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ASOC: dwc: Fix 16-bit audio handling

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IMO the Synopsys datasheet could be clearer in this area, but it seems
that the DMA data ports (DMATX and DMARX) expect left and right samples
in alternate writes; if a stereo pair is pushed in a single 32-bit
write, the upper half is ignored, leading to double speed audio with a
confused stereo image. Make sure the necessary changes happen by
updating the DMA configuration data in the hw_params method.

The set_bclk_ratio change was made at a time when it looked like it
could be causing an error, but I think the division of responsibilities
is clearer this way (and the kernel log clearer without the info-level
message).

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
This commit is contained in:
Phil Elwell
2023-07-21 12:07:16 +01:00
committed by Phil Elwell
parent e6baee4502
commit 9c6694c24f
1 changed files with 15 additions and 7 deletions
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22
sound/soc/dwc/dwc-i2s.c
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@@ -223,23 +223,34 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
{
struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
struct i2s_clk_config_data *config = &dev->config;
union dw_i2s_snd_dma_data *dma_data = NULL;
int ret;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
dma_data = &dev->play_dma_data;
else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
dma_data = &dev->capture_dma_data;
else
return -1;
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE:
config->data_width = 16;
dma_data->dt.addr_width = 2;
dev->ccr = 0x00;
dev->xfer_resolution = 0x02;
break;
case SNDRV_PCM_FORMAT_S24_LE:
config->data_width = 24;
dma_data->dt.addr_width = 4;
dev->ccr = 0x08;
dev->xfer_resolution = 0x04;
break;
case SNDRV_PCM_FORMAT_S32_LE:
config->data_width = 32;
dma_data->dt.addr_width = 4;
dev->ccr = 0x10;
dev->xfer_resolution = 0x05;
break;
@@ -418,24 +429,21 @@ static int dw_i2s_set_bclk_ratio(struct snd_soc_dai *cpu_dai,
struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
struct i2s_clk_config_data *config = &dev->config;
dev_err(dev->dev, "%s(%d)\n", __func__, ratio);
dev_dbg(dev->dev, "%s(%d)\n", __func__, ratio);
if (ratio < config->data_width * 2)
return -EINVAL;
switch (ratio) {
case 32:
config->data_width = 16;
dev->ccr = 0x00;
dev->xfer_resolution = 0x02;
break;
case 48:
config->data_width = 24;
dev->ccr = 0x08;
dev->xfer_resolution = 0x04;
break;
case 64:
config->data_width = 32;
dev->ccr = 0x10;
dev->xfer_resolution = 0x05;
break;
default:
return -EINVAL;