Re: [PATCH v19 04/18] leds: multicolor: Introduce a multicolor class definition

["Vesa Jääskeläinen" <dachaac@gmail.com>]

Hi,

On 2.4.2020 23.42, Dan Murphy wrote:
> Introduce a multicolor class that groups colored LEDs
> within a LED node.
> 
> The multi color class groups monochrome LEDs and allows controlling two
> aspects of the final combined color: hue and lightness. The former is
> controlled via <color>_intensity files and the latter is controlled
> via brightness file.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
>   .../ABI/testing/sysfs-class-led-multicolor    |  42 ++++
>   Documentation/leds/index.rst                  |   1 +
>   Documentation/leds/leds-class-multicolor.rst  |  95 ++++++++
>   drivers/leds/Kconfig                          |  10 +
>   drivers/leds/Makefile                         |   1 +
>   drivers/leds/led-class-multicolor.c           | 206 ++++++++++++++++++
>   include/linux/led-class-multicolor.h          | 121 ++++++++++
>   7 files changed, 476 insertions(+)
>   create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor
>   create mode 100644 Documentation/leds/leds-class-multicolor.rst
>   create mode 100644 drivers/leds/led-class-multicolor.c
>   create mode 100644 include/linux/led-class-multicolor.h
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-led-multicolor b/Documentation/ABI/testing/sysfs-class-led-multicolor
> new file mode 100644
> index 000000000000..1f50324d24fd
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-led-multicolor
> @@ -0,0 +1,42 @@
> +What:		/sys/class/leds/<led>/brightness
> +Date:		March 2020
> +KernelVersion:	5.8
> +Contact:	Dan Murphy <dmurphy@ti.com>
> +Description:	read/write
> +		Writing to this file will update all LEDs within the group to a
> +		calculated percentage of what each color LED intensity is set
> +		to. The percentage is calculated for each grouped LED via the
> +		equation below:
> +
> +		led_brightness = brightness * color_intensity/max_brightness
> +
> +		For additional details please refer to
> +		Documentation/leds/leds-class-multicolor.rst.
> +
> +		The value of the color is from 0 to
> +		/sys/class/leds/<led>/max_brightness.
> +
> +What:		/sys/class/leds/<led>/color_index
> +Date:		March 2020
> +KernelVersion:	5.8
> +Contact:	Dan Murphy <dmurphy@ti.com>
> +Description:	read
> +		The color_index array, when read, will output the LED colors
> +		by name as they are indexed in the color_intensity array.
> +
> +What:		/sys/class/leds/<led>/num_colors
> +Date:		March 2020
> +KernelVersion:	5.8
> +Contact:	Dan Murphy <dmurphy@ti.com>
> +Description:	read
> +		The num_colors indicates the number of LEDs defined in the
> +		color_intensity and color_index arrays.
> +
> +What:		/sys/class/leds/<led>/color_intensity
> +Date:		March 2020
> +KernelVersion:	5.8
> +Contact:	Dan Murphy <dmurphy@ti.com>
> +Description:	read/write
> +		Intensity level for the LED color within the array.
> +		The intensities for each color must be entered based on the
> +		color_index array.

For what it is worth --

I see that this interface covers our use cases and I assume that GPIO 
LED and PWM LED drivers can be implemented for this after this set is 
integrated.

Thanks,
Vesa Jääskeläinen