Re: [PATCH v8 1/9] leds: multicolor: Add sysfs interface definition

Dan Murphy
2019-09-23T14:19:04Z

Jacek

Thanks for the review

On 9/21/19 5:55 AM, Jacek Anaszewski wrote:
> Dan,
>
> On 9/20/19 7:41 PM, Dan Murphy wrote:
>> Add a documentation of LED Multicolor LED class specific
>> sysfs attributes.
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>> .../ABI/testing/sysfs-class-led-multicolor | 43 +++++++++++++++++++
>> 1 file changed, 43 insertions(+)
>> create mode 100644 Documentation/ABI/testing/sysfs-class-led-multicolor
>>
>> diff --git a/Documentation/ABI/testing/sysfs-class-led-multicolor b/Documentation/ABI/testing/sysfs-class-led-multicolor
>> new file mode 100644
>> index 000000000000..39fc73becfec
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-class-led-multicolor
>> @@ -0,0 +1,43 @@
>> +What: /sys/class/leds/<led>/brightness
>> +Date: Sept 2019
>> +KernelVersion: 5.5
>> +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 via the equation below:
>> +
>> + led_brightness = requested_value * led_color_intensity/led_color_max_intensity
> How about:
>
> led_brightness = brightness * <color>_intensity/<color>_max_intensity

Ack

>> +
>> + 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>/colors/<led_color>_intensity
> s/led_color/color/

Ack

>> +Date: Sept 2019
>> +KernelVersion: 5.5
>> +Contact: Dan Murphy <dmurphy@ti.com>
>> +Description: read/write
>> + The led_color directory is dynamically created based on the
>> + colors defined by the registrar of the class.
>> + The value for the led_color is defined in the
>> + include/dt-bindings/leds/common.h. There is one directory per
>> + color presented. The intensity file is created under each
>> + led_color directory and controls the individual LED color
>> + setting.
> We no longer have led_color directories so this description needs
> to be adjusted.
>
> And I'd not mention where the colors are defined. This is documentation
> for the user, who does not need to know about implementation details.

I thought I updated this but I will re-write this

Ack

>> +
>> + The value of the color is from 0 to
>> + /sys/class/leds/<led>/colors/<led_color>_max_intensity.
>> +
>> +What: /sys/class/leds/<led>/colors/<led_color>_max_intensity
>> +Date: Sept 2019
>> +KernelVersion: 5.5
>> +Contact: Dan Murphy <dmurphy@ti.com>
>> +Description: read only
>> + Maximum intensity level for the LED color, default is
>> + 255 (LED_FULL).
> Mentioning the default value here is pointless IMO. Userspace cannot
> change it anyway.
>
Ack

>> +
>> + If the LED does not support different intensity levels, this
>> + should be 1.
>>
> This is less relevant for MC class, and also it is rather obvious.
> I'd skip this sentence.
>
Ack

Dan