[ALSA] ice1724 - Add PCM Playback Switch to Revo 7.1

This patch adds the support of mute for front channels of M-Audio
Revolution 7.1 (the DAC AK4381 features a mute bit).

Signed-off-by: Pavel Hofman <dustin@seznam.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

3 files changed, 29 insertions, 3 deletions

diff --git a/include/sound/ak4xxx-adda.h b/include/sound/ak4xxx-adda.h
index aa49dda4f410..fd0a6c46f497 100644
--- a/include/sound/ak4xxx-adda.h
+++ b/include/sound/ak4xxx-adda.h
@@ -43,6 +43,7 @@ struct snd_ak4xxx_ops {
 struct snd_akm4xxx_dac_channel {
         char *name;             /* mixer volume name */
         unsigned int num_channels;
+        char *switch_name;              /* mixer switch*/
 };
 
 /* ADC labels and channels */
diff --git a/sound/i2c/other/ak4xxx-adda.c b/sound/i2c/other/ak4xxx-adda.c
index 8805110017a7..fd335159f849 100644
--- a/sound/i2c/other/ak4xxx-adda.c
+++ b/sound/i2c/other/ak4xxx-adda.c
@@ -481,8 +481,8 @@ static int ak4xxx_switch_get(struct snd_kcontrol *kcontrol,
         int addr = AK_GET_ADDR(kcontrol->private_value);
         int shift = AK_GET_SHIFT(kcontrol->private_value);
         int invert = AK_GET_INVERT(kcontrol->private_value);
-        unsigned char val = snd_akm4xxx_get(ak, chip, addr);
-
+        /* we observe the (1<<shift) bit only */
+        unsigned char val = snd_akm4xxx_get(ak, chip, addr) & (1<<shift);
         if (invert)
                 val = ! val;
         ucontrol->value.integer.value[0] = (val & (1<<shift)) != 0;
@@ -585,6 +585,26 @@ static int build_dac_controls(struct snd_akm4xxx *ak)
 
         mixer_ch = 0;
         for (idx = 0; idx < ak->num_dacs; ) {
+                /* mute control for Revolution 7.1 - AK4381 */
+                if (ak->type == SND_AK4381 
+                                &&  ak->dac_info[mixer_ch].switch_name) {
+                        memset(&knew, 0, sizeof(knew));
+                        knew.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+                        knew.count = 1;
+                        knew.access = SNDRV_CTL_ELEM_ACCESS_READWRITE;
+                        knew.name = ak->dac_info[mixer_ch].switch_name;
+                        knew.info = ak4xxx_switch_info;
+                        knew.get = ak4xxx_switch_get;
+                        knew.put = ak4xxx_switch_put;
+                        knew.access = 0;
+                        /* register 1, bit 0 (SMUTE): 0 = normal operation,
+                           1 = mute */
+                        knew.private_value =
+                                AK_COMPOSE(idx/2, 1, 0, 0) | AK_INVERT;
+                        err = snd_ctl_add(ak->card, snd_ctl_new1(&knew, ak));
+                        if (err < 0)
+                                return err;
+                }
                 memset(&knew, 0, sizeof(knew));
                 if (! ak->dac_info || ! ak->dac_info[mixer_ch].name) {
                         knew.name = "DAC Volume";
diff --git a/sound/pci/ice1712/revo.c b/sound/pci/ice1712/revo.c
index 690ceb340644..d18a31e188a9 100644
--- a/sound/pci/ice1712/revo.c
+++ b/sound/pci/ice1712/revo.c
@@ -186,7 +186,12 @@ static int revo51_i2c_init(struct snd_ice1712 *ice,
 #define AK_DAC(xname,xch) { .name = xname, .num_channels = xch }
 
 static const struct snd_akm4xxx_dac_channel revo71_front[] = {
-        AK_DAC("PCM Playback Volume", 2)
+        {
+                .name = "PCM Playback Volume",
+                .num_channels = 2,
+                /* front channels DAC supports muting */
+                .switch_name = "PCM Playback Switch",
+        },
 };
 
 static const struct snd_akm4xxx_dac_channel revo71_surround[] = {