ASoC: omap-pcm: Prepare to configure the DMA data_type based on stream properties

Based on the format of the stream the omap-pcm can decide alone what data
type should be used with by the sDMA.
Keep the possibility for OMAP dai drivers to tell omap-pcm if they want to
use different data type. This is needed for the omap-hdmi for example which
needs 32bit data type even if the stream format is S16_LE.

The check if (dma_data->data_type) is safe at the moment since omap-pcm
does not support 8bit samples (OMAP_DMA_DATA_TYPE_S8 == 0x00).

The next step is to redefine the meaning of dma_data->data_type to unblock
this limitation.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 29 insertions, 2 deletions

diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
index 02eeb2e7ceda..4c13a5f4eebb 100644
--- a/sound/soc/omap/omap-pcm.c
+++ b/sound/soc/omap/omap-pcm.c
@@ -149,6 +149,24 @@ static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
         return 0;
 }
 
+static int omap_pcm_get_dma_type(int num_bits)
+{
+        int data_type;
+
+        switch (num_bits) {
+        case 16:
+                data_type = OMAP_DMA_DATA_TYPE_S16;
+                break;
+        case 32:
+                data_type = OMAP_DMA_DATA_TYPE_S32;
+                break;
+        default:
+                data_type = -EINVAL;
+                break;
+        }
+        return data_type;
+}
+
 static int omap_pcm_prepare(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
@@ -163,7 +181,16 @@ static int omap_pcm_prepare(struct snd_pcm_substream *substream)
                 return 0;
 
         memset(&dma_params, 0, sizeof(dma_params));
-        dma_params.data_type                    = dma_data->data_type;
+
+        if (dma_data->data_type)
+                dma_params.data_type = dma_data->data_type;
+        else
+                dma_params.data_type = omap_pcm_get_dma_type(
+                                snd_pcm_format_physical_width(runtime->format));
+
+        if (dma_params.data_type < 0)
+                return dma_params.data_type;
+
         dma_params.trigger                      = dma_data->dma_req;
 
         if (dma_data->packet_size)
@@ -195,7 +222,7 @@ static int omap_pcm_prepare(struct snd_pcm_substream *substream)
          * still can get an interrupt at each period bounary
          */
         bytes = snd_pcm_lib_period_bytes(substream);
-        dma_params.elem_count   = bytes >> dma_data->data_type;
+        dma_params.elem_count   = bytes >> dma_params.data_type;
         dma_params.frame_count  = runtime->periods;
         omap_set_dma_params(prtd->dma_ch, &dma_params);