diff options
| -rw-r--r-- | include/sound/control.h | 5 | ||||
| -rw-r--r-- | sound/core/vmaster.c | 46 |
2 files changed, 50 insertions, 1 deletions
diff --git a/include/sound/control.h b/include/sound/control.h index b2796e83c7ac..eff96dc7a278 100644 --- a/include/sound/control.h +++ b/include/sound/control.h @@ -227,6 +227,11 @@ snd_ctl_add_slave_uncached(struct snd_kcontrol *master, return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE); } +int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kctl, + void (*hook)(void *private_data, int), + void *private_data); +void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kctl); + /* * Helper functions for jack-detection controls */ diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c index 130cfe677d60..14a286a7bf2b 100644 --- a/sound/core/vmaster.c +++ b/sound/core/vmaster.c @@ -37,6 +37,8 @@ struct link_master { struct link_ctl_info info; int val; /* the master value */ unsigned int tlv[4]; + void (*hook)(void *private_data, int); + void *hook_private_data; }; /* @@ -126,7 +128,9 @@ static int master_init(struct link_master *master) master->info.count = 1; /* always mono */ /* set full volume as default (= no attenuation) */ master->val = master->info.max_val; - return 0; + if (master->hook) + master->hook(master->hook_private_data, master->val); + return 1; } return -ENOENT; } @@ -329,6 +333,8 @@ static int master_put(struct snd_kcontrol *kcontrol, slave_put_val(slave, uval); } kfree(uval); + if (master->hook && !err) + master->hook(master->hook_private_data, master->val); return 1; } @@ -408,3 +414,41 @@ struct snd_kcontrol *snd_ctl_make_virtual_master(char *name, return kctl; } EXPORT_SYMBOL(snd_ctl_make_virtual_master); + +/** + * snd_ctl_add_vmaster_hook - Add a hook to a vmaster control + * @kcontrol: vmaster kctl element + * @hook: the hook function + * + * Adds the given hook to the vmaster control element so that it's called + * at each time when the value is changed. + */ +int snd_ctl_add_vmaster_hook(struct snd_kcontrol *kcontrol, + void (*hook)(void *private_data, int), + void *private_data) +{ + struct link_master *master = snd_kcontrol_chip(kcontrol); + master->hook = hook; + master->hook_private_data = private_data; + return 0; +} +EXPORT_SYMBOL_GPL(snd_ctl_add_vmaster_hook); + +/** + * snd_ctl_sync_vmaster_hook - Sync the vmaster hook + * @kcontrol: vmaster kctl element + * + * Call the hook function to synchronize with the current value of the given + * vmaster element. NOP when NULL is passed to @kcontrol or the hook doesn't + * exist. + */ +void snd_ctl_sync_vmaster_hook(struct snd_kcontrol *kcontrol) +{ + struct link_master *master; + if (!kcontrol) + return; + master = snd_kcontrol_chip(kcontrol); + if (master->hook) + master->hook(master->hook_private_data, master->val); +} +EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster_hook); |