sound/core/seq/seq_fifo.h

Source file repositories/reference/linux-study-clean/sound/core/seq/seq_fifo.h

File Facts

System
Linux kernel
Corpus path
sound/core/seq/seq_fifo.h
Extension
.h
Size
1796 bytes
Lines
61
Domain
Driver Families
Bucket
sound/core
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct snd_seq_fifo {
	struct snd_seq_pool *pool;		/* FIFO pool */
	struct snd_seq_event_cell *head;    	/* pointer to head of fifo */
	struct snd_seq_event_cell *tail;    	/* pointer to tail of fifo */
	int cells;
	spinlock_t lock;
	snd_use_lock_t use_lock;
	wait_queue_head_t input_sleep;
	atomic_t overflow;

};

/* create new fifo (constructor) */
struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);

/* delete fifo (destructor) */
void snd_seq_fifo_delete(struct snd_seq_fifo **f);


/* enqueue event to fifo */
int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);

/* lock fifo from release */
#define snd_seq_fifo_lock(fifo)		snd_use_lock_use(&(fifo)->use_lock)
#define snd_seq_fifo_unlock(fifo)	snd_use_lock_free(&(fifo)->use_lock)
DEFINE_GUARD(snd_seq_fifo, struct snd_seq_fifo *, snd_seq_fifo_lock(_T), snd_seq_fifo_unlock(_T))

/* get a cell from fifo - fifo should be locked */
int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);

/* free dequeued cell - fifo should be locked */
void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);

/* clean up queue */
void snd_seq_fifo_clear(struct snd_seq_fifo *f);

/* polling */
int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);

/* resize pool in fifo */
int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);

/* get the number of unused cells safely */
int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);

#endif

Annotation

Implementation Notes