Dne 19. 03. 21 v 17:34 Hans de Goede napsal(a):
> Hi,
>
> On 3/17/21 6:29 PM, Jaroslav Kysela wrote:
>> We need to manage the kcontrol entries association for the LED trigger
>> from the user space. This patch adds a layer to the sysfs tree like:
>>
>> /sys/devices/virtual/sound/ctl-led/mic
>> + card0
>> | + attach
>> | + detach
>> | ...
>> + card1
>> + attach
>> ...
>>
>> Operations:
>>
>> attach and detach
>> - amixer style ID is accepted and easy strings for numid and
>> simple names
>> reset
>> - reset all associated kcontrol entries
>> list
>> - list associated kcontrol entries (numid values only)
>>
>> Additional symlinks:
>>
>> /sys/devices/virtual/sound/ctl-led/mic/card0/card ->
>> /sys/class/sound/card0
>>
>> /sys/class/sound/card0/controlC0/led-mic ->
>> /sys/devices/virtual/sound/ctl-led/mic/card0
>>
>> Signed-off-by: Jaroslav Kysela <perex@xxxxxxxx>
>
> Thank you so much for this patch.
>
> I've given this new version a try, dropping my sound/soc/codecs/rt56??.c patches to set the access-flags directly.
>
> And with these 3 lines in /etc/rc.d/rc.local I get nicely working control of the mute
> LED build into the (detachable) USB-keyboard's mute hot-key:
>
> modprobe snd_ctl_led
> echo -n name="Speaker Channel Switch" > /sys/class/sound/card1/controlC1/led-speaker/attach
> echo -n name="HP Channel Switch" > /sys/class/sound/card1/controlC1/led-speaker/attach
>
> This needs to be replaced by some UCM profile code doing the equivalent of course,
> but for a proof-of-concept test of the kernel API this introduces the above will do.
I added already the FixedBootSequence support to alsa-lib and alsactl and the "sysset" sequence command. But looking to this command now, it may be better to rename it to "sysw" ("double s" does not look so great).
> Only complaint which I have is the need to add "-n" to the echo commands,
> it would be nice if set_led_id() would check if the copy which it stores in buf2
> ends with "\n" and if it does if it would then strip that from the copy in buf2.
Yes, I will fix that. It's possible to use the shorter string:
echo "Speaker Channel Switch" > /sys/class/sound/card1/controlC1/led-speaker/attach
Jaroslav
--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
