DaVinci does not support true I2S or right justified mode so not all I2S codecs will work with it when the codec is master. Document this limitation.
Signed-off-by: Troy Kisky troy.kisky@boundarydevices.com
diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c index c425c86..735ec86 100644 --- a/sound/soc/davinci/davinci-i2s.c +++ b/sound/soc/davinci/davinci-i2s.c @@ -241,9 +241,26 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai, rcr = DAVINCI_MCBSP_RCR_RFRLEN1(1); xcr = DAVINCI_MCBSP_XCR_XFIG | DAVINCI_MCBSP_XCR_XFRLEN1(1); switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) { - case SND_SOC_DAIFMT_RIGHT_J: + case SND_SOC_DAIFMT_DSP_A: break; case SND_SOC_DAIFMT_I2S: + /* Davinci doesn't support TRUE I2S, but some codecs will have + * the left and right channels contiguous. This allows + * dsp_b mode to be used with an inverted normal frame clk. + * If your codec is master and does not have contiguous + * channels, then you will have sound on only one channel. + * Try using a different mode, or codec as slave. + * + * The TLV320AIC33 is an example of a codec where this works. + * It has a variable bit clock frequency allowing it to have + * valid data on every bit clock. + * + * The TLV320AIC23 is an example of a codec where this does not + * work. It has a fixed bit clock frequency with progressively + * more empty bit clock slots between channels as the sample + * rate is lowered. + */ + fmt ^= SND_SOC_DAIFMT_NB_IF; case SND_SOC_DAIFMT_DSP_B: rcr |= DAVINCI_MCBSP_RCR_RDATDLY(1); xcr |= DAVINCI_MCBSP_XCR_XDATDLY(1);