Re: [alsa-devel] [PATCH] cs4270: add support for slave mode configurations

On Wed, Feb 25, 2009 at 7:37 AM, Daniel Mack daniel@caiaq.de wrote:

Added support for scenarios where the Cirrus CS4270 audio codec is slave to the bitclk and lrclk. Mixed setups are unsupported.

Signed-off-by: Daniel Mack daniel@caiaq.de

FYI, it's customary to CC: the author of a driver when posting patches for it.

•   /* set master/slave audio interface */
  

•   switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
  

•   case SND_SOC_DAIFMT_CBS_CFS:
  

•           cs4270->slave_mode = 1;
  

•           break;
  

•   case SND_SOC_DAIFMT_CBM_CFM:
  

•           cs4270->slave_mode = 0;
  

•           break;
  

•   case SND_SOC_DAIFMT_CBM_CFS:
  

•           /* unsupported - cs4270 can eigther be slave or master to
  

Typo. However, I suggest you get rid of the "case SND_SOC_DAIFMT_CBM_CFS" and in the "default:", just have this:

•   default:
  

/* all other modes are unsupported by the hardware */

•           ret = -EINVAL;
  

•   }
  

   reg = snd_soc_read(codec, CS4270_MODE);
   reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);

•   reg |= cs4270_mode_ratios[i].speed_mode | cs4270_mode_ratios[i].mclk;
  

•   reg |= cs4270_mode_ratios[i].mclk;
  

•   if (cs4270->slave_mode)
  

•           reg |= CS4270_MODE_SLAVE;
  

•   else
  

•           reg |= cs4270_mode_ratios[i].speed_mode;
  

Are you sure that the mclk bits are still correct in slave mode? I'm looking at table 5 in the CS4270 manual, and it lists settings for 1x,2x,4x speed even though the register is set to slave mode instead.