1 files changed, 31 insertions, 0 deletions

diff --git a/sound/core/vmaster.c b/sound/core/vmaster.c
index 6c58e6f73a01..e43af18d4383 100644
--- 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);