LXR linux/include/sound/timer.h

   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
  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 tasklet_struct task_queue;
  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 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
 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