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Subject[PATCH v8 0/5] Add a generic driver for LED-based backlight
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 v8:
- use class_find_device_by_of_node() instead of class_find_device()
- renamed devm_led_get() as devm_of_led_get()

changes in v7:
- rebased on top of linux-leds/for-next
- populate the of_node member of the LED device if fwnode is a of_node
(this is a new patch and the first of the series).
- devm_led_get() works only when the device tree is used. Add a few checks
for that.

changes in v6:
- trim the list of included headers
- remove useless definition of BKL_FULL_BRIGHTNESS

changes in v5:
- removed LED brightness scaling
- disable sysfs the interface of the LEDs when used by the backlight device

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 (3):
leds: populate the device's of_node when possible
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 | 98 ++++++-
drivers/video/backlight/Kconfig | 7 +
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/led_bl.c | 260 ++++++++++++++++++
include/linux/leds.h | 6 +
6 files changed, 399 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
create mode 100644 drivers/video/backlight/led_bl.c


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