ASoC: DaVinci: McASP FIFO related updates

The DMA params for McASP with FIFO has been updated so that it works for
various FIFO levels. A member- 'fifo_level' has been added to the DMA
params data structure. The fifo_level can be adjusted by the tx[rx]_numevt
platform data. This is relevant only for DA8xx/OMAP-L1xx platforms. This
implementation has been tested for numevt values 1, 2, 4, 8.
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/davinci/davinci-i2s.c

@@ -397,6 +397,8 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	dma_params->acnt  = dma_params->data_type;
+	dma_params->fifo_level = 0;
+
 	rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(1);
 	xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(1);
 

sound/soc/davinci/davinci-mcasp.c

@@ -714,16 +714,13 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
 	struct davinci_pcm_dma_params *dma_params =
 					&dev->dma_params[substream->stream];
 	int word_length;
-	u8 numevt;
+	u8 fifo_level;
 
 	davinci_hw_common_param(dev, substream->stream);
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-		numevt = dev->txnumevt;
+		fifo_level = dev->txnumevt;
 	else
-		numevt = dev->rxnumevt;
-
-	if (!numevt)
-		numevt = 1;
+		fifo_level = dev->rxnumevt;
 
 	if (dev->op_mode == DAVINCI_MCASP_DIT_MODE)
 		davinci_hw_dit_param(dev);
@@ -751,12 +748,12 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
-	if (dev->version == MCASP_VERSION_2) {
-		dma_params->data_type *= numevt;
-		dma_params->acnt = 4 * numevt;
-	} else
+	if (dev->version == MCASP_VERSION_2 && !fifo_level)
+		dma_params->acnt = 4;
+	else
 		dma_params->acnt = dma_params->data_type;
 
+	dma_params->fifo_level = fifo_level;
 	davinci_config_channel_size(dev, word_length);
 
 	return 0;

sound/soc/davinci/davinci-pcm.c

@@ -66,38 +66,53 @@ static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
 	dma_addr_t dma_pos;
 	dma_addr_t src, dst;
 	unsigned short src_bidx, dst_bidx;
+	unsigned short src_cidx, dst_cidx;
 	unsigned int data_type;
 	unsigned short acnt;
 	unsigned int count;
+	unsigned int fifo_level;
 
 	period_size = snd_pcm_lib_period_bytes(substream);
 	dma_offset = prtd->period * period_size;
 	dma_pos = runtime->dma_addr + dma_offset;
+	fifo_level = prtd->params->fifo_level;
 
 	pr_debug("davinci_pcm: audio_set_dma_params_play channel = %d "
 		"dma_ptr = %x period_size=%x\n", lch, dma_pos, period_size);
 
 	data_type = prtd->params->data_type;
 	count = period_size / data_type;
+	if (fifo_level)
+		count /= fifo_level;
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		src = dma_pos;
 		dst = prtd->params->dma_addr;
 		src_bidx = data_type;
 		dst_bidx = 0;
+		src_cidx = data_type * fifo_level;
+		dst_cidx = 0;
 	} else {
 		src = prtd->params->dma_addr;
 		dst = dma_pos;
 		src_bidx = 0;
 		dst_bidx = data_type;
+		src_cidx = 0;
+		dst_cidx = data_type * fifo_level;
 	}
 
 	acnt = prtd->params->acnt;
 	edma_set_src(lch, src, INCR, W8BIT);
 	edma_set_dest(lch, dst, INCR, W8BIT);
-	edma_set_src_index(lch, src_bidx, 0);
-	edma_set_dest_index(lch, dst_bidx, 0);
-	edma_set_transfer_params(lch, acnt, count, 1, 0, ASYNC);
+
+	edma_set_src_index(lch, src_bidx, src_cidx);
+	edma_set_dest_index(lch, dst_bidx, dst_cidx);
+
+	if (!fifo_level)
+		edma_set_transfer_params(lch, acnt, count, 1, 0, ASYNC);
+	else
+		edma_set_transfer_params(lch, acnt, fifo_level, count,
+							fifo_level, ABSYNC);
 
 	prtd->period++;
 	if (unlikely(prtd->period >= runtime->periods))

sound/soc/davinci/davinci-pcm.h

@@ -23,6 +23,7 @@ struct davinci_pcm_dma_params {
 	enum dma_event_q eventq_no;	/* event queue number */
 	unsigned char data_type;	/* xfer data type */
 	unsigned char convert_mono_stereo;
+	unsigned int fifo_level;
 };