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

[Dan Murphy <dmurphy@ti.com>]

Vesa

On 4/9/20 12:25 AM, Vesa Jääskeläinen wrote:
> 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.
>
Thank you for looking

Dan


> Thanks,
> Vesa Jääskeläinen