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ASoC: EDB93xx: Manage I2S rates according to datasheet for CS4271 CODEC. 

Manage I2S rates according to datasheet for CS4271 CODEC in EDB93xx
machine driver.

Signed-off-by: Alexander Sverdlin <subaparts@yandex.ru>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Alexander Sverdlin 2011-03-07 20:29:53 +03:00 committed by Mark Brown
parent 5c3a12e96c
commit 6d33cd771b
1 changed files with 8 additions and 8 deletions
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16
sound/soc/ep93xx/edb93xx.c
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@ -41,17 +41,17 @@ static int edb93xx_hw_params(struct snd_pcm_substream *substream,
struct snd_soc_dai *codec_dai = rtd->codec_dai;
struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
int err;
unsigned int mclk_rate;
unsigned int rate = params_rate(params);
/*
* We set LRCLK equal to `rate' and SCLK = LRCLK * 64,
* because our sample size is 32 bit * 2 channels.
* I2S standard permits us to transmit more bits than
* the codec uses.
* MCLK = SCLK * 4 is the best recommended value,
* but we have to fall back to ratio 2 for higher
* sample rates.
* According to CS4271 datasheet we use MCLK/LRCK=256 for
* rates below 50kHz and 128 for higher sample rates
*/
unsigned int mclk_rate = rate * 64 * ((rate <= 48000) ? 4 : 2);
if (rate < 50000)
mclk_rate = rate * 64 * 4;
else
mclk_rate = rate * 64 * 2;
err = snd_soc_dai_set_fmt(codec_dai, SND_SOC_DAIFMT_I2S |
SND_SOC_DAIFMT_NB_IF |