[PATCH v8] ASoC: bcm2835: Add 8 channel (multitrack) capability
Matt Flax
flatmax at flatmax.org
Tue Feb 21 22:56:40 PST 2017
This patch adds multitrack capability if in DSP mode A and the
codec is master.
In bcm2835_i2s_startup, snd_pcm_hw_constraint_single is used to set
channels to 8 if both SND_SOC_DAIFMT_CBM_CFM and SND_SOC_DAIFMT_DSP_A
are set. Otherwise, channels are set to 2. These settings are
accomplished using the SNDRV_PCM_HW_PARAM_CHANNELS variable.
In bcm2835_i2s_shutdown the channels are set to 2 by default.
In bcm2835_i2s_hw_params, DSP mode A format is now an option.
Before replicating the format variable (from ch2 to ch1) for
register loading, requested channels are checked to be either 2 or 8.
This can be expanded later to accomodate other channel counts if
supported by the sound card hardware.
Signed-off-by: Matt Flax <flatmax at flatmax.org>
---
sound/soc/bcm/bcm2835-i2s.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c
index 6ba2049..4b5f3f1 100644
--- a/sound/soc/bcm/bcm2835-i2s.c
+++ b/sound/soc/bcm/bcm2835-i2s.c
@@ -296,6 +296,7 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
case SND_SOC_DAIFMT_I2S:
+ case SND_SOC_DAIFMT_DSP_A:
data_delay = 1;
break;
default:
@@ -312,6 +313,7 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
switch (params_channels(params)) {
case 2:
+ case 8:
format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
format |= BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(ch1pos));
format |= BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(ch2pos));
@@ -526,7 +528,17 @@ static int bcm2835_i2s_startup(struct snd_pcm_substream *substream,
regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
BCM2835_I2S_STBY, BCM2835_I2S_STBY);
- return 0;
+ /* Set the max channels to 8 if the codec is master and
+ * we are in DSP A mode. Otherwise only allow 2 channels.
+ */
+ if ((dev->fmt &
+ (SND_SOC_DAIFMT_MASTER_MASK | SND_SOC_DAIFMT_FORMAT_MASK))
+ == (SND_SOC_DAIFMT_CBM_CFM | SND_SOC_DAIFMT_DSP_A))
+ return snd_pcm_hw_constraint_single(substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS, 8);
+ else
+ return snd_pcm_hw_constraint_single(substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS, 2);
}
static void bcm2835_i2s_shutdown(struct snd_pcm_substream *substream,
@@ -549,6 +561,10 @@ static void bcm2835_i2s_shutdown(struct snd_pcm_substream *substream,
* not stop the clock when SND_SOC_DAIFMT_CONT
*/
bcm2835_i2s_stop_clock(dev);
+
+ /* Default to 2 channels */
+ snd_pcm_hw_constraint_single(substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS, 2);
}
static const struct snd_soc_dai_ops bcm2835_i2s_dai_ops = {
@@ -576,16 +592,12 @@ static struct snd_soc_dai_driver bcm2835_i2s_dai = {
.name = "bcm2835-i2s",
.probe = bcm2835_i2s_dai_probe,
.playback = {
- .channels_min = 2,
- .channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S24_LE
| SNDRV_PCM_FMTBIT_S32_LE
},
.capture = {
- .channels_min = 2,
- .channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_192000,
.formats = SNDRV_PCM_FMTBIT_S16_LE
| SNDRV_PCM_FMTBIT_S24_LE
--
2.7.4
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