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_TASKLET 0x00000010 /* timer is called from tasklet */ 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 tasklet) */ 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 tasklet_struct task_queue; 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 tasklet */ 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