ASoC: Add SND_SOC_DAPM_PIN_SWITCH controls for exposing DAPM pins

On some systems it is desirable for control for DAPM pins to be provided
to user space. This is the case with things like GSM modems which are
controlled primarily from user space, for example. Provide a helper which
exposes the state of a DAPM pin to user space for use in cases like this.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc-dapm.h

@@ -192,6 +192,12 @@
 	.get = snd_soc_dapm_get_value_enum_double, \
 	.put = snd_soc_dapm_put_value_enum_double, \
 	.private_value = (unsigned long)&xenum }
+#define SOC_DAPM_PIN_SWITCH(xname) \
+{	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname " Switch", \
+	.info = snd_soc_dapm_info_pin_switch, \
+	.get = snd_soc_dapm_get_pin_switch, \
+	.put = snd_soc_dapm_put_pin_switch, \
+	.private_value = (unsigned long)xname }
 
 /* dapm stream operations */
 #define SND_SOC_DAPM_STREAM_NOP			0x0
@@ -238,6 +244,12 @@ int snd_soc_dapm_get_value_enum_double(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
 int snd_soc_dapm_put_value_enum_double(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
+int snd_soc_dapm_info_pin_switch(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_info *uinfo);
+int snd_soc_dapm_get_pin_switch(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *uncontrol);
+int snd_soc_dapm_put_pin_switch(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *uncontrol);
 int snd_soc_dapm_new_control(struct snd_soc_codec *codec,
 	const struct snd_soc_dapm_widget *widget);
 int snd_soc_dapm_new_controls(struct snd_soc_codec *codec,

sound/soc/soc-dapm.c

@@ -1420,6 +1420,76 @@ out:
 }
 EXPORT_SYMBOL_GPL(snd_soc_dapm_put_value_enum_double);
 
+/**
+ * snd_soc_dapm_info_pin_switch - Info for a pin switch
+ *
+ * @kcontrol: mixer control
+ * @uinfo: control element information
+ *
+ * Callback to provide information about a pin switch control.
+ */
+int snd_soc_dapm_info_pin_switch(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dapm_info_pin_switch);
+
+/**
+ * snd_soc_dapm_get_pin_switch - Get information for a pin switch
+ *
+ * @kcontrol: mixer control
+ * @ucontrol: Value
+ */
+int snd_soc_dapm_get_pin_switch(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+	const char *pin = (const char *)kcontrol->private_value;
+
+	mutex_lock(&codec->mutex);
+
+	ucontrol->value.integer.value[0] =
+		snd_soc_dapm_get_pin_status(codec, pin);
+
+	mutex_unlock(&codec->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dapm_get_pin_switch);
+
+/**
+ * snd_soc_dapm_put_pin_switch - Set information for a pin switch
+ *
+ * @kcontrol: mixer control
+ * @ucontrol: Value
+ */
+int snd_soc_dapm_put_pin_switch(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+	const char *pin = (const char *)kcontrol->private_value;
+
+	mutex_lock(&codec->mutex);
+
+	if (ucontrol->value.integer.value[0])
+		snd_soc_dapm_enable_pin(codec, pin);
+	else
+		snd_soc_dapm_disable_pin(codec, pin);
+
+	snd_soc_dapm_sync(codec);
+
+	mutex_unlock(&codec->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dapm_put_pin_switch);
+
 /**
  * snd_soc_dapm_new_control - create new dapm control
  * @codec: audio codec