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ASoC: davinci-mcasp: Add support for multichannel playback
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Davinci McASP has support for I2S multichannel playback.
For I2S playback/receive, each serializer is capable to play 2 channels
(L/R) audio data.Serializer function (Playback-receive-none) is configured
in DT, depending on hardware specification. It is possible to play less
channels than configured in DT. For that purpose,only specific number of
active serializers are enabled. McASP FIFO need to have DMA transfer Bcnt
set to number of enabled serializers, otherwise no data are transfered to
McASP and Alsa generates "DMA/IRQ playback write error (DMA or IRQ trouble?)"
error. For TDM mode, McASP is capable to play or receive 32 channels for one
serializer. McAsp has support for max 16 serializer, therefore max channels
is 32 * 8.

Signed-off-by: Michal Bachraty <michal.bachraty@streamunlimited.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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Michal Bachraty authored and Mark Brown committed Mar 4, 2013
1 parent 6dbe51c commit 2952b27
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Showing 3 changed files with 68 additions and 15 deletions.
66 changes: 58 additions & 8 deletions sound/soc/davinci/davinci-mcasp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -235,6 +235,10 @@
#define DISMOD (val)(val<<2)
#define TXSTATE BIT(4)
#define RXSTATE BIT(5)
#define SRMOD_MASK 3
#define SRMOD_INACTIVE 0
#define SRMOD_TX 1
#define SRMOD_RX 2

/*
* DAVINCI_MCASP_LBCTL_REG - Loop Back Control Register Bits
Expand Down Expand Up @@ -657,12 +661,15 @@ static int davinci_config_channel_size(struct davinci_audio_dev *dev,
return 0;
}

static void davinci_hw_common_param(struct davinci_audio_dev *dev, int stream)
static int davinci_hw_common_param(struct davinci_audio_dev *dev, int stream,
int channels)
{
int i;
u8 tx_ser = 0;
u8 rx_ser = 0;

u8 ser;
u8 slots = dev->tdm_slots;
u8 max_active_serializers = (channels + slots - 1) / slots;
/* Default configuration */
mcasp_set_bits(dev->base + DAVINCI_MCASP_PWREMUMGT_REG, MCASP_SOFT);

Expand All @@ -679,17 +686,43 @@ static void davinci_hw_common_param(struct davinci_audio_dev *dev, int stream)
RXDATADMADIS);
}

for (i = 0; i < dev->num_serializer; i++) {
if (dev->serial_dir[i] == TX_MODE)
tx_ser++;
if (dev->serial_dir[i] == RX_MODE)
rx_ser++;
}

if (stream == SNDRV_PCM_STREAM_PLAYBACK)
ser = tx_ser;
else
ser = rx_ser;

if (ser < max_active_serializers) {
dev_warn(dev->dev, "stream has more channels (%d) than are "
"enabled in mcasp (%d)\n", channels, ser * slots);
return -EINVAL;
}

tx_ser = 0;
rx_ser = 0;

for (i = 0; i < dev->num_serializer; i++) {
mcasp_set_bits(dev->base + DAVINCI_MCASP_XRSRCTL_REG(i),
dev->serial_dir[i]);
if (dev->serial_dir[i] == TX_MODE) {
if (dev->serial_dir[i] == TX_MODE &&
tx_ser < max_active_serializers) {
mcasp_set_bits(dev->base + DAVINCI_MCASP_PDIR_REG,
AXR(i));
tx_ser++;
} else if (dev->serial_dir[i] == RX_MODE) {
} else if (dev->serial_dir[i] == RX_MODE &&
rx_ser < max_active_serializers) {
mcasp_clr_bits(dev->base + DAVINCI_MCASP_PDIR_REG,
AXR(i));
rx_ser++;
} else {
mcasp_mod_bits(dev->base + DAVINCI_MCASP_XRSRCTL_REG(i),
SRMOD_INACTIVE, SRMOD_MASK);
}
}

Expand Down Expand Up @@ -729,6 +762,8 @@ static void davinci_hw_common_param(struct davinci_audio_dev *dev, int stream)
((dev->rxnumevt * rx_ser) << 8), NUMEVT_MASK);
}
}

return 0;
}

static void davinci_hw_param(struct davinci_audio_dev *dev, int stream)
Expand Down Expand Up @@ -812,8 +847,14 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
&dev->dma_params[substream->stream];
int word_length;
u8 fifo_level;
u8 slots = dev->tdm_slots;
int channels;
struct snd_interval *pcm_channels = hw_param_interval(params,
SNDRV_PCM_HW_PARAM_CHANNELS);
channels = pcm_channels->min;

davinci_hw_common_param(dev, substream->stream);
if (davinci_hw_common_param(dev, substream->stream, channels) == -EINVAL)
return -EINVAL;
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
fifo_level = dev->txnumevt;
else
Expand Down Expand Up @@ -862,6 +903,7 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
dma_params->acnt = dma_params->data_type;

dma_params->fifo_level = fifo_level;
dma_params->active_serializers = (channels + slots - 1) / slots;
davinci_config_channel_size(dev, word_length);

return 0;
Expand Down Expand Up @@ -936,13 +978,13 @@ static struct snd_soc_dai_driver davinci_mcasp_dai[] = {
.name = "davinci-mcasp.0",
.playback = {
.channels_min = 2,
.channels_max = 2,
.channels_max = 32 * 16,
.rates = DAVINCI_MCASP_RATES,
.formats = DAVINCI_MCASP_PCM_FMTS,
},
.capture = {
.channels_min = 2,
.channels_max = 2,
.channels_max = 32 * 16,
.rates = DAVINCI_MCASP_RATES,
.formats = DAVINCI_MCASP_PCM_FMTS,
},
Expand Down Expand Up @@ -1015,8 +1057,16 @@ static struct snd_platform_data *davinci_mcasp_set_pdata_from_of(
pdata->op_mode = val;

ret = of_property_read_u32(np, "tdm-slots", &val);
if (ret >= 0)
if (ret >= 0) {
if (val < 2 || val > 32) {
dev_err(&pdev->dev,
"tdm-slots must be in rage [2-32]\n");
ret = -EINVAL;
goto nodata;
}

pdata->tdm_slots = val;
}

ret = of_property_read_u32(np, "num-serializer", &val);
if (ret >= 0)
Expand Down
16 changes: 9 additions & 7 deletions sound/soc/davinci/davinci-pcm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -181,6 +181,7 @@ static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
unsigned short acnt;
unsigned int count;
unsigned int fifo_level;
unsigned char serializers = prtd->params->active_serializers;

period_size = snd_pcm_lib_period_bytes(substream);
dma_offset = prtd->period * period_size;
Expand All @@ -194,22 +195,22 @@ static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
data_type = prtd->params->data_type;
count = period_size / data_type;
if (fifo_level)
count /= fifo_level;
count /= fifo_level * serializers;

if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
src = dma_pos;
dst = prtd->params->dma_addr;
src_bidx = data_type;
dst_bidx = 0;
src_cidx = data_type * fifo_level;
dst_bidx = 4;
src_cidx = data_type * fifo_level * serializers;
dst_cidx = 0;
} else {
src = prtd->params->dma_addr;
dst = dma_pos;
src_bidx = 0;
dst_bidx = data_type;
src_cidx = 0;
dst_cidx = data_type * fifo_level;
dst_cidx = data_type * fifo_level * serializers;
}

acnt = prtd->params->acnt;
Expand All @@ -223,9 +224,10 @@ static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
edma_set_transfer_params(prtd->asp_link[0], acnt, count, 1, 0,
ASYNC);
else
edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
count, fifo_level,
ABSYNC);
edma_set_transfer_params(prtd->asp_link[0], acnt,
fifo_level * serializers,
count, fifo_level * serializers,
ABSYNC);
}

static void davinci_pcm_dma_irq(unsigned link, u16 ch_status, void *data)
Expand Down
1 change: 1 addition & 0 deletions sound/soc/davinci/davinci-pcm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ struct davinci_pcm_dma_params {
unsigned char data_type; /* xfer data type */
unsigned char convert_mono_stereo;
unsigned int fifo_level;
unsigned char active_serializers; /* num. of active audio serializers */
};

int davinci_soc_platform_register(struct device *dev);
Expand Down

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