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ASoC: davinci-mcasp: Place constraint on number of channels

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In IIS (I2S, TDM, etc) mode the maximum number of allowed channels for
either direction can be:
number of serializers for the direction * tdm_slots.
This constraint applicable for the first stream, while consequent stream
should not have more channels then the first stream.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Peter Ujfalusi 2014-11-10 12:32:16 +02:00 committed by Mark Brown
parent 1a5923da4e
commit 11277833ce
1 changed files with 60 additions and 0 deletions
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60
sound/soc/davinci/davinci-mcasp.c
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@ -90,6 +90,9 @@ struct davinci_mcasp {
bool dat_port;
/* Used for comstraint setting on the second stream */
u32 channels;
#ifdef CONFIG_PM_SLEEP
struct davinci_mcasp_context context;
#endif
@ -811,6 +814,9 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
davinci_config_channel_size(mcasp, word_length);
if (mcasp->op_mode == DAVINCI_MCASP_IIS_MODE)
mcasp->channels = channels;
return 0;
}
@ -839,7 +845,61 @@ static int davinci_mcasp_trigger(struct snd_pcm_substream *substream,
return ret;
}
static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *cpu_dai)
{
struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
u32 max_channels = 0;
int i, dir;
if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
return 0;
/*
* Limit the maximum allowed channels for the first stream:
* number of serializers for the direction * tdm slots per serializer
*/
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
dir = TX_MODE;
else
dir = RX_MODE;
for (i = 0; i < mcasp->num_serializer; i++) {
if (mcasp->serial_dir[i] == dir)
max_channels++;
}
max_channels *= mcasp->tdm_slots;
/*
* If the already active stream has less channels than the calculated
* limnit based on the seirializers * tdm_slots, we need to use that as
* a constraint for the second stream.
* Otherwise (first stream or less allowed channels) we use the
* calculated constraint.
*/
if (mcasp->channels && mcasp->channels < max_channels)
max_channels = mcasp->channels;
snd_pcm_hw_constraint_minmax(substream->runtime,
SNDRV_PCM_HW_PARAM_CHANNELS,
2, max_channels);
return 0;
}
static void davinci_mcasp_shutdown(struct snd_pcm_substream *substream,
struct snd_soc_dai *cpu_dai)
{
struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
return;
if (!cpu_dai->active)
mcasp->channels = 0;
}
static const struct snd_soc_dai_ops davinci_mcasp_dai_ops = {
.startup = davinci_mcasp_startup,
.shutdown = davinci_mcasp_shutdown,
.trigger = davinci_mcasp_trigger,
.hw_params = davinci_mcasp_hw_params,
.set_fmt = davinci_mcasp_set_dai_fmt,