Hi Pavel,
On Sun, Mar 8, 2015 at 9:57 PM, Pavel Machek <pa...@ucw.cz> wrote:
> Ok, so I played with RGB LED a bit, and we have quite a gap in
> documentation: what 50% brightness means is non-trivial and very
> important in case we want to do smooth blinking and color transitions.
>
> Signed-off-by: Pavel Machek <pa...@ucw.cz>
>
> diff --git a/Documentation/ABI/testing/sysfs-class-led
> b/Documentation/ABI/testing/sysfs-class-led
> index 3646ec8..649d7a6 100644
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -8,6 +8,11 @@ Description:
> non-zero brightness settings. The value is between 0 and
> /sys/class/leds/<led>/max_brightness.
>
> + If LED supports continuous brightness settings, 50% brightness
> + should correspond to 50% brightness perceived by human, in a
> similar
> + manner pixel brightness on monitor does (not 50% PWM).
How many drivers do it right? How many don't?
For those that don't, perhaps we handle the conversion between perceived and
pwm in the core, e.g. by adding a new flag to led_classdev.flags to indicate
the need for conversion?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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