[PATCH] ASoC: amd: Reporting accurate hw_ptr for acp3x dma

[Vijendar Mukunda]

From: Ravulapati Vishnu vardhan rao <vishnuvardhanrao.ravulap...@amd.com>

acp3x dma pointer callback has issues in reporting hw_ptr.
Modified logic to use linear position registers to
retrieve accurate hw_ptr.

Signed-off-by: Ravulapati Vishnu vardhan rao 
<vishnuvardhanrao.ravulap...@amd.com>
Signed-off-by: Vijendar Mukunda <vijendar.muku...@amd.com>
---
 sound/soc/amd/raven/acp3x-pcm-dma.c | 43 ++++++++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/sound/soc/amd/raven/acp3x-pcm-dma.c 
b/sound/soc/amd/raven/acp3x-pcm-dma.c
index 9775bda..a4ade6b 100644
--- a/sound/soc/amd/raven/acp3x-pcm-dma.c
+++ b/sound/soc/amd/raven/acp3x-pcm-dma.c
@@ -32,6 +32,7 @@ struct i2s_stream_instance {
        u16 channels;
        u32 xfer_resolution;
        struct page *pg;
+       u64 bytescount;
        void __iomem *acp3x_base;
 };
 
@@ -317,6 +318,24 @@ static int acp3x_dma_open(struct snd_pcm_substream 
*substream)
        return 0;
 }
 
+static u64 acp_get_byte_count(struct i2s_stream_instance *rtd, int direction)
+{
+       u64 byte_count;
+
+       if (direction == SNDRV_PCM_STREAM_PLAYBACK) {
+               byte_count = rv_readl(rtd->acp3x_base +
+                                     mmACP_BT_TX_LINEARPOSITIONCNTR_HIGH);
+               byte_count |= rv_readl(rtd->acp3x_base +
+                                      mmACP_BT_TX_LINEARPOSITIONCNTR_LOW);
+       } else {
+               byte_count = rv_readl(rtd->acp3x_base +
+                                     mmACP_BT_RX_LINEARPOSITIONCNTR_HIGH);
+               byte_count |= rv_readl(rtd->acp3x_base +
+                                      mmACP_BT_RX_LINEARPOSITIONCNTR_LOW);
+       }
+       return byte_count;
+}
+
 static int acp3x_dma_hw_params(struct snd_pcm_substream *substream,
                               struct snd_pcm_hw_params *params)
 {
@@ -350,18 +369,17 @@ static int acp3x_dma_hw_params(struct snd_pcm_substream 
*substream,
 static snd_pcm_uframes_t acp3x_dma_pointer(struct snd_pcm_substream *substream)
 {
        u32 pos = 0;
-       struct i2s_stream_instance *rtd = substream->runtime->private_data;
-
-       if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-               pos = rv_readl(rtd->acp3x_base +
-                              mmACP_BT_TX_LINKPOSITIONCNTR);
-       else
-               pos = rv_readl(rtd->acp3x_base +
-                              mmACP_BT_RX_LINKPOSITIONCNTR);
-
-       if (pos >= MAX_BUFFER)
-               pos = 0;
-
+       u32 buffersize = 0;
+       u64 bytescount = 0;
+       struct i2s_stream_instance *rtd =
+               substream->runtime->private_data;
+
+       buffersize = frames_to_bytes(substream->runtime,
+                                    substream->runtime->buffer_size);
+       bytescount = acp_get_byte_count(rtd, substream->stream);
+       if (bytescount > rtd->bytescount)
+               bytescount -= rtd->bytescount;
+       pos = do_div(bytescount, buffersize);
        return bytes_to_frames(substream->runtime, pos);
 }
 
@@ -521,6 +539,7 @@ static int acp3x_dai_i2s_trigger(struct snd_pcm_substream 
*substream,
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+               rtd->bytescount = acp_get_byte_count(rtd, substream->stream);
                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                        rv_writel(period_bytes, rtd->acp3x_base +
                                  mmACP_BT_TX_INTR_WATERMARK_SIZE);
-- 
2.7.4