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Commit Graph

46 Commits

Author SHA1 Message Date
Luca Ceresoli
9722c3b66e of: remove internal arguments from of_property_for_each_u32()
The of_property_for_each_u32() macro needs five parameters, two of which
are primarily meant as internal variables for the macro itself (in the
for() clause). Yet these two parameters are used by a few drivers, and this
can be considered misuse or at least bad practice.

Now that the kernel uses C11 to build, these two parameters can be avoided
by declaring them internally, thus changing this pattern:

  struct property *prop;
  const __be32 *p;
  u32 val;

  of_property_for_each_u32(np, "xyz", prop, p, val) { ... }

to this:

  u32 val;

  of_property_for_each_u32(np, "xyz", val) { ... }

However two variables cannot be declared in the for clause even with C11,
so declare one struct that contain the two variables we actually need. As
the variables inside this struct are not meant to be used by users of this
macro, give the struct instance the noticeable name "_it" so it is visible
during code reviews, helping to avoid new code to use it directly.

Most usages are trivially converted as they do not use those two
parameters, as expected. The non-trivial cases are:

 - drivers/clk/clk.c, of_clk_get_parent_name(): easily doable anyway
 - drivers/clk/clk-si5351.c, si5351_dt_parse(): this is more complex as the
   checks had to be replicated in a different way, making code more verbose
   and somewhat uglier, but I refrained from a full rework to keep as much
   of the original code untouched having no hardware to test my changes

All the changes have been build tested. The few for which I have the
hardware have been runtime-tested too.

Reviewed-by: Andre Przywara <andre.przywara@arm.com> # drivers/clk/sunxi/clk-simple-gates.c, drivers/clk/sunxi/clk-sun8i-bus-gates.c
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # drivers/gpio/gpio-brcmstb.c
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> # drivers/irqchip/irq-atmel-aic-common.c
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # drivers/iio/adc/ti_am335x_adc.c
Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> # drivers/pwm/pwm-samsung.c
Acked-by: Richard Leitner <richard.leitner@linux.dev> # drivers/usb/misc/usb251xb.c
Acked-by: Mark Brown <broonie@kernel.org> # sound/soc/codecs/arizona.c
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com> # sound/soc/codecs/arizona.c
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # arch/powerpc/sysdev/xive/spapr.c
Acked-by: Stephen Boyd <sboyd@kernel.org> # clk
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20240724-of_property_for_each_u32-v3-1-bea82ce429e2@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-07-25 06:53:47 -05:00
Jeff Johnson
2c69747c10 pwm: add missing MODULE_DESCRIPTION() macros
make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-imx1.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-imx27.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-intel-lgm.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-mediatek.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-pxa.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-samsung.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-spear.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/pwm/pwm-visconti.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240610-md-drivers-pwm-v2-1-b337cfaa70ea@quicinc.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
2024-07-10 17:52:46 +02:00
Uwe Kleine-König
6727fdf748 pwm: samsung: Make use of devm_pwmchip_alloc() function
This prepares the pwm-samsung driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Link: https://lore.kernel.org/r/f188e68bdea8d5a24277a10c8c9a6350a9c246ac.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
f83c29f43d pwm: samsung: Simplify using dev_err_probe()
dev_err_probe() simplifies and improves the idiom "emit error message +
return error code". Apply it accordingly.

Link: https://lore.kernel.org/r/27a55fc05eb13802c9eddc600d0460e279388999.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
ef2092b5af pwm: samsung: Simplify by using devm functions in probe
With using devm_clk_get_enabled() and devm_pwmchip_add() the
.remove_new() callback can be dropped and an error path in .probe()
simplified.

Link: https://lore.kernel.org/r/d46ec625c14c460039082f74ec8ca3084b7c8e3a.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
87b63f73e2 pwm: samsung: Make use of pwmchip_parent() accessor
struct pwm_chip::dev is about to change. To not have to touch this
driver in the same commit as struct pwm_chip::dev, use the accessor
function provided for exactly this purpose.

Link: https://lore.kernel.org/r/421ee291a065aeae7a1552f22da4173313e789ad.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
70efbf8891 pwm: samsung: Change prototype of helpers to prepare further changes
This prepares the driver for further changes that will make it harder to
determine the pwm_chip from a given samsung_pwm_chip. To just not have
to do that, rework pwm_samsung_calc_tin() and pwm_samsung_parse_dt take
a pwm_chip. Also use the pwm_chip as driver data instead of the
samsung_pwm_chip.

Link: https://lore.kernel.org/r/33ea7d7fbf3be4a542ae8aafa213470c5831487e.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
56696c1c04 pwm: samsung: Simplify code to determine the pwmchip's parent device
There is already a pointer to the pwmchip, make use of it directly
instead of using the struct samsung_pwm_chip *our_chip just obtained
from it. This also has the advantage of not using struct
samsung_pwm_chip::chip any more which will be dropped soon.

Link: https://lore.kernel.org/r/4e8400a42979b6be0b80dff5ae964d8e9d6232eb.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19 11:04:14 +01:00
Uwe Kleine-König
e9ebab624d pwm: samsung: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
This macro has the advantage over SIMPLE_DEV_PM_OPS that we don't have to
care about when the functions are actually used, so the corresponding
#ifdef can be dropped.

Also make use of pm_ptr() to discard all PM related stuff if CONFIG_PM
isn't enabled.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-12-20 16:04:13 +01:00
Dan Carpenter
a2da597ff6 pwm: samsung: Fix a bit test in pwm_samsung_resume()
The PWMF_REQUESTED enum is supposed to be used with test_bit() and not
used as in a bitwise AND.  In this specific code the flag will never be
set so the function is effectively a no-op.

Fixes: e3fe982b2e ("pwm: samsung: Put per-channel data into driver data")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-11-10 09:20:48 +01:00
Uwe Kleine-König
40592064a1 pwm: samsung: Document new member .channel in struct samsung_pwm_chip
My earlier commit reworking how driver data is tracked added a new
member to struct samsung_pwm_chip but failed to add matching
documentation. Make up leeway.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310130404.uQ33q5Dk-lkp@intel.com/
Fixes: e3fe982b2e ("pwm: samsung: Put per-channel data into driver data")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-11-03 12:00:41 +01:00
Uwe Kleine-König
9608405bda pwm: samsung: Consistently use the same name for driver data
The driver uses mostly "chip" to name samsung_pwm_chip pointers:

$ git grep -Pho 'samsung_pwm_chip \*[a-zA-Z0-9_]+(*nla:[a-zA-Z0-9_(])' v6.5-rc1 -- drivers/pwm/pwm-samsung.c | sort | uniq -c
     10 samsung_pwm_chip *chip
      6 samsung_pwm_chip *our_chip
      1 samsung_pwm_chip *pwm

However "chip" is supposed to be used for struct pwm_chip pointers and
"pwm" for struct pwm_device pointers. So consistently use "our_chip".

Link: https://lore.kernel.org/r/20230929161918.2410424-11-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>
2023-10-13 10:07:18 +02:00
Uwe Kleine-König
e3fe982b2e pwm: samsung: Put per-channel data into driver data
Instead of allocating extra data in .request() provide the needed memory
in struct samsung_pwm_chip. This reduces the number of allocations. Even
though now all 5 channel structs are allocated this is probably
outweighed by the reduced overhead to track up to 6 smaller allocations.

Link: https://lore.kernel.org/r/20230705080650.2353391-3-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>
2023-10-13 10:07:17 +02:00
Uwe Kleine-König
384461abca 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>
2023-10-13 10:07:17 +02:00
Uwe Kleine-König
1d4f9972dc pwm: samsung: 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>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-03-30 16:26:34 +02:00
Uwe Kleine-König
daa986d5f8 pwm: samsung: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

The size check for state->period is moved to .apply() to make sure that
the values of state->duty_cycle and state->period are passed to
pwm_samsung_config without change while they are discarded to int.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-05-20 15:59:34 +02:00
Mårten Lindahl
5d82e66139 pwm: pwm-samsung: Trigger manual update when disabling PWM
When duty-cycle is at full level (100%), the TCNTn and TCMPn registers
needs to be flushed in order to disable the signal. The PWM manual does
not say anything about this, but states that only clearing the TCON
auto-reload bit should be needed, and this seems to be true when the PWM
duty-cycle is not at full level. This can be observed on an Axis
ARTPEC-8, by running:

  echo <period> > pwm/period
  echo <period> > pwm/duty_cycle
  echo 1 > pwm/enable
  echo 0 > pwm/enable

Since the TCNTn and TCMPn registers are activated when enabling the PWM
(setting TCON auto-reload bit), and are not touched when disabling the
PWM, the double buffered auto-reload function seems to be still active.
Lowering duty-cycle, and restoring it again in between the enabling and
disabling, makes the disable work since it triggers a reload of the
TCNTn and TCMPn registers.

Fix this by securing a reload of the TCNTn and TCMPn registers when
disabling the PWM and having a full duty-cycle.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-11-05 11:51:42 +01:00
Uwe Kleine-König
4e33497354 pwm: samsung: Don't check the return code of pwmchip_remove()
pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. Also the
driver core ignores the return value of pwm_samsung_remove()
and considers the device removed anyhow. So returning early results
in a resource leak.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:54 +02:00
Uwe Kleine-König
e9fdf122cf pwm: Simplify all drivers with explicit of_pwm_n_cells = 3
With the previous commit there is no need for the lowlevel driver any
more to specify it it uses two or three cells. So simplify accordingly.

The only non-trival change affects the pwm-rockchip driver: It used to only
support three cells if the hardware supports polarity. Now the default
number depends on the device tree which has to match hardware anyhow
(and if it doesn't the error is just a bit delayed as a PWM handle with
an inverted setting is catched when pwm_apply_state() is called).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:19:15 +02:00
Uwe Kleine-König
f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("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>
2021-03-22 11:53:00 +01:00
Yangtao Li
cc1cc4ba36 pwm: samsung: Convert to devm_platform_ioremap_resource()
Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:18:43 +01:00
Thomas Gleixner
84a14ae8c4 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178
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 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 24 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.162703968@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:19 -07:00
Uwe Kleine-König
b05232d624 pwm: samsung: Don't uses devm_*() functions in ->request()
A call to ->request() is always paired by a call to ->free() before a
given device is disposed. So the simplification that usually is possible
when using devm_*() functions cannot be used here. So use plain
kzalloc() and kfree() for improved runtime behaviour and reduced memory
footprint.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix build failure]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09 17:29:15 +02:00
Uwe Kleine-König
e926b12c61 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>
2019-05-09 17:09:54 +02:00
Bartlomiej Zolnierkiewicz
08a4d8ec42 pwm: pwm-samsung: fix suspend/resume support
Fix suspend/resume support:

- add disabled_mask to struct samsung_pwm_chip to track PWM
  disabled state information in pwm_samsung_{disable,enable}()

- rename pwm_samsung_config() to __pwm_samsung_config() and
  add extra force_period parameter to be used during resume
  (to force tin_ns and tcnt recalculation)

- add pwm_samsung_config() wrapper for preserving old behavior

- properly restore PWM configuration in pwm_samsung_resume()

- remove no longer needed pwm_samsung_suspend()

- update Copyrights

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 10:39:12 +02:00
Bartlomiej Zolnierkiewicz
23aa19a22e pwm: samsung: Remove redundant checks from pwm_samsung_config()
If the requested period_ns and duty_ns values are identical to the last
programmed ones pwm_samsung_config() returns early and skips the
hardware configuration. The same checks are now done by the PWM core so
the driver specific ones can be removed.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 10:39:11 +02:00
Seung-Woo Kim
04d68dea26 pwm: samsung: Fix to use lowest div for large enough modulation bits
From pwm_samsung_calc_tin(), there is routine to find the lowest divider
possible to generate lower frequency than requested one. But it is
always possible to generate requested frequency with large enough
modulation bits except on s3c24xx, so this patch fixes to use lowest div
for the case. This patch removes following UBSAN warning:

   UBSAN: Undefined behaviour in drivers/pwm/pwm-samsung.c:197:13
   shift exponent 32 is too large for 32-bit type 'long unsigned int'
   [...]
   [<c0670248>] (ubsan_epilogue) from [<c06707b4>] (__ubsan_handle_shift_out_of_bounds+0xd8/0x120)
   [<c06707b4>] (__ubsan_handle_shift_out_of_bounds) from [<c0694b28>] (pwm_samsung_config+0x508/0x6a4)
   [<c0694b28>] (pwm_samsung_config) from [<c069286c>] (pwm_apply_state+0x174/0x40c)
   [<c069286c>] (pwm_apply_state) from [<c0b2e070>] (pwm_fan_probe+0xc8/0x488)
   [<c0b2e070>] (pwm_fan_probe) from [<c07ba8b0>] (platform_drv_probe+0x70/0x150)
   [...]

Cc: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06 10:48:55 +02:00
Javier Martinez Canillas
cccb94543c pwm: samsung: Use MODULE_DEVICE_TABLE() to include OF modalias
If the pwm-samsung driver is built as a module, modalias information is
not filled so the module is not autoloaded. Use the MODULE_DEVICE_TABLE()
macro to export the OF device ID so the module contains that information.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-05-21 15:56:53 +02:00
Sjoerd Simons
4a1c683c98 pwm: samsung: Fix output race on disabling
When disabling the Samsung PWM the output state remains at the level it
was at the end of a PWM cycle. In other words, calling pwm_disable()
when at 100% duty cycle will keep the output active, while at all other
settings the output will go/stay inactive. On top of that the Samsung
PWM settings are double-buffered, which means the new settings only get
applied at the start of a new PWM cycle.

This results in a race if the PWM is at 100% duty cycle and a driver
calls:

  pwm_config(pwm, 0, period);
  pwm_disable(pwm);

In this case the PWMs output will unexpectedly stay active, unless a new
PWM cycle happened to start between the register writes in pwm_config()
and pwm_disable(). As far as I can tell this is a regression introduced
by 3bdf878, before that a call to pwm_config() would call
pwm_samsung_enable() which, while heavy-handed, made sure the expected
settings were live.

To resolve this, while not re-introducing the issues 3bdf878 (flickering
as the PWM got reset while in a PWM cycle) fixed, only force an update
of the settings when at 100% duty cycle, which shouldn't have any
noticeable effect on the output but is enough to ensure the behaviour is
as expected on disable.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-27 13:06:47 +01:00
Wolfram Sang
f05fae14a1 pwm: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:28 +02:00
Ajay Kumar
3bdf878102 pwm: samsung: do not set manual update bit in pwm_samsung_config
pwm_samsung_config() sets the manual update bit via a call to the
pwm_samsung_enable() function even when the channel is already running.
This causes noticable flicker on display if we try to change the
backlight brightness from minimum to maximum, continuously.

So, we remove the call to pwm_samsung_enable() from pwm_samsung_config
to avoid the flicker and this change doesn't harm normal working since
the pwm-backlight driver already calls pwm_samsung_enable() where
needed.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-21 12:24:00 +02:00
Jingoo Han
4407b6d243 pwm: samsung: Use SIMPLE_DEV_PM_OPS macro
Use SIMPLE_DEV_PM_OPS macro in order to make the code simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-02-26 16:14:57 +01:00
Sachin Kamat
b577cdcf17 pwm: samsung: Fix kernel warning while unexporting a channel
PWM channel data was set to NULL before freeing it. This caused the
following kernel warning while unexporting the channel. Set the channel
data to NULL after freeing it.

[   70.495000] WARNING: CPU: 0 PID: 1 at drivers/base/devres.c:805 pwm_put+0x48/0x80()
[   70.505000] Modules linked in:
[   70.505000] CPU: 0 PID: 1 Comm: sh Not tainted 3.12.0-rc6-next-20131024-00012-gd4aec04-dirty #58
[   70.515000] [<c0014ddc>] (unwind_backtrace+0x0/0xf4) from [<c0011784>] (show_stack+0x10/0x14)
[   70.525000] [<c0011784>] (show_stack+0x10/0x14) from [<c03a3cbc>] (dump_stack+0x7c/0xb0)
[   70.530000] [<c03a3cbc>] (dump_stack+0x7c/0xb0) from [<c001de68>] (warn_slowpath_common+0x6c/0x88)
[   70.540000] [<c001de68>] (warn_slowpath_common+0x6c/0x88) from [<c001df20>] (warn_slowpath_null+0x1c/0x24)
[   70.550000] [<c001df20>] (warn_slowpath_null+0x1c/0x24) from [<c01d1af8>] (pwm_put+0x48/0x80)
[   70.560000] [<c01d1af8>] (pwm_put+0x48/0x80) from [<c01d21c8>] (pwm_unexport_store+0x94/0xac)
[   70.565000] [<c01d21c8>] (pwm_unexport_store+0x94/0xac) from [<c010991c>] (sysfs_write_file+0x148/0x1d8)
[   70.575000] [<c010991c>] (sysfs_write_file+0x148/0x1d8) from [<c00b2a80>] (vfs_write+0xb4/0x1a0)
[   70.585000] [<c00b2a80>] (vfs_write+0xb4/0x1a0) from [<c00b3068>] (SyS_write+0x3c/0x78)
[   70.595000] [<c00b3068>] (SyS_write+0x3c/0x78) from [<c000e2e0>] (ret_fast_syscall+0x0/0x30)

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-11-01 11:17:57 +01:00
Sachin Kamat
c3bdfe1f1e pwm: samsung: Include linux/of.h header
'of_match_ptr' is defined in linux/of.h. Include it explicitly.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-10-08 15:45:44 +02:00
Tomasz Figa
11ad39ede2 pwm: Add new pwm-samsung driver
This patch introduces new Samsung PWM driver, which is completely
rewritten to be multiplatform- and DeviceTree-aware.

In addition, remaining problems of old driver are fixed, such as:
 - proper handling of hardware variants,
 - synchronization on SMP systems,
 - handling of boundary parameter values,
 - hardware sharing with PWM clocksource driver,
 - undefined state of PWM output after stopping PWM channel.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Mark Brown <broonie@linaro.org>
Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
2013-08-12 21:53:22 +02:00
Tomasz Figa
615c19e160 pwm: samsung: Rename to pwm-samsung-legacy
This patch renames the old pwm-samsung driver to pwm-samsung-legacy to
create place for the new, rewritten, DT-aware pwm-samsung driver.

Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Mark Brown <broonie@linaro.org>
Tested-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
2013-08-06 01:21:49 +02:00
Jingoo Han
c509a8e521 pwm: samsung: convert s3c_pwm to dev_pm_ops
Instead of using legacy suspend/resume methods, using newer dev_pm_ops
structure allows better control over power management.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2013-03-08 08:30:55 +01:00
Linus Torvalds
74779e2226 pwm: Changes for v3.8-rc1
A new driver has been added for the SPEAr platform and the TWL4030/6030
 driver has been replaced by two drivers that control the regular PWMs
 and the PWM driven LEDs provided by the chips.
 
 The vt8500, tiecap, tiehrpwm, i.MX, LPC32xx and Samsung drivers have all
 been improved and the device tree bindings now support the PWM signal
 polarity.
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Merge tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwm

Pull pwm changes from Thierry Reding:
 "A new driver has been added for the SPEAr platform and the
  TWL4030/6030 driver has been replaced by two drivers that control the
  regular PWMs and the PWM driven LEDs provided by the chips.

  The vt8500, tiecap, tiehrpwm, i.MX, LPC32xx and Samsung drivers have
  all been improved and the device tree bindings now support the PWM
  signal polarity."

Fix up trivial conflicts due to __devinit/exit removal.

* tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwm: (21 commits)
  pwm: samsung: add missing s3c->pwm_id assignment
  pwm: lpc32xx: Set the chip base for dynamic allocation
  pwm: lpc32xx: Properly disable the clock on device removal
  pwm: lpc32xx: Fix the PWM polarity
  pwm: i.MX: eliminate build warning
  pwm: Export of_pwm_xlate_with_flags()
  pwm: Remove pwm-twl6030 driver
  pwm: New driver to support PWM driven LEDs on TWL4030/6030 series of PMICs
  pwm: New driver to support PWMs on TWL4030/6030 series of PMICs
  pwm: pwm-tiehrpwm: pinctrl support
  pwm: tiehrpwm: Add device-tree binding
  pwm: pwm-tiehrpwm: Adding TBCLK gating support.
  pwm: pwm-tiecap: pinctrl support
  pwm: tiecap: Add device-tree binding
  pwm: Add TI PWM subsystem driver
  pwm: Device tree support for PWM polarity
  pwm: vt8500: Ensure PWM clock is enabled during pwm_config
  pwm: vt8500: Fix build error
  pwm: spear: Staticize spear_pwm_config()
  pwm: Add SPEAr PWM chip driver support
  ...
2012-12-19 08:19:07 -08:00
Joonyoung Shim
20e8ac3eea pwm: samsung: add missing s3c->pwm_id assignment
The s3c->pwm_id is used to calculate offset of related register.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-12-14 08:32:58 +01:00
Bill Pemberton
77f37917a6 pwm: remove use of __devexit
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28 12:23:41 -08:00
Bill Pemberton
fd1091125a pwm: remove use of __devexit_p
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28 12:23:41 -08:00
Thierry Reding
c2d476a98f 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>
2012-10-05 20:56:43 +02:00
Jingoo Han
ecefeb7921 pwm: samsung: add missing device pointer to struct pwm_chip
This patch adds missing device pointer to struct pwm_chip. If the
device pointer is NULL, pwmchip_add() will return error.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-08-17 14:08:24 +02:00
Sachin Kamat
2437b0d95c pwm: Use pr_* functions in pwm-samsung.c file
Replace printk with pr_* functions to avoid checkpatch warnings.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:24:03 +02:00
Axel Lin
6192fa8744 pwm: Convert pwm-samsung to use devm_* APIs
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:24:03 +02:00
Sascha Hauer
215c29d3d0 ARM Samsung: Move s3c pwm driver to pwm framework
Move the driver to drivers/pwm/ and convert it to use the framework.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
[eric@eukrea.com: fix pwmchip_add return code test]
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-02 21:39:02 +02:00