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	ALSA: control - add sysfs support to the LED trigger module
Create SYSFS/devices/virtual/sound/ctl-led tree
(with SYSFS/class/sound/ctl-led symlink).
  speaker/
    +-- mode
    +-- brightness
  mic/
    +-- mode
    +-- brightness
Copy the idea from the HDA driver and allow to set the audio
LEDs based on the various modes:
- follow mute
- follow moute (inverted to follow mute)
- off
- on
Also, the actual LED state is exposed.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210317172945.842280-6-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
			
			
This commit is contained in:
		
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						commit
						cb17fe0045
					
				
					 1 changed files with 163 additions and 29 deletions
				
			
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			@ -17,7 +17,23 @@ MODULE_LICENSE("GPL");
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#define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
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			>> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
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enum snd_ctl_led_mode {
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	 MODE_FOLLOW_MUTE = 0,
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	 MODE_FOLLOW_ROUTE,
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	 MODE_OFF,
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	 MODE_ON,
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};
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struct snd_ctl_led {
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	struct device dev;
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	struct list_head controls;
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	const char *name;
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	unsigned int group;
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	enum led_audio trigger_type;
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	enum snd_ctl_led_mode mode;
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};
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struct snd_ctl_led_ctl {
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	struct list_head list;
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	struct snd_card *card;
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	unsigned int access;
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			@ -26,8 +42,21 @@ struct snd_ctl_led {
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};
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static DEFINE_MUTEX(snd_ctl_led_mutex);
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static struct list_head snd_ctl_led_controls[MAX_LED];
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static bool snd_ctl_led_card_valid[SNDRV_CARDS];
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static struct snd_ctl_led snd_ctl_leds[MAX_LED] = {
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	{
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		.name = "speaker",
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		.group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
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		.trigger_type = LED_AUDIO_MUTE,
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		.mode = MODE_FOLLOW_MUTE,
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	},
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	{
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		.name = "mic",
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		.group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
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		.trigger_type = LED_AUDIO_MICMUTE,
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		.mode = MODE_FOLLOW_MUTE,
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	},
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};
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#define UPDATE_ROUTE(route, cb) \
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	do { \
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			@ -47,15 +76,15 @@ static inline unsigned int group_to_access(unsigned int group)
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	return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
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}
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static struct list_head *snd_ctl_led_controls_by_access(unsigned int access)
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static struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
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{
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	unsigned int group = access_to_group(access);
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	if (group >= MAX_LED)
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		return NULL;
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	return &snd_ctl_led_controls[group];
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	return &snd_ctl_leds[group];
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}
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static int snd_ctl_led_get(struct snd_ctl_led *lctl)
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static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
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{
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	struct snd_kcontrol *kctl = lctl->kctl;
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	struct snd_ctl_elem_info info;
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			@ -91,22 +120,14 @@ static int snd_ctl_led_get(struct snd_ctl_led *lctl)
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static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
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				  struct snd_kcontrol *kctl, unsigned int ioff)
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{
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	struct list_head *controls;
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	struct snd_ctl_led *lctl;
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	enum led_audio led_trigger_type;
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	struct snd_ctl_led *led;
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	struct snd_ctl_led_ctl *lctl;
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	int route;
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	bool found;
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	controls = snd_ctl_led_controls_by_access(access);
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	if (!controls)
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	led = snd_ctl_led_get_by_access(access);
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	if (!led)
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		return;
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	if (access == SNDRV_CTL_ELEM_ACCESS_SPK_LED) {
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		led_trigger_type = LED_AUDIO_MUTE;
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	} else if (access == SNDRV_CTL_ELEM_ACCESS_MIC_LED) {
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		led_trigger_type = LED_AUDIO_MICMUTE;
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	} else {
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		return;
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	}
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	route = -1;
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	found = false;
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	mutex_lock(&snd_ctl_led_mutex);
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			@ -115,7 +136,7 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
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		mutex_unlock(&snd_ctl_led_mutex);
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		return;
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	}
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	list_for_each_entry(lctl, controls, list) {
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	list_for_each_entry(lctl, &led->controls, list) {
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		if (lctl->kctl == kctl && lctl->index_offset == ioff)
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			found = true;
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		UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
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			@ -127,23 +148,29 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
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			lctl->access = access;
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			lctl->kctl = kctl;
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			lctl->index_offset = ioff;
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			list_add(&lctl->list, controls);
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			list_add(&lctl->list, &led->controls);
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			UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
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		}
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	}
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	mutex_unlock(&snd_ctl_led_mutex);
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	switch (led->mode) {
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	case MODE_OFF:		route = 1; break;
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	case MODE_ON:		route = 0; break;
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	case MODE_FOLLOW_ROUTE:	if (route >= 0) route ^= 1; break;
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	case MODE_FOLLOW_MUTE:	/* noop */ break;
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	}
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	if (route >= 0)
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		ledtrig_audio_set(led_trigger_type, route ? LED_OFF : LED_ON);
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		ledtrig_audio_set(led->trigger_type, route ? LED_OFF : LED_ON);
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}
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static struct snd_ctl_led *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
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static struct snd_ctl_led_ctl *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
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{
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	struct list_head *controls;
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	struct snd_ctl_led *lctl;
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	struct snd_ctl_led_ctl *lctl;
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	unsigned int group;
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	for (group = 0; group < MAX_LED; group++) {
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		controls = &snd_ctl_led_controls[group];
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		controls = &snd_ctl_leds[group].controls;
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		list_for_each_entry(lctl, controls, list)
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			if (lctl->kctl == kctl && lctl->index_offset == ioff)
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				return lctl;
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			@ -154,7 +181,7 @@ static struct snd_ctl_led *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned
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static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff,
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				       unsigned int access)
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{
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	struct snd_ctl_led *lctl;
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	struct snd_ctl_led_ctl *lctl;
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	unsigned int ret = 0;
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	mutex_lock(&snd_ctl_led_mutex);
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			@ -206,13 +233,13 @@ static void snd_ctl_led_refresh(void)
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static void snd_ctl_led_clean(struct snd_card *card)
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{
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	unsigned int group;
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	struct list_head *controls;
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	struct snd_ctl_led *lctl;
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	struct snd_ctl_led *led;
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	struct snd_ctl_led_ctl *lctl;
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	for (group = 0; group < MAX_LED; group++) {
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		controls = &snd_ctl_led_controls[group];
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		led = &snd_ctl_leds[group];
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repeat:
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		list_for_each_entry(lctl, controls, list)
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		list_for_each_entry(lctl, &led->controls, list)
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			if (!card || lctl->card == card) {
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				list_del(&lctl->list);
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				kfree(lctl);
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			@ -248,6 +275,82 @@ static void snd_ctl_led_disconnect(struct snd_card *card)
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	snd_ctl_led_refresh();
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}
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/*
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 * sysfs
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 */
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static ssize_t show_mode(struct device *dev,
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			 struct device_attribute *attr, char *buf)
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{
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	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
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	const char *str;
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	switch (led->mode) {
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	case MODE_FOLLOW_MUTE:	str = "follow-mute"; break;
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	case MODE_FOLLOW_ROUTE:	str = "follow-route"; break;
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	case MODE_ON:		str = "on"; break;
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	case MODE_OFF:		str = "off"; break;
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	}
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	return sprintf(buf, "%s\n", str);
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}
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static ssize_t store_mode(struct device *dev, struct device_attribute *attr,
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			  const char *buf, size_t count)
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{
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	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
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	char _buf[16];
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	size_t l = min(count, sizeof(_buf) - 1) + 1;
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	enum snd_ctl_led_mode mode;
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	memcpy(_buf, buf, l);
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	_buf[l] = '\0';
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	if (strstr(_buf, "mute"))
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		mode = MODE_FOLLOW_MUTE;
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	else if (strstr(_buf, "route"))
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		mode = MODE_FOLLOW_ROUTE;
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	else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "0", 1) == 0)
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		mode = MODE_OFF;
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	else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
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		mode = MODE_ON;
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	else
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		return count;
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	mutex_lock(&snd_ctl_led_mutex);
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	led->mode = mode;
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	mutex_unlock(&snd_ctl_led_mutex);
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	snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
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	return count;
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}
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static ssize_t show_brightness(struct device *dev,
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			       struct device_attribute *attr, char *buf)
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{
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	struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
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	return sprintf(buf, "%u\n", ledtrig_audio_get(led->trigger_type));
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}
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static DEVICE_ATTR(mode, 0644, show_mode, store_mode);
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static DEVICE_ATTR(brightness, 0444, show_brightness, NULL);
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static struct attribute *snd_ctl_led_dev_attrs[] = {
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	&dev_attr_mode.attr,
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	&dev_attr_brightness.attr,
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	NULL,
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};
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static const struct attribute_group snd_ctl_led_dev_attr_group = {
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	.attrs = snd_ctl_led_dev_attrs,
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};
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static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
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	&snd_ctl_led_dev_attr_group,
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	NULL,
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};
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static struct device snd_ctl_led_dev;
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/*
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 * Control layer registration
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 */
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			@ -260,16 +363,47 @@ static struct snd_ctl_layer_ops snd_ctl_led_lops = {
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static int __init snd_ctl_led_init(void)
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{
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	struct snd_ctl_led *led;
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	unsigned int group;
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	for (group = 0; group < MAX_LED; group++)
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		INIT_LIST_HEAD(&snd_ctl_led_controls[group]);
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	device_initialize(&snd_ctl_led_dev);
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	snd_ctl_led_dev.class = sound_class;
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	dev_set_name(&snd_ctl_led_dev, "ctl-led");
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	if (device_add(&snd_ctl_led_dev)) {
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		put_device(&snd_ctl_led_dev);
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		return -ENOMEM;
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	}
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	for (group = 0; group < MAX_LED; group++) {
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		led = &snd_ctl_leds[group];
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		INIT_LIST_HEAD(&led->controls);
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		device_initialize(&led->dev);
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		led->dev.parent = &snd_ctl_led_dev;
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		led->dev.groups = snd_ctl_led_dev_attr_groups;
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		dev_set_name(&led->dev, led->name);
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		if (device_add(&led->dev)) {
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			put_device(&led->dev);
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			for (; group > 0; group--) {
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				led = &snd_ctl_leds[group];
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				device_del(&led->dev);
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			}
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			device_del(&snd_ctl_led_dev);
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			return -ENOMEM;
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		}
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	}
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	snd_ctl_register_layer(&snd_ctl_led_lops);
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	return 0;
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}
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static void __exit snd_ctl_led_exit(void)
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{
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	struct snd_ctl_led *led;
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	unsigned int group;
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	for (group = 0; group < MAX_LED; group++) {
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		led = &snd_ctl_leds[group];
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		device_del(&led->dev);
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	}
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	device_del(&snd_ctl_led_dev);
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	snd_ctl_disconnect_layer(&snd_ctl_led_lops);
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	snd_ctl_led_clean(NULL);
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}
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