From: Eero Nurkkala ext-eero.nurkkala@nokia.com
All these steps are required for ASoC to behave correctly. rccr and xccr are format dependent, for example TDM audio has different values than I2S or DSP_A. Also the omap_mcbsp_xmit_enable and/or omap_mcbsp_recv_enable must be called right after the DMA has started. This provides no longer L and R channels switching at random.
Signed-off-by: Eero Nurkkala ext-eero.nurkkala@nokia.com --- sound/soc/omap/omap-mcbsp.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c index a7b0961..6e85508 100644 --- a/sound/soc/omap/omap-mcbsp.c +++ b/sound/soc/omap/omap-mcbsp.c @@ -191,6 +191,11 @@ static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd, case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: mcbsp_data->active++; omap_mcbsp_start(mcbsp_data->bus_id, play, !play); + /* Make sure data transfer is frame synchronized */ + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + omap_mcbsp_xmit_enable(mcbsp_data->bus_id, 1); + else + omap_mcbsp_recv_enable(mcbsp_data->bus_id, 1); break;
case SNDRV_PCM_TRIGGER_STOP: @@ -336,11 +341,15 @@ static int omap_mcbsp_dai_set_dai_fmt(struct snd_soc_dai *cpu_dai, /* 1-bit data delay */ regs->rcr2 |= RDATDLY(1); regs->xcr2 |= XDATDLY(1); + regs->rccr |= RFULL_CYCLE | RDMAEN | RDISABLE; + regs->xccr |= (DXENDLY(1) | XDMAEN | XDISABLE); break; case SND_SOC_DAIFMT_DSP_A: /* 1-bit data delay */ regs->rcr2 |= RDATDLY(1); regs->xcr2 |= XDATDLY(1); + regs->rccr |= RFULL_CYCLE | RDMAEN | RDISABLE; + regs->xccr |= (DXENDLY(1) | XDMAEN | XDISABLE); /* Invert FS polarity configuration */ temp_fmt ^= SND_SOC_DAIFMT_NB_IF; break;