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path: root/drivers/pwm/pwm-samsung.c
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2017-08-21pwm: pwm-samsung: fix suspend/resume supportBartlomiej Zolnierkiewicz1-32/+35
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>
2017-08-21pwm: samsung: Remove redundant checks from pwm_samsung_config()Bartlomiej Zolnierkiewicz1-3/+0
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>
2016-09-06pwm: samsung: Fix to use lowest div for large enough modulation bitsSeung-Woo Kim1-3/+12
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>
2015-05-21pwm: samsung: Use MODULE_DEVICE_TABLE() to include OF modaliasJavier Martinez Canillas1-0/+1
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>
2015-03-27pwm: samsung: Fix output race on disablingSjoerd Simons1-1/+31
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>
2014-10-20pwm: drop owner assignment from platform_driversWolfram Sang1-1/+0
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>
2014-05-21pwm: samsung: do not set manual update bit in pwm_samsung_configAjay Kumar1-3/+0
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>
2014-02-26pwm: samsung: Use SIMPLE_DEV_PM_OPS macroJingoo Han1-3/+2
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>
2013-11-01pwm: samsung: Fix kernel warning while unexporting a channelSachin Kamat1-1/+1
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>
2013-10-08pwm: samsung: Include linux/of.h headerSachin Kamat1-0/+1
'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>
2013-08-12pwm: Add new pwm-samsung driverTomasz Figa1-0/+618
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>
2013-08-06pwm: samsung: Rename to pwm-samsung-legacyTomasz Figa1-353/+0
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>
2013-03-08pwm: samsung: convert s3c_pwm to dev_pm_opsJingoo Han1-11/+9
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>
2012-12-19Merge tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwmLinus Torvalds1-0/+1
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 ...
2012-12-14pwm: samsung: add missing s3c->pwm_id assignmentJoonyoung Shim1-0/+1
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>
2012-11-28pwm: remove use of __devexitBill Pemberton1-1/+1
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>
2012-11-28pwm: remove use of __devexit_pBill Pemberton1-1/+1
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>
2012-10-05pwm: Check for negative duty-cycle and periodThierry Reding1-3/+0
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>
2012-08-17pwm: samsung: add missing device pointer to struct pwm_chipJingoo Han1-0/+1
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>
2012-07-23pwm: Use pr_* functions in pwm-samsung.c fileSachin Kamat1-2/+4
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>
2012-07-23pwm: Convert pwm-samsung to use devm_* APIsAxel Lin1-18/+6
Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-02ARM Samsung: Move s3c pwm driver to pwm frameworkSascha Hauer1-0/+366
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 BĂ©nard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

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