ASoC: pxa-ssp: Use 16-bit DMA for magician stereo

Now magician and similar boards can use network mode with only one
active slot to explicitly set 16 bit frame width, even for S16_LE
stereo sound.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/sound/soc/pxa/pxa-ssp.c b/sound/soc/pxa/pxa-ssp.c
index b0bf40973d5b..c7c1996a5447 100644
--- a/sound/soc/pxa/pxa-ssp.c
+++ b/sound/soc/pxa/pxa-ssp.c
@@ -627,12 +627,18 @@ static int pxa_ssp_hw_params(struct snd_pcm_substream *substream,
         u32 sscr0;
         u32 sspsp;
         int width = snd_pcm_format_physical_width(params_format(params));
+        int ttsa = ssp_read_reg(ssp, SSTSA) & 0xf;
 
         /* select correct DMA params */
         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
                 dma = 1; /* capture DMA offset is 1,3 */
-        if (chn == 2)
-                dma += 2; /* stereo DMA offset is 2, mono is 0 */
+        /* Network mode with one active slot (ttsa == 1) can be used
+         * to force 16-bit frame width on the wire (for S16_LE), even
+         * with two channels. Use 16-bit DMA transfers for this case.
+         */
+        if (((chn == 2) && (ttsa != 1)) || (width == 32))
+                dma += 2; /* 32-bit DMA offset is 2, 16-bit is 0 */
+
         cpu_dai->dma_data = ssp_dma_params[cpu_dai->id][dma];
 
         dev_dbg(&ssp->pdev->dev, "pxa_ssp_hw_params: dma %d\n", dma);
@@ -712,7 +718,7 @@ static int pxa_ssp_hw_params(struct snd_pcm_substream *substream,
         /* When we use a network mode, we always require TDM slots
          * - complain loudly and fail if they've not been set up yet.
          */
-        if ((sscr0 & SSCR0_MOD) && !(ssp_read_reg(ssp, SSTSA) & 0xf)) {
+        if ((sscr0 & SSCR0_MOD) && !ttsa) {
                 dev_err(&ssp->pdev->dev, "No TDM timeslot configured\n");
                 return -EINVAL;
         }