int snd_ac97_mixer (snd_card_t * card, ac97_t * _ac97, ac97_t ** rac97);
Creates an AC97 codec component. An ac97_t instance is newly allocated and initialized from the template (_ac97). The codec is then initialized by the standard procedure.
The template must include the valid callbacks (at least read and write), the codec number (num) and address (addr), and the private data (private_data). The other callbacks, wait and reset, are not mandatory.
The clock is set to 48000. If another clock is needed, reset ac97->clock manually afterwards.
The ac97 instance is registered as a low-level device, so you don't have to release it manually.
The MCs (Modem Codecs only) are only detected but valid. The PCM driver have to check for MCs using the !ac97_is_audio function.
Returns zero if successful, or a negative error code on failure.