ASoC: Add cs4270 support for slave mode configurations

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>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c
index cd4a9ee38e46..339e0f6b0fe2 100644
--- a/sound/soc/codecs/cs4270.c
+++ b/sound/soc/codecs/cs4270.c
@@ -109,6 +109,7 @@ struct cs4270_private {
         u8 reg_cache[CS4270_NUMREGS];
         unsigned int mclk; /* Input frequency of the MCLK pin */
         unsigned int mode; /* The mode (I2S or left-justified) */
+        unsigned int slave_mode;
 };
 
 /**
@@ -247,6 +248,7 @@ static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
         struct cs4270_private *cs4270 = codec->private_data;
         int ret = 0;
 
+        /* set DAI format */
         switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
         case SND_SOC_DAIFMT_I2S:
         case SND_SOC_DAIFMT_LEFT_J:
@@ -257,6 +259,21 @@ static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
                 ret = -EINVAL;
         }
 
+        /* 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
+                 * both the bitclk and the lrclk. */
+        default:
+                ret = -EINVAL;
+        }
+
         return ret;
 }
 
@@ -399,7 +416,12 @@ static int cs4270_hw_params(struct snd_pcm_substream *substream,
 
         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;
 
         ret = snd_soc_write(codec, CS4270_MODE, reg);
         if (ret < 0) {