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

On Mon, May 11, 2015 at 11:12:00AM +0200, Sergej Sawazki wrote:

On 11.05.2015 at 10:12, Charles Keepax wrote:

...

On Tue, May 05, 2015 at 10:46:31PM +0200, Sergej Sawazki wrote:

...

+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.
  

•  */
  

Would it not be better to add controls but with a channel neutral name and then the machine driver can use the name_prefix stuff to stick left and right onto them? Seems a bit odd for the machine driver to have to know exact register details of the CODEC and manually add the volume controls?

Thanks, Charles

Charles, could you point me to an "name_prefix" example please?

Thanks, Sergej

The wm9081's handling in sound/soc/samsung/bells.c would be a reasonable example.

Thanks, Charles