[PATCH 5/5] ALSA: control - add sysfs support to the LED trigger module
Jaroslav Kysela
perex at perex.cz
Thu Feb 11 12:14:00 CET 2021
Create SYSFS/devices/virtual/sound/ctl-led tree
(with SYSFS/class/sound/ctl-led symlink).
speaker/
+-- mode
+-- state
mic/
+-- mode
+-- state
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 at perex.cz>
---
sound/core/control_led.c | 193 ++++++++++++++++++++++++++++++++-------
1 file changed, 162 insertions(+), 31 deletions(-)
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index 49b78c12e0e9..638808e397fe 100644
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -17,7 +17,23 @@ MODULE_LICENSE("GPL");
#define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
>> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
+enum snd_ctl_led_mode {
+ MODE_FOLLOW_MUTE = 0,
+ MODE_FOLLOW_ROUTE,
+ MODE_OFF,
+ MODE_ON,
+};
+
struct snd_ctl_led {
+ struct device dev;
+ struct list_head controls;
+ const char *name;
+ unsigned int group;
+ enum led_audio trigger_type;
+ enum snd_ctl_led_mode mode;
+};
+
+struct snd_ctl_led_ctl {
struct list_head list;
struct snd_card *card;
struct snd_kcontrol *kctl;
@@ -25,8 +41,21 @@ struct snd_ctl_led {
};
static DEFINE_MUTEX(snd_ctl_led_mutex);
-static struct list_head snd_ctl_led_controls[MAX_LED];
static bool snd_ctl_led_card_valid[SNDRV_CARDS];
+static struct snd_ctl_led snd_ctl_leds[MAX_LED] = {
+ {
+ .name = "speaker",
+ .group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+ .trigger_type = LED_AUDIO_MUTE,
+ .mode = MODE_FOLLOW_MUTE,
+ },
+ {
+ .name = "mic",
+ .group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
+ .trigger_type = LED_AUDIO_MICMUTE,
+ .mode = MODE_FOLLOW_MUTE,
+ },
+};
#define UPDATE_ROUTE(route, cb) \
do { \
@@ -46,15 +75,15 @@ static inline unsigned int group_to_access(unsigned int group)
return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
}
-struct list_head *snd_ctl_led_controls_by_access(unsigned int access)
+struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
{
unsigned int group = access_to_group(access);
if (group >= MAX_LED)
return NULL;
- return &snd_ctl_led_controls[group];
+ return &snd_ctl_leds[group];
}
-static int snd_ctl_led_get(struct snd_ctl_led *lctl)
+static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
{
struct snd_kcontrol *kctl = lctl->kctl;
struct snd_ctl_elem_info info;
@@ -87,7 +116,7 @@ static int snd_ctl_led_get(struct snd_ctl_led *lctl)
return 0;
}
-static int snd_ctl_led_get_lock(struct snd_ctl_led *lctl)
+static int snd_ctl_led_get_lock(struct snd_ctl_led_ctl *lctl)
{
struct snd_card *card = lctl->card;
int route;
@@ -101,22 +130,14 @@ static int snd_ctl_led_get_lock(struct snd_ctl_led *lctl)
static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
struct snd_kcontrol *kctl, unsigned int ioff)
{
- struct list_head *controls;
- struct snd_ctl_led *lctl;
- enum led_audio led_trigger_type;
+ struct snd_ctl_led *led;
+ struct snd_ctl_led_ctl *lctl;
int route;
bool found;
- controls = snd_ctl_led_controls_by_access(access);
- if (!controls)
+ led = snd_ctl_led_get_by_access(access);
+ if (!led)
return;
- if (access == SNDRV_CTL_ELEM_ACCESS_SPK_LED) {
- led_trigger_type = LED_AUDIO_MUTE;
- } else if (access == SNDRV_CTL_ELEM_ACCESS_MIC_LED) {
- led_trigger_type = LED_AUDIO_MICMUTE;
- } else {
- return;
- }
route = -1;
found = false;
mutex_lock(&snd_ctl_led_mutex);
@@ -125,7 +146,7 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
mutex_unlock(&snd_ctl_led_mutex);
return;
}
- list_for_each_entry(lctl, controls, list) {
+ list_for_each_entry(lctl, &led->controls, list) {
if (lctl->kctl == kctl && lctl->index_offset == ioff)
found = true;
UPDATE_ROUTE(route, snd_ctl_led_get_lock(lctl));
@@ -136,27 +157,33 @@ static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
lctl->card = card;
lctl->kctl = kctl;
lctl->index_offset = ioff;
- list_add(&lctl->list, controls);
+ list_add(&lctl->list, &led->controls);
UPDATE_ROUTE(route, snd_ctl_led_get_lock(lctl));
}
}
mutex_unlock(&snd_ctl_led_mutex);
+ switch (led->mode) {
+ case MODE_OFF: route = 1; break;
+ case MODE_ON: route = 0; break;
+ case MODE_FOLLOW_ROUTE: if (route >= 0) route ^= 1; break;
+ case MODE_FOLLOW_MUTE: /* noop */ break;
+ }
if (route >= 0)
- ledtrig_audio_set(led_trigger_type, route ? LED_OFF : LED_ON);
+ ledtrig_audio_set(led->trigger_type, route ? LED_OFF : LED_ON);
}
static void snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff)
{
struct snd_kcontrol_volatile *vd;
- struct list_head *controls;
- struct snd_ctl_led *lctl;
+ struct snd_ctl_led *led;
+ struct snd_ctl_led_ctl *lctl;
vd = &kctl->vd[ioff];
- controls = snd_ctl_led_controls_by_access(vd->access);
- if (!controls)
+ led = snd_ctl_led_get_by_access(vd->access);
+ if (!led)
return;
mutex_lock(&snd_ctl_led_mutex);
- list_for_each_entry(lctl, controls, list)
+ list_for_each_entry(lctl, &led->controls, list)
if (lctl->kctl == kctl && lctl->index_offset == ioff) {
list_del(&lctl->list);
kfree(lctl);
@@ -193,13 +220,13 @@ static void snd_ctl_led_refresh(void)
static void snd_ctl_led_clean(struct snd_card *card)
{
unsigned int group;
- struct list_head *controls;
- struct snd_ctl_led *lctl;
+ struct snd_ctl_led *led;
+ struct snd_ctl_led_ctl *lctl;
for (group = 0; group < MAX_LED; group++) {
- controls = &snd_ctl_led_controls[group];
+ led = &snd_ctl_leds[group];
repeat:
- list_for_each_entry(lctl, controls, list)
+ list_for_each_entry(lctl, &led->controls, list)
if (!card || lctl->card == card) {
list_del(&lctl->list);
kfree(lctl);
@@ -246,6 +273,90 @@ void snd_ctl_led_hello(void)
}
EXPORT_SYMBOL(snd_ctl_led_hello);
+/*
+ * sysfs
+ */
+
+static ssize_t show_mode(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+ const char *str;
+
+ switch (led->mode) {
+ case MODE_FOLLOW_MUTE: str = "follow-mute"; break;
+ case MODE_FOLLOW_ROUTE: str = "follow-route"; break;
+ case MODE_ON: str = "on"; break;
+ case MODE_OFF: str = "off"; break;
+ }
+ return sprintf(buf, "%s\n", str);
+}
+
+static ssize_t store_mode(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+ char _buf[16];
+ size_t l = min(count, sizeof(_buf) - 1) + 1;
+ enum snd_ctl_led_mode mode;
+
+ memcpy(_buf, buf, l);
+ _buf[l] = '\0';
+ if (strstr(_buf, "mute"))
+ mode = MODE_FOLLOW_MUTE;
+ else if (strstr(_buf, "route"))
+ mode = MODE_FOLLOW_ROUTE;
+ else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "0", 1) == 0)
+ mode = MODE_OFF;
+ else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
+ mode = MODE_ON;
+ else
+ return count;
+
+ mutex_lock(&snd_ctl_led_mutex);
+ led->mode = mode;
+ mutex_unlock(&snd_ctl_led_mutex);
+
+ snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
+ return count;
+}
+
+static ssize_t show_state(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
+ enum led_brightness b;
+ const char *str;
+
+ b = ledtrig_audio_get(led->trigger_type);
+ switch (b) {
+ case LED_ON: str = "on"; break;
+ case LED_OFF: str = "off"; break;
+ default: str = "?"; break;
+ }
+ return sprintf(buf, "%s\n", str);
+}
+
+static DEVICE_ATTR(mode, 0644, show_mode, store_mode);
+static DEVICE_ATTR(state, 0444, show_state, NULL);
+
+static struct attribute *snd_ctl_led_dev_attrs[] = {
+ &dev_attr_mode.attr,
+ &dev_attr_state.attr,
+ NULL,
+};
+
+static const struct attribute_group snd_ctl_led_dev_attr_group = {
+ .attrs = snd_ctl_led_dev_attrs,
+};
+
+static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
+ &snd_ctl_led_dev_attr_group,
+ NULL,
+};
+
+static struct device snd_ctl_led_dev;
+
/*
* Control layer registration
*/
@@ -258,16 +369,36 @@ static struct snd_ctl_layer_ops snd_ctl_led_lops = {
static int __init snd_ctl_led_init(void)
{
+ struct snd_ctl_led *led;
unsigned int group;
- for (group = 0; group < MAX_LED; group++)
- INIT_LIST_HEAD(&snd_ctl_led_controls[group]);
+ device_initialize(&snd_ctl_led_dev);
+ snd_ctl_led_dev.class = sound_class;
+ dev_set_name(&snd_ctl_led_dev, "ctl-led");
+ if (device_add(&snd_ctl_led_dev)) {
+ put_device(&snd_ctl_led_dev);
+ return -ENOMEM;
+ }
+ for (group = 0; group < MAX_LED; group++) {
+ led = &snd_ctl_leds[group];
+ INIT_LIST_HEAD(&led->controls);
+ device_initialize(&led->dev);
+ led->dev.parent = &snd_ctl_led_dev;
+ led->dev.groups = snd_ctl_led_dev_attr_groups;
+ dev_set_name(&led->dev, led->name);
+ if (device_add(&led->dev)) {
+ put_device(&led->dev);
+ device_del(&snd_ctl_led_dev);
+ return -ENOMEM;
+ }
+ }
snd_ctl_register_layer(&snd_ctl_led_lops);
return 0;
}
static void __exit snd_ctl_led_exit(void)
{
+ device_del(&snd_ctl_led_dev);
snd_ctl_disconnect_layer(&snd_ctl_led_lops);
snd_ctl_led_clean(NULL);
}
--
2.29.2
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