[PATCH v2] ASoC: wm8741: Add differential mono mode support

Sergej Sawazki
2015-05-05T20:47:10Z

The WM8741 DAC supports several differential output modes (stereo,
stereo reversed, mono left, mono right). Add platform data and DT
bindings to configure it.

Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
---
Documentation/devicetree/bindings/sound/wm8741.txt | 11 +++
sound/soc/codecs/wm8741.c | 108 ++++++++++++++++++---
sound/soc/codecs/wm8741.h | 10 ++
3 files changed, 117 insertions(+), 12 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/wm8741.txt b/Documentation/devicetree/bindings/sound/wm8741.txt
index 74bda58..a133154 100644
--- a/Documentation/devicetree/bindings/sound/wm8741.txt
+++ b/Documentation/devicetree/bindings/sound/wm8741.txt
@@ -10,9 +10,20 @@ Required properties:
- reg : the I2C address of the device for I2C, the chip select
number for SPI.

+Optional properties:
+
+ - diff-mode: Differential output mode configuration. Default value for field
+ DIFF in register R8 (MODE_CONTROL_2). If absent, the default is 0, shall be:
+ 0 = stereo
+ 1 = mono left
+ 2 = stereo reversed
+ 3 = mono right
+
Example:

codec: wm8741@1a {
compatible = "wlf,wm8741";
reg = <0x1a>;
+
+ diff-mode = <3>;
};
diff --git a/sound/soc/codecs/wm8741.c b/sound/soc/codecs/wm8741.c
index 9e71c76..cbf90ab 100644
--- a/sound/soc/codecs/wm8741.c
+++ b/sound/soc/codecs/wm8741.c
@@ -41,6 +41,7 @@ static const char *wm8741_supply_names[WM8741_NUM_SUPPLIES] = {

/* codec private data */
struct wm8741_priv {
+ struct wm8741_platform_data pdata;
struct regmap *regmap;
struct regulator_bulk_data supplies[WM8741_NUM_SUPPLIES];
unsigned int sysclk;
@@ -398,7 +399,7 @@ static struct snd_soc_dai_driver wm8741_dai = {
.name = "wm8741",
.playback = {
.stream_name = "Playback",
- .channels_min = 2, /* Mono modes not yet supported */
+ .channels_min = 2,
.channels_max = 2,
.rates = WM8741_RATES,
.formats = WM8741_FORMATS,
@@ -416,6 +417,60 @@ static int wm8741_resume(struct snd_soc_codec *codec)
#define wm8741_resume NULL
#endif

+static int wm8741_configure(struct snd_soc_codec *codec)
+{
+ struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec);
+
+ /* Configure differential mode */
+ switch (wm8741->pdata.diff_mode) {
+ case WM8741_DIFF_MODE_STEREO:
+ case WM8741_DIFF_MODE_STEREO_REVERSED:
+ case WM8741_DIFF_MODE_MONO_LEFT:
+ case WM8741_DIFF_MODE_MONO_RIGHT:
+ snd_soc_update_bits(codec, WM8741_MODE_CONTROL_2,
+ WM8741_DIFF_MASK,
+ wm8741->pdata.diff_mode << WM8741_DIFF_SHIFT);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Change some default settings - latch VU */
+ snd_soc_update_bits(codec, WM8741_DACLLSB_ATTENUATION,
+ WM8741_UPDATELL, WM8741_UPDATELL);
+ snd_soc_update_bits(codec, WM8741_DACLMSB_ATTENUATION,
+ WM8741_UPDATELM, WM8741_UPDATELM);
+ snd_soc_update_bits(codec, WM8741_DACRLSB_ATTENUATION,
+ WM8741_UPDATERL, WM8741_UPDATERL);
+ snd_soc_update_bits(codec, WM8741_DACRMSB_ATTENUATION,
+ WM8741_UPDATERM, WM8741_UPDATERM);
+
+ return 0;
+}
+
+static int wm8741_add_controls(struct snd_soc_codec *codec)
+{
+ struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec);
+
+ switch (wm8741->pdata.diff_mode) {
+ case WM8741_DIFF_MODE_STEREO:
+ case WM8741_DIFF_MODE_STEREO_REVERSED:
+ snd_soc_add_codec_controls(codec, wm8741_snd_controls,
+ ARRAY_SIZE(wm8741_snd_controls));
+ break;
+ case WM8741_DIFF_MODE_MONO_LEFT:
+ case WM8741_DIFF_MODE_MONO_RIGHT:
+ /* The machine driver is responsible for mixer controls
+ * if the codec is configured in differential mono mode.
+ */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int wm8741_probe(struct snd_soc_codec *codec)
{
struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec);
@@ -434,15 +489,17 @@ static int wm8741_probe(struct snd_soc_codec *codec)
goto err_enable;
}

- /* Change some default settings - latch VU */
- snd_soc_update_bits(codec, WM8741_DACLLSB_ATTENUATION,
- WM8741_UPDATELL, WM8741_UPDATELL);
- snd_soc_update_bits(codec, WM8741_DACLMSB_ATTENUATION,
- WM8741_UPDATELM, WM8741_UPDATELM);
- snd_soc_update_bits(codec, WM8741_DACRLSB_ATTENUATION,
- WM8741_UPDATERL, WM8741_UPDATERL);
- snd_soc_update_bits(codec, WM8741_DACRMSB_ATTENUATION,
- WM8741_UPDATERM, WM8741_UPDATERM);
+ ret = wm8741_configure(codec);
+ if (ret < 0) {
+ dev_err(codec->dev, "Failed to change default settings\n");
+ goto err_enable;
+ }
+
+ ret = wm8741_add_controls(codec);
+ if (ret < 0) {
+ dev_err(codec->dev, "Failed to add controls\n");
+ goto err_enable;
+ }

dev_dbg(codec->dev, "Successful registration\n");
return ret;
@@ -467,8 +524,6 @@ static struct snd_soc_codec_driver soc_codec_dev_wm8741 = {
.remove = wm8741_remove,
.resume = wm8741_resume,

- .controls = wm8741_snd_controls,
- .num_controls = ARRAY_SIZE(wm8741_snd_controls),
.dapm_widgets = wm8741_dapm_widgets,
.num_dapm_widgets = ARRAY_SIZE(wm8741_dapm_widgets),
.dapm_routes = wm8741_dapm_routes,
@@ -493,6 +548,23 @@ static const struct regmap_config wm8741_regmap = {
.readable_reg = wm8741_readable,
};

+static int wm8741_set_pdata(struct device *dev, struct wm8741_priv *wm8741)
+{
+ const struct wm8741_platform_data *pdata = dev_get_platdata(dev);
+ u32 diff_mode;
+
+ if (dev->of_node) {
+ if (of_property_read_u32(dev->of_node, "diff-mode", &diff_mode)
+ >= 0)
+ wm8741->pdata.diff_mode = diff_mode;
+ } else {
+ if (pdata != NULL)
+ memcpy(&wm8741->pdata, pdata, sizeof(wm8741->pdata));
+ }
+
+ return 0;
+}
+
#if IS_ENABLED(CONFIG_I2C)
static int wm8741_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
@@ -522,6 +594,12 @@ static int wm8741_i2c_probe(struct i2c_client *i2c,
return ret;
}

+ wm8741_set_pdata(&i2c->dev, wm8741);
+ if (ret != 0) {
+ dev_err(&i2c->dev, "Failed to set pdata: %d\n", ret);
+ return ret;
+ }
+
i2c_set_clientdata(i2c, wm8741);

ret = snd_soc_register_codec(&i2c->dev,
@@ -582,6 +660,12 @@ static int wm8741_spi_probe(struct spi_device *spi)
return ret;
}

+ wm8741_set_pdata(&spi->dev, wm8741);
+ if (ret != 0) {
+ dev_err(&spi->dev, "Failed to set pdata: %d\n", ret);
+ return ret;
+ }
+
spi_set_drvdata(spi, wm8741);

ret = snd_soc_register_codec(&spi->dev,
diff --git a/sound/soc/codecs/wm8741.h b/sound/soc/codecs/wm8741.h
index 56c1b1d..c8835f6 100644
--- a/sound/soc/codecs/wm8741.h
+++ b/sound/soc/codecs/wm8741.h
@@ -194,6 +194,12 @@
#define WM8741_DITHER_SHIFT 0 /* DITHER - [1:0] */
#define WM8741_DITHER_WIDTH 2 /* DITHER - [1:0] */

+/* DIFF field values */
+#define WM8741_DIFF_MODE_STEREO 0 /* stereo normal */
+#define WM8741_DIFF_MODE_STEREO_REVERSED 2 /* stereo reversed */
+#define WM8741_DIFF_MODE_MONO_LEFT 1 /* mono left */
+#define WM8741_DIFF_MODE_MONO_RIGHT 3 /* mono right */
+
/*
* R32 (0x20) - ADDITONAL_CONTROL_1
*/
@@ -208,4 +214,8 @@

#define WM8741_SYSCLK 0

+struct wm8741_platform_data {
+ u32 diff_mode; /* Differential Output Mode */
+};
+
#endif
--
1.9.1