(Since the original post mysteriously disappeared, I'm retrying this question.)
We are using the (Arago) linux kernel 2.6.37 (also labelled v2.6.37_DAVINCIPSP_03.21.00.04). There are several TLV320AIC3256 codec connected to an OMAP-L138 SoM board via I2C and McASP. The board is based on the DA850 EVM.
To support the codec, I've backported the tlv320aic32x4 driver from the 2.6.39 linux kernel.
The I2C part is configured correctly, and I can get and set mixer components and other settings via I2C to the codec.
However, setting up the McASP data path is a complete riddle, and I need help to get this to work.
In the board files, the following structs "glue" the codec to the audio data transfer unit:
static struct snd_soc_dai_link da8xx_evm_dai[] = {
{
.name = "TLV320AIC3X-1",
.stream_name = "AIC3X-1",
.cpu_dai_name= "davinci-mcasp.0",
.codec_dai_name = "tlv320aic32x4-hifi",
.codec_name = "tlv320aic32x4.11-0018",
.platform_name = "davinci-pcm-audio",
.init = evm_aic3x_init_analog,
.ops = &evm_ops,
},
{
.name = "TLV320AIC3X-2",
.stream_name = "AIC3X-2",
.cpu_dai_name= "davinci-mcasp.0",
.codec_dai_name = "tlv320aic32x4-hifi",
.codec_name = "tlv320aic32x4.12-0018",
.platform_name = "davinci-pcm-audio",
.init = evm_aic3x_init_analog,
.ops = &evm_ops,
},
The string "davinci-mcasp.0" refers to the struct in sound/soc/davinci/davinci-mcasp.c:
static struct snd_soc_dai_driver davinci_mcasp_dai[] = {
{
.name = "davinci-mcasp.0",
.playback = {
.channels_min = 2,
.channels_max = 2,
.rates = DAVINCI_MCASP_RATES,
.formats = SNDRV_PCM_FMTBIT_S8 |
SNDRV_PCM_FMTBIT_S16_LE |
SNDRV_PCM_FMTBIT_S32_LE,
},
.capture = {
.channels_min = 2,
.channels_max = 2,
.rates = DAVINCI_MCASP_RATES,
.formats = SNDRV_PCM_FMTBIT_S8 |
SNDRV_PCM_FMTBIT_S16_LE |
SNDRV_PCM_FMTBIT_S32_LE,
},
.ops = &davinci_mcasp_dai_ops,
},
And in the board config files, there is also a struct that configures the McASP ports:
static u8 da850_iis_serializer_direction[] = {
INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE,
INACTIVE_MODE, INACTIVE_MODE, RX_MODE, TX_MODE,
INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE,
INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE,
};
static struct snd_platform_data da850_evm_snd_data = {
.tx_dma_offset = 0x2000,
.rx_dma_offset = 0x2000,
.op_mode = DAVINCI_MCASP_IIS_MODE,
.num_serializer = ARRAY_SIZE(da850_iis_serializer_direction),
.tdm_slots = 2,
.serial_dir = da850_iis_serializer_direction,
.asp_chan_q = EVENTQ_1,
.version = MCASP_VERSION_2,
.txnumevt = 1,
.rxnumevt = 1,
};
...
da8xx_register_mcasp(0, &da850_evm_snd_data);
Now this part is a complete mystery. To have multiple CODECs, do i need to register multiple instances of the McASP driver and fill in the serializer structs for each? And if not, how does it know which input is for which codec? And what are all the fields? There's no documentation whatsoever, so the above was my best guess to get at least one codec functioning. It sort of seems to do something, but all samples are zero and I get lots of overrun errors when using arecord to capture data from it.
