ASoC: arizona: Allow number of channels clocked to be restricted

Place a cap on the number of channels clocks are generated for. This is
intended for use with systems which have the WM5102 master an I2S bus with
multiple data lines.

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

1 files changed, 12 insertions, 2 deletions

diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 845d25630ba2..d855a6c098d4 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -762,18 +762,28 @@ static int arizona_hw_params(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
 {
         struct snd_soc_codec *codec = dai->codec;
+        struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+        struct arizona *arizona = priv->arizona;
         int base = dai->driver->base;
         const int *rates;
         int i, ret;
-        int bclk, lrclk, wl, frame;
+        int chan_limit = arizona->pdata.max_channels_clocked[dai->id - 1];
+        int bclk, lrclk, wl, frame, bclk_target;
 
         if (params_rate(params) % 8000)
                 rates = &arizona_44k1_bclk_rates[0];
         else
                 rates = &arizona_48k_bclk_rates[0];
 
+        bclk_target = snd_soc_params_to_bclk(params);
+        if (chan_limit && chan_limit < params_channels(params)) {
+                arizona_aif_dbg(dai, "Limiting to %d channels\n", chan_limit);
+                bclk_target /= params_channels(params);
+                bclk_target *= chan_limit;
+        }
+
         for (i = 0; i < ARRAY_SIZE(arizona_44k1_bclk_rates); i++) {
-                if (rates[i] >= snd_soc_params_to_bclk(params) &&
+                if (rates[i] >= bclk_target &&
                     rates[i] % params_rate(params) == 0) {
                         bclk = i;
                         break;