[PATCH 3/3] ALSA: hda/realtek - Add LED class support for micmute LED

[Takashi Iwai]

On Thu, 30 Apr 2020 10:32:53 +0200,
Kai-Heng Feng wrote:
> 
> Currently DMIC controls micmute LED via "audio mute LED trigger".
> 
> However, unlike Dell and Lenovo platforms, HP platforms don't provide a
> way to control micmute LED via ACPI, it's controlled by HDA codec
> instead.
> 
> So let's register an LED class for micmute so other subsystems like DMIC
> can facilitate the codec-controlled LED.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>

I guess this requires the Kconfig change to select CONFIG_LEDS_*
or make the code conditionally built.  So far the latter strategy is
taken for the code in hda_generic.c.


thanks,

Takashi

> ---
>  sound/pci/hda/patch_realtek.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
> index 6f164ccddde3..82eb7624bbba 100644
> --- a/sound/pci/hda/patch_realtek.c
> +++ b/sound/pci/hda/patch_realtek.c
> @@ -17,6 +17,7 @@
>  #include <linux/dmi.h>
>  #include <linux/module.h>
>  #include <linux/input.h>
> +#include <linux/leds.h>
>  #include <sound/core.h>
>  #include <sound/jack.h>
>  #include <sound/hda_codec.h>
> @@ -4103,6 +4104,24 @@ static void alc_gpio_micmute_update(struct hda_codec *codec)
>  			    spec->gen.micmute_led.led_value);
>  }
>  
> +static int micmute_led_set(struct led_classdev *led_cdev,
> +			   enum led_brightness brightness)
> +{
> +	struct hda_codec *codec = dev_to_hda_codec(led_cdev->dev->parent);
> +	struct alc_spec *spec = codec->spec;
> +
> +	alc_update_gpio_led(codec, spec->gpio_mic_led_mask,
> +			    spec->micmute_led_polarity, !!brightness);
> +	return 0;
> +}
> +
> +static struct led_classdev micmute_led_cdev = {
> +	.name = "hda::micmute",
> +	.max_brightness = 1,
> +	.brightness_set_blocking = micmute_led_set,
> +	.default_trigger = "audio-micmute",
> +};
> +
>  /* setup mute and mic-mute GPIO bits, add hooks appropriately */
>  static void alc_fixup_hp_gpio_led(struct hda_codec *codec,
>  				  int action,
> @@ -4110,6 +4129,7 @@ static void alc_fixup_hp_gpio_led(struct hda_codec *codec,
>  				  unsigned int micmute_mask)
>  {
>  	struct alc_spec *spec = codec->spec;
> +	int err;
>  
>  	alc_fixup_gpio(codec, action, mute_mask | micmute_mask);
>  
> @@ -4122,6 +4142,11 @@ static void alc_fixup_hp_gpio_led(struct hda_codec *codec,
>  	if (micmute_mask) {
>  		spec->gpio_mic_led_mask = micmute_mask;
>  		snd_hda_gen_add_micmute_led(codec, alc_gpio_micmute_update);
> +
> +		micmute_led_cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
> +		err = devm_led_classdev_register(&codec->core.dev, &micmute_led_cdev);
> +		if (err)
> +			codec_warn(codec, "failed to register micmute LED\n");
>  	}
>  }
>  
> -- 
> 2.17.1
>