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

From: Jean-Jacques Hiblot
Date: Wed Jul 17 2019 - 10:15:45 EST

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:

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

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
- 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
- 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