include/sound/timer.h

Source file repositories/reference/linux-study-clean/include/sound/timer.h

File Facts

System
Linux kernel
Corpus path
include/sound/timer.h
Extension
.h
Size
5372 bytes
Lines
141
Domain
Driver Families
Bucket
include/sound
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_timer_hardware {
	/* -- must be filled with low-level driver */
	unsigned int flags;		/* various flags */
	unsigned long resolution;	/* average timer resolution for one tick in nsec */
	unsigned long resolution_min;	/* minimal resolution */
	unsigned long resolution_max;	/* maximal resolution */
	unsigned long ticks;		/* max timer ticks per interrupt */
	/* -- low-level functions -- */
	int (*open) (struct snd_timer * timer);
	int (*close) (struct snd_timer * timer);
	unsigned long (*c_resolution) (struct snd_timer * timer);
	int (*start) (struct snd_timer * timer);
	int (*stop) (struct snd_timer * timer);
	int (*set_period) (struct snd_timer * timer, unsigned long period_num, unsigned long period_den);
	int (*precise_resolution) (struct snd_timer * timer, unsigned long *num, unsigned long *den);
};

struct snd_timer {
	int tmr_class;
	struct snd_card *card;
	struct module *module;
	int tmr_device;
	int tmr_subdevice;
	char id[64];
	char name[80];
	unsigned int flags;
	int running;			/* running instances */
	unsigned long sticks;		/* schedule ticks */
	void *private_data;
	void (*private_free) (struct snd_timer *timer);
	struct snd_timer_hardware hw;
	spinlock_t lock;
	struct list_head device_list;
	struct list_head open_list_head;
	struct list_head active_list_head;
	struct list_head ack_list_head;
	struct list_head sack_list_head; /* slow ack list head */
	struct work_struct task_work;
	struct kref kref;
	int max_instances;	/* upper limit of timer instances */
	int num_instances;	/* current number of timer instances */
};

struct snd_timer_instance {
	struct snd_timer *timer;
	char *owner;
	unsigned int flags;
	void *private_data;
	void (*private_free) (struct snd_timer_instance *ti);
	void (*callback) (struct snd_timer_instance *timeri,
			  unsigned long ticks, unsigned long resolution);
	void (*ccallback) (struct snd_timer_instance * timeri,
			   int event,
			   struct timespec64 * tstamp,
			   unsigned long resolution);
	void (*disconnect)(struct snd_timer_instance *timeri);
	void *callback_data;
	unsigned long ticks;		/* auto-load ticks when expired */
	unsigned long cticks;		/* current ticks */
	unsigned long pticks;		/* accumulated ticks for callback */
	unsigned long resolution;	/* current resolution for work */
	unsigned long lost;		/* lost ticks */
	int slave_class;
	unsigned int slave_id;
	struct list_head open_list;
	struct list_head active_list;
	struct list_head master_list;
	struct list_head ack_list;
	struct list_head slave_list_head;
	struct list_head slave_active_head;
	struct snd_timer_instance *master;
};

/*
 *  Registering
 */

int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp);
int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
int snd_timer_global_free(struct snd_timer *timer);
int snd_timer_global_register(struct snd_timer *timer);

struct snd_timer_instance *snd_timer_instance_new(const char *owner);
void snd_timer_instance_free(struct snd_timer_instance *timeri);
int snd_timer_open(struct snd_timer_instance *timeri, struct snd_timer_id *tid, unsigned int slave_id);
void snd_timer_close(struct snd_timer_instance *timeri);
unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
int snd_timer_stop(struct snd_timer_instance *timeri);

Annotation

Implementation Notes