ASoC: soc-dapm: Introduce the new snd_soc_dapm_virt_mux type

This new type is a virtual version of snd_soc_dapm_mux.  It is used
when a backing register value is not necessary for deciding which
input path to connect.  A simple virtual enumeration control e.g.
SOC_DAPM_ENUM_VIRT() can be exposed to userspace which will be used
to choose which path to connect.

The snd_soc_dapm_virt_mux type ensures that during the initial
path setup, the first (which is also the default) input path will
be connected.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 1debc3b05665..50f5c785cb61 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -56,6 +56,7 @@ static int dapm_up_seq[] = {
         [snd_soc_dapm_aif_out] = 3,
         [snd_soc_dapm_mic] = 4,
         [snd_soc_dapm_mux] = 5,
+        [snd_soc_dapm_virt_mux] = 5,
         [snd_soc_dapm_value_mux] = 5,
         [snd_soc_dapm_dac] = 6,
         [snd_soc_dapm_mixer] = 7,
@@ -81,6 +82,7 @@ static int dapm_down_seq[] = {
         [snd_soc_dapm_mic] = 7,
         [snd_soc_dapm_micbias] = 8,
         [snd_soc_dapm_mux] = 9,
+        [snd_soc_dapm_virt_mux] = 9,
         [snd_soc_dapm_value_mux] = 9,
         [snd_soc_dapm_aif_in] = 10,
         [snd_soc_dapm_aif_out] = 10,
@@ -216,6 +218,20 @@ static void dapm_set_path_status(struct snd_soc_dapm_widget *w,
                 }
         }
         break;
+        case snd_soc_dapm_virt_mux: {
+                struct soc_enum *e = (struct soc_enum *)w->kcontrols[i].private_value;
+
+                p->connect = 0;
+                /* since a virtual mux has no backing registers to
+                 * decide which path to connect, it will try to match
+                 * with the first enumeration.  This is to ensure
+                 * that the default mux choice (the first) will be
+                 * correctly powered up during initialization.
+                 */
+                if (!strcmp(p->name, e->texts[0]))
+                        p->connect = 1;
+        }
+        break;
         case snd_soc_dapm_value_mux: {
                 struct soc_enum *e = (struct soc_enum *)
                         w->kcontrols[i].private_value;
@@ -1228,6 +1244,7 @@ static int dapm_mux_update_power(struct snd_soc_dapm_widget *widget,
         int found = 0;
 
         if (widget->id != snd_soc_dapm_mux &&
+            widget->id != snd_soc_dapm_virt_mux &&
             widget->id != snd_soc_dapm_value_mux)
                 return -ENODEV;
 
@@ -1534,6 +1551,7 @@ static int snd_soc_dapm_add_route(struct snd_soc_dapm_context *dapm,
                 path->connect = 1;
                 return 0;
         case snd_soc_dapm_mux:
+        case snd_soc_dapm_virt_mux:
         case snd_soc_dapm_value_mux:
                 ret = dapm_connect_mux(dapm, wsource, wsink, path, control,
                         &wsink->kcontrols[0]);
@@ -1623,6 +1641,7 @@ int snd_soc_dapm_new_widgets(struct snd_soc_dapm_context *dapm)
                         dapm_new_mixer(dapm, w);
                         break;
                 case snd_soc_dapm_mux:
+                case snd_soc_dapm_virt_mux:
                 case snd_soc_dapm_value_mux:
                         w->power_check = dapm_generic_check_power;
                         dapm_new_mux(dapm, w);