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

[Sergej Sawazki <ce3a@gmx.de>]

On 05.05.2015 22:46, Sergej Sawazki wrote:
> 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
>

Gentle ping.

Best regards,
Sergej