[PATCH 0/3] Convert LP8864 LED driver to backlight class

From: Alexander Sverdlin <[email protected]>

This series converts the TI LP8864/LP8866 driver from a pure LED class
driver to a backlight class driver, while preserving backward-compatible
LED class device registration.

The motivation is a use case on a hot-pluggable segment of an I2C bus.
The generic led-backlight driver (drivers/video/backlight/led_bl.c) is
a platform driver and thus inherently non-hotpluggable -- it cannot react
to dynamic appearance/disappearance of the underlying I2C device. By
making the LP8864 driver directly register a backlight class device, it
becomes a self-contained I2C driver that properly supports hot-plug/unplug
events without depending on a separate platform device for backlight
functionality.

The LED class device registration is retained for backward compatibility:
if the "led" child node is present in the device-tree, an LED class device
is registered in addition to the backlight device.

No in-tree device-trees reference this driver, so there is no mainline
impact. Out-of-tree users who previously relied on the LP8864 as a backend
for the generic led-backlight platform driver will notice a backlight class
device appearing directly.

Alexander Sverdlin (3):
  dt-bindings: backlight: ti,lp8864: Add backlight class properties
  leds: lp8864: Rename struct lp8864_led and local variables
  backlight: lp8864: Convert from LED to backlight class driver

 .../bindings/leds/backlight/ti,lp8864.yaml    |  16 +-
 MAINTAINERS                                   |   2 +-
 drivers/leds/Kconfig                          |  12 --
 drivers/leds/Makefile                         |   1 -
 drivers/video/backlight/Kconfig               |  15 ++
 drivers/video/backlight/Makefile              |   1 +
 .../backlight/lp8864_bl.c}                    | 169 ++++++++++++------
 7 files changed, 147 insertions(+), 69 deletions(-)
 rename drivers/{leds/leds-lp8864.c => video/backlight/lp8864_bl.c} (55%)

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2.54.0