[PATCH v8 0/6] Add a multicolor LED driver for groups of monochromatic LEDs

From: Jean-Jacques Hiblot
Date: Tue Mar 28 2023 - 12:35:37 EST


Some HW design implement multicolor LEDs with several monochromatic LEDs.
Grouping the monochromatic LEDs allows to configure them in sync and use
the triggers.
The PWM multicolor LED driver implements such grouping but only for
PWM-based LEDs. As this feature is also desirable for the other types of
LEDs, this series implements it for any kind of LED device.

changes v7->v8:
- consistently use "LEDs group multicolor" throughout the code.
- rename some variables with more explicit names.
- improve comments.
- use the 100-characters per line limit.

changes v6->v7:
- in led_mcg_probe() increment the counter at the end of the loop for
clarity.

changes v5->v6:
- restore sysfs access to the leds when the device is removed

changes v4->v5:
- Use "depends on COMPILE_TEST || OF" in Kconfig to indicate that OF
is a functional requirement, not just a requirement for the
compilation.
- in led_mcg_probe() check if devm_of_led_get_optional() returns an
error before testing for the end of the list.
- use sysfs_emit() instead of sprintf() in color_show().
- some grammar fixes in the comments and the commit logs.

changes v2->v3, only minor changes:
- rephrased the Kconfig descritpion
- make the sysfs interface of underlying LEDs read-only only if the probe
is successful.
- sanitize the header files
- removed the useless call to dev_set_drvdata()
- use dev_fwnode() to get the fwnode to the device.

changes v1->v2:
- Followed Rob Herrings's suggestion to make the dt binding much simpler.
- Added a patch to store the color property of a LED in its class
structure (struct led_classdev).


Jean-Jacques Hiblot (6):
devres: provide devm_krealloc_array()
leds: class: simplify the implementation of devm_of_led_get()
leds: provide devm_of_led_get_optional()
leds: class: store the color index in struct led_classdev
dt-bindings: leds: Add binding for a multicolor group of LEDs
leds: Add a multicolor LED driver to group monochromatic LEDs

Documentation/ABI/testing/sysfs-class-led | 9 +
.../bindings/leds/leds-group-multicolor.yaml | 64 +++++++
drivers/leds/led-class.c | 65 +++++--
drivers/leds/rgb/Kconfig | 13 ++
drivers/leds/rgb/Makefile | 1 +
drivers/leds/rgb/leds-group-multicolor.c | 164 ++++++++++++++++++
include/linux/device.h | 13 ++
include/linux/leds.h | 3 +
8 files changed, 318 insertions(+), 14 deletions(-)
create mode 100644 Documentation/devicetree/bindings/leds/leds-group-multicolor.yaml
create mode 100644 drivers/leds/rgb/leds-group-multicolor.c

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2.25.1