Merge remote-tracking branch 'asoc/topic/pcm512x' into asoc-next

[sfrench/cifs-2.6.git] / sound / core / vmaster.c

diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 6c58e6f73a013bd33e47cc9a7ea8c1b46b7f17df..e43af18d43836367e263356eb2377cc4e08e8368 100644 (file)
--- a/sound/core/vmaster.c
+++ b/sound/core/vmaster.c
@@ -484,3 +484,34 @@ void snd_ctl_sync_vmaster(struct snd_kcontrol *kcontrol, bool hook_only)
                master->hook(master->hook_private_data, master->val);
 }
 EXPORT_SYMBOL_GPL(snd_ctl_sync_vmaster);
+
+/**
+ * snd_ctl_apply_vmaster_slaves - Apply function to each vmaster slave
+ * @kctl: vmaster kctl element
+ * @func: function to apply
+ * @arg: optional function argument
+ *
+ * Apply the function @func to each slave kctl of the given vmaster kctl.
+ * Returns 0 if successful, or a negative error code.
+ */
+int snd_ctl_apply_vmaster_slaves(struct snd_kcontrol *kctl,
+                                int (*func)(struct snd_kcontrol *, void *),
+                                void *arg)
+{
+       struct link_master *master;
+       struct link_slave *slave;
+       int err;
+
+       master = snd_kcontrol_chip(kctl);
+       err = master_init(master);
+       if (err < 0)
+               return err;
+       list_for_each_entry(slave, &master->slaves, list) {
+               err = func(&slave->slave, arg);
+               if (err < 0)
+                       return err;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(snd_ctl_apply_vmaster_slaves);