#include <linux/slab.h>
#include <linux/module.h>
#include <linux/leds.h>
#include <sound/core.h>
#include <sound/control.h>
MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
MODULE_DESCRIPTION("ALSA control interface to LED trigger code.");
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)
#define to_led_card_dev(_dev) \
container_of(_dev, struct snd_ctl_led_card, dev)
enum snd_ctl_led_mode {
MODE_FOLLOW_MUTE = 0,
MODE_FOLLOW_ROUTE,
MODE_OFF,
MODE_ON,
};
struct snd_ctl_led_card {
struct device dev;
int number;
struct snd_ctl_led *led;
};
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_card *cards[SNDRV_CARDS];
};
struct snd_ctl_led_ctl {
struct list_head list;
struct snd_card *card;
unsigned int access;
struct snd_kcontrol *kctl;
unsigned int index_offset;
};
static DEFINE_MUTEX(snd_ctl_led_mutex);
static bool snd_ctl_led_card_valid[SNDRV_CARDS];
static struct led_trigger *snd_ctl_ledtrig_audio[NUM_AUDIO_LEDS];
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,
},
};
static void snd_ctl_led_sysfs_add(struct snd_card *card);
static void snd_ctl_led_sysfs_remove(struct snd_card *card);
#define UPDATE_ROUTE(route, cb) \
do { \
int route2 = (cb); \
if (route2 >= 0) \
route = route < 0 ? route2 : (route | route2); \
} while (0)
static inline unsigned int access_to_group(unsigned int access)
{
return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >>
SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1;
}
static inline unsigned int group_to_access(unsigned int group)
{
return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
}
static 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_leds[group];
}
static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
{
static struct snd_ctl_elem_info info;
static struct snd_ctl_elem_value value;
struct snd_kcontrol *kctl = lctl->kctl;
unsigned int i;
int result;
memset(&info, 0, sizeof(info));
info.id = kctl->id;
info.id.index += lctl->index_offset;
info.id.numid += lctl->index_offset;
result = kctl->info(kctl, &info);
if (result < 0)
return -1;
memset(&value, 0, sizeof(value));
value.id = info.id;
result = kctl->get(kctl, &value);
if (result < 0)
return -1;
if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
for (i = 0; i < info.count; i++)
if (value.value.integer.value[i] != info.value.integer.min)
return 1;
} else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) {
for (i = 0; i < info.count; i++)
if (value.value.integer64.value[i] != info.value.integer64.min)
return 1;
}
return 0;
}
static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
struct snd_kcontrol *kctl, unsigned int ioff)
{
struct snd_ctl_led *led;
struct snd_ctl_led_ctl *lctl;
int route;
bool found;
led = snd_ctl_led_get_by_access(access);
if (!led)
return;
route = -1;
found = false;
scoped_guard(mutex, &snd_ctl_led_mutex) {
if (card && !snd_ctl_led_card_valid[card->number])
return;
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(lctl));
}
if (!found && kctl && card) {
lctl = kzalloc(sizeof(*lctl), GFP_KERNEL);
if (lctl) {
lctl->card = card;
lctl->access = access;
lctl->kctl = kctl;
lctl->index_offset = ioff;
list_add(&lctl->list, &led->controls);
UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
}
}
}
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: break;
}
if (route >= 0) {
struct led_trigger *trig = snd_ctl_ledtrig_audio[led->trigger_type];
led_trigger_event(trig, route ? LED_OFF : LED_ON);
}
}
static struct snd_ctl_led_ctl *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
{
struct list_head *controls;
struct snd_ctl_led_ctl *lctl;
unsigned int group;
for (group = 0; group < MAX_LED; group++) {
controls = &snd_ctl_leds[group].controls;
list_for_each_entry(lctl, controls, list)
if (lctl->kctl == kctl && lctl->index_offset == ioff)
return lctl;
}
return NULL;
}
static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff,
unsigned int access)
{
struct snd_ctl_led_ctl *lctl;
unsigned int ret = 0;
guard(mutex)(&snd_ctl_led_mutex);
lctl = snd_ctl_led_find(kctl, ioff);
if (lctl && (access == 0 || access != lctl->access)) {
ret = lctl->access;
list_del(&lctl->list);
kfree(lctl);
}
return ret;
}
static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask,
struct snd_kcontrol *kctl, unsigned int ioff)
{
struct snd_kcontrol_volatile *vd;
unsigned int access, access2;
if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) {
access = snd_ctl_led_remove(kctl, ioff, 0);
if (access)
snd_ctl_led_set_state(card, access, NULL, 0);
} else if (mask & SNDRV_CTL_EVENT_MASK_INFO) {
vd = &kctl->vd[ioff];
access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
access2 = snd_ctl_led_remove(kctl, ioff, access);
if (access2)
snd_ctl_led_set_state(card, access2, NULL, 0);
if (access)
snd_ctl_led_set_state(card, access, kctl, ioff);
} else if ((mask & (SNDRV_CTL_EVENT_MASK_ADD |
SNDRV_CTL_EVENT_MASK_VALUE)) != 0) {
vd = &kctl->vd[ioff];
access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
if (access)
snd_ctl_led_set_state(card, access, kctl, ioff);
}
}
DEFINE_FREE(snd_card_unref, struct snd_card *, if (_T) snd_card_unref(_T))
static int snd_ctl_led_set_id(int card_number, struct snd_ctl_elem_id *id,
unsigned int group, bool set)
{
struct snd_kcontrol *kctl;
struct snd_kcontrol_volatile *vd;
unsigned int ioff, access, new_access;
struct snd_card *card __free(snd_card_unref) =
snd_card_ref(card_number);
if (!card)
return -ENXIO;
guard(rwsem_write)(&card->controls_rwsem);
kctl = snd_ctl_find_id(card, id);
if (!kctl)
return -ENOENT;
ioff = snd_ctl_get_ioff(kctl, id);
vd = &kctl->vd[ioff];
access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
if (access != 0 && access != group_to_access(group))
return -EXDEV;
new_access = vd->access & ~SNDRV_CTL_ELEM_ACCESS_LED_MASK;
if (set)
new_access |= group_to_access(group);
if (new_access != vd->access) {
vd->access = new_access;
snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, ioff);
}
return 0;
}
static void snd_ctl_led_refresh(void)
{
unsigned int group;
for (group = 0; group < MAX_LED; group++)
snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
}
static void snd_ctl_led_ctl_destroy(struct snd_ctl_led_ctl *lctl)
{
list_del(&lctl->list);
kfree(lctl);
}
static void snd_ctl_led_clean(struct snd_card *card)
{
unsigned int group;
struct snd_ctl_led_ctl *lctl, *_lctl;
struct snd_ctl_led *led;
for (group = 0; group < MAX_LED; group++) {
led = &snd_ctl_leds[group];
list_for_each_entry_safe(lctl, _lctl, &led->controls, list)
if (!card || lctl->card == card)
snd_ctl_led_ctl_destroy(lctl);
}
}
static int snd_ctl_led_reset(int card_number, unsigned int group)
{
struct snd_ctl_led_ctl *lctl, *_lctl;
struct snd_ctl_led *led;
struct snd_kcontrol_volatile *vd;
bool change = false;
struct snd_card *card __free(snd_card_unref) =
snd_card_ref(card_number);
if (!card)
return -ENXIO;
scoped_guard(mutex, &snd_ctl_led_mutex) {
if (!snd_ctl_led_card_valid[card_number])
return -ENXIO;
led = &snd_ctl_leds[group];
list_for_each_entry_safe(lctl, _lctl, &led->controls, list)
if (lctl->card == card) {
vd = &lctl->kctl->vd[lctl->index_offset];
vd->access &= ~group_to_access(group);
snd_ctl_led_ctl_destroy(lctl);
change = true;
}
}
if (change)
snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
return 0;
}
static void snd_ctl_led_register(struct snd_card *card)
{
struct snd_kcontrol *kctl;
unsigned int ioff;
if (snd_BUG_ON(card->number < 0 ||
card->number >= ARRAY_SIZE(snd_ctl_led_card_valid)))
return;
scoped_guard(mutex, &snd_ctl_led_mutex)
snd_ctl_led_card_valid[card->number] = true;
list_for_each_entry(kctl, &card->controls, list)
for (ioff = 0; ioff < kctl->count; ioff++)
snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
snd_ctl_led_refresh();
snd_ctl_led_sysfs_add(card);
}
static void snd_ctl_led_disconnect(struct snd_card *card)
{
snd_ctl_led_sysfs_remove(card);
scoped_guard(mutex, &snd_ctl_led_mutex) {
snd_ctl_led_card_valid[card->number] = false;
snd_ctl_led_clean(card);
}
snd_ctl_led_refresh();
}
static void snd_ctl_led_card_release(struct device *dev)
{
struct snd_ctl_led_card *led_card = to_led_card_dev(dev);
kfree(led_card);
}
static void snd_ctl_led_release(struct device *dev)
{
}
static void snd_ctl_led_dev_release(struct device *dev)
{
}
static ssize_t mode_show(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 = NULL;
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 sysfs_emit(buf, "%s\n", str);
}
static ssize_t mode_store(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);
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;
scoped_guard(mutex, &snd_ctl_led_mutex)
led->mode = mode;
snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
return count;
}
static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
struct led_trigger *trig = snd_ctl_ledtrig_audio[led->trigger_type];
return sysfs_emit(buf, "%u\n", led_trigger_get_brightness(trig));
}
static DEVICE_ATTR_RW(mode);
static DEVICE_ATTR_RO(brightness);
static struct attribute *snd_ctl_led_dev_attrs[] = {
&dev_attr_mode.attr,
&dev_attr_brightness.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 char *find_eos(char *s)
{
while (*s && *s != ',')
s++;
if (*s)
s++;
return s;
}
static char *parse_uint(char *s, unsigned int *val)
{
unsigned long long res;
if (kstrtoull(s, 10, &res))
res = 0;
*val = res;
return find_eos(s);
}
static char *parse_string(char *s, char *val, size_t val_size)
{
if (*s == '"' || *s == '\'') {
char c = *s;
s++;
while (*s && *s != c) {
if (val_size > 1) {
*val++ = *s;
val_size--;
}
s++;
}
} else {
while (*s && *s != ',') {
if (val_size > 1) {
*val++ = *s;
val_size--;
}
s++;
}
}
*val = '\0';
if (*s)
s++;
return s;
}
static char *parse_iface(char *s, snd_ctl_elem_iface_t *val)
{
if (!strncasecmp(s, "card", 4))
*val = SNDRV_CTL_ELEM_IFACE_CARD;
else if (!strncasecmp(s, "mixer", 5))
*val = SNDRV_CTL_ELEM_IFACE_MIXER;
return find_eos(s);
}
static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, size_t count,
bool attach)
{
char buf2[256], *s, *os;
struct snd_ctl_elem_id id;
int err;
if (strscpy(buf2, buf, sizeof(buf2)) < 0)
return -E2BIG;
memset(&id, 0, sizeof(id));
id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
s = buf2;
while (*s) {
os = s;
if (!strncasecmp(s, "numid=", 6)) {
s = parse_uint(s + 6, &id.numid);
} else if (!strncasecmp(s, "iface=", 6)) {
s = parse_iface(s + 6, &id.iface);
} else if (!strncasecmp(s, "device=", 7)) {
s = parse_uint(s + 7, &id.device);
} else if (!strncasecmp(s, "subdevice=", 10)) {
s = parse_uint(s + 10, &id.subdevice);
} else if (!strncasecmp(s, "name=", 5)) {
s = parse_string(s + 5, id.name, sizeof(id.name));
} else if (!strncasecmp(s, "index=", 6)) {
s = parse_uint(s + 6, &id.index);
} else if (s == buf2) {
while (*s) {
if (*s < '0' || *s > '9')
break;
s++;
}
if (*s == '\0')
parse_uint(buf2, &id.numid);
else {
for (; *s >= ' '; s++);
*s = '\0';
strscpy(id.name, buf2, sizeof(id.name));
}
break;
}
if (*s == ',')
s++;
if (s == os)
break;
}
err = snd_ctl_led_set_id(led_card->number, &id, led_card->led->group, attach);
if (err < 0)
return err;
return count;
}
static ssize_t attach_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
return set_led_id(led_card, buf, count, true);
}
static ssize_t detach_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
return set_led_id(led_card, buf, count, false);
}
static ssize_t reset_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
int err;
if (count > 0 && buf[0] == '1') {
err = snd_ctl_led_reset(led_card->number, led_card->led->group);
if (err < 0)
return err;
}
return count;
}
static ssize_t list_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
struct snd_ctl_led_ctl *lctl;
size_t l = 0;
struct snd_card *card __free(snd_card_unref) =
snd_card_ref(led_card->number);
if (!card)
return -ENXIO;
guard(rwsem_read)(&card->controls_rwsem);
guard(mutex)(&snd_ctl_led_mutex);
if (snd_ctl_led_card_valid[led_card->number]) {
list_for_each_entry(lctl, &led_card->led->controls, list) {
if (lctl->card != card)
continue;
if (l)
l += sysfs_emit_at(buf, l, " ");
l += sysfs_emit_at(buf, l, "%u",
lctl->kctl->id.numid + lctl->index_offset);
}
}
return l;
}
static DEVICE_ATTR_WO(attach);
static DEVICE_ATTR_WO(detach);
static DEVICE_ATTR_WO(reset);
static DEVICE_ATTR_RO(list);
static struct attribute *snd_ctl_led_card_attrs[] = {
&dev_attr_attach.attr,
&dev_attr_detach.attr,
&dev_attr_reset.attr,
&dev_attr_list.attr,
NULL,
};
static const struct attribute_group snd_ctl_led_card_attr_group = {
.attrs = snd_ctl_led_card_attrs,
};
static const struct attribute_group *snd_ctl_led_card_attr_groups[] = {
&snd_ctl_led_card_attr_group,
NULL,
};
static struct device snd_ctl_led_dev;
static void snd_ctl_led_sysfs_add(struct snd_card *card)
{
unsigned int group;
struct snd_ctl_led_card *led_card;
struct snd_ctl_led *led;
char link_name[32];
for (group = 0; group < MAX_LED; group++) {
led = &snd_ctl_leds[group];
led_card = kzalloc_obj(*led_card);
if (!led_card)
goto cerr2;
led_card->number = card->number;
led_card->led = led;
device_initialize(&led_card->dev);
led_card->dev.release = snd_ctl_led_card_release;
if (dev_set_name(&led_card->dev, "card%d", card->number) < 0)
goto cerr;
led_card->dev.parent = &led->dev;
led_card->dev.groups = snd_ctl_led_card_attr_groups;
if (device_add(&led_card->dev))
goto cerr;
led->cards[card->number] = led_card;
snprintf(link_name, sizeof(link_name), "led-%s", led->name);
if (sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj,
link_name))
dev_err(card->dev,
"%s: can't create symlink to controlC%i device\n",
__func__, card->number);
if (sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj,
"card"))
dev_err(card->dev,
"%s: can't create symlink to card%i\n",
__func__, card->number);
continue;
cerr:
put_device(&led_card->dev);
cerr2:
dev_err(card->dev, "snd_ctl_led: unable to add card%d", card->number);
}
}
static void snd_ctl_led_sysfs_remove(struct snd_card *card)
{
unsigned int group;
struct snd_ctl_led_card *led_card;
struct snd_ctl_led *led;
char link_name[32];
for (group = 0; group < MAX_LED; group++) {
led = &snd_ctl_leds[group];
led_card = led->cards[card->number];
if (!led_card)
continue;
snprintf(link_name, sizeof(link_name), "led-%s", led->name);
sysfs_remove_link(&card->ctl_dev->kobj, link_name);
sysfs_remove_link(&led_card->dev.kobj, "card");
device_unregister(&led_card->dev);
led->cards[card->number] = NULL;
}
}
static struct snd_ctl_layer_ops snd_ctl_led_lops = {
.module_name = SND_CTL_LAYER_MODULE_LED,
.lregister = snd_ctl_led_register,
.ldisconnect = snd_ctl_led_disconnect,
.lnotify = snd_ctl_led_notify,
};
static int __init snd_ctl_led_init(void)
{
struct snd_ctl_led *led;
unsigned int group;
led_trigger_register_simple("audio-mute", &snd_ctl_ledtrig_audio[LED_AUDIO_MUTE]);
led_trigger_register_simple("audio-micmute", &snd_ctl_ledtrig_audio[LED_AUDIO_MICMUTE]);
device_initialize(&snd_ctl_led_dev);
snd_ctl_led_dev.class = &sound_class;
snd_ctl_led_dev.release = snd_ctl_led_dev_release;
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.release = snd_ctl_led_release;
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);
for (; group > 0; group--) {
led = &snd_ctl_leds[group - 1];
device_unregister(&led->dev);
}
device_unregister(&snd_ctl_led_dev);
return -ENOMEM;
}
}
snd_ctl_register_layer(&snd_ctl_led_lops);
return 0;
}
static void __exit snd_ctl_led_exit(void)
{
struct snd_ctl_led *led;
struct snd_card *card;
unsigned int group, card_number;
snd_ctl_disconnect_layer(&snd_ctl_led_lops);
for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
if (!snd_ctl_led_card_valid[card_number])
continue;
card = snd_card_ref(card_number);
if (card) {
snd_ctl_led_sysfs_remove(card);
snd_card_unref(card);
}
}
for (group = 0; group < MAX_LED; group++) {
led = &snd_ctl_leds[group];
device_unregister(&led->dev);
}
device_unregister(&snd_ctl_led_dev);
snd_ctl_led_clean(NULL);
led_trigger_unregister_simple(snd_ctl_ledtrig_audio[LED_AUDIO_MUTE]);
led_trigger_unregister_simple(snd_ctl_ledtrig_audio[LED_AUDIO_MICMUTE]);
}
module_init(snd_ctl_led_init)
module_exit(snd_ctl_led_exit)
MODULE_ALIAS("ledtrig:audio-mute");
MODULE_ALIAS("ledtrig:audio-micmute");
