int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, struct file *file,
struct snd_pcm_substream **rsubstream);
void snd_pcm_detach_substream(struct snd_pcm_substream *substream);
-void snd_pcm_vma_notify_data(void *client, void *data);
int snd_pcm_mmap_data(struct snd_pcm_substream *substream, struct file *file, struct vm_area_struct *area);
ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples);
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format);
int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int frames);
-snd_pcm_format_t snd_pcm_build_linear_format(int width, int unsigned, int big_endian);
void snd_pcm_set_ops(struct snd_pcm * pcm, int direction,
const struct snd_pcm_ops *ops);
void snd_pcm_set_sync(struct snd_pcm_substream *substream);
-int snd_pcm_lib_interleave_len(struct snd_pcm_substream *substream);
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
unsigned int cmd, void *arg);
int snd_pcm_update_state(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime);
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
-int snd_pcm_playback_xrun_check(struct snd_pcm_substream *substream);
-int snd_pcm_capture_xrun_check(struct snd_pcm_substream *substream);
-int snd_pcm_playback_xrun_asap(struct snd_pcm_substream *substream);
-int snd_pcm_capture_xrun_asap(struct snd_pcm_substream *substream);
void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr);
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream);
snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream,