Re: [PATCH v2 1/3] leds: turris-omnia: change max brightness from 255 to 1

[Pavel Machek <pavel@ucw.cz>]

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Hi!

> The HW exposes color control for three channels (RGB), each channel with
> range 0-255 (so 16M colors). The driver exposes this via the
> multi_intensity sysfs file. This is communicated to the HW via
> LED_SET_COLOR I2C command.
> 
> HW also exposes setting the LED ON and OFF, via the LED_SET_STATE
> I2C command.
> 
> We currently have the following sysfs files via which we set LED state
> and color:
>   brightness
>   multi_intensity
> 
> Because currently the driver sets max_brightness to 255, the actual
> color that is sent to HW is recalculated via
> led_mc_calc_color_components(). For example with
> 
>   $ echo 255 255 100 >multi_intensity
>   $ echo 150 >brightness
> 
> the led_mc_calc_color_components() function recalculates the channel
> intensities with formula
>   brightness * channel_intensity / max_brightness
> and so the (255, 255, 100) tuple is converted to (150, 150, 58) before
> sending to HW.

And this seems ok.

> What I think would make more sense is to make the two sysfs files
>   brightness
>   multi_intensity
> correspond 1-to-1 with I2C commands LED_SET_STATE and LED_SET_COLOR.

We want your driver to be have same API as other drivers, 1-to-1
correspondence with I2c commands is not important.

NAK-ed-by: Pavel

Best regards,
								Pavel
-- 
People of Russia, stop Putin before his war on Ukraine escalates.

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