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@perex.cz --- sound/core/control_led.c | 366 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 362 insertions(+), 4 deletions(-)
diff --git a/sound/core/control_led.c b/sound/core/control_led.c index dfa51d8461e1..d4fb8b873f34 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -24,6 +24,12 @@ enum snd_ctl_led_mode { 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; @@ -31,6 +37,7 @@ struct snd_ctl_led { 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 { @@ -58,6 +65,9 @@ static struct snd_ctl_led snd_ctl_leds[MAX_LED] = { }, };
+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); \ @@ -222,6 +232,46 @@ static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask, } }
+static int snd_ctl_led_set_id(int card_number, struct snd_ctl_elem_id *id, + unsigned int group, bool set) +{ + struct snd_card *card; + struct snd_kcontrol *kctl; + struct snd_kcontrol_volatile *vd; + unsigned int ioff, access, new_access; + int err = 0; + + card = snd_card_ref(card_number); + if (card) { + down_write(&card->controls_rwsem); + kctl = snd_ctl_find_id(card, id); + if (kctl) { + 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)) { + err = -EXDEV; + goto unlock; + } + 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); + } + } else { + err = -ENOENT; + } +unlock: + up_write(&card->controls_rwsem); + snd_card_unref(card); + } else { + err = -ENXIO; + } + return err; +} + static void snd_ctl_led_refresh(void) { unsigned int group; @@ -230,6 +280,12 @@ static void snd_ctl_led_refresh(void) 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; @@ -241,13 +297,47 @@ static void snd_ctl_led_clean(struct snd_card *card) repeat: list_for_each_entry(lctl, &led->controls, list) if (!card || lctl->card == card) { - list_del(&lctl->list); - kfree(lctl); + snd_ctl_led_ctl_destroy(lctl); goto repeat; } } }
+static int snd_ctl_led_reset(int card_number, unsigned int group) +{ + struct snd_card *card; + struct snd_ctl_led *led; + struct snd_ctl_led_ctl *lctl; + struct snd_kcontrol_volatile *vd; + bool change = false; + + card = snd_card_ref(card_number); + if (!card) + return -ENXIO; + + mutex_lock(&snd_ctl_led_mutex); + if (!snd_ctl_led_card_valid[card_number]) { + mutex_unlock(&snd_ctl_led_mutex); + snd_card_unref(card); + return -ENXIO; + } + led = &snd_ctl_leds[group]; +repeat: + list_for_each_entry(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; + goto repeat; + } + mutex_unlock(&snd_ctl_led_mutex); + if (change) + snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0); + snd_card_unref(card); + return 0; +} + static void snd_ctl_led_register(struct snd_card *card) { struct snd_kcontrol *kctl; @@ -264,10 +354,12 @@ static void snd_ctl_led_register(struct snd_card *card) 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); mutex_lock(&snd_ctl_led_mutex); snd_ctl_led_card_valid[card->number] = false; snd_ctl_led_clean(card); @@ -349,8 +441,264 @@ static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = { 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, unsigned int *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); +} + +/* + * These types of input strings are accepted: + * + * unsigned integer - numid (equivaled to numid=UINT) + * string - basic mixer name (equivalent to iface=MIXER,name=STR) + * numid=UINT + * [iface=MIXER,][device=UINT,][subdevice=UINT,]name=STR[,index=UINT] + */ +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; + size_t len = max(sizeof(s) - 1, count); + struct snd_ctl_elem_id id; + int err; + + strncpy(buf2, buf, len); + buf2[len] = '\0'; + memset(&id, 0, sizeof(id)); + id.iface = SNDRV_CTL_ELEM_IFACE_MIXER; + s = buf2; + while (*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'; + strlcpy(id.name, buf2, sizeof(id.name)); + } + break; + } + if (*s == ',') + s++; + } + + 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 parse_attach(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 parse_detach(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 ctl_reset(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 ctl_list(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_card *card; + struct snd_ctl_led_ctl *lctl; + char *buf2 = buf; + size_t l; + + card = snd_card_ref(led_card->number); + if (!card) + return -ENXIO; + down_read(&card->controls_rwsem); + mutex_lock(&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) { + if (buf2 - buf > PAGE_SIZE - 16) + break; + if (buf2 != buf) + *buf2++ = ' '; + l = scnprintf(buf2, 15, "%u", + lctl->kctl->id.numid + + lctl->index_offset); + buf2[l] = '\0'; + buf2 += l + 1; + } + } + mutex_unlock(&snd_ctl_led_mutex); + up_read(&card->controls_rwsem); + snd_card_unref(card); + return buf2 - buf; +} + +static DEVICE_ATTR(attach, 0200, NULL, parse_attach); +static DEVICE_ATTR(detach, 0200, NULL, parse_detach); +static DEVICE_ATTR(reset, 0200, NULL, ctl_reset); +static DEVICE_ATTR(list, 0444, ctl_list, NULL); + +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(sizeof(*led_card), GFP_KERNEL); + if (!led_card) + goto cerr2; + led_card->number = card->number; + led_card->led = led; + device_initialize(&led_card->dev); + 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); + WARN(sysfs_create_link(&card->ctl_dev.kobj, &led_card->dev.kobj, link_name), + "can't create symlink to controlC%i device\n", card->number); + WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"), + "can't create symlink to card%i\n", card->number); + + continue; +cerr: + put_device(&led_card->dev); +cerr2: + printk(KERN_ERR "snd_ctl_led: unable to add card%d", card->number); + kfree(led_card); + } +} + +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_del(&led_card->dev); + kfree(led_card); + led->cards[card->number] = NULL; + } +} + /* * Control layer registration */ @@ -397,14 +745,24 @@ static int __init snd_ctl_led_init(void) static void __exit snd_ctl_led_exit(void) { struct snd_ctl_led *led; - unsigned int group; + 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_del(&led->dev); } device_del(&snd_ctl_led_dev); - snd_ctl_disconnect_layer(&snd_ctl_led_lops); snd_ctl_led_clean(NULL); }