Re: Maximum values for multi_intensity sysfs attribute

[Werner Sembach <wse@tuxedocomputers.com>]

Am 03.03.26 um 21:35 schrieb Werner Sembach:
>
> Am 03.03.26 um 21:11 schrieb Armin Wolf:
>> Am 14.02.26 um 20:15 schrieb Armin Wolf:
>>
>>> Hello,
>>>
>>> i am currently adding support for RGB keyboard backlight control to the 
>>> uniwill-laptop
>>> driver, and want to use the multicolor LED class for that. However the 
>>> hardware interface
>>> is a bit exotic:
>>>
>>> - 5 global brightness levels
>>> - 50 intensity levels for each R/G/B channel
>>>
>>> I am now asking myself how this should be mapped onto the multi_intensity 
>>> sysfs attribute.
>>> Should i set max_brightness to 5 and reject intensity values larger that 50? 
>>> Or should
>>> i set max_brightness to 50 and interpolate? What is the input range of 
>>> intensity values?
>>>
>>> Thanks,
>>> Armin Wolf 
>>
>> Any ideas on this? My current approach would be to use 5 for the max 
>> brightness and clamp intensity
>> values to 50.
> Another idea is to have multi_intensity values 0-255 and then map it to the 
> closest color so normal rgb values can be passed
this would also offer a hook point for some scaling: some uniwill devices have a 
noticeable color hue like pinkish or greenish because the leds max brightness is 
not well balanced, in tuxedo-drivers we sometimes apply some adjustments 
regulating 1 or 2 of the colors generally down like 5 or 10%
>>
>> Thanks,
>> Armin Wolf
>>