kernel/linux.git/drivers/video/backlight, branch v5.15.7

video: backlight: Drop maximum brightness override for brightness zero

2021-11-18T18:17:17+00:00

commit 33a5471f8da976bf271a1ebbd6b9d163cb0cb6aa upstream. The note in c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") says that gpio-backlight uses brightness as power state. This has been fixed since in ec665b756e6f7 ("backlight: gpio-backlight: Correct initial power state handling") and other backlight drivers do not require this workaround. Drop the workaround. This fixes the case where e.g. pwm-backlight can perfectly well be set to brightness 0 on boot in DT, which without this patch leads to the display brightness to be max instead of off. Fixes: c2adda27d202f ("video: backlight: Add of_find_backlight helper in backlight.c") Cc: # 5.4+ Cc: # 4.19.x: ec665b756e6f7: backlight: gpio-backlight: Correct initial power state handling Signed-off-by: Marek Vasut Acked-by: Noralf Trønnes Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman

backlight: pwm_bl: Improve bootloader/kernel device handover

2021-08-19T09:59:03+00:00

Currently there are (at least) two problems in the way pwm_bl starts managing the enable_gpio pin. Both occur when the backlight is initially off and the driver finds the pin not already in output mode and, as a result, unconditionally switches it to output-mode and asserts the signal. Problem 1: This could cause the backlight to flicker since, at this stage in driver initialisation, we have no idea what the PWM and regulator are doing (an unconfigured PWM could easily "rest" at 100% duty cycle). Problem 2: This will cause us not to correctly honour the post_pwm_on_delay (which also risks flickers). Fix this by moving the code to configure the GPIO output mode until after we have examines the handover state. That allows us to initialize enable_gpio to off if the backlight is currently off and on if the backlight is on. Cc: stable@vger.kernel.org Reported-by: Marek Vasut Signed-off-by: Daniel Thompson Acked-by: Marek Vasut Tested-by: Marek Vasut Signed-off-by: Lee Jones

backlight: ktd253: Stabilize backlight

2021-07-21T16:27:27+00:00

Remove interrupt disablement during backlight setting. It is way to dangerous and makes platforms instable by having it miss vblank IRQs leading to the graphics derailing. The code is using ndelay() which is not available on platforms such as ARM and will result in 32 * udelay(1) which is substantial. Add some code to detect if an interrupt occurs during the tight loop and in that case just redo it from the top. Fixes: 5317f37e48b9 ("backlight: Add Kinetic KTD253 backlight driver") Cc: Stephan Gerhold Reported-by: newbyte@disroot.org Reviewed-by: Daniel Thompson Signed-off-by: Linus Walleij Signed-off-by: Lee Jones

backlight: lm3630a: Convert to atomic PWM API and check for errors

2021-06-22T13:11:37+00:00

The practical upside here is that this only needs a single API call to program the hardware which (depending on the underlaying hardware) can be more effective and prevents glitches. Up to now the return value of the pwm functions was ignored. Fix this and propagate the error to the caller. Signed-off-by: Uwe Kleine-König Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: lm3630a: Fix return code of .update_status() callback

2021-06-22T13:10:19+00:00

According to .update_status() is supposed to return 0 on success and a negative error code otherwise. Adapt lm3630a_bank_a_update_status() and lm3630a_bank_b_update_status() to actually do it. While touching that also add the error code to the failure message. Signed-off-by: Uwe Kleine-König Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: Kconfig whitespace and indentation cleanups

2021-06-01T12:36:24+00:00

Remove leading whitespaces, replace multi spaces with tabs, and fix help text indentation. Signed-off-by: Juerg Haefliger Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

video: backlight: qcom-wled: Add PMI8994 compatible

2021-05-27T16:23:43+00:00

Add a compatible for PMI8994 WLED. It uses the V4 of WLED IP. Signed-off-by: Konrad Dybcio Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: rt4831: Adds support for Richtek RT4831 backlight

2021-05-19T14:52:25+00:00

Adds support for Richtek RT4831 backlight. Signed-off-by: ChiYuan Huang Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: lm3630a_bl: Put fwnode in error case during ->probe()

2021-05-19T14:31:03+00:00

device_for_each_child_node() bumps a reference counting of a returned variable. We have to balance it whenever we return to the caller. Cc: Brian Masney Cc: Dan Murphy Fixes: 8fbce8efe15cd ("backlight: lm3630a: Add firmware node support") Signed-off-by: Andy Shevchenko Reviewed-by: Brian Masney Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: journada720: Fix Wmisleading-indentation warning

2021-03-23T09:42:55+00:00

With gcc-11, we get a warning about code that looks correct but badly indented: drivers/video/backlight/jornada720_bl.c: In function ‘jornada_bl_update_status’: drivers/video/backlight/jornada720_bl.c:66:11: error: this ‘else’ clause does not guard... [-Werror=misleading-indentation] 66 | } else /* turn on backlight */ | ^~~~ Change the formatting according to our normal conventions. Fixes: 13a7b5dc0d17 ("backlight: Adds HP Jornada 700 series backlight driver") Signed-off-by: Arnd Bergmann Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones