Re: [alsa-devel] [RFC PATCH 1/1] ASoC: dsd1791: Introduce driver for TI DSD1791 stereo codec

On 12/15/2011 12:40 AM, Michael Williamson wrote:

This patch introduces a (spi) codec driver for the Texas Instruments DSD1791 24 bit audio stereo DAC.

Testing for basic operation using 16 and 24 bit I2S mode has been performed.

http://www.ti.com/product/dsd1791

Signed-off-by: Michael Williamson michael.williamson@criticallink.com

[...]

+static int dsd1791_hw_params(struct snd_pcm_substream *substream,

• 	     struct snd_pcm_hw_params *params,
  

• 	     struct snd_soc_dai *dai)
  

+{

• struct snd_soc_pcm_runtime *rtd = substream->private_data;
• struct snd_soc_codec *codec = rtd->codec;
• struct dsd1791 *dsd1791 = snd_soc_codec_get_drvdata(codec);
• switch (params_format(params)) {
• case SNDRV_PCM_FORMAT_S16_LE:

• dsd1791->pcm_fmt = DSD1971_FORMAT_S16_LE;
  

• break;
  

• case SNDRV_PCM_FORMAT_S24_LE:

• dsd1791->pcm_fmt = DSD1971_FORMAT_S24_LE;
  

• break;
  

There is really no need to add your own constants here. Just reuse the SNDRV_PCM_FORMAT constants and assign params_format(params) directly to dsd1791->pcm_fmt.

• default:

• dev_dbg(&dsd1791->spi->dev, "bad format\n");
  

• return -EINVAL;
  

• }
• return dsd1791_set_format_word(dsd1791, codec);

+}

[...] +static int dsd1791_set_fmt(struct snd_soc_dai *codec_dai,

• 	     unsigned int fmt)
  

+{

• struct snd_soc_codec *codec = codec_dai->codec;
• struct dsd1791 *dsd1791 = snd_soc_codec_get_drvdata(codec);
• switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
• case SND_SOC_DAIFMT_I2S:

• dsd1791->dai_fmt = DSD1791_DAIFMT_I2S;
  

• break;
  

• case SND_SOC_DAIFMT_RIGHT_J:

• dsd1791->dai_fmt = DSD1791_DAIFMT_RIGHT_J;
  

• break;
  

• case SND_SOC_DAIFMT_LEFT_J:

• dsd1791->dai_fmt = DSD1791_DAIFMT_LEFT_J;
  

• break;
  

Same here for the SND_SOC_DAIFMT constants.

• default:

• dev_dbg(&dsd1791->spi->dev, "bad format\n");
  

• return -EINVAL;
  

• }
• return dsd1791_set_format_word(dsd1791, codec);

+}

+#define DSD1791_RATES SNDRV_PCM_RATE_8000_192000 +#define DSD1791_FORMATS (SNDRV_PCM_FMTBIT_S16_LE |\

• 	 SNDRV_PCM_FMTBIT_S24_LE)
  

+static struct snd_soc_dai_ops dsd1791_dai_ops = {

const

• .hw_params = dsd1791_hw_params,
• .set_sysclk = dsd1791_set_sysclk,
• .set_fmt = dsd1791_set_fmt,

+};

[...]

+struct snd_soc_codec_driver dsd1791_soc_codec_dev = {

static, and maybe rename it to dsd1719_codec_driver. The "_soc_codec_dev" suffix which you can see in other drivers in from old times, where this used to be a struct snd_soc_codec_device.

• .probe = dsd1791_probe,
• .read = dsd1791_read,
• .write = dsd1791_write,
• .reg_word_size = sizeof(u8),

+};

+static int dsd1791_spi_probe(struct spi_device *spi)

__devinit

+{ [...]

+static int dsd1791_spi_remove(struct spi_device *spi)

__devexit

+{ [...] +}

+static struct spi_driver dsd1791_spi = {

• .driver = {

• .name = "dsd1791-codec",
  

• .owner = THIS_MODULE,
  

• },
• .probe = dsd1791_spi_probe,
• .remove = dsd1791_spi_remove,

__devexit_p

+};