ASoC/mpc5200: fix enable/disable of AC97 slots

The MPC5200 AC97 driver is disabling the slots when a stop
trigger is received, but not reenabling them if the stream
is started again without processing the hw_params again.

This patch fixes the problem by caching the slot enable bit
settings calculated at hw_params time so that they can be
reapplied every time the start trigger is received.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/fsl/mpc5200_dma.h b/sound/soc/fsl/mpc5200_dma.h
index 956d6a5..22208b3 100644 (file)
--- a/sound/soc/fsl/mpc5200_dma.h
+++ b/sound/soc/fsl/mpc5200_dma.h
@@ -16,6 +16,7 @@
  * @period_end:                physical address of end of DMA region
  * @period_next_pt:    physical address of next DMA buffer to enqueue
  * @period_bytes:      size of DMA period in bytes
+ * @ac97_slot_bits:    Enable bits for turning on the correct AC97 slot
  */
 struct psc_dma_stream {
        struct snd_pcm_runtime *runtime;
@@ -28,6 +29,9 @@ struct psc_dma_stream {
        int period_current;
        int period_bytes;
        int period_count;
+
+       /* AC97 state */
+       u32 ac97_slot_bits;
 };
 
 /**

diff --git a/sound/soc/fsl/mpc5200_psc_ac97.c b/sound/soc/fsl/mpc5200_psc_ac97.c
index c4ae3e0..3dbc7f7 100644 (file)
--- a/sound/soc/fsl/mpc5200_psc_ac97.c
+++ b/sound/soc/fsl/mpc5200_psc_ac97.c
@@ -130,6 +130,7 @@ static int psc_ac97_hw_analog_params(struct snd_pcm_substream *substream,
                                 struct snd_soc_dai *cpu_dai)
 {
        struct psc_dma *psc_dma = cpu_dai->private_data;
+       struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
 
        dev_dbg(psc_dma->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
                " periods=%i buffer_size=%i  buffer_bytes=%i channels=%i"
@@ -140,20 +141,10 @@ static int psc_ac97_hw_analog_params(struct snd_pcm_substream *substream,
                params_channels(params), params_rate(params),
                params_format(params));
 
-
-       if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE) {
-               if (params_channels(params) == 1)
-                       psc_dma->slots |= 0x00000100;
-               else
-                       psc_dma->slots |= 0x00000300;
-       } else {
-               if (params_channels(params) == 1)
-                       psc_dma->slots |= 0x01000000;
-               else
-                       psc_dma->slots |= 0x03000000;
-       }
-       out_be32(&psc_dma->psc_regs->ac97_slots, psc_dma->slots);
-
+       /* Determine the set of enable bits to turn on */
+       s->ac97_slot_bits = (params_channels(params) == 1) ? 0x100 : 0x300;
+       if (substream->pstr->stream != SNDRV_PCM_STREAM_CAPTURE)
+               s->ac97_slot_bits <<= 16;
        return 0;
 }
 
@@ -163,6 +154,8 @@ static int psc_ac97_hw_digital_params(struct snd_pcm_substream *substream,
 {
        struct psc_dma *psc_dma = cpu_dai->private_data;
 
+       dev_dbg(psc_dma->dev, "%s(substream=%p)\n", __func__, substream);
+
        if (params_channels(params) == 1)
                out_be32(&psc_dma->psc_regs->ac97_slots, 0x01000000);
        else
@@ -176,14 +169,24 @@ static int psc_ac97_trigger(struct snd_pcm_substream *substream, int cmd,
 {
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct psc_dma *psc_dma = rtd->dai->cpu_dai->private_data;
+       struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
 
        switch (cmd) {
+       case SNDRV_PCM_TRIGGER_START:
+               dev_dbg(psc_dma->dev, "AC97 START: stream=%i\n",
+                       substream->pstr->stream);
+
+               /* Set the slot enable bits */
+               psc_dma->slots |= s->ac97_slot_bits;
+               out_be32(&psc_dma->psc_regs->ac97_slots, psc_dma->slots);
+               break;
+
        case SNDRV_PCM_TRIGGER_STOP:
-               if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
-                       psc_dma->slots &= 0xFFFF0000;
-               else
-                       psc_dma->slots &= 0x0000FFFF;
+               dev_dbg(psc_dma->dev, "AC97 STOP: stream=%i\n",
+                       substream->pstr->stream);
 
+               /* Clear the slot enable bits */
+               psc_dma->slots &= ~(s->ac97_slot_bits);
                out_be32(&psc_dma->psc_regs->ac97_slots, psc_dma->slots);
                break;
        }