snd_power_wait – wait until the power-state is changed. Synopsis int snd_power_wait(struct snd_card *card, unsigned int power_state); Arguments card soundcard structure power_state expected power state Description Waits until the power-state is changed. Return Zero if successful, or a negative error code. Note the power lock must be active before call. Copyright
snd_pcm_trigger_done – Mark the master substream Synopsis void snd_pcm_trigger_done(struct snd_pcm_substream *substream, struct snd_pcm_substream *master); Arguments substream the pcm substream instance master the linked master substream Description When multiple substreams of the same card are linked and the hardware supports the single-shot operation, the driver calls this in the loop in snd_pcm_group_for_each_entry for marking the substream…
snd_pcm_suspend_all – trigger SUSPEND to all substreams in the given pcm Synopsis int snd_pcm_suspend_all(struct snd_pcm *pcm); Arguments pcm the PCM instance Description After this call, all streams are changed to SUSPENDED state. Return Zero if successful (or pcm is NULL), or a negative error code. Copyright
snd_pcm_suspend – trigger SUSPEND to all linked streams Synopsis int snd_pcm_suspend(struct snd_pcm_substream *substream); Arguments substream the PCM substream Description After this call, all streams are changed to SUSPENDED state. Return Zero if successful (or substream is NULL), or a negative error code. Copyright
snd_pcm_substream_to_dma_direction – Get dma_transfer_direction for a PCM substream Synopsis enum dma_transfer_direction snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream * substream); Arguments substream PCM substream Copyright
snd_pcm_stream_unlock_irqrestore – Unlock the PCM stream Synopsis void snd_pcm_stream_unlock_irqrestore(struct snd_pcm_substream *substream, unsigned long flags); Arguments substream PCM substream flags irq flags Description This is a counter-part of snd_pcm_stream_lock_irqsave. Copyright
snd_pcm_stream_unlock_irq – Unlock the PCM stream Synopsis void snd_pcm_stream_unlock_irq(struct snd_pcm_substream *substream); Arguments substream PCM substream Description This is a counter-part of snd_pcm_stream_lock_irq. Copyright
snd_pcm_stream_unlock – Unlock the PCM stream Synopsis void snd_pcm_stream_unlock(struct snd_pcm_substream *substream); Arguments substream PCM substream Description This unlocks the PCM stream that has been locked via snd_pcm_stream_lock. Copyright
snd_pcm_stream_str – Get a string naming the direction of a stream Synopsis const char *snd_pcm_stream_str(struct snd_pcm_substream *substream); Arguments substream the pcm substream instance Return A string naming the direction of the stream. Copyright
snd_pcm_stream_lock_irqsave – Lock the PCM stream Synopsis snd_pcm_stream_lock_irqsave(substream, flags); Arguments substream PCM substream flags irq flags Description This locks the PCM stream like snd_pcm_stream_lock but with the local IRQ (only when nonatomic is false). In nonatomic case, this is identical as snd_pcm_stream_lock. Copyright
snd_pcm_stream_lock_irq – Lock the PCM stream Synopsis void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream); Arguments substream PCM substream Description This locks the PCM stream like snd_pcm_stream_lock and disables the local IRQ (only when nonatomic is false). In nonatomic case, this is identical as snd_pcm_stream_lock. Copyright
snd_pcm_stream_lock – Lock the PCM stream Synopsis void snd_pcm_stream_lock(struct snd_pcm_substream *substream); Arguments substream PCM substream Description This locks the PCM stream’s spinlock or mutex depending on the nonatomic flag of the given substream. This also takes the global link rw lock (or rw sem), too, for avoiding the race with linked streams. Copyright
snd_pcm_stream_linked – Check whether the substream is linked with others Synopsis int snd_pcm_stream_linked(struct snd_pcm_substream *substream); Arguments substream substream to check Description Returns true if the given substream is being linked with others. Copyright
snd_pcm_stop_xrun – stop the running streams as XRUN Synopsis int snd_pcm_stop_xrun(struct snd_pcm_substream *substream); Arguments substream the PCM substream instance Description This stops the given running substream (and all linked substreams) as XRUN. Unlike snd_pcm_stop, this function takes the substream lock by itself. Return Zero if successful, or a negative error code. Copyright
snd_pcm_stop – try to stop all running streams in the substream group Synopsis int snd_pcm_stop(struct snd_pcm_substream *substream, snd_pcm_state_t state); Arguments substream the PCM substream instance state PCM state after stopping the stream Description The state of each stream is then changed to the given state unconditionally. Return Zero if successful, or a negative error code….
snd_pcm_sgbuf_ops_page – get the page struct at the given offset Synopsis struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset); Arguments substream the pcm substream instance offset the buffer offset Description Used as the page callback of PCM ops. Return The page struct at the given buffer offset. NULL on failure. Copyright
snd_pcm_sgbuf_get_ptr – Get the virtual address at the corresponding offset Synopsis void *snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs); Arguments substream PCM substream ofs byte offset Copyright
snd_pcm_sgbuf_get_chunk_size – Compute the max size that fits within the contig. page from the given size Synopsis unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream, unsigned int ofs, unsigned int size); Arguments substream PCM substream ofs byte offset size byte size to examine Copyright
snd_pcm_sgbuf_get_addr – Get the DMA address at the corresponding offset Synopsis dma_addr_t snd_pcm_sgbuf_get_addr(struct snd_pcm_substream * substream, unsigned int ofs); Arguments substream PCM substream ofs byte offset Copyright
snd_pcm_set_sync – set the PCM sync id Synopsis void snd_pcm_set_sync(struct snd_pcm_substream *substream); Arguments substream the pcm substream Description Sets the PCM sync identifier for the card. Copyright