cregit-Linux how code gets into the kernel

Release 4.12 include/sound/timer.h

Directory: include/sound
#ifndef __SOUND_TIMER_H

#define __SOUND_TIMER_H

 *  Timer abstract layer
 *  Copyright (c) by Jaroslav Kysela <>,
 *                   Abramo Bagnara <>
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   GNU General Public License for more details.
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

#include <sound/asound.h>
#include <linux/interrupt.h>

#define snd_timer_chip(timer) ((timer)->private_data)


#define SNDRV_TIMER_DEV_FLG_PCM	0x10000000

#define SNDRV_TIMER_HW_AUTO	0x00000001	
/* auto trigger is supported */

#define SNDRV_TIMER_HW_STOP	0x00000002	
/* call stop before start */

#define SNDRV_TIMER_HW_SLAVE	0x00000004	
/* only slave timer (variable resolution) */

#define SNDRV_TIMER_HW_FIRST	0x00000008	
/* first tick can be incomplete */

#define SNDRV_TIMER_HW_TASKLET	0x00000010	
/* timer is called from tasklet */

#define SNDRV_TIMER_IFLG_SLAVE	  0x00000001

#define SNDRV_TIMER_IFLG_RUNNING  0x00000002

#define SNDRV_TIMER_IFLG_START	  0x00000004

#define SNDRV_TIMER_IFLG_AUTO	  0x00000008	
/* auto restart */

#define SNDRV_TIMER_IFLG_FAST	  0x00000010	
/* fast callback (do not use tasklet) */

#define SNDRV_TIMER_IFLG_CALLBACK 0x00000020	
/* timer callback is active */

#define SNDRV_TIMER_IFLG_EXCLUSIVE 0x00000040	
/* exclusive owner - no more instances */

#define SNDRV_TIMER_IFLG_EARLY_EVENT 0x00000080	
/* write early event to the poll queue */

#define SNDRV_TIMER_FLG_CHANGE	0x00000001

#define SNDRV_TIMER_FLG_RESCHED	0x00000002	
/* need reschedule */

struct snd_timer;

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 tasklet_struct task_queue;

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 timespec * 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 tasklet */
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 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 timespec *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);

int snd_timer_open(struct snd_timer_instance **ti, char *owner, struct snd_timer_id *tid, unsigned int slave_id);
int 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);
int snd_timer_continue(struct snd_timer_instance *timeri);
int snd_timer_pause(struct snd_timer_instance *timeri);

void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);

#endif /* __SOUND_TIMER_H */

Overall Contributors

Jaroslav Kysela53581.06%770.00%
Takashi Iwai12018.18%220.00%
Clemens Ladisch50.76%110.00%
Directory: include/sound
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.