[alsa-devel] [PATCH 20/20] ASoC: Always syncronize audio transfers on frames

[Eduardo Valentin]

From: Eero Nurkkala <ext-eero.nurkkala at nokia.com>

All these steps are required for ASoC to behave correctly.
This is, no RFIG or XFIG (Not defined in 34xx), correct
initiliazation of rccr and xccr. They 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 at nokia.com>
---
 sound/soc/omap/omap-mcbsp.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index a5d46a7..0272d3f 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:
 		if (!mcbsp_data->active++)
 			omap_mcbsp_start(mcbsp_data->bus_id);
+		/* 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:
@@ -321,8 +326,11 @@ static int omap_mcbsp_dai_set_dai_fmt(struct snd_soc_dai *cpu_dai,
 	/* Generic McBSP register settings */
 	regs->spcr2	|= XINTM(3) | FREE;
 	regs->spcr1	|= RINTM(3);
-	regs->rcr2	|= RFIG;
-	regs->xcr2	|= XFIG;
+	/* RFIG and XFIG are not defined in 34xx */
+	if (!cpu_is_omap34xx()) {
+		regs->rcr2	|= RFIG;
+		regs->xcr2	|= XFIG;
+	}
 	if (cpu_is_omap2430() || cpu_is_omap34xx()) {
 		regs->xccr = DXENDLY(1) | XDMAEN;
 		regs->rccr = RFULL_CYCLE | RDMAEN;
@@ -333,11 +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;
-- 
1.6.2.GIT

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