[PATCH 02/10] ASoC: soc-component: Add notify control helper function

[Charles Keepax <ckeepax@opensource.cirrus.com>]

Add a function to allow ASoC drivers to easily notify an ALSA control
change. This function will automatically add any component naming
prefix into the control name.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---
 include/sound/soc-component.h |  4 ++++
 sound/soc/soc-component.c     | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/sound/soc-component.h b/include/sound/soc-component.h
index 0814ed1438640..0b47603c9db29 100644
--- a/include/sound/soc-component.h
+++ b/include/sound/soc-component.h
@@ -454,6 +454,10 @@ int snd_soc_component_force_enable_pin_unlocked(
 	struct snd_soc_component *component,
 	const char *pin);
 
+/* component controls */
+int snd_soc_component_notify_control(struct snd_soc_component *component,
+				     const char * const ctl);
+
 /* component driver ops */
 int snd_soc_component_open(struct snd_soc_component *component,
 			   struct snd_pcm_substream *substream);
diff --git a/sound/soc/soc-component.c b/sound/soc/soc-component.c
index ff25718ff2e88..4356cc320fea0 100644
--- a/sound/soc/soc-component.c
+++ b/sound/soc/soc-component.c
@@ -236,6 +236,28 @@ int snd_soc_component_force_enable_pin_unlocked(
 }
 EXPORT_SYMBOL_GPL(snd_soc_component_force_enable_pin_unlocked);
 
+int snd_soc_component_notify_control(struct snd_soc_component *component,
+				     const char * const ctl)
+{
+	char name[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	struct snd_kcontrol *kctl;
+
+	if (component->name_prefix)
+		snprintf(name, ARRAY_SIZE(name), "%s %s", component->name_prefix, ctl);
+	else
+		snprintf(name, ARRAY_SIZE(name), "%s", ctl);
+
+	kctl = snd_soc_card_get_kcontrol(component->card, name);
+	if (!kctl)
+		return soc_component_ret(component, -EINVAL);
+
+	snd_ctl_notify(component->card->snd_card,
+		       SNDRV_CTL_EVENT_MASK_VALUE, &kctl->id);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_notify_control);
+
 /**
  * snd_soc_component_set_jack - configure component jack.
  * @component: COMPONENTs
-- 
2.30.2