root/include/sound/timer.h

INCLUDED FROM

   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 timespec * 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 timespec *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 int snd_timer_open(struct snd_timer_instance **ti, char *owner, struct snd_timer_id *tid, unsigned int slave_id);
 122 int snd_timer_close(struct snd_timer_instance *timeri);
 123 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
 124 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
 125 int snd_timer_stop(struct snd_timer_instance *timeri);
 126 int snd_timer_continue(struct snd_timer_instance *timeri);
 127 int snd_timer_pause(struct snd_timer_instance *timeri);
 128 
 129 void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);
 130 
 131 #endif /* __SOUND_TIMER_H */