spi: spi-fsl-lpspi: remove redundant spi_controller_put call

devm_spi_alloc_controller will allocate an SPI controller and
automatically release a reference on it when dev is unbound from
its driver. It doesn't need to call spi_controller_put explicitly
to put the reference when lpspi driver failed initialization.

Fixes: 2ae0ab0143fc ("spi: lpspi: Avoid potential use-after-free in probe()")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://msgid.link/r/20240403084029.2000544-1-carlos.song@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Avoid potential use-after-free in probe()

fsl_lpspi_probe() is allocating/disposing memory manually with
spi_alloc_host()/spi_alloc_target(), but uses
devm_spi_register_controller(). In case of error after the latter call the
memory will be explicitly freed in the probe function by
spi_controller_put() call, but used afterwards by "devm" management outside
probe() (spi_unregister_controller() <- devm_spi_unregister() below).

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
...
Call trace:
kernfs_find_ns
kernfs_find_and_get_ns
sysfs_remove_group
sysfs_remove_groups
device_remove_attrs
device_del
spi_unregister_controller
devm_spi_unregister
release_nodes
devres_release_all
really_probe
driver_probe_device
__device_attach_driver
bus_for_each_drv
__device_attach
device_initial_probe
bus_probe_device
deferred_probe_work_func
process_one_work
worker_thread
kthread
ret_from_fork

Fixes: 5314987de5e5 ("spi: imx: add lpspi bus driver")
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://msgid.link/r/20240312112050.2503643-1-alexander.sverdlin@siemens.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: switch to use modern name

Change legacy name master/target to modern name host/target

No functional changed.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230807124105.3429709-9-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Read chip-select amount from hardware for i.MX93

PARAM.PCSNUM register on i.MX93 indicates the number of supported
(hw) chip-selects. LPSPI4 has 3 while others have only 2.
Still allow overwriting from DT.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230717085934.409476-3-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Move controller initialization further down

This is a preparation for reading number of chip-selects from hardware.
This needs IO resources mapped and peripheral clocking enabled.
No functional changes intended.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230717085934.409476-2-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Remove num_cs from device struct

This is only used during probe() call, so there is no need to store it
longer than that.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230705090145.1354663-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: 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>
Link: https://lore.kernel.org/r/20230714174955.4064174-1-robh@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: Get rid of old SPI_MASTER_MUST_TX & SPI_MASTER_MUST_RX

Convert the users from SPI_MASTER_MUST_TX and/or SPI_MASTER_MUST_RX
to SPI_CONTROLLER_MUST_TX and/or SPI_CONTROLLER_MUST_RX respectively
and kill the not used anymore definitions.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230710154932.68377-13-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: downgrade log level for pio mode

Having no DMA is not an error. The simplest reason is not having it
configured. SPI will still be usable, so raise a warning instead to
get still some attention.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230531072850.739021-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: disable lpspi module irq in DMA mode

When all bits of IER are set to 0, we still can observe the lpspi irq events
when using DMA mode to transfer data.

So disable irq to avoid the too much irq events.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20230505063557.3962220-1-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: run transfer speed_hz sanity check

Avoid config.speed_hz is 0 when it is a divisor.

Signed-off-by: Han Xu <han.xu@nxp.com
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com
Link: https://lore.kernel.org/r/20230505064159.3964473-1-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org

spi: Replace all spi->chip_select and spi->cs_gpiod references with function call

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de> # Rockchip drivers
Reviewed-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org> # Aspeed driver
Reviewed-by: Dhruva Gole <d-gole@ti.com> # SPI Cadence QSPI
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> # spi-stm32-qspi
Acked-by: William Zhang <william.zhang@broadcom.com> # bcm63xx-hsspi driver
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> # DW SSI part
Link: https://lore.kernel.org/r/167847070432.26.15076794204368669839@mailman-core.alsa-project.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230303172041.2103336-27-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: support multiple cs for lpspi

support to get chip select number from DT file.

Signed-off-by: Han Xu <han.xu@nxp.com>
Link: https://lore.kernel.org/r/20221206225410.604482-1-han.xu@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Use devm_platform_get_and_ioremap_resource()

Use the devm_platform_get_and_ioremap_resource() helper instead of calling
platform_get_resource() and devm_ioremap_resource() separately.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220924131854.964923-2-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Remove the unneeded result variable

Return the value pm_runtime_force_suspend() directly instead of storing
it in another redundant variable.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/20220908010429.342875-1-ye.xingchen@zte.com.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Simplify some error message

dev_err_probe() already prints the error code in a human readable way, so
there is no need to duplicate it as a numerical value at the end of the
message.

Fixes: 12f62a857c83 ("spi: lpspi: Silence error message upon deferred probe")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-By: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/253543c462b765eca40ba54c66f4e3fdf4acdeb7.1659735546.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown <broonie@kernel.org>

dmaengine: imx: Move header to include/dma/

The i.MX DMA drivers are device tree only, nothing in
include/linux/platform_data/dma-imx.h has platform_data in it, so move
the file to include/linux/dma/imx-dma.h.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-By: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20220414162249.3934543-10-s.hauer@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: release requested DMA channels

The requested DMA channels are never released. Do this in .remove as well
as in .probe. spi_register_controller() can return -EPROBE_DEFER if
cs-gpios are not probed yet.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211109103134.184216-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Silence error message upon deferred probe

Do not print error messages with error code -517. Silences the following
errors upon on imx8qm:
fsl_lpspi 5a000000.spi: spi_register_controller error: -517
fsl_lpspi 5a010000.spi: spi_register_controller error: -517
fsl_lpspi 5a020000.spi: spi_register_controller error: -517

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211108145523.1797609-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Fix PM reference leak in lpspi_prepare_xfer_hardware()

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Li <wangli74@huawei.com>
Link: https://lore.kernel.org/r/20210409095430.29868-1-wangli74@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Fix use-after-free on unbind

Normally the last reference on an spi_controller is released by
spi_unregister_controller(). In the case of the i.MX lpspi driver,
the spi_controller is registered with devm_spi_register_controller(),
so spi_unregister_controller() is invoked automatically after the driver
has unbound.

However the driver already releases the last reference in
fsl_lpspi_remove() through a gratuitous call to spi_master_put(),
causing a use-after-free when spi_unregister_controller() is
subsequently invoked by the devres framework.

Fix by dropping the superfluous spi_master_put().

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v5.2+
Cc: Han Xu <han.xu@nxp.com>
Link: https://lore.kernel.org/r/ab3c0b18bd820501a12c85e440006e09ec0e275f.1604874488.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Remove CONFIG_PM_SLEEP ifdefery

Use __maybe_unused for the suspend()/resume() hooks and get rid of
the CONFIG_PM_SLEEP ifdefery to improve the code.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20200817235812.19518-1-festevam@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: fix using CS discontinuously on i.MX8DXLEVK

SPI common code does not support using CS discontinuously for now.
However, i.MX8DXL-EVK only uses CS1 without CS0. Therefore, add a flag
is_only_cs1 to set the correct TCR[PCS].

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20200727031448.31661-4-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: remove unused fsl_lpspi->chipselect

The cs-gpio is initailized by spi_get_gpio_descs() now. Remove the
chipselect.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20200727031448.31661-3-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Fix kernel warning dump when probe fail after calling spi_register

Calling devm_spi_register_controller() too early will cause problem.
When probe failed occurs after calling devm_spi_register_controller(),
the call of spi_controller_put() will trigger the following warning dump.

[ 2.092138] ------------[ cut here ]------------
[ 2.096876] kernfs: can not remove 'uevent', no directory
[ 2.102440] WARNING: CPU: 0 PID: 181 at fs/kernfs/dir.c:1503 kernfs_remove_by_name_ns+0xa0/0xb0
[ 2.111142] Modules linked in:
[ 2.114207] CPU: 0 PID: 181 Comm: kworker/0:7 Not tainted 5.4.24-05024-g775c6e8a738c-dirty #1314
[ 2.122991] Hardware name: Freescale i.MX8DXL EVK (DT)
[ 2.128141] Workqueue: events deferred_probe_work_func
[ 2.133281] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 2.138076] pc : kernfs_remove_by_name_ns+0xa0/0xb0
[ 2.142958] lr : kernfs_remove_by_name_ns+0xa0/0xb0
[ 2.147837] sp : ffff8000122bba70
[ 2.151145] x29: ffff8000122bba70 x28: ffff8000119d6000
[ 2.156462] x27: 0000000000000000 x26: ffff800011edbce8
[ 2.161779] x25: 0000000000000000 x24: ffff00003ae4f700
[ 2.167096] x23: ffff000010184c10 x22: ffff00003a3d6200
[ 2.172412] x21: ffff800011a464a8 x20: ffff000010126a68
[ 2.177729] x19: ffff00003ae5c800 x18: 000000000000000e
[ 2.183046] x17: 0000000000000001 x16: 0000000000000019
[ 2.188362] x15: 0000000000000004 x14: 000000000000004c
[ 2.193679] x13: 0000000000000000 x12: 0000000000000001
[ 2.198996] x11: 0000000000000000 x10: 00000000000009c0
[ 2.204313] x9 : ffff8000122bb7a0 x8 : ffff00003a3d6c20
[ 2.209630] x7 : ffff00003a3d6380 x6 : 0000000000000001
[ 2.214946] x5 : 0000000000000001 x4 : ffff00003a05eb18
[ 2.220263] x3 : 0000000000000005 x2 : ffff8000119f1c48
[ 2.225580] x1 : 2bcbda323bf5a800 x0 : 0000000000000000
[ 2.230898] Call trace:
[ 2.233345] kernfs_remove_by_name_ns+0xa0/0xb0
[ 2.237879] sysfs_remove_file_ns+0x14/0x20
[ 2.242065] device_del+0x12c/0x348
[ 2.245555] device_unregister+0x14/0x30
[ 2.249492] spi_unregister_controller+0xac/0x120
[ 2.254201] devm_spi_unregister+0x10/0x18
[ 2.258304] release_nodes+0x1a8/0x220
[ 2.262055] devres_release_all+0x34/0x58
[ 2.266069] really_probe+0x1b8/0x318
[ 2.269733] driver_probe_device+0x54/0xe8
[ 2.273833] __device_attach_driver+0x80/0xb8
[ 2.278194] bus_for_each_drv+0x74/0xc0
[ 2.282034] __device_attach+0xdc/0x138
[ 2.285876] device_initial_probe+0x10/0x18
[ 2.290063] bus_probe_device+0x90/0x98
[ 2.293901] deferred_probe_work_func+0x64/0x98
[ 2.298442] process_one_work+0x198/0x320
[ 2.302451] worker_thread+0x1f0/0x420
[ 2.306208] kthread+0xf0/0x120
[ 2.309352] ret_from_fork+0x10/0x18
[ 2.312927] ---[ end trace 58abcdfae01bd3c7 ]---

So put this function at the end of the probe sequence.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20200727031448.31661-2-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: fix the imbalance of runtime pm function call

Call the put function after probe successfully. Otherwise, the lpspi
module will keep active status until the first spi transfer called.

Disable runtime pm when probe fails. There is no need to active runtime
pm after probe failed.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Link: https://lore.kernel.org/r/20200714075251.12777-2-xiaoning.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: imx/fsl-lpspi: Convert to GPIO descriptors

This converts the two Freescale i.MX SPI drivers
Freescale i.MX (CONFIG_SPI_IMX) and Freescale i.MX LPSPI
(CONFIG_SPI_FSL_LPSPI) to use GPIO descriptors handled in
the SPI core for GPIO chip selects whether defined in
the device tree or a board file.

The reason why both are converted at the same time is
that they were both using the same platform data and
platform device population helpers when using
board files intertwining the code so this gives a cleaner
cut.

The platform device creation was passing a platform data
container from each boardfile down to the driver using
struct spi_imx_master from <linux/platform_data/spi-imx.h>,
but this was only conveying the number of chipselects and
an int * array of the chipselect GPIO numbers.

The imx27 and imx31 platforms had code passing the
now-unused platform data when creating the platform devices,
this has been repurposed to pass around GPIO descriptor
tables. The platform data struct that was just passing an
array of integers and number of chip selects for the GPIO
lines has been removed.

The number of chipselects used to be passed from the board
file, because this number also limits the number of native
chipselects that the platform can use. To deal with this we
just augment the i.MX (CONFIG_SPI_IMX) driver to support 3
chipselects if the platform does not define "num-cs" as a
device property (such as from the device tree). This covers
all the legacy boards as these use <= 3 native chip selects
(or GPIO lines, and in that case the number of chip selects
is determined by the core from the number of available
GPIO lines). Any new boards should use device tree, so
this is a reasonable simplification to cover all old
boards.

The LPSPI driver never assigned the number of chipselects
and thus always fall back to the core default of 1 chip
select if no GPIOs are defined in the device tree.

The Freescale i.MX driver was already partly utilizing
the SPI core to obtain the GPIO numbers from the device tree,
so this completes the transtion to let the core handle all
of it.

All board files and the core i.MX boardfile registration
code is augmented to account for these changes.

This has been compile-tested with the imx_v4_v5_defconfig
and the imx_v6_v7_defconfig.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Robin Gong <yibin.gong@nxp.com>
Cc: Trent Piepho <tpiepho@impinj.com>
Cc: Clark Wang <xiaoning.wang@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Link: https://lore.kernel.org/r/20200625200252.207614-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Fix runtime PM imbalance on error

pm_runtime_get_sync() increments the runtime PM usage counter even
when it returns an error code. Thus a pairing decrement is needed on
the error handling path to keep the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Link: https://lore.kernel.org/r/20200523133859.5625-1-dinghao.liu@zju.edu.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Fix indentation and open brace should be on the previous line

Resolved open brace { should be on the previous line checkpatch
error and fix the indentation

Signed-off-by: Aishwarya R <aishwaryarj100@gmail.com>
Link: https://lore.kernel.org/r/20200407125557.6520-1-aishwaryarj100@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: spi-fsl-lpspi: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200320232515.GA24800@embeddedor.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: remove unneeded array

- replace the array with the shift operation
- remove the extra comparing operation.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Link: https://lore.kernel.org/r/20200220141143.3902922-2-oleksandr.suvorov@toradex.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: fix only one cs-gpio working

Why it does not work at the moment:
- num_chipselect sets the number of cs-gpios that are in the DT.
This comes from drivers/spi/spi.c
- num_chipselect gets set with devm_spi_register_controller, that is
called in drivers/spi/spi.c
- devm_spi_register_controller got called after num_chipselect has
been used.

How this commit fixes the issue:
- devm_spi_register_controller gets called before num_chipselect is
being used.

Fixes: c7a402599504 ("spi: lpspi: use the core way to implement cs-gpio function")
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Link: https://lore.kernel.org/r/20191204141312.1411251-1-philippe.schenker@toradex.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: use true,false for bool variable

Fixes coccicheck warning:

drivers/spi/spi-fsl-lpspi.c:472:2-19: WARNING: Assignment of 0/1 to bool variable
drivers/spi/spi-fsl-lpspi.c:474:2-19: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1577159526-33689-2-git-send-email-zhengbin13@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Use dma_request_chan() directly for channel request

dma_request_slave_channel_reason() is:
#define dma_request_slave_channel_reason(dev, name) \
dma_request_chan(dev, name)

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191113094256.1108-4-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: fix memory leak in fsl_lpspi_probe

In fsl_lpspi_probe an SPI controller is allocated either via
spi_alloc_slave or spi_alloc_master. In all but one error cases this
controller is put by going to error handling code. This commit fixes the
case when pm_runtime_get_sync fails and it should go to the error
handling path.

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Link: https://lore.kernel.org/r/20190930034602.1467-1-navid.emamdoost@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: clean up indentation issue

The complete call is indented incorrectly, remove the extraneous tabs.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190926113701.26986-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Clean up fsl_lpspi_probe

Use is_slave local variable to avoid calling of_property_read_bool() twice.
Remove redudant assignment for controller->bus_num, set it once is enough.
Move setting controller->bits_per_word_mask close to the code init other
controller fields.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Fix build warning when !CONFIG_PM

Add #ifdef CONFIG_PM guard to fix build warning when !CONFIG_PM
drivers/spi/spi-fsl-lpspi.c:810:12: warning: ‘fsl_lpspi_runtime_suspend’ defined but not used [-Wunused-function]
static int fsl_lpspi_runtime_suspend(struct device *dev)
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/spi/spi-fsl-lpspi.c:789:12: warning: ‘fsl_lpspi_runtime_resume’ defined but not used [-Wunused-function]
static int fsl_lpspi_runtime_resume(struct device *dev)
^~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Fix problematic dev_set_drvdata call

The original code already set controller as drvdata:
platform_set_drvdata(pdev, controller);

But commit 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
added dev_set_drvdata(&pdev->dev, fsl_lpspi);
so fsl_lpspi_remove() will get wrong pointer by platform_get_drvdata().

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: add missing complete in abort func at dma mode

Add the missing complete operations for dma_completion to fix the
problem of blocking at the wait_for_completion_interruptible()
function when use spi_slave_abort().

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: fix dataloss when SS is inactivated between every words

If we don't use CONT to keep SS activated or use DMA mode without
cs-gpio, SS will be inactivated between every words. The word here
means the data sent once which length can be set as 1/2/4 bytes.

In the isr function, we read the FSR_RXCOUNT just behind the
fsl_lpspi_read_rx_fifo. This causes the value of FSR_RXCOUNT cannot
reflect whether there is still data not sent timely. So do this
judgement by FSR_TXCOUNT.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: fsl_lpspi_runtime_resume() can be static

Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Code cleanup

Delete the extra space.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Add the missing NULL check

The spi_transfer *t will be used in one transfer whatever. If t is NULL,
there has no need to try sending data, so add an error return here.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: add dma mode support

Add dma mode support for LPSPI. Any frame longer than half txfifosize will
be sent by dma mode.

For now, there are some limits:
1. The maximum transfer speed in master mode depends on the slave device,
at least 40MHz(tested by spi-nor on 8qm-lpddr4-arm2 base board);
2. The maximum transfer speed in slave mode is 15MHz(imx7ulp),
22MHz(8qm/qxp). In order to reach the maximum speed which is mentioned
in datasheet, the load of connect wires between master and slave
should be less than 15pF.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: use the core way to implement cs-gpio function

Use the default implementation of transfer_one_msg/chipselect/setup
functions in spi core to implement cs-gpio control.
Use fsl_lpspi_prepare_message to init the cs_gpio pin.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Acked-by: Fugang Duan <Fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: add the error info of transfer speed setting

Add a error info when set a speed which greater than half of per-clk of
spi module.

The minimum SCK period is 2 cycles(CCR[SCKDIV]). So the maximum transfer
speed is half of spi per-clk.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: enable runtime pm for lpspi

Enable the runtime power management for lpspi module.

Do some adaptation work from kernel 4.9 to 4.14.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Add i.MX8 boards support for lpspi

Add both ipg and per clock for lpspi to support i.MX8QM/QXP boards.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Fix CLK pin becomes low before one transfer

Remove Reset operation in fsl_lpspi_config(). This RST may cause both CLK
and CS pins go from high to low level under cs-gpio mode.
Add fsl_lpspi_reset() function after one message transfer to clear all
flags in use.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Fix wrong transmission when don't use CONT

Add judgment on SR_MBF and FSR_RXCOUNT.

In PIO mode, if don't use CONT to keep cs selected in one transfer, the
transfer will go wrong. FCIE will be set after one frame transfer
finish. If use CONT, the frame refer to the whole data in one transfer.
If don't use CONT, the frame refer to one byte of whole data. This will
cause the transfer ending early.

This patch add a register reading in isr function, it might lead to a
slight decrease in the max transmission speed in PIO mode.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Improve the stability of lpspi data transmission

Use SR_TDF to judge if need to send data, and SR_FCF is to judge if
transmission end and to replace the waiting after transmission end.
This waiting has no actual meaning, for module will set the FCF
flag at the real end.

The changes of interrupt flag and ISR function reduce the times of
calling ISR. The use of the FCF flag improves the stability of the
data transmission. These two points generally improve the data
transfer speed of lpspi, especially when it is set to slave mode
it can support higher transfer speed of the host.

After making these changes, there is no need to use
fsl_lpspi_txfifo_empty(), so remove it.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Let watermark change with send data length

Configure watermark to change with the length of the sent data.
Support LPSPI sending message shorter than tx/rxfifosize.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Add slave mode support

Add slave mode support to the fsl-lpspi driver, only in PIO mode.

For now, there are some limitations for slave mode transmission:
1. The stale data in RXFIFO will be dropped when the Slave does any new
transfer.
2. One transfer can be finished only after all transfer->len data been
transferred to master device
3. Slave device only accepts transfer->len data. Any data longer than
this from master device will be dropped. Any data shorter than this
from master will cause LPSPI to stuck due to mentioned limitation 2.
4. Only PIO transfer is supported in Slave Mode.

Wire connection:
GND, SCK, MISO(to MISO of slave), MOSI(to MOSI of slave), SCS

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Replace all "master" with "controller"

In order to enable the slave mode and make the code more readable,
replace all related structure names and object names which is
named "master" with "controller".

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Prevent FIFO under/overrun by default

Certain devices don't work well when a transmit FIFO underrun or
receive FIFO overrun occurs. Example is the SAF400x radio chip when
running at high speed which leads to garbage being sent to/received from
the chip. In which case, it should stall waiting for further data to be
available before proceeding. This patch unset the NOSTALL bit in CFGR1
by default to prevent this issue.

Signed-off-by: Hieu Tran Dang <dangtranhieu2012@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: lpspi: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: fix indentation error

This patch fixes the indentation error in spi-fsl-lpspi.c.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: Pre-initialize ret in fsl_lpspi_transfer_one_msg()

With gcc 4.1.2:

drivers/spi/spi-fsl-lpspi.c: In function ‘fsl_lpspi_transfer_one_msg’:
drivers/spi/spi-fsl-lpspi.c:369: warning: ‘ret’ may be used uninitialized in this function

If the message contains no transfers, the function will set the
message's status to an uninitialized value, and will return that
uninitialized value.

While __spi_validate() should have been called in all paths leading to
this, and thus have rejected such messages, we better pre-initialize ret
to be safe for future modifications (spi_transfer_one_message() also
does this).

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: quit reading rx fifo under error condition

In case that error occurs during waiting for txfifo empty, it is
not necessary to read rx fifo. It's better to return directly.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: use GPL as module license

At the beginning of lpspi driver, it is claimed that the dirver
is under the terms of the GNU General Public License, either
version 2 of the License. While at the end I only declared GPL V2.

This patch make the license consistent.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: read lpspi tx/rx fifo size in probe()

The lpspi tx/rx fifo size is a read only parameter resides
lpspi Parameter Register. It's better to read lpspi tx/rx
fifo size in probe().

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: fsl-lpspi: use wait_for_completion_timeout() while waiting transfer done

It's a potential problem to use wait_for_completion() because the
completion condition may never come. Thus, it's better to repalce
wait_for_completion() with wait_for_completion_timeout().

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: imx: replace schedule() with cond_resched()

It's more rational that just do the schedule when necessary
other than do it every time. Thus, it's better to replace
schedule() with cond_resched() in fsl_lpspi_txfifo_empty(),
which contributes to saving cpu time.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: imx: fix potential shift truncation

There is a static checker warning in fsl_lpspi_set_cmd().
I intended to write "temp |= (fsl_lpspi->config.mode & 0x3) << 30",
but used "temp |= (fsl_lpspi->config.mode & 0x11) << 30" by mistake.

This patch fixes this potential shift truncation.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: imx: use prepare_transfer_hardware() for lpspi

The old driver enable clk in fsl_lpspi_prepare_message() and
disable clk in fsl_lpspi_unprepare_message().

Rather than doing this per message it's a bit better to do it
in prepare_transfer_hardware(), that way if there's a sequence
of messages queued one after another we don't turn the clock on
and off all the time.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: imx: add lpspi bus driver

This patch adds lpspi driver to support new i.MX products which use
lpspi instead of ecspi.

The lpspi can continue operating in stop mode when an appropriate
clock is available. It is also designed for low CPU overhead with
DMA offloading of FIFO register accesses.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>