ASoC: tpa6130a2: Support for limiting gain

Add support for platform dependent gain limiting on the
tpa6130a2 (and tpa6140a2) Headset amplifier.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

2 files changed, 69 insertions, 8 deletions

diff --git a/include/sound/tpa6130a2-plat.h b/include/sound/tpa6130a2-plat.h
index e29fde6b5cbe..426f62767dab 100644
--- a/include/sound/tpa6130a2-plat.h
+++ b/include/sound/tpa6130a2-plat.h
@@ -31,6 +31,7 @@ enum tpa_model {
 struct tpa6130a2_platform_data {
         enum tpa_model id;
         int power_gpio;
+        int limit_gain;
 };
 
 #endif
diff --git a/sound/soc/codecs/tpa6130a2.c b/sound/soc/codecs/tpa6130a2.c
index 0cf3e3862e7b..31f67b527ca1 100644
--- a/sound/soc/codecs/tpa6130a2.c
+++ b/sound/soc/codecs/tpa6130a2.c
@@ -46,6 +46,9 @@ static const char *tpa6140a2_supply_names[TPA6130A2_NUM_SUPPLIES] = {
         "AVdd",
 };
 
+#define TPA6130A2_GAIN_MAX      0x3f
+#define TPA6140A2_GAIN_MAX      0x1f
+
 /* This struct is used to save the context */
 struct tpa6130a2_data {
         struct mutex mutex;
@@ -54,6 +57,7 @@ struct tpa6130a2_data {
         int power_gpio;
         unsigned char power_state;
         enum tpa_model id;
+        int gain_limit;
 };
 
 static int tpa6130a2_i2c_read(int reg)
@@ -176,6 +180,40 @@ exit:
         return ret;
 }
 
+static int tpa6130a2_info_volsw(struct snd_kcontrol *kcontrol,
+                struct snd_ctl_elem_info *uinfo)
+{
+        struct soc_mixer_control *mc =
+                (struct soc_mixer_control *)kcontrol->private_value;
+        struct tpa6130a2_data *data;
+
+        BUG_ON(tpa6130a2_client == NULL);
+        data = i2c_get_clientdata(tpa6130a2_client);
+
+        mutex_lock(&data->mutex);
+        switch (mc->reg) {
+        case TPA6130A2_REG_VOL_MUTE:
+                if (data->gain_limit != mc->max)
+                        mc->max = data->gain_limit;
+                break;
+        default:
+                dev_err(&tpa6130a2_client->dev,
+                        "Invalid register: 0x02%x\n", mc->reg);
+                goto out;
+        }
+        if (unlikely(mc->max == 1))
+                uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+        else
+                uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+
+        uinfo->count = 1;
+        uinfo->value.integer.min = 0;
+        uinfo->value.integer.max = mc->max;
+out:
+        mutex_unlock(&data->mutex);
+        return 0;
+}
+
 static int tpa6130a2_get_reg(struct snd_kcontrol *kcontrol,
                 struct snd_ctl_elem_value *ucontrol)
 {
@@ -239,6 +277,15 @@ static int tpa6130a2_set_reg(struct snd_kcontrol *kcontrol,
         return 1;
 }
 
+#define SOC_SINGLE_EXT_TLV_TPA(xname, xreg, xshift, xmax, xinvert, tlv_array) \
+{       .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = xname, \
+        .access = SNDRV_CTL_ELEM_ACCESS_TLV_READ |\
+                 SNDRV_CTL_ELEM_ACCESS_READWRITE,\
+        .tlv.p = (tlv_array), \
+        .info = tpa6130a2_info_volsw, \
+        .get = tpa6130a2_get_reg, .put = tpa6130a2_set_reg, \
+        .private_value = SOC_SINGLE_VALUE(xreg, xshift, xmax, xinvert) }
+
 /*
  * TPA6130 volume. From -59.5 to 4 dB with increasing step size when going
  * down in gain.
@@ -258,10 +305,9 @@ static const unsigned int tpa6130_tlv[] = {
 };
 
 static const struct snd_kcontrol_new tpa6130a2_controls[] = {
-        SOC_SINGLE_EXT_TLV("TPA6130A2 Headphone Playback Volume",
-                       TPA6130A2_REG_VOL_MUTE, 0, 0x3f, 0,
-                       tpa6130a2_get_reg, tpa6130a2_set_reg,
-                       tpa6130_tlv),
+        SOC_SINGLE_EXT_TLV_TPA("TPA6130A2 Headphone Playback Volume",
+                        TPA6130A2_REG_VOL_MUTE, 0, TPA6130A2_GAIN_MAX, 0,
+                        tpa6130_tlv),
 };
 
 static const unsigned int tpa6140_tlv[] = {
@@ -272,10 +318,9 @@ static const unsigned int tpa6140_tlv[] = {
 };
 
 static const struct snd_kcontrol_new tpa6140a2_controls[] = {
-        SOC_SINGLE_EXT_TLV("TPA6140A2 Headphone Playback Volume",
-                       TPA6130A2_REG_VOL_MUTE, 1, 0x1f, 0,
-                       tpa6130a2_get_reg, tpa6130a2_set_reg,
-                       tpa6140_tlv),
+        SOC_SINGLE_EXT_TLV_TPA("TPA6140A2 Headphone Playback Volume",
+                        TPA6130A2_REG_VOL_MUTE, 1, TPA6140A2_GAIN_MAX, 0,
+                        tpa6140_tlv),
 };
 
 /*
@@ -454,16 +499,31 @@ static int __devinit tpa6130a2_probe(struct i2c_client *client,
         case TPA6130A2:
                 for (i = 0; i < ARRAY_SIZE(data->supplies); i++)
                         data->supplies[i].supply = tpa6130a2_supply_names[i];
+                if (pdata->limit_gain > 0 &&
+                    pdata->limit_gain < TPA6130A2_GAIN_MAX)
+                        data->gain_limit = pdata->limit_gain;
+                else
+                        data->gain_limit = TPA6130A2_GAIN_MAX;
                 break;
         case TPA6140A2:
                 for (i = 0; i < ARRAY_SIZE(data->supplies); i++)
                         data->supplies[i].supply = tpa6140a2_supply_names[i];;
+                if (pdata->limit_gain > 0 &&
+                    pdata->limit_gain < TPA6140A2_GAIN_MAX)
+                        data->gain_limit = pdata->limit_gain;
+                else
+                        data->gain_limit = TPA6140A2_GAIN_MAX;
                 break;
         default:
                 dev_warn(dev, "Unknown TPA model (%d). Assuming 6130A2\n",
                          pdata->id);
                 for (i = 0; i < ARRAY_SIZE(data->supplies); i++)
                         data->supplies[i].supply = tpa6130a2_supply_names[i];
+                if (pdata->limit_gain > 0 &&
+                    pdata->limit_gain < TPA6130A2_GAIN_MAX)
+                        data->gain_limit = pdata->limit_gain;
+                else
+                        data->gain_limit = TPA6130A2_GAIN_MAX;
         }
 
         ret = regulator_bulk_get(dev, ARRAY_SIZE(data->supplies),