ASoC: Add virtual enumeration support for DAPM muxes

Sometimes it is desirable to have a mux which does not reflect any
direct register configuration but which will instead only have an
effect implicitly (for example, as a result of changing which parts
of the device are powered up). Provide a virtual mux for this purpose.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h
index 67224db..c5c95e1d 100644
--- a/include/sound/soc-dapm.h
+++ b/include/sound/soc-dapm.h
@@ -206,6 +206,12 @@
  	.get = snd_soc_dapm_get_enum_double, \
  	.put = snd_soc_dapm_put_enum_double, \
   	.private_value = (unsigned long)&xenum }
+#define SOC_DAPM_ENUM_VIRT(xname, xenum)		    \
+{	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, \
+	.info = snd_soc_info_enum_double, \
+	.get = snd_soc_dapm_get_enum_virt, \
+	.put = snd_soc_dapm_put_enum_virt, \
+	.private_value = (unsigned long)&xenum }
 #define SOC_DAPM_VALUE_ENUM(xname, xenum) \
 {	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, \
 	.info = snd_soc_info_enum_double, \
@@ -260,6 +266,10 @@
 	struct snd_ctl_elem_value *ucontrol);
 int snd_soc_dapm_put_enum_double(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
+int snd_soc_dapm_get_enum_virt(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol);
+int snd_soc_dapm_put_enum_virt(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol);
 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,