[alsa-devel] How to use soc API without codec driver

[Marc Garnier]

You mean I just have to use snd_soc_register_dai()? Things like 
soc_init_card() and snd_soc_new_pcms() are not mandatory?
So, i think code like this one could be ok :

#define Q2686_RATES (SNDRV_PCM_RATE_8000_192000)

#define Q2686_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE |\
    SNDRV_PCM_FMTBIT_S24_LE)

static struct snd_soc_dai_ops q2686_dai_ops = {
};

struct snd_soc_dai q2686_dai = {
    .name = "Q2686",
    .playback = {
        .stream_name = "Playback",
        .channels_min = 2,
        .channels_max = 2,
        .rates = Q2686_RATES,
        .formats = Q2686_FORMATS,
    },
    .capture = {
        .stream_name = "Capture",
        .channels_min = 2,
        .channels_max = 2,
        .rates = Q2686_RATES,
        .formats = Q2686_FORMATS,},
    .ops = &wm8728_dai_ops,
};
EXPORT_SYMBOL_GPL(q2686_dai);

static int __init q2686_modinit(void)
{
    return snd_soc_register_dai(&q2686_dai);
}
module_init(q2686_modinit);

static void __exit q2686_exit(void)
{
    snd_soc_unregister_dai(&q2686_dai);
}
module_exit(q2686_exit);

MODULE_DESCRIPTION("ASoC Q2686 driver");
MODULE_AUTHOR("Marc Garnier");
MODULE_LICENSE("GPL");

Mark Brown wrote:
> On Tue, Dec 08, 2009 at 03:46:53PM +0100, Marc Garnier wrote:
>
>   
>> I need to receive and transmit PCM data through SSC port of a sam9261 to 
>> a device which doesn't have any kind of I/O controls (neither i2c nor 
>> spi). So, I wonder how to deal with the codec driver side.
>> Someone could explain me what are the minimum requirements to write a 
>> Asoc driver of this kind?
>>     
>
> There's a couple of drivers for such CODECs in the tree already - have a
> look at the wm8727 driver for one example.  You need to register at
> least a DAI with whatever the capabilities of the hardware are and can
> leave all the operations blank.
>