linux/drivers/pwm
Hans de Goede 2153bbc12f pwm: lpss: Only set update bit if we are actually changing the settings
According to the datasheet the update bit must be set if the on-time-div
or the base-unit changes.

Now that we properly order device resume on Cherry Trail so that the GFX0
_PS0 method no longer exits with an error, we end up with a sequence of
events where we are writing the same values twice in a row.

First the _PS0 method restores the duty cycle of 0% the GPU driver set
on suspend and then the GPU driver first updates just the enabled bit in
the pwm_state from 0 to 1, causing us to write the same values again,
before restoring the pre-suspend duty-cycle in a separate pwm_apply call.

When writing the update bit the second time, without changing any of
the values the update bit clears immediately / instantly, instead of
staying 1 for a while as usual. After this the next setting of the update
bit seems to be ignored, causing the restoring of the pre-suspend
duty-cycle to not get applied. This makes the backlight come up with
a 0% dutycycle after suspend/resume.

Any further brightness changes after this do work.

This commit moves the setting of the update bit into pwm_lpss_prepare()
and only sets the bit if we have actually changed any of the values.

This avoids the setting of the update bit the second time we configure
the PWM to 0% dutycycle, this fixes the backlight coming up with 0%
duty-cycle after a suspend/resume.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-10-16 13:16:15 +02:00
..
core.c pwm: Silently error out on EPROBE_DEFER 2017-07-06 08:29:16 +02:00
Kconfig pwm: Enable TI ECAP driver for ARCH_K3 2018-10-16 13:14:52 +02:00
Makefile pwm: remove pwm-bfin driver 2018-03-26 15:57:08 +02:00
pwm-ab8500.c pwm: drop owner assignment from platform_drivers 2014-10-20 16:21:28 +02:00
pwm-atmel-hlcdc.c pwm: atmel-hlcdc: Implement the suspend/resume hooks 2017-04-06 17:45:02 +02:00
pwm-atmel-tcb.c pwm: simplify getting .drvdata 2018-04-30 10:40:57 +02:00
pwm-atmel.c pwm: atmel: Enable PWM on sama5d2 2017-04-06 17:45:03 +02:00
pwm-bcm2835.c pwm: bcm2835: Support for polarity setting via DT 2017-08-21 07:27:58 +02:00
pwm-bcm-iproc.c pwm: Add support for Broadcom iProc PWM controller 2016-07-11 12:49:25 +02:00
pwm-bcm-kona.c pwm: Remove .can_sleep from struct pwm_chip 2017-01-04 09:40:54 +01:00
pwm-berlin.c pwm: berlin: Don't use broken prescaler values 2018-07-09 18:57:03 +02:00
pwm-brcmstb.c pwm: Remove .can_sleep from struct pwm_chip 2017-01-04 09:40:54 +01:00
pwm-clps711x.c pwm: clps711x: Changing the compatibility string to match with the smallest supported chip 2016-07-06 17:38:17 +02:00
pwm-crc.c pwm: Use pwm_get/set_xxx() helpers where appropriate 2016-05-17 14:44:59 +02:00
pwm-cros-ec.c pwm: cros-ec: Switch to SPDX identifier 2018-07-09 19:02:23 +02:00
pwm-ep93xx.c pwm: Add the pwm_is_enabled() helper 2015-07-20 09:46:06 +02:00
pwm-fsl-ftm.c pwm: fsl-ftm: Enable support for the new SoC i.MX8QM 2018-07-09 19:08:26 +02:00
pwm-hibvt.c pwm: hibvt: Explicitly request exclusive reset control 2017-08-21 08:52:40 +02:00
pwm-img.c pwm: img: Add runtime PM 2017-11-15 10:38:37 +01:00
pwm-imx.c pwm: imx: Switch to SPDX identifier 2018-07-09 18:59:14 +02:00
pwm-jz4740.c pwm: jz4740: Add support for devicetree 2018-03-28 00:23:56 +02:00
pwm-lp3943.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
pwm-lpc18xx-sct.c pwm: lpc-18xx: use pwm_set_chip_data 2016-09-08 10:55:05 +02:00
pwm-lpc32xx.c pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value 2016-07-11 12:49:29 +02:00
pwm-lpss-pci.c pwm: lpss: Set enable-bit before waiting for update-bit to go low 2017-04-06 14:48:14 +02:00
pwm-lpss-platform.c pwm: lpss: Force runtime-resume on suspend on Cherry Trail 2018-10-16 13:15:57 +02:00
pwm-lpss.c pwm: lpss: Only set update bit if we are actually changing the settings 2018-10-16 13:16:15 +02:00
pwm-lpss.h pwm: lpss: Force runtime-resume on suspend on Cherry Trail 2018-10-16 13:15:57 +02:00
pwm-mediatek.c pwm: mediatek: Add MT7628 support 2018-08-20 11:36:07 +02:00
pwm-meson.c pwm: meson: Fix mux clock names 2018-08-20 11:32:25 +02:00
pwm-mtk-disp.c pwm: Add MediaTek MT2701 display PWM driver support 2016-09-06 10:48:53 +02:00
pwm-mxs.c pwm: mxs: Switch to SPDX identifier 2018-07-12 09:03:06 +02:00
pwm-omap-dmtimer.c pwm: omap-dmtimer: Return -EPROBE_DEFER if no dmtimer platform data 2018-08-20 11:32:19 +02:00
pwm-pca9685.c pwm: pca9685: clarify pca9685_set_sleep_mode() interface. 2017-07-25 13:41:59 +02:00
pwm-puv3.c pwm: puv3: Delete an error message for a failed memory allocation 2018-03-27 23:27:05 +02:00
pwm-pxa.c pwm: constify pwm_ops structures 2017-01-19 00:38:17 +01:00
pwm-rcar.c pwm: Use SPDX identifier for Renesas drivers 2018-10-12 13:35:45 +02:00
pwm-renesas-tpu.c pwm: Use SPDX identifier for Renesas drivers 2018-10-12 13:35:45 +02:00
pwm-rockchip.c pwm: rockchip: Add rk3328 support 2017-08-18 17:44:34 +02:00
pwm-samsung.c pwm: pwm-samsung: fix suspend/resume support 2017-08-21 10:39:12 +02:00
pwm-spear.c pwm: drop owner assignment from platform_drivers 2014-10-20 16:21:28 +02:00
pwm-sti.c pwm: Remove .can_sleep from struct pwm_chip 2017-01-04 09:40:54 +01:00
pwm-stm32-lp.c pwm: stm32-lp: Remove useless loop in stm32_pwm_lp_remove() 2018-08-20 11:32:25 +02:00
pwm-stm32.c pwm: Changes for v4.18-rc1 2018-06-14 16:25:43 +09:00
pwm-stmpe.c pwm: stmpe: Fix wrong register offset for hwpwm=2 case 2017-12-05 09:33:05 +01:00
pwm-sun4i.c pwm: sun4i: Simplify controller mapping 2018-03-28 01:12:12 +02:00
pwm-tegra.c pwm: tegra: Remove gratuituous blank line 2018-09-26 16:01:39 +02:00
pwm-tiecap.c pwm: tiecap: Set driver data before runtime PM enable 2017-08-21 08:31:37 +02:00
pwm-tiehrpwm.c pwm: tiehrpwm: Fix disabling of output of PWMs 2018-07-09 18:58:22 +02:00
pwm-tipwmss.c pwm: pwm-tipwmss: Remove all runtime PM gets/puts 2016-09-06 10:48:54 +02:00
pwm-twl-led.c mfd: twl: Move header file out of I2C realm 2017-09-04 14:41:02 +01:00
pwm-twl.c mfd: twl: Move header file out of I2C realm 2017-09-04 14:41:02 +01:00
pwm-vt8500.c pwm: vt8500: Undo preparation of a clock source. 2017-07-25 13:43:28 +02:00
pwm-zx.c pwm: Add ZTE ZX PWM device driver 2017-08-21 08:11:24 +02:00
sysfs.c pwm: Send a uevent on the pwmchip device upon channel sysfs (un)export 2018-10-12 13:51:33 +02:00