This patch adds multitrack capability if in DSP mode A and the codec is master.
In bcm2835_i2s_startup, snd_pcm_hw_constraint_minmax is used to set max channels to 8 if both SND_SOC_DAIFMT_CBM_CFM and SND_SOC_DAIFMT_DSP_A are set. Otherwise, max channels is set to 2. Min channels is always set to 2. These settings are accomplished using the SNDRV_PCM_HW_PARAM_CHANNELS variable.
In bcm2835_i2s_shutdown max channels is 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 expaneded later to accomodate other channel counts if supported by the sound card hardware.
Signed-off-by: Matt Flax flatmax@flatmax.org --- sound/soc/bcm/bcm2835-i2s.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c index 6ba2049..300516d 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 +528,16 @@ 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_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 +560,10 @@ 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 +591,12 @@ 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