Re: [PATCH v4 0/4] Add a generic driver for LED-based backlight

From: Jacek Anaszewski
Date: Thu Jul 18 2019 - 09:19:52 EST


On 7/17/19 4:15 PM, Jean-Jacques Hiblot wrote:
> This series aims to add a led-backlight driver, similar to pwm-backlight,
> but using a LED class device underneath.
>
> A few years ago (2015), Tomi Valkeinen posted a series implementing a
> backlight driver on top of a LED device:
> https://patchwork.kernel.org/patch/7293991/
> https://patchwork.kernel.org/patch/7294001/
> https://patchwork.kernel.org/patch/7293981/
>
> The discussion stopped because Tomi lacked the time to work on it.
>
> changes in v4:
> - fix dev_err() messages and commit logs following the advices of Pavel
> - cosmetic changes (indents, getting rid of "? 1 : 0" in
> led_match_led_node())
>
> changes in v3:
> - dt binding: don't limit the brightness range to 0-255. Use the range of
> the underlying LEDs. as a side-effect, all LEDs must now have the same
> range
> - driver: Adapt to dt binding update.
> - driver: rework probe() for clarity and remove the remaining goto.
>
> changes in v2:
> - handle more than one LED.
> - don't make the backlight device a child of the LED controller.
> - make brightness-levels and default-brightness-level optional
> - removed the option to use a GPIO enable.
> - removed the option to use a regulator. It should be handled by the LED
> core
> - don't make any change to the LED core (not needed anymore)
>
> Jean-Jacques Hiblot (2):
> leds: Add managed API to get a LED from a device driver
> dt-bindings: backlight: Add led-backlight binding
>
> Tomi Valkeinen (2):
> leds: Add of_led_get() and led_put()
> backlight: add led-backlight driver
>
> .../bindings/leds/backlight/led-backlight.txt | 28 ++
> drivers/leds/led-class.c | 92 ++++++
> drivers/video/backlight/Kconfig | 7 +
> drivers/video/backlight/Makefile | 1 +
> drivers/video/backlight/led_bl.c | 268 ++++++++++++++++++
> include/linux/leds.h | 6 +
> 6 files changed, 402 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> create mode 100644 drivers/video/backlight/led_bl.c
>

For the whole set:

Acked-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>

Lee - we need to create immutable branch for this set since there will
be some interfering changes in the LED core in this cycle.

I can create the branch and send the pull request once we will
obtain the ack from Rob for DT bindings, unless you have other
preference.

--
Best regards,
Jacek Anaszewski