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 
38 struct snd_timer;
39 
40 struct 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 
57 struct 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 
82 struct 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 
115 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
116 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp);
117 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
118 int snd_timer_global_free(struct snd_timer *timer);
119 int snd_timer_global_register(struct snd_timer *timer);
120 
121 struct snd_timer_instance *snd_timer_instance_new(const char *owner);
122 void snd_timer_instance_free(struct snd_timer_instance *timeri);
123 int snd_timer_open(struct snd_timer_instance *timeri, struct snd_timer_id *tid, unsigned int slave_id);
124 void snd_timer_close(struct snd_timer_instance *timeri);
125 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
126 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
127 int snd_timer_stop(struct snd_timer_instance *timeri);
128 int snd_timer_continue(struct snd_timer_instance *timeri);
129 int snd_timer_pause(struct snd_timer_instance *timeri);
130 
131 void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);
132 
133 #endif /* __SOUND_TIMER_H */
134