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authorMark Brown <broonie@opensource.wolfsonmicro.com>2013-03-20 10:12:10 +0100
committerMark Brown <broonie@opensource.wolfsonmicro.com>2013-03-21 17:27:32 +0100
commit3cf956eebe54cdb7cf1701642085507f0354e56a (patch)
treed89eaea525d68b6ed17b8802f62ac44886c6c694 /sound/soc/codecs/wm8994.c
parenta937536b868b8369b98967929045f1df54234323 (diff)
ASoC: wm8994: Support constraining the maximum number of channels clocked
Some systems use the audio CODEC to clock a DAI with multiple data lines in parallel, meaning that bit clocks are only required for a smaller number of channels than data is sent for. In some cases providing the extra bit clocks can take the other devices on the audio bus out of spec. Support such systems by allowing a maximum number of channels to be specified. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound/soc/codecs/wm8994.c')
-rw-r--r--sound/soc/codecs/wm8994.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c
index c9bd445c497..318ea64b980 100644
--- a/sound/soc/codecs/wm8994.c
+++ b/sound/soc/codecs/wm8994.c
@@ -2656,6 +2656,8 @@ static int wm8994_hw_params(struct snd_pcm_substream *substream,
{
struct snd_soc_codec *codec = dai->codec;
struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
+ struct wm8994 *control = wm8994->wm8994;
+ struct wm8994_pdata *pdata = &control->pdata;
int aif1_reg;
int aif2_reg;
int bclk_reg;
@@ -2723,7 +2725,14 @@ static int wm8994_hw_params(struct snd_pcm_substream *substream,
}
wm8994->channels[id] = params_channels(params);
- switch (params_channels(params)) {
+ if (pdata->max_channels_clocked[id] &&
+ wm8994->channels[id] > pdata->max_channels_clocked[id]) {
+ dev_dbg(dai->dev, "Constraining channels to %d from %d\n",
+ pdata->max_channels_clocked[id], wm8994->channels[id]);
+ wm8994->channels[id] = pdata->max_channels_clocked[id];
+ }
+
+ switch (wm8994->channels[id]) {
case 1:
case 2:
bclk_rate *= 2;
@@ -2745,7 +2754,7 @@ static int wm8994_hw_params(struct snd_pcm_substream *substream,
dev_dbg(dai->dev, "AIF%dCLK is %dHz, target BCLK %dHz\n",
dai->id, wm8994->aifclk[id], bclk_rate);
- if (params_channels(params) == 1 &&
+ if (wm8994->channels[id] == 1 &&
(snd_soc_read(codec, aif1_reg) & 0x18) == 0x18)
aif2 |= WM8994_AIF1_MONO;