linux/drivers/pwm
Hans de Goede 6cf9481b44 pwm: Fallback to the static lookup-list when acpi_pwm_get fails
Commit 4a6ef8e37c ("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: 4a6ef8e37c ("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>
2019-08-08 13:17:38 +02:00
..
Kconfig pwm: Changes for v5.3-rc1 2019-07-09 08:57:45 -07:00
Makefile pwm: sifive: Add a driver for SiFive SoC PWM 2019-06-25 14:48:12 +02:00
core.c pwm: Fallback to the static lookup-list when acpi_pwm_get fails 2019-08-08 13:17:38 +02:00
pwm-ab8500.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
pwm-atmel-hlcdc.c pwm: Changes for v5.3-rc1 2019-07-09 08:57:45 -07:00
pwm-atmel-tcb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
pwm-atmel.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191 2019-05-30 11:29:21 -07:00
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: bcm-kona: Update macros to remove braces around numbers 2019-03-04 12:52:49 +01:00
pwm-bcm2835.c pwm: bcm2835: Improve precision of PWM 2019-06-26 11:39:12 +02:00
pwm-berlin.c pwm: Clear chip_data in pwm_put() 2019-05-09 17:09:54 +02:00
pwm-brcmstb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
pwm-clps711x.c pwm: clps711x: Switch to SPDX identifier 2018-12-24 12:06:56 +01:00
pwm-crc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
pwm-cros-ec.c pwm: cros-ec: Switch to SPDX identifier 2018-07-09 19:02:23 +02:00
pwm-ep93xx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
pwm-fsl-ftm.c pwm: Changes for v5.3-rc1 2019-07-09 08:57:45 -07:00
pwm-hibvt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
pwm-img.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178 2019-05-30 11:29:19 -07:00
pwm-imx-tpm.c pwm: Add i.MX TPM PWM driver support 2019-05-09 17:01:48 +02:00
pwm-imx1.c pwm: imx: Split into two drivers 2019-01-16 08:45:33 +01:00
pwm-imx27.c pwm: imx27: Use devm_platform_ioremap_resource() to simplify code 2019-05-09 16:53:59 +02:00
pwm-jz4740.c pwm: Changes for v5.3-rc1 2019-07-09 08:57:45 -07:00
pwm-lp3943.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372 2019-06-05 17:37:10 +02:00
pwm-lpc18xx-sct.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178 2019-05-30 11:29:19 -07:00
pwm-lpc32xx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372 2019-06-05 17:37:10 +02:00
pwm-lpss-pci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-lpss-platform.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-lpss.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-lpss.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-mediatek.c pwm: mediatek: Add MT7628 support 2018-08-20 11:36:07 +02:00
pwm-meson.c pwm: meson: Add documentation to the driver 2019-06-26 11:39:10 +02:00
pwm-mtk-disp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
pwm-mxs.c pwm: mxs: Switch to SPDX identifier 2018-07-12 09:03:06 +02:00
pwm-omap-dmtimer.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-pca9685.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
pwm-puv3.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-pxa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-rcar.c pwm: rcar: Remove suspend/resume support 2019-06-26 11:39:11 +02:00
pwm-renesas-tpu.c pwm: Use SPDX identifier for Renesas drivers 2018-10-12 13:35:45 +02:00
pwm-rockchip.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-samsung.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178 2019-05-30 11:29:19 -07:00
pwm-sifive.c pwm: sifive: Add a driver for SiFive SoC PWM 2019-06-25 14:48:12 +02:00
pwm-spear.c pwm: drop owner assignment from platform_drivers 2014-10-20 16:21:28 +02:00
pwm-sti.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
pwm-stm32-lp.c pwm: stm32-lp: Add power management support 2019-06-25 14:49:50 +02:00
pwm-stm32.c pwm: stm32: Use 3 cells ->of_xlate() 2019-06-25 14:53:51 +02:00
pwm-stmpe.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
pwm-sun4i.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191 2019-05-30 11:29:21 -07:00
pwm-tegra.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1 2019-05-21 11:28:39 +02:00
pwm-tiecap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
pwm-tiehrpwm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
pwm-tipwmss.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
pwm-twl-led.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
pwm-twl.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
pwm-vt8500.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
pwm-zx.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sysfs.c pwm: Changes for v5.3-rc1 2019-07-09 08:57:45 -07:00