[PATCH 3/3] ASoC: AMD: Set delay value for the capture case

From: Akshu Agrawal
Date: Thu Aug 02 2018 - 12:02:22 EST


ACP->SYSMEM DMA happens at every I2S->SYSMEM period
completion. Thus, there is delay of x frames till
I2S->SYSMEM reaches a period length. This delay is
communicated to user space.

Signed-off-by: Akshu Agrawal <akshu.agrawal@xxxxxxx>
---
sound/soc/amd/acp-pcm-dma.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index 6240a77..c24611c 100644
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -922,6 +922,10 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
rtd->destination = FROM_BLUETOOTH;
rtd->dma_dscr_idx_1 = CAPTURE_START_DMA_DESCR_CH10;
rtd->dma_dscr_idx_2 = CAPTURE_START_DMA_DESCR_CH11;
+ rtd->byte_cnt_high_reg_offset =
+ mmACP_I2S_BT_RECEIVE_BYTE_CNT_HIGH;
+ rtd->byte_cnt_low_reg_offset =
+ mmACP_I2S_BT_RECEIVE_BYTE_CNT_LOW;
rtd->dma_curr_dscr = mmACP_DMA_CUR_DSCR_11;
rtd->cur_trans_cnt = mmACP_DMA_CUR_TRANS_CNT_11;
rtd->end_dma_dscr = CAPTURE_END_DMA_DESCR_CH10;
@@ -944,6 +948,10 @@ static int acp_dma_hw_params(struct snd_pcm_substream *substream,
rtd->destination = FROM_ACP_I2S_1;
rtd->dma_dscr_idx_1 = CAPTURE_START_DMA_DESCR_CH14;
rtd->dma_dscr_idx_2 = CAPTURE_START_DMA_DESCR_CH15;
+ rtd->byte_cnt_high_reg_offset =
+ mmACP_I2S_RECEIVED_BYTE_CNT_HIGH;
+ rtd->byte_cnt_low_reg_offset =
+ mmACP_I2S_RECEIVED_BYTE_CNT_LOW;
rtd->dma_curr_dscr = mmACP_DMA_CUR_DSCR_15;
rtd->cur_trans_cnt = mmACP_DMA_CUR_TRANS_CNT_15;
rtd->end_dma_dscr = CAPTURE_END_DMA_DESCR_CH14;
@@ -1002,7 +1010,7 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
u64 bytescount = 0;
u32 dma_count = 0;
u16 dscr;
- u32 period_bytes;
+ u32 period_bytes, delay;

struct snd_pcm_runtime *runtime = substream->runtime;
struct audio_substream_data *rtd = runtime->private_data;
@@ -1011,6 +1019,10 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
return -EINVAL;

buffersize = frames_to_bytes(runtime, runtime->buffer_size);
+ bytescount = acp_get_byte_count(rtd);
+ if (bytescount > rtd->bytescount)
+ bytescount -= rtd->bytescount;
+
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
period_bytes = frames_to_bytes(runtime, runtime->period_size);
dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr);
@@ -1018,10 +1030,9 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
if (dscr == rtd->end_dma_dscr)
dma_count += period_bytes;
pos = dma_count % buffersize;
+ delay = do_div(bytescount, period_bytes);
+ runtime->delay = bytes_to_frames(runtime, delay);
} else {
- bytescount = acp_get_byte_count(rtd);
- if (bytescount > rtd->bytescount)
- bytescount -= rtd->bytescount;
pos = do_div(bytescount, buffersize);
}
return bytes_to_frames(runtime, pos);
--
1.9.1