not make use of chip_data any more, so it can go away. Link: https://lore.kernel.org/r/20230705080650.2353391-9-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
384461ab |
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04-Aug-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Manage owner assignment implicitly for drivers Instead of requiring each driver to care for assigning the owner member of struct pwm_ops, handle that implicitly using a macro. Note that the owner member has to be moved to struct pwm_chip, as the ops structure usually lives in read-only memory and so cannot be modified. The upside is that new low level drivers cannot forget the assignment and save one line each. The pwm-crc driver didn't assign .owner, that's not a problem in practice though as the driver cannot be compiled as a module. Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i Acked-by: Andi Shyti <andi.shyti@kernel.org> Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
86eed2a1 |
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25-Jul-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Fix order of freeing resources in pwmchip_remove() pwmchip_add() calls of_pwmchip_add() only after adding the chip to pwm_chips and releasing pwm_lock. So the proper order in pwmchip_remove() is to call of_pwmchip_remove() before taking the mutex and removing the chip from pwm_chips. This way pwmchip_remove() releases the resources in reverse order compared to pwmchip_add() requesting them. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
84c33f42 |
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28-Jul-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop unused #include <linux/radix-tree.h> core.c doens't use any of the symbols provided by linux/radix-tree.h and compiles just fine without this include. So drop the #include. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
018121e6 |
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25-Jul-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Remove outdated documentation for pwmchip_remove() pwmchip_remove() returns void since some time but the documentation still mentions the situations where it used to return an error code. Just remove this old and now wrong text. Fixes: 8083f58d08fd ("pwm: Make pwmchip_remove() return void") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
0a41b0c5 |
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14-Jul-2023 |
Rob Herring <robh@kernel.org> |
pwm: Explicitly include correct DT includes The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b4f78ff7 |
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14-Jul-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Use a consistent name for pwm_chip pointers in the core Most variables of type struct pwm_chip * are named "chip", there are only three outliers called "pc". Change these three to "chip", too, for consistency. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
247ee6c7 |
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13-Apr-2023 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Remove unused radix tree The radix tree's only use was to map PWM channels to the global number space. With that number space gone, the radix tree is now unused, so it can simply be removed. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
0af4d704 |
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12-Apr-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Delete deprecated functions pwm_request() and pwm_free() Since commit 5a7fbe452ad9 ("backlight: pwm_bl: Drop support for legacy PWM probing") the last user of pwm_request() and pwm_free() is gone. So remove these functions that were deprecated over 10 years ago in commit 8138d2ddbcca ("pwm: Add table-based lookup for static mappings"). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [thierry.reding@gmail.com: clean up a bit after removal] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
1271a7b9 |
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22-Mar-2023 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Zero-initialize the pwm_state passed to driver's .get_state() This is just to ensure that .usage_power is properly initialized and doesn't contain random stack data. The other members of struct pwm_state should get a value assigned in a successful call to .get_state(). So in the absence of bugs in driver implementations, this is only a safe-guard and no fix. Reported-by: Munehisa Kamata <kamatam@amazon.com> Link: https://lore.kernel.org/r/20230310214004.2619480-1-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
c73a3107 |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Handle .get_state() failures This suppresses diagnosis for PWM_DEBUG routines and makes sure that pwm->state isn't modified in pwm_device_request() if .get_state() fails. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-12-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
3dae106f |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm/tracing: Also record trace events for failed API calls Record and report an error code for the events. This allows to report about failed calls without ambiguity and so gives a more complete picture. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-3-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
55f363e1 |
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02-Dec-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Remove S_IFREG from debugfs_create_file() The debugfs_create_file() already has a check and adds S_IFREG automatically. Remove unneeded flag. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20221117165812.27757-1-andriy.shevchenko@linux.intel.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
fa1b9aa4 |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Don't initialize list head before calling list_add() list_add() just overwrites the members of the element to add (here: chip->list) without any checks, even in the DEBUG_LIST case. So save the effort to initialize the list. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221117211143.3817381-5-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
4034e594 |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Mark free pwm IDs as used in alloc_pwms() alloc_pwms() only identified a free range of IDs and this range was marked as used only later by pwmchip_add(). Instead let alloc_pwms() already do the marking (which makes the function actually allocating the range and so justifies the function name). This way access to the allocated_pwms bitfield is limited to two functions only. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221117211143.3817381-4-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
c8135b51 |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Reduce time the pwm_lock mutex is held in pwmchip_add() This simplifies error handling as the need for goto error handling goes away and at the end of the function the code can be simplified as this code isn't used in the error case any more. Now memory allocation and the call to of_pwmchip_add() are done without holding the lock. Both don't access the data structures protected by &pwm_lock. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221117211143.3817381-3-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
e51b156b |
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02-Dec-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Document variables protected by pwm_lock To simplify validation of the used locking, document for the global pwm mutex what it actually protects against concurrent access. Also note for two functions modifying these that pwm_lock is held by the caller. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221117211143.3817381-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b4319802 |
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27-Sep-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Replace custom implementation of device_match_fwnode() Replace custom implementation of the device_match_fwnode(). This hides the implementation details and makes future changes easier. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b5ae0ad5 |
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26-Aug-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Make of_pwm_get() static There are no users outside of PWM core of the of_pwm_get(). Make it static. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220826172642.16404-3-andriy.shevchenko@linux.intel.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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#
b88c48bf |
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26-Aug-2022 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Get rid of unused devm_of_pwm_get() The devm_of_pwm_get() has recently lost its single user, drop the dead API as well. Note, the new code should use either plain pwm_get() or managed devm_pwm_get() or devm_fwnode_pwm_get() APIs. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220826172642.16404-2-andriy.shevchenko@linux.intel.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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#
0829c35d |
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21-May-2022 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop support for legacy drivers There are no drivers left providing the legacy callbacks. So drop support for these. If this commit breaks your out-of-tree pwm driver, look at e.g. commit ec00cd5e63f0 ("pwm: renesas-tpu: Implement .apply() callback") for an example of the needed conversion for your driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
e45a178e |
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01-Jul-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Restore initial state if a legacy callback fails It is not entirely accurate to go back to the initial state after e.g. .enable() failed, as .config() still modified the hardware, but this same inconsistency exists for drivers that implement .apply(). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
92f69e58 |
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01-Jul-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Prevent a glitch for legacy drivers If a running PWM is reconfigured to disabled calling the ->config() callback before disabling the hardware might result in a glitch where the (maybe) new period and duty_cycle are visible on the output before disabling the hardware. So handle disabling before calling ->config(). Also exit early in this case which is possible because period and duty_cycle don't matter for disabled PWMs. In return however ->config has to be called even if state->period == pwm->state.period && state->duty_cycle != pwm->state.duty_cycle because setting these might have been skipped in the previous call. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
77965c98 |
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01-Jul-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Move legacy driver handling into a dedicated function There is no change in behaviour, only some code is moved from pwm_apply_state to a separate function. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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3ab7b6ac |
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25-Oct-2021 |
Bjorn Andersson <bjorn.andersson@linaro.org> |
pwm: Introduce single-PWM of_xlate function The existing pxa driver and the upcoming addition of PWM support in the TI sn565dsi86 DSI/eDP bridge driver both has a single PWM channel and thereby a need for a of_xlate function with the period as its single argument. Introduce a common helper function in the core that can be used as of_xlate by such drivers and migrate the pxa driver to use this. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Steev Klimaszewski <steev@kali.org> Tested-By: Steev Klimaszewski <steev@kali.org> Signed-off-by: Robert Foss <robert.foss@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211025170925.3096444-1-bjorn.andersson@linaro.org
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#
4ad91a22 |
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09-Sep-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Make it explicit that pwm_apply_state() might sleep At least some implementations sleep. So mark pwm_apply_state() with a might_sleep() to make callers aware. In the worst case this uncovers a valid atomic user, then we revert this patch and at least gained some more knowledge and then can work on a concept similar to gpio_get_value/gpio_get_value_cansleep. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
8083f58d |
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07-Jul-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Make pwmchip_remove() return void Since some time pwmchip_remove() always returns 0 so the return value isn't usefull. Now that all callers are converted to ignore its value the function can be changed to return void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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bebedf2b |
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06-Jul-2021 |
Colin Ian King <colin.king@canonical.com> |
pwm: Remove redundant assignment to pointer pwm The pointer pwm is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
9ae241d0 |
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07-Jun-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Simplify some devm_*pwm*() functions Use devm_add_action_or_reset() instead of devres_alloc() and devres_add(), which works the same. This will simplify the code. There is no functional changes. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
c333b936 |
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07-Jun-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Remove unused devm_pwm_put() There are no users and seems no will come of the devm_pwm_put(). Remove the function. While at it, slightly update documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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e625fb70 |
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07-Jun-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Unify fwnode checks in the module Historically we have two different approaches on how to check type of fwnode. Unify them using the latest and greatest fwnode related APIs. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
e5c38ba9 |
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07-Jun-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Reuse fwnode_to_pwmchip() in ACPI case In ACPI case we may use matching by fwnode as provided via fwnode_to_pwmchip(). This makes device_to_pwmchip() not needed anymore. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
ca06616b |
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07-Jun-2021 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
pwm: core: Convert to use fwnode for matching When we traverse the list of the registered PWM controllers, use fwnode to match. This will help for further cleanup. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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ad5e085c |
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23-Apr-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop irrelevant error path from pwmchip_remove() Since the PWM core uses device links (commit b2c200e3f2fd ("pwm: Add consumer device link")) each consumer driver that requested the PWMs is already gone. If they called pwm_put() (as they should) the PWMF_REQUESTED bit is not set. If they failed (which is a bug) the PWMF_REQUESTED bit might still be set, but the driver that cared is gone, so nothing bad happens if the PWM chip goes away even if the PWMF_REQUESTED is still present. So the check can be dropped. With this change pwmchip_remove() returns always 0, so lowlevel drivers don't need to check the return code any more. Once all drivers dropped this check this function can be changed to return void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
bcda91bf |
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07-Apr-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Add a device-managed function to add PWM chips This potentially simplifies low-level PWM drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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9e40ee18 |
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07-May-2021 |
Clemens Gruber <clemens.gruber@pqgruber.com> |
pwm: core: Support new usage_power setting in PWM state If usage_power is set, the PWM driver is only required to maintain the power output but has more freedom regarding signal form. If supported, the signal can be optimized, for example to improve EMI by phase shifting individual channels. Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
69230cfa |
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10-May-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Autodetect default value for of_pwm_n_cells from device tree This allows to simplify all drivers that use three pwm-cells. The only ugly side effect is that if a driver specified of_pwm_n_cells = 2 it suddenly supports device trees that use #pwm-cells = <3>. This however isn't a bad thing because the driver doesn't need explicit support for three cells as the core handles all the details. Also there is no such in-tree driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
5447e783 |
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10-May-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop of_pwm_simple_xlate() in favour of of_pwm_xlate_with_flags() Since the previous commit the latter function can do everything that the former does. So simplify accordingly. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
cf38c978 |
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10-May-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Make of_pwm_xlate_with_flags() work with #pwm-cells = <2> The two functions of_pwm_simple_xlate() and of_pwm_xlate_with_flags() are quite similar. of_pwm_simple_xlate() only supports two-cell PWM specifiers while of_pwm_xlate_with_flags() only supports PWM specifiers with 3 or more cells. The latter can easily be modified to behave identically to of_pwm_simple_xlate() for two-cell PWM specifiers. This is implemented here and allows to drop of_pwm_simple_xlate() in the next commit. There is a small detail that is different now in the two-cell specifier case in of_pwm_xlate_with_flags(): pwm->args.polarity is unconditionally initialized to PWM_POLARITY_NORMAL in the latter. I didn't find a case where this matters and doing that explicitly is the more robust approach. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [thierry.reding@gmail.com: fix up checkpatch warnings] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
9666cec3 |
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07-Dec-2020 |
Uwe Kleine-König <uwe@kleine-koenig.org> |
pwm: Drop function pwmchip_add_with_polarity() pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All other users of pwmchip_add_with_polarity() are gone. So drop pwmchip_add_with_polarity() and move the code instead to pwmchip_add(). The initial assignment to pwm->state.polarity is dropped. In every correct usage of the PWM API this value is overwritten later anyhow. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
d58cb0ee |
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01-Mar-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Return -EINVAL for old-style drivers without .set_polarity callback Since commit 2b1c1a5d5148 ("pwm: Use -EINVAL for unsupported polarity") all drivers implementing the apply callback are unified to return -EINVAL if an unsupported polarity is requested. Do the same in the compat code for old-style drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
f9a8ee8c |
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01-Mar-2021 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Always allocate PWM chip base ID dynamically Since commit 5e5da1e9fbee ("pwm: ab8500: Explicitly allocate pwm chip base dynamically") all drivers use dynamic ID allocation explicitly. New drivers are supposed to do the same, so remove support for driver specified base IDs and drop all assignments in the low-level drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
765edf0b |
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18-Nov-2020 |
Soham Biswas <sohambiswas41@gmail.com> |
pwm: core: Use octal permission Permission bits are easier readable in octal than with using the symbolic names. Fixes the following warning generated by checkpatch: WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'. #1341: FILE: drivers/pwm/core.c:1341: + debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, Signed-off-by: Soham Biswas <sohambiswas41@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
f339e79b |
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15-Sep-2020 |
Liu Shixin <liushixin2@huawei.com> |
pwm: Convert to use DEFINE_SEQ_ATTRIBUTE macro Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code. Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
a9d887dc |
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02-Jun-2020 |
Guru Das Srinagesh <gurus@codeaurora.org> |
pwm: Convert period and duty cycle to u64 Because period and duty cycle are defined as ints with units of nanoseconds, the maximum time duration that can be set is limited to ~2.147 seconds. Change their definitions to u64 in the structs of the PWM framework so that higher durations may be set. Also use the right format specifiers in debug prints in both core.c, pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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f5641d05 |
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03-Jun-2020 |
Kees Cook <keescook@chromium.org> |
pwm: Add missing "CONFIG_" prefix The IS_ENABLED() use was missing the CONFIG_ prefix which would have lead to skipping this code. Fixes: 3ad1f3a33286 ("pwm: Implement some checks for lowlevel drivers") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
db539cb9 |
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11-Apr-2020 |
Christophe JAILLET <christophe.jaillet@wanadoo.fr> |
pwm: Add missing '\n' in log messages Message logged by 'dev_xxx()' or 'pr_xxx()' should end with a '\n'. Fixes: 3ad1f3a33286 ("pwm: Implement some checks for lowlevel drivers") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
374c1104 |
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02-Apr-2020 |
Jason Yan <yanaijie@huawei.com> |
pwm: Make pwm_apply_state_debug() static Fix the following gcc warning: drivers/pwm/core.c:467:6: warning: symbol 'pwm_apply_state_debug' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
3ad1f3a3 |
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10-Feb-2020 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Implement some checks for lowlevel drivers There are some expectations which the callbacks provided by lowlevel drivers should fulfill. Implement checks that help driver authors to get these semantics right. As these have some overhead the checks can be disabled using a Kconfig setting. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
1188829a |
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24-Oct-2019 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Implement tracing for .get_state() and .apply_state() This allows to log all calls to the driver's lowlevel functions which simplifies debugging in some cases. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
cfc4c189 |
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20-Oct-2019 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Read initial hardware state at request time Drivers that support reading the hardware state (using ->get_state()) may want to rely on per-PWM data to do so. Defer reading the hardware state for the first time until the PWM has been requested and after drivers have had a chance to allocate per-PWM data. Conceptually this is also a more natural place to read the hardware state because the PWM core doesn't need to know the hardware state of a PWM unless there is a user for it. This also ensures that the state is read everytime a user requests a PWM. If the PWM changes between users for some reason, the PWM core will reload the state from hardware and keep its copy of the state up-to-date. Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Tested-by: Michal Vokáč <michal.vokac@ysoft.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
40a6b9a0 |
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20-Oct-2019 |
Thierry Reding <thierry.reding@gmail.com> |
Revert "pwm: Let pwm_get_state() return the last implemented state" It turns out that commit 01ccf903edd6 ("pwm: Let pwm_get_state() return the last implemented state") causes backlight failures on a number of boards. The reason is that some of the drivers do not write the full state through to the hardware registers, which means that ->get_state() subsequently does not return the correct state. Consumers which rely on pwm_get_state() returning the current state will therefore get confused and subsequently try to program a bad state. Before this change can be made, existing drivers need to be more carefully audited and fixed to behave as the framework expects. Until then, keep the original behaviour of returning the software state that was applied rather than reading the state back from hardware. Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Tested-by: Michal Vokáč <michal.vokac@ysoft.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
71523d18 |
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24-Aug-2019 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Ensure pwm_apply_state() doesn't modify the state argument It is surprising for a PWM consumer when the variable holding the requested state is modified by pwm_apply_state(). Consider for example a driver doing: #define PERIOD 5000000 #define DUTY_LITTLE 10 ... struct pwm_state state = { .period = PERIOD, .duty_cycle = DUTY_LITTLE, .polarity = PWM_POLARITY_NORMAL, .enabled = true, }; pwm_apply_state(mypwm, &state); ... state.duty_cycle = PERIOD / 2; pwm_apply_state(mypwm, &state); For sure the second call to pwm_apply_state() should still have state.period = PERIOD and not something the hardware driver chose for a reason that doesn't necessarily apply to the second call. So declare the state argument as a pointer to a const type and adapt all drivers' .apply callbacks. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
01ccf903 |
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24-Aug-2019 |
Uwe Kleine-König <uwe@kleine-koenig.org> |
pwm: Let pwm_get_state() return the last implemented state When pwm_apply_state() is called the lowlevel driver usually has to apply some rounding because the hardware doesn't support nanosecond resolution. So let pwm_get_state() return the actually implemented state instead of the last applied one if possible. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
fc3c5512 |
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24-Aug-2019 |
Uwe Kleine-König <uwe@kleine-koenig.org> |
pwm: Introduce local struct pwm_chip in pwm_apply_state() pwm->chip is dereferenced several times in the pwm_apply_state() function. Introducing a local variable for it helps keeping some lines a bit shorter. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
6cf9481b |
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30-Jul-2019 |
Hans de Goede <hdegoede@redhat.com> |
pwm: Fallback to the static lookup-list when acpi_pwm_get fails Commit 4a6ef8e37c4d ("pwm: Add support referencing PWMs from ACPI") made pwm_get unconditionally return the acpi_pwm_get return value if the device passed to pwm_get has an ACPI fwnode. But even if the passed in device has an ACPI fwnode, it does not necessarily have the necessary ACPI package defining its pwm bindings, especially since the binding / API of this ACPI package has only been introduced very recently. Up until now X86/ACPI devices which use a separate pwm controller for controlling their LCD screen's backlight brightness have been relying on the static lookup-list to get their pwm. pwm_get unconditionally returning the acpi_pwm_get return value breaks this, breaking backlight control on these devices. This commit fixes this by making pwm_get fall back to the static lookup-list if acpi_pwm_get returns -ENOENT. BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=96571 Reported-by: youling257@gmail.com Fixes: 4a6ef8e37c4d ("pwm: Add support referencing PWMs from ACPI") Cc: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
4a6ef8e3 |
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12-Jun-2019 |
Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> |
pwm: Add support referencing PWMs from ACPI In analogy to referencing a GPIO using the "gpios" property from ACPI, support referencing a PWM using the "pwms" property. ACPI entries must look like Package () {"pwms", Package () { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}} In contrast to the DT implementation, only _one_ PWM entry in the "pwms" property is supported. As a consequence "pwm-names"-property and con_id lookup aren't supported. Support for ACPI is added via the firmware-node framework which is an abstraction layer on top of ACPI/DT. To keep this patch clean, DT and ACPI paths are kept separate. The firmware-node framework could be used to unify both paths in a future patch. To support leds-pwm driver, an additional method devm_fwnode_pwm_get() which supports both ACPI and DT configuration is exported. Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> [thierry.reding@gmail.com: fix build failures for !ACPI] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b2c200e3 |
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18-Apr-2019 |
Fabrice Gasnier <fabrice.gasnier@st.com> |
pwm: Add consumer device link Add a device link between the PWM consumer and the PWM provider. This enforces the PWM user to get suspended before the PWM provider. It allows proper synchronization of suspend/resume sequences: the PWM user is responsible for properly stopping PWM, before the provider gets suspended: see [1]. Add the device link in: - of_pwm_get() - pwm_get() - devm_*pwm_get() variants as it requires a reference to the device for the PWM consumer. [1] https://lkml.org/lkml/2019/2/5/770 Suggested-by: Thierry Reding <thierry.reding@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
c82ee6d3 |
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19-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program see the file copying if not write to the free software foundation 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 52 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154042.342335923@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
e926b12c |
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25-Mar-2019 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Clear chip_data in pwm_put() After a PWM is disposed by its user the per chip data becomes invalid. Clear the data in common code instead of the device drivers to get consistent behaviour. Before this patch only three of nine drivers cleaned up here. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
347ab948 |
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19-Mar-2019 |
Phong Hoang <phong.hoang.wz@renesas.com> |
pwm: Fix deadlock warning when removing PWM device This patch fixes deadlock warning if removing PWM device when CONFIG_PROVE_LOCKING is enabled. This issue can be reproceduced by the following steps on the R-Car H3 Salvator-X board if the backlight is disabled: # cd /sys/class/pwm/pwmchip0 # echo 0 > export # ls device export npwm power pwm0 subsystem uevent unexport # cd device/driver # ls bind e6e31000.pwm uevent unbind # echo e6e31000.pwm > unbind [ 87.659974] ====================================================== [ 87.666149] WARNING: possible circular locking dependency detected [ 87.672327] 5.0.0 #7 Not tainted [ 87.675549] ------------------------------------------------------ [ 87.681723] bash/2986 is trying to acquire lock: [ 87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0 [ 87.694528] [ 87.694528] but task is already holding lock: [ 87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.707405] [ 87.707405] which lock already depends on the new lock. [ 87.707405] [ 87.715574] [ 87.715574] the existing dependency chain (in reverse order) is: [ 87.723048] [ 87.723048] -> #1 (pwm_lock){+.+.}: [ 87.728017] __mutex_lock+0x70/0x7e4 [ 87.732108] mutex_lock_nested+0x1c/0x24 [ 87.736547] pwm_request_from_chip.part.6+0x34/0x74 [ 87.741940] pwm_request_from_chip+0x20/0x40 [ 87.746725] export_store+0x6c/0x1f4 [ 87.750820] dev_attr_store+0x18/0x28 [ 87.754998] sysfs_kf_write+0x54/0x64 [ 87.759175] kernfs_fop_write+0xe4/0x1e8 [ 87.763615] __vfs_write+0x40/0x184 [ 87.767619] vfs_write+0xa8/0x19c [ 87.771448] ksys_write+0x58/0xbc [ 87.775278] __arm64_sys_write+0x18/0x20 [ 87.779721] el0_svc_common+0xd0/0x124 [ 87.783986] el0_svc_compat_handler+0x1c/0x24 [ 87.788858] el0_svc_compat+0x8/0x18 [ 87.792947] [ 87.792947] -> #0 (kn->count#58){++++}: [ 87.798260] lock_acquire+0xc4/0x22c [ 87.802353] __kernfs_remove+0x258/0x2c4 [ 87.806790] kernfs_remove_by_name_ns+0x50/0xa0 [ 87.811836] remove_files.isra.1+0x38/0x78 [ 87.816447] sysfs_remove_group+0x48/0x98 [ 87.820971] sysfs_remove_groups+0x34/0x4c [ 87.825583] device_remove_attrs+0x6c/0x7c [ 87.830197] device_del+0x11c/0x33c [ 87.834201] device_unregister+0x14/0x2c [ 87.838638] pwmchip_sysfs_unexport+0x40/0x4c [ 87.843509] pwmchip_remove+0xf4/0x13c [ 87.847773] rcar_pwm_remove+0x28/0x34 [ 87.852039] platform_drv_remove+0x24/0x64 [ 87.856651] device_release_driver_internal+0x18c/0x21c [ 87.862391] device_release_driver+0x14/0x1c [ 87.867175] unbind_store+0xe0/0x124 [ 87.871265] drv_attr_store+0x20/0x30 [ 87.875442] sysfs_kf_write+0x54/0x64 [ 87.879618] kernfs_fop_write+0xe4/0x1e8 [ 87.884055] __vfs_write+0x40/0x184 [ 87.888057] vfs_write+0xa8/0x19c [ 87.891887] ksys_write+0x58/0xbc [ 87.895716] __arm64_sys_write+0x18/0x20 [ 87.900154] el0_svc_common+0xd0/0x124 [ 87.904417] el0_svc_compat_handler+0x1c/0x24 [ 87.909289] el0_svc_compat+0x8/0x18 [ 87.913378] [ 87.913378] other info that might help us debug this: [ 87.913378] [ 87.921374] Possible unsafe locking scenario: [ 87.921374] [ 87.927286] CPU0 CPU1 [ 87.931808] ---- ---- [ 87.936331] lock(pwm_lock); [ 87.939293] lock(kn->count#58); [ 87.945120] lock(pwm_lock); [ 87.950599] lock(kn->count#58); [ 87.953908] [ 87.953908] *** DEADLOCK *** [ 87.953908] [ 87.959821] 4 locks held by bash/2986: [ 87.963563] #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c [ 87.971044] #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8 [ 87.978872] #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c [ 87.988001] #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.995481] [ 87.995481] stack backtrace: [ 87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7 [ 88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT) [ 88.012791] Call trace: [ 88.015235] dump_backtrace+0x0/0x190 [ 88.018891] show_stack+0x14/0x1c [ 88.022204] dump_stack+0xb0/0xec [ 88.025514] print_circular_bug.isra.32+0x1d0/0x2e0 [ 88.030385] __lock_acquire+0x1318/0x1864 [ 88.034388] lock_acquire+0xc4/0x22c [ 88.037958] __kernfs_remove+0x258/0x2c4 [ 88.041874] kernfs_remove_by_name_ns+0x50/0xa0 [ 88.046398] remove_files.isra.1+0x38/0x78 [ 88.050487] sysfs_remove_group+0x48/0x98 [ 88.054490] sysfs_remove_groups+0x34/0x4c [ 88.058580] device_remove_attrs+0x6c/0x7c [ 88.062671] device_del+0x11c/0x33c [ 88.066154] device_unregister+0x14/0x2c [ 88.070070] pwmchip_sysfs_unexport+0x40/0x4c [ 88.074421] pwmchip_remove+0xf4/0x13c [ 88.078163] rcar_pwm_remove+0x28/0x34 [ 88.081906] platform_drv_remove+0x24/0x64 [ 88.085996] device_release_driver_internal+0x18c/0x21c [ 88.091215] device_release_driver+0x14/0x1c [ 88.095478] unbind_store+0xe0/0x124 [ 88.099048] drv_attr_store+0x20/0x30 [ 88.102704] sysfs_kf_write+0x54/0x64 [ 88.106359] kernfs_fop_write+0xe4/0x1e8 [ 88.110275] __vfs_write+0x40/0x184 [ 88.113757] vfs_write+0xa8/0x19c [ 88.117065] ksys_write+0x58/0xbc [ 88.120374] __arm64_sys_write+0x18/0x20 [ 88.124291] el0_svc_common+0xd0/0x124 [ 88.128034] el0_svc_compat_handler+0x1c/0x24 [ 88.132384] el0_svc_compat+0x8/0x18 The sysfs unexport in pwmchip_remove() is completely asymmetric to what we do in pwmchip_add_with_polarity() and commit 0733424c9ba9 ("pwm: Unexport children before chip removal") is a strong indication that this was wrong to begin with. We should just move pwmchip_sysfs_unexport() where it belongs, which is right after pwmchip_sysfs_unexport_children(). In that case, we do not need separate functions anymore either. We also really want to remove sysfs irrespective of whether or not the chip will be removed as a result of pwmchip_remove(). We can only assume that the driver will be gone after that, so we shouldn't leave any dangling sysfs files around. This warning disappears if we move pwmchip_sysfs_unexport() to the top of pwmchip_remove(), pwmchip_sysfs_unexport_children(). That way it is also outside of the pwm_lock section, which indeed doesn't seem to be needed. Moving the pwmchip_sysfs_export() call outside of that section also seems fine and it'd be perfectly symmetric with pwmchip_remove() again. So, this patch fixes them. Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com> [shimoda: revise the commit log and code] Fixes: 76abbdde2d95 ("pwm: Add sysfs interface") Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
cc2d2247 |
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07-Jan-2019 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Drop per-chip dbg_show callback This callback was introduced in commit 62099abf67a2 ("pwm: Add debugfs interface") in 2012 and up to now there is not a single user. So drop this unused code. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [thierry.reding@gmail.com: remove kerneldoc for ->dbg_show()] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
309b32fb |
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07-Jan-2019 |
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> |
pwm: Don't use memcmp() to compare state variables Given that struct pwm_state is sparse (at least on some platforms), variables of this type might represent the same state because all fields are pairwise identical but still memcmp() returns a difference because some of the unused bits are different. To prevent surprises compare member by member instead of the whole occupied memory. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
93c292ef |
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23-May-2017 |
Jerome Brunet <jbrunet@baylibre.com> |
pwm: Silently error out on EPROBE_DEFER In of_pwm_get(), if we fail to get the PWM chip due to probe deferal, we shouldn't print an error message. Just be silent in this case. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Reviewed-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
b526a314 |
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22-Jan-2017 |
Hans de Goede <hdegoede@redhat.com> |
pwm: Try to load modules during pwm_get() Add a module name string to the pwm_lookup struct and if specified try to load the module using request_module() if pwmchip_find_by_name() is unable to find the PWM chip. This is a last resort to work around drivers that can't - and can't be made to - deal with deferred probe. Signed-off-by: Hans de Goede <hdegoede@redhat.com> [thierry.reding@gmail.com: rename new macro, reword commit message] [thierry.reding@gmail.com: add comment explaining use-case] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
69efb343 |
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22-Jan-2017 |
Hans de Goede <hdegoede@redhat.com> |
pwm: Don't hold pwm_lookup_lock longer than necessary There is no need to hold pwm_lookup_lock after we're done with looping over pwm_lookup_list, so release it earlier. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
42883cbc |
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29-Jan-2017 |
Lothar Wassmann <LW@KARO-electronics.de> |
pwm: Make the PWM_POLARITY flag in DTB optional Change the PWM chip driver registration so that a chip driver that supports polarity inversion can still be used with DTBs that don't provide the polarity flag as part of the specifier. This is done to provide polarity inversion support for the pwm-imx driver without having to modify all existing DTS files. Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Suggested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Lukasz Majewski <l.majewski@majess.pl> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
f2dafc09 |
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29-Jan-2017 |
Lothar Wassmann <LW@KARO-electronics.de> |
pwm: Print error messages with pr_err() instead of pr_debug() Make the messages that are printed in case of fatal errors actually visible to the user without having to recompile the driver with debugging enabled. Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
fe2858c8 |
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04-Jan-2017 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Remove pwm_can_sleep() The last user of this function has been removed, so it is no longer needed. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
0733424c |
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09-Aug-2016 |
David Hsu <davidhsu@google.com> |
pwm: Unexport children before chip removal Exported pwm channels aren't removed before the pwmchip and are leaked. This results in invalid sysfs files. This fix removes all exported pwm channels before chip removal. Signed-off-by: David Hsu <davidhsu@google.com> Fixes: 76abbdde2d95 ("pwm: Add sysfs interface") Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
3a3d1a4e |
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08-Jun-2016 |
Lee Jones <lee.jones@linaro.org> |
pwm: Add PWM capture support Supply a PWM capture callback op in order to pass back information obtained by running analysis on a PWM signal. This would normally (at least during testing) be called from the sysfs routines with a view to printing out PWM capture data which has been encoded into a string. Signed-off-by: Lee Jones <lee.jones@linaro.org> [thierry.reding@gmail.com: make capture data unsigned int for symmetry] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
ef2bf499 |
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27-May-2016 |
Brian Norris <briannorris@chromium.org> |
pwm: Improve args checking in pwm_apply_state() It seems like in the process of refactoring pwm_config() to utilize the newly-introduced pwm_apply_state() API, some args/bounds checking was dropped. In particular, I noted that we are now allowing invalid period selections, e.g.: # echo 1 > /sys/class/pwm/pwmchip0/export # cat /sys/class/pwm/pwmchip0/pwm1/period 100 # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle [... driver may or may not reject the value, or trigger some logic bug ...] It's better to see: # echo 1 > /sys/class/pwm/pwmchip0/export # cat /sys/class/pwm/pwmchip0/pwm1/period 100 # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle -bash: echo: write error: Invalid argument This patch reintroduces some bounds checks in both pwm_config() (for its signed parameters; we don't want to convert negative values into large unsigned values) and in pwm_apply_state() (which fix the above described behavior, as well as other potential API misuses). Fixes: 5ec803edcb70 ("pwm: Add core infrastructure to allow atomic updates") Signed-off-by: Brian Norris <briannorris@chromium.org> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
23e3523f |
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14-Apr-2016 |
Heiko Stübner <heiko@sntech.de> |
pwm: Add information about polarity, duty cycle and period to debugfs The PWM states make it possible to also output the polarity, duty cycle and period information in the debugfs summary output. This simplifies gathering information about PWMs without needing to walk through the sysfs attributes of every PWM. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: use more spaces in debugfs output] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
39100cee |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Switch to the atomic API Replace legacy pwm_get/set_xxx() and pwm_config/enable/disable() calls by pwm_get/apply_state(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
5ec803ed |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Add core infrastructure to allow atomic updates Add an ->apply() method to the pwm_ops struct to allow PWM drivers to implement atomic updates. This method is preferred over the ->enable(), ->disable() and ->config() methods if available. Add the pwm_apply_state() function to the PWM user API. Note that the pwm_apply_state() does not guarantee the atomicity of the update operation, it all depends on the availability and implementation of the ->apply() method. pwm_enable/disable/set_polarity/config() are now implemented as wrappers around the pwm_apply_state() function. pwm_adjust_config() is allowing smooth handover between the bootloader and the kernel. This function tries to adapt the current PWM state to the PWM arguments coming from a PWM lookup table or a DT definition without changing the duty_cycle/period proportion. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: fix a couple of typos] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
15fa8a43 |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Add hardware readout infrastructure Add a ->get_state() function to the pwm_ops struct to let PWM drivers initialize the PWM state attached to a PWM device. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
09a7e4a3 |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Move the enabled/disabled info into pwm_state Prepare the transition to PWM atomic update by moving the enabled and disabled state into the pwm_state struct. This way we can easily update the whole PWM state by copying the new state in the ->state field. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
43a276b0 |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Introduce the pwm_state concept The PWM state, represented by its period, duty_cycle and polarity is currently directly stored in the PWM device. Declare a pwm_state structure embedding those field so that we can later use this struct to atomically update all the PWM parameters at once. All pwm_get_xxx() helpers are now implemented as wrappers around pwm_get_state(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
a8c38625 |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Keep PWM state in sync with hardware state Before the introduction of pwm_args, the core was resetting the PWM period and polarity states to the reference values (those provided through the DT, a PWM lookup table or hardcoded in the driver). Now that all PWM users are correctly using pwm_args to configure their PWM device, we can safely remove the pwm_apply_args() call in pwm_get() and of_pwm_get(). We can also get rid of the pwm_set_period() call in pwm_apply_args(), because PWM users are now directly using pargs->period instead of pwm_get_period(). By doing that we avoid messing with the current PWM period. The only remaining bit in pwm_apply_args() is the initial polarity setting, and it should go away when all PWM users have been patched to use the atomic API (with this API the polarity will be set along with other PWM arguments when configuring the PWM). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
459a25af |
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30-Mar-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Get rid of pwm->lock PWM devices are not protected against concurrent accesses. The lock in struct pwm_device might let PWM users think it is, but it's actually only protecting the enabled state. Removing this lock should be fine as long as all PWM users are aware that accesses to the PWM device have to be serialized, which seems to be the case for all of them except the sysfs interface. Patch the sysfs code by adding a lock to the pwm_export struct and making sure it's taken for all relevant accesses to the exported PWM device. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
fbd45a12 |
|
17-May-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Fix pwm_apply_args() call sites pwm_apply_args() is supposed to initialize a PWM device according to the arguments provided by the DT or the PWM lookup, but this function was called inside pwm_device_request(), which in turn was called before the core had a chance to initialize the pwm->args fields. Fix that by calling pwm_apply_args directly in pwm_get() and of_pwm_get() after initializing pwm->args field. This commit also fixes an invalid pointer dereference introduced by commit e39c0df1be5a ("pwm: Introduce the pwm_args concept"). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Fixes: e39c0df1be5a ("pwm: Introduce the pwm_args concept") Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
2907f8ab |
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01-May-2016 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Use kcalloc() instead of kzalloc() kcalloc() should be preferred for allocations of arrays over kzalloc() with multiplication. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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83a98864 |
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01-May-2016 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Add missing newline checkpatch requires that declarations be separated from code by a blank line. Add one for readability and to silence the warning. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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e39c0df1 |
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14-Apr-2016 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Introduce the pwm_args concept Currently the PWM core mixes the current PWM state with the per-platform reference config (specified through the PWM lookup table, DT definition or directly hardcoded in PWM drivers). Create a struct pwm_args to store this reference configuration, so that PWM users can differentiate between the current and reference configurations. Patch all places where pwm->args should be initialized. We keep the pwm_set_polarity/period() calls until all PWM users are patched to use pwm_args instead of pwm_get_period/polarity(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: reword kerneldoc comments] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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ff01c944 |
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21-Jan-2016 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Mark all devices as "might sleep" Commit d1cd21427747 ("pwm: Set enable state properly on failed call to enable") introduced a mutex that is needed to protect internal state of PWM devices. Since that mutex is acquired in pwm_set_polarity() and in pwm_enable() and might potentially block, all PWM devices effectively become "might sleep". It's rather pointless to keep the .can_sleep field around, but given that there are external users let's postpone the removal for the next release cycle. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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655a0355 |
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05-Oct-2015 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Return -ENODEV if no PWM lookup match is found When looking up a PWM using the lookup table, assume that all entries will have been added already, so failure to find a match means that no corresponding entry has been registered. This fixes an issue where -EPROBE_DEFER would be returned if the PWM lookup table is empty. After this fix, -EPROBE_DEFER is reserved for situations where no provider has yet registered for a matching entry. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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d1cd2142 |
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16-Oct-2015 |
Jonathan Richardson <jonathar@broadcom.com> |
pwm: Set enable state properly on failed call to enable The pwm_enable() function didn't clear the enabled bit if a call to the driver's ->enable() callback returned an error. The result was that the state of the PWM core was wrong. Clearing the bit when enable returns an error ensures the state is properly set. Tested-by: Jonathan Richardson <jonathar@broadcom.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: add missing kerneldoc for the lock] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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04883802 |
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27-Jul-2015 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Clean up kerneldoc Clean up kerneldoc in preparation for including the PWM documentation in DocBook. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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6bc7064a |
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27-Jul-2015 |
Thierry Reding <thierry.reding@gmail.com> |
pwm: Remove useless whitespace Remove useless tabs used for padding in structure definitions as well as some blank lines. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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5c31252c |
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01-Jul-2015 |
Boris Brezillon <bbrezillon@kernel.org> |
pwm: Add the pwm_is_enabled() helper Some PWM drivers are testing the PWMF_ENABLED flag. Create a helper function to hide the logic behind enabled test. This will allow us to smoothly move from the current approach to an atomic PWM update approach. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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b6a00fae |
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26-May-2015 |
Tim Kryger <tim.kryger@gmail.com> |
pwm: Add pwmchip_add_with_polarity() API Add a new function to register a PWM chip with channels that have their initial polarity as specified by an additional parameter. This benefits drivers of controllers that by default operate with inversed polarity by removing the need to modify the polarity during initialization. Signed-off-by: Tim Kryger <tim.kryger@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: export pwmchip_add_with_polarity()] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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efb0de55 |
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05-May-2015 |
Shobhit Kumar <shobhit.kumar@intel.com> |
pwm: Add support to remove registered consumer lookup tables In case some drivers are unloading, they can remove lookup tables which they had registered during their load time to avoid redundant entries if loaded again. CC: Samuel Ortiz <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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c264f111 |
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12-Mar-2015 |
Shobhit Kumar <shobhit.kumar@intel.com> |
pwm: Remove __init initializer for pwm_add_table() For platforms that don't support DT, some early MFD modules can register lookup tables. Remove the __init annotation so that this works. This is similar to gpio_add_lookup_table() which allows late additions. CC: Samuel Ortiz <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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8d6cc073 |
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03-Feb-2015 |
Markus Elfring <elfring@users.sourceforge.net> |
pwm: Remove unnecessary check before of_node_put() The of_node_put() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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70145f87 |
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28-Aug-2014 |
Geert Uytterhoeven <geert+renesas@glider.be> |
pwm: Fix uninitialized warnings in pwm_get() With some versions of gcc (e.g. 4.1.2): drivers/pwm/core.c: In function ‘pwm_get’: drivers/pwm/core.c:610: warning: ‘polarity’ may be used uninitialized in this function drivers/pwm/core.c:609: warning: ‘period’ may be used uninitialized in this function While these are false positives, we can get rid of them by refactoring the code to store a pointer to the best match, as suggested before by Thierry Reding. This does require moving the mutex_unlock() down. Fixes: d717ea73e36dd565 ("pwm: Fix period and polarity in pwm_get() for non-perfect matches") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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533acc0e |
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18-Aug-2014 |
Xiubo Li <Li.Xiubo@freescale.com> |
pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error. Since we cannot make sure the 'chip->npwm' will always be none zero here, and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR, which equals to ((void *)16). So this patch fix this with just doing the zero check before calling kzalloc(). Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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d717ea73 |
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13-Aug-2014 |
Geert Uytterhoeven <geert+renesas@glider.be> |
pwm: Fix period and polarity in pwm_get() for non-perfect matches If pwm_get() finds a look-up entry with a perfect match (both dev_id and con_id match), the loop is aborted, and "p" still points to the correct struct pwm_lookup. If only an entry with a matching dev_id or con_id is found, the loop terminates after traversing the whole list, and "p" now points to arbitrary memory, not part of the pwm_lookup list. Then pwm_set_period() and pwm_set_polarity() will set random values for period resp. polarity. To fix this, save period and polarity when finding a new best match, just like is done for chip (for the provider) and index. This fixes the LCD backlight on r8a7740/armadillo-legacy, which was fed period 0 and polarity -1068821144 instead of 33333 resp. 1. Fixes: 3796ce1d4d4b ("pwm: add period and polarity to struct pwm_lookup") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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3796ce1d |
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19-May-2014 |
Alexandre Belloni <alexandre.belloni@bootlin.com> |
pwm: add period and polarity to struct pwm_lookup Add period and polarity members to struct pwm_lookup so that platforms using the lookup table can be treated the same way as those using the device tree. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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adcba1e3 |
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18-Dec-2013 |
Jingoo Han <jg1.han@samsung.com> |
pwm: use seq_puts() instead of seq_printf() For a constant format without additional arguments, use seq_puts() instead of seq_printf(). Also, the following checkpatch warning is fixed. WARNING: Prefer seq_puts to seq_printf Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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208be769 |
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17-Jul-2013 |
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> |
pwm: Use the DT macro directly when parsing PWM DT flags Don't redefine a PWM_SPEC_POLARITY macro with a value identical to PWM_POLARITY_INVERTED, use the PWM DT macro directly. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
76abbdde |
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11-Jun-2013 |
H Hartley Sweeten <hartleys@visionengravers.com> |
pwm: Add sysfs interface Add a simple sysfs interface to the generic PWM framework. /sys/class/pwm/ `-- pwmchipN/ for each PWM chip |-- export (w/o) ask the kernel to export a PWM channel |-- npwm (r/o) number of PWM channels in this PWM chip |-- pwmX/ for each exported PWM channel | |-- duty_cycle (r/w) duty cycle (in nanoseconds) | |-- enable (r/w) enable/disable PWM | |-- period (r/w) period (in nanoseconds) | `-- polarity (r/w) polarity of PWM (normal/inversed) `-- unexport (w/o) return a PWM channel to the kernel Based on work by Lars Poeschel. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Lars Poeschel <poeschel@lemonage.de> Cc: Ryan Mallon <rmallon@gmail.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
77f0b9d2 |
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03-Jun-2013 |
Wolfram Sang <wsa@kernel.org> |
pwm: devm: alloc correct pointer size The allocated object should be the size of what the pointer is pointing to and not the size of the pointer itself. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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#
261a5edd |
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21-Dec-2012 |
Peter Ujfalusi <peter.ujfalusi@ti.com> |
pwm: Add devm_of_pwm_get() as exported API for users When booted with DT users can use devm version of of_pwm_get() to benefit from automatic resource release. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
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#
8eb96127 |
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21-Dec-2012 |
Peter Ujfalusi <peter.ujfalusi@ti.com> |
pwm: core: Rename of_pwm_request() to of_pwm_get() and export it Allow client driver to use of_pwm_get() to get the PWM they need. This is needed for drivers which handle more than one PWM separately, like leds-pwm driver, which have: pwmleds { compatible = "pwm-leds"; kpad { label = "omap4::keypad"; pwms = <&twl_pwm 0 7812500>; max-brightness = <127>; }; charging { label = "omap4:green:chrg"; pwms = <&twl_pwmled 0 7812500>; max-brightness = <255>; }; }; in the dts files. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Bryan Wu <cooloney@gmail.com>
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928c4477 |
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30-Jan-2013 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Export pwm_{set,get}_chip_data() When building a driver as a module, these functions need to be exported for linking to succeed. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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6e69ab13 |
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28-Jan-2013 |
Florian Vaussard <florian.vaussard@epfl.ch> |
pwm: Add pwm_can_sleep() as exported API to users Calls to some external PWM chips can sleep. To help users, add pwm_can_sleep() API. Cc: Thierry Reding <thierry.reding@avionic-design.de> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch> Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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417328c3 |
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28-Nov-2012 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Export of_pwm_xlate_with_flags() Drivers may want to use this function if they support any of the flags that can be passed via a third cell in the DT specifier. Since those drivers may be built as modules the symbol needs to be exported to make sure that it can be accessed. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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#
83af2402 |
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21-Nov-2012 |
Philip, Avinash <avinashphilip@ti.com> |
pwm: Device tree support for PWM polarity Add support for encoding PWM properties in bit encoded form with of_pwm_xlate_with_flags() function support. Platforms require platform specific PWM properties has to populate in 3rd cell of the pwm-specifier and PWM driver should also set .of_xlate support with this function. Currently PWM property polarity encoded in bit position 0 of the third cell in pwm-specifier. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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#
c2d476a9 |
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02-Sep-2012 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Check for negative duty-cycle and period Make sure the duty-cycle and period passed in are not negative. This should eventually be made implicit by making them unsigned. While at it, the drivers' .config() implementations can have the equivalent checks removed. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sachin Kamat <sachin.kamat@linaro.org> Cc: Axel Lin <axel.lin@gmail.com> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Jingoo Han <jg1.han@samsung.com> Cc: Jonghwan Choi <jhbird.choi@samsung.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: "Philip, Avinash" <avinashphilip@ti.com> Cc: Vaibhav Bedia <vaibhav.bedia@ti.com> Acked-by: Jingoo Han <jg1.han@samsung.com>
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6354316d |
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01-Aug-2012 |
Alexandre Courbot <acourbot@nvidia.com> |
pwm: add devm_pwm_get() and devm_pwm_put() Add resource managed variants of pwm_get() and pwm_put() for convenience. Code is largely inspired by the equivalent devm functions of the regulator framework. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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0aa0869c |
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24-Jul-2012 |
Philip, Avinash <avinashphilip@ti.com> |
pwm: Add support for configuring the PWM polarity Some hardware supports inverting the polarity of the PWM signal. This commit adds support to the PWM framework to allow users of the PWM API to configure the polarity. Note that in order to reduce complexity, changing the polarity of a PWM signal is only allowed while the PWM is disabled. A practical example where this can prove useful is to simulate inversion of the duty cycle. While inversion of polarity and duty cycle are not exactly the same, the differences for most use-cases are negligible. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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e50d3523 |
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10-Aug-2012 |
Sachin Kamat <sachin.kamat@linaro.org> |
pwm: core: Fix coding style issues Fixes the following: WARNING: line over 80 characters ERROR: spaces required around that ':' (ctx:VxW) WARNING: Prefer pr_warn(... to pr_warning(... Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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dfeb86ec |
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01-Aug-2012 |
Sachin Kamat <sachin.kamat@linaro.org> |
pwm: Add missing static storage class specifiers in core.c file Fixes the following sparse warnings: drivers/pwm/core.c:152:6: warning: symbol 'of_pwmchip_add' was not declared. Should it be static? drivers/pwm/core.c:165:6: warning: symbol 'of_pwmchip_remove' was not declared. Should it be static? Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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d295b129 |
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11-Jul-2012 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: fix used-uninitialized warning in pwm_get() Some versions of GCC don't seem no notice that the initialization of the index variable is tied to that of the chip variable and falsely report it as potentially being used uninitialized. However, to save anybody else from tripping over this, we now initialize the index variable unconditionally. Originally-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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7299ab70 |
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14-Dec-2011 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Add device tree support This patch adds helpers to support device tree bindings for the generic PWM API. Device tree binding documentation for PWM controllers is also provided. Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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8138d2dd |
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26-Mar-2012 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Add table-based lookup for static mappings In order to get rid of the global namespace for PWM devices, this commit provides an alternative method, similar to that of the regulator or clock frameworks, for registering a static mapping for PWM devices. This works by providing a table with a provider/consumer map in the board setup code. With the new pwm_get() and pwm_put() functions available, usage of pwm_request() and pwm_free() becomes deprecated. Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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62099abf |
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26-Mar-2012 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Add debugfs interface This commit adds a debugfs interface that can be used to list the current internal state of the PWM devices registered with the PWM framework. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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f051c466 |
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14-Dec-2011 |
Thierry Reding <thierry.reding@avionic-design.de> |
pwm: Allow chips to support multiple PWMs Many PWM controllers provide access to more than a single PWM output and may even share some resource among them. Allowing a PWM chip to provide multiple PWM devices enables better sharing of those resources. As a side-effect this change allows easy integration with the device tree where a given PWM can be looked up based on the PWM chip's phandle and a corresponding index. This commit modifies the PWM core to support multiple PWMs per struct pwm_chip. It achieves this in a similar way to how gpiolib works, by allowing PWM ranges to be requested dynamically (pwm_chip.base == -1) or starting at a given offset (pwm_chip.base >= 0). A chip specifies how many PWMs it controls using the npwm member. Each of the functions in the pwm_ops structure gets an additional argument that specified the PWM number (it can be converted to a per-chip index by subtracting the chip's base). The total maximum number of PWM devices is currently fixed to 1024 while the data is actually stored in a radix tree, thus saving resources if not all of them are used. Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [eric@eukrea.com: fix error handling in pwmchip_add] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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#
0c2498f1 |
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28-Jan-2011 |
Sascha Hauer <s.hauer@pengutronix.de> |
pwm: Add PWM framework support This patch adds framework support for PWM (pulse width modulation) devices. The is a barebone PWM API already in the kernel under include/linux/pwm.h, but it does not allow for multiple drivers as each of them implements the pwm_*() functions. There are other PWM framework patches around from Bill Gatliff. Unlike his framework this one does not change the existing API for PWMs so that this framework can act as a drop in replacement for the existing API. Why another framework? Several people argue that there should not be another framework for PWMs but they should be integrated into one of the existing frameworks like led or hwmon. Unlike these frameworks the PWM framework is agnostic to the purpose of the PWM. In fact, a PWM can drive a LED, but this makes the LED framework a user of a PWM, like already done in leds-pwm.c. The gpio framework also is not suitable for PWMs. Every gpio could be turned into a PWM using timer based toggling, but on the other hand not every PWM hardware device can be turned into a gpio due to the lack of hardware capabilities. This patch does not try to improve the PWM API yet, this could be done in subsequent patches. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Matthias Kaehlcke <matthias@kaehlcke.net> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> [thierry.reding@avionic-design.de: fixup typos, kerneldoc comments] Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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