1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef __SOUND_TIMER_H
3#define __SOUND_TIMER_H
4
5/*
6 *  Timer abstract layer
7 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
8 *		     Abramo Bagnara <abramo@alsa-project.org>
9 */
10
11#include <sound/asound.h>
12#include <linux/interrupt.h>
13
14#define snd_timer_chip(timer) ((timer)->private_data)
15
16#define SNDRV_TIMER_DEVICES	16
17
18#define SNDRV_TIMER_DEV_FLG_PCM	0x10000000
19
20#define SNDRV_TIMER_HW_AUTO	0x00000001	/* auto trigger is supported */
21#define SNDRV_TIMER_HW_STOP	0x00000002	/* call stop before start */
22#define SNDRV_TIMER_HW_SLAVE	0x00000004	/* only slave timer (variable resolution) */
23#define SNDRV_TIMER_HW_FIRST	0x00000008	/* first tick can be incomplete */
24#define SNDRV_TIMER_HW_WORK	0x00000010	/* timer is called from work */
25
26#define SNDRV_TIMER_IFLG_SLAVE	  0x00000001
27#define SNDRV_TIMER_IFLG_RUNNING  0x00000002
28#define SNDRV_TIMER_IFLG_START	  0x00000004
29#define SNDRV_TIMER_IFLG_AUTO	  0x00000008	/* auto restart */
30#define SNDRV_TIMER_IFLG_FAST	  0x00000010	/* fast callback (do not use work) */
31#define SNDRV_TIMER_IFLG_CALLBACK 0x00000020	/* timer callback is active */
32#define SNDRV_TIMER_IFLG_EXCLUSIVE 0x00000040	/* exclusive owner - no more instances */
33#define SNDRV_TIMER_IFLG_EARLY_EVENT 0x00000080	/* write early event to the poll queue */
34
35#define SNDRV_TIMER_FLG_CHANGE	0x00000001
36#define SNDRV_TIMER_FLG_RESCHED	0x00000002	/* need reschedule */
37
38struct snd_timer;
39
40struct snd_timer_hardware {
41	/* -- must be filled with low-level driver */
42	unsigned int flags;		/* various flags */
43	unsigned long resolution;	/* average timer resolution for one tick in nsec */
44	unsigned long resolution_min;	/* minimal resolution */
45	unsigned long resolution_max;	/* maximal resolution */
46	unsigned long ticks;		/* max timer ticks per interrupt */
47	/* -- low-level functions -- */
48	int (*open) (struct snd_timer * timer);
49	int (*close) (struct snd_timer * timer);
50	unsigned long (*c_resolution) (struct snd_timer * timer);
51	int (*start) (struct snd_timer * timer);
52	int (*stop) (struct snd_timer * timer);
53	int (*set_period) (struct snd_timer * timer, unsigned long period_num, unsigned long period_den);
54	int (*precise_resolution) (struct snd_timer * timer, unsigned long *num, unsigned long *den);
55};
56
57struct snd_timer {
58	int tmr_class;
59	struct snd_card *card;
60	struct module *module;
61	int tmr_device;
62	int tmr_subdevice;
63	char id[64];
64	char name[80];
65	unsigned int flags;
66	int running;			/* running instances */
67	unsigned long sticks;		/* schedule ticks */
68	void *private_data;
69	void (*private_free) (struct snd_timer *timer);
70	struct snd_timer_hardware hw;
71	spinlock_t lock;
72	struct list_head device_list;
73	struct list_head open_list_head;
74	struct list_head active_list_head;
75	struct list_head ack_list_head;
76	struct list_head sack_list_head; /* slow ack list head */
77	struct work_struct task_work;
78	int max_instances;	/* upper limit of timer instances */
79	int num_instances;	/* current number of timer instances */
80};
81
82struct snd_timer_instance {
83	struct snd_timer *timer;
84	char *owner;
85	unsigned int flags;
86	void *private_data;
87	void (*private_free) (struct snd_timer_instance *ti);
88	void (*callback) (struct snd_timer_instance *timeri,
89			  unsigned long ticks, unsigned long resolution);
90	void (*ccallback) (struct snd_timer_instance * timeri,
91			   int event,
92			   struct timespec64 * tstamp,
93			   unsigned long resolution);
94	void (*disconnect)(struct snd_timer_instance *timeri);
95	void *callback_data;
96	unsigned long ticks;		/* auto-load ticks when expired */
97	unsigned long cticks;		/* current ticks */
98	unsigned long pticks;		/* accumulated ticks for callback */
99	unsigned long resolution;	/* current resolution for work */
100	unsigned long lost;		/* lost ticks */
101	int slave_class;
102	unsigned int slave_id;
103	struct list_head open_list;
104	struct list_head active_list;
105	struct list_head ack_list;
106	struct list_head slave_list_head;
107	struct list_head slave_active_head;
108	struct snd_timer_instance *master;
109};
110
111/*
112 *  Registering
113 */
114
115int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
116void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp);
117int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
118int snd_timer_global_free(struct snd_timer *timer);
119int snd_timer_global_register(struct snd_timer *timer);
120
121struct snd_timer_instance *snd_timer_instance_new(const char *owner);
122void snd_timer_instance_free(struct snd_timer_instance *timeri);
123int snd_timer_open(struct snd_timer_instance *timeri, struct snd_timer_id *tid, unsigned int slave_id);
124void snd_timer_close(struct snd_timer_instance *timeri);
125unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
126int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
127int snd_timer_stop(struct snd_timer_instance *timeri);
128int snd_timer_continue(struct snd_timer_instance *timeri);
129int snd_timer_pause(struct snd_timer_instance *timeri);
130
131void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);
132
133#endif /* __SOUND_TIMER_H */
134