ASoC: omap-mcpdm: Fix threshold and dma configuration

DMA packet_size must be configured based on the McPDM FIFO threshold
value, number of channels.
Due to the FIFO operation the DMA muse be configured differently for
playback, and capture.
At the same time fix the McPDM threshold values used for playback, and
capture to avoid broken code.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>

sound/soc/omap/omap-mcpdm.c

@@ -46,13 +46,13 @@ static struct omap_mcpdm_link omap_mcpdm_links[] = {
 	/* downlink */
 	{
 		.irq_mask = MCPDM_DN_IRQ_EMPTY | MCPDM_DN_IRQ_FULL,
-		.threshold = 1,
+		.threshold = 2,
 		.format = PDMOUTFORMAT_LJUST,
 	},
 	/* uplink */
 	{
 		.irq_mask = MCPDM_UP_IRQ_EMPTY | MCPDM_UP_IRQ_FULL,
-		.threshold = 1,
+		.threshold = UP_THRES_MAX - 3,
 		.format = PDMOUTFORMAT_LJUST,
 	},
 };
@@ -136,12 +136,11 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,
 {
 	struct omap_mcpdm_data *mcpdm_priv = snd_soc_dai_get_drvdata(dai);
 	struct omap_mcpdm_link *mcpdm_links = mcpdm_priv->links;
+	struct omap_pcm_dma_data *dma_data;
+	int threshold;
 	int stream = substream->stream;
 	int channels, err, link_mask = 0;
 
-	snd_soc_dai_set_dma_data(dai, substream,
-				 &omap_mcpdm_dai_dma_params[stream]);
-
 	channels = params_channels(params);
 	switch (channels) {
 	case 4:
@@ -164,14 +163,22 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	dma_data = &omap_mcpdm_dai_dma_params[stream];
+	threshold = mcpdm_links[stream].threshold;
+
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		mcpdm_links[stream].channels = link_mask << 3;
+		dma_data->packet_size = (DN_THRES_MAX - threshold) * channels;
+
 		err = omap_mcpdm_playback_open(&mcpdm_links[stream]);
 	} else {
 		mcpdm_links[stream].channels = link_mask << 0;
+		dma_data->packet_size = threshold * channels;
+
 		err = omap_mcpdm_capture_open(&mcpdm_links[stream]);
 	}
 
+	snd_soc_dai_set_dma_data(dai, substream, dma_data);
 	return err;
 }