On 03.06.2019 13:19, Willem Romkes wrote: > > * > * > > Hi, > > We are using linux-at91 and lately I have been working on adding support > for a custom soundcard, a dual tlv320aic3x codec on SAMA5D3 platform. > This soundcard uses DSP A mode. > > We are facing audio issues: When we playback a WAV file with a sine > wave, the codec outputs far from a clean sine wave. The problem I think > is that the CKI settings for the TMCR register isn't set correctly. > see commit 20cf2603b122bf71fb54def1de6a2ad73d5ddb0b > Author: Bo Shen <voice.shen@xxxxxxxxx> > Date: Fri Jan 30 17:38:42 2015 +0800 > > ASoC: atmel_ssc_dai: fix the setting for DSP mode > > When SCC work in DSP A mode, the data outputs/inputs are shift out on > falling edge, the frame sync are sample on the rising edge. > > Reported-by: Songjun Wu <songjun.wu@xxxxxxxxx> > Signed-off-by: Bo Shen <voice.shen@xxxxxxxxx> > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> > > diff --git a/sound/soc/atmel/atmel_ssc_dai.c > b/sound/soc/atmel/atmel_ssc_dai.c > index e691aab..35e44e4 100644 > --- a/sound/soc/atmel/atmel_ssc_dai.c > +++ b/sound/soc/atmel/atmel_ssc_dai.c > @@ -502,7 +502,7 @@ static int atmel_ssc_hw_params(struct > snd_pcm_substream *substream, > rcmr = SSC_BF(RCMR_PERIOD, ssc_p->rcmr_period) > | SSC_BF(RCMR_STTDLY, 1) > | SSC_BF(RCMR_START, SSC_START_RISING_RF) > - | SSC_BF(RCMR_CKI, SSC_CKI_RISING) > + | SSC_BF(RCMR_CKI, SSC_CKI_FALLING) > | SSC_BF(RCMR_CKO, SSC_CKO_NONE) > | SSC_BF(RCMR_CKS, SSC_CKS_DIV); > > @@ -517,7 +517,7 @@ static int atmel_ssc_hw_params(struct > snd_pcm_substream *substream, > tcmr = SSC_BF(TCMR_PERIOD, ssc_p->tcmr_period) > | SSC_BF(TCMR_STTDLY, 1) > | SSC_BF(TCMR_START, SSC_START_RISING_RF) > - | SSC_BF(TCMR_CKI, SSC_CKI_RISING) > + | SSC_BF(TCMR_CKI, SSC_CKI_FALLING) > | SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS) > | SSC_BF(TCMR_CKS, SSC_CKS_DIV); > > @@ -546,7 +546,7 @@ static int atmel_ssc_hw_params(struct > snd_pcm_substream *substream, > rcmr = SSC_BF(RCMR_PERIOD, 0) > | SSC_BF(RCMR_STTDLY, START_DELAY) > | SSC_BF(RCMR_START, SSC_START_RISING_RF) > - | SSC_BF(RCMR_CKI, SSC_CKI_RISING) > + | SSC_BF(RCMR_CKI, SSC_CKI_FALLING) > | SSC_BF(RCMR_CKO, SSC_CKO_NONE) > | SSC_BF(RCMR_CKS, ssc->clk_from_rk_pin ? > SSC_CKS_PIN : SSC_CKS_CLOCK); > > For both the TCMR and RCMR the CKI is set to SSC_CKI_FALLING, but I > think for the TCMR the CKI should be set to SSC_CKI_RISING. See datasheet: > > TCMR CKI: "1: The data outputs (Data and Frame Sync signals) are shifted > out on Transmit Clock rising edge. The Frame sync signal > input is sampled on Transmit clock falling edge." > > RCMR CKI: "0: The data inputs (Data and Frame Sync signals) are sampled > on Receive Clock falling edge. The Frame Sync signal out- > put is shifted out on Receive Clock rising edge." > > Setting the CKI in TCMR to SSC_CKI_RISING to fixes our issues. Hi Willem, It this DS of the codec you are using? http://www.ti.com/lit/ds/symlink/tlv320aic33.pdf Are you using the DSP mode described in figure 25 DSP Serial Bus Mode Operation? If yes, then you should use the DSP_B mode... Thanks and best regards, Codrin _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
