ASoC: wm8523: Set bclk ratio for master mode

When running in master mode the bclk divider must be configured to generate a
sane bitclock. Pick the smallest fs multiplicator, which can hold all
transmitted bits.

Signed-off-by: Julian Scheel <julian@jusst.de>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8523.c b/sound/soc/codecs/wm8523.c
index b1cc94f5fc4b..f9dffd2d5eea 100644
--- a/sound/soc/codecs/wm8523.c
+++ b/sound/soc/codecs/wm8523.c
@@ -113,6 +113,15 @@ static struct {
         { 7, 1152 },
 };
 
+static struct {
+        int value;
+        int ratio;
+} bclk_ratios[WM8523_NUM_RATES] = {
+        { 2, 32 },
+        { 3, 64 },
+        { 4, 128 },
+};
+
 static int wm8523_startup(struct snd_pcm_substream *substream,
                           struct snd_soc_dai *dai)
 {
@@ -162,6 +171,23 @@ static int wm8523_hw_params(struct snd_pcm_substream *substream,
         aifctrl2 &= ~WM8523_SR_MASK;
         aifctrl2 |= lrclk_ratios[i].value;
 
+        if (aifctrl1 & WM8523_AIF_MSTR) {
+                /* Find a fs->bclk ratio */
+                for (i = 0; i < ARRAY_SIZE(bclk_ratios); i++)
+                        if (params_width(params) * 2 <= bclk_ratios[i].ratio)
+                                break;
+
+                if (i == ARRAY_SIZE(bclk_ratios)) {
+                        dev_err(codec->dev,
+                                "No matching BCLK/fs ratio for word length %d\n",
+                                params_width(params));
+                        return -EINVAL;
+                }
+
+                aifctrl2 &= ~WM8523_BCLKDIV_MASK;
+                aifctrl2 |= bclk_ratios[i].value << WM8523_BCLKDIV_SHIFT;
+        }
+
         aifctrl1 &= ~WM8523_WL_MASK;
         switch (params_width(params)) {
         case 16: