The normal mode of SSI allows it to send/receive data to/from the first
slot of each period. So we can use this normal mode to trick I2S signal
by puting/getting data to/from the first slot only (the left channel)
so as to support monaural audio playback and recording.
Signed-off-by: Nicolin Chen <b42378@xxxxxxxxxxxxx>
---
sound/soc/fsl/fsl_ssi.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index f43be6d..ccf1d38 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -517,10 +517,12 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
{
struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
+ unsigned int channels = params_channels(hw_params);
unsigned int sample_size =
snd_pcm_format_width(params_format(hw_params));
u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
int enabled = read_ssi(&ssi->scr) & CCSR_SSI_SCR_SSIEN;
+ static u8 i2s_mode;
/*
* If we're in synchronous mode, and the SSI is already enabled,
@@ -546,6 +548,21 @@ static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
else
write_ssi_mask(&ssi->srccr, CCSR_SSI_SxCCR_WL_MASK, wl);
+ if (ssi_private->imx_ac97)
+ return 0;
+
+ /* Save i2s mode configuration so that we can restore it later */
+ switch (read_ssi(&ssi->scr) & CCSR_SSI_SCR_I2S_MODE_MASK) {
+ case CCSR_SSI_SCR_I2S_MODE_SLAVE:
+ case CCSR_SSI_SCR_I2S_MODE_MASTER:
+ i2s_mode = read_ssi(&ssi->scr) & CCSR_SSI_SCR_I2S_MODE_MASK;
+ default:
+ break;
+ }
+
+ write_ssi_mask(&ssi->scr, CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
+ channels == 1 ? 0 : CCSR_SSI_SCR_NET | i2s_mode);
+
return 0;
}
@@ -658,14 +675,13 @@ static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
static struct snd_soc_dai_driver fsl_ssi_dai_template = {
.probe = fsl_ssi_dai_probe,
.playback = {
- /* The SSI does not support monaural audio. */
- .channels_min = 2,
+ .channels_min = 1,
.channels_max = 2,
.rates = FSLSSI_I2S_RATES,
.formats = FSLSSI_I2S_FORMATS,
},
.capture = {
- .channels_min = 2,
+ .channels_min = 1,
.channels_max = 2,
.rates = FSLSSI_I2S_RATES,
.formats = FSLSSI_I2S_FORMATS,
--
1.8.4
--
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