include/sound/timer.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 #ifndef __SOUND_TIMER_H
0003 #define __SOUND_TIMER_H
0004
0005 /*
0006  *  Timer abstract layer
0007  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
0008  *           Abramo Bagnara <abramo@alsa-project.org>
0009  */
0010
0011 #include <sound/asound.h>
0012 #include <linux/interrupt.h>
0013
0014 #define snd_timer_chip(timer) ((timer)->private_data)
0015
0016 #define SNDRV_TIMER_DEVICES 16
0017
0018 #define SNDRV_TIMER_DEV_FLG_PCM 0x10000000
0019
0020 #define SNDRV_TIMER_HW_AUTO 0x00000001  /* auto trigger is supported */
0021 #define SNDRV_TIMER_HW_STOP 0x00000002  /* call stop before start */
0022 #define SNDRV_TIMER_HW_SLAVE    0x00000004  /* only slave timer (variable resolution) */
0023 #define SNDRV_TIMER_HW_FIRST    0x00000008  /* first tick can be incomplete */
0024 #define SNDRV_TIMER_HW_WORK 0x00000010  /* timer is called from work */
0025
0026 #define SNDRV_TIMER_IFLG_SLAVE    0x00000001
0027 #define SNDRV_TIMER_IFLG_RUNNING  0x00000002
0028 #define SNDRV_TIMER_IFLG_START    0x00000004
0029 #define SNDRV_TIMER_IFLG_AUTO     0x00000008    /* auto restart */
0030 #define SNDRV_TIMER_IFLG_FAST     0x00000010    /* fast callback (do not use work) */
0031 #define SNDRV_TIMER_IFLG_CALLBACK 0x00000020    /* timer callback is active */
0032 #define SNDRV_TIMER_IFLG_EXCLUSIVE 0x00000040   /* exclusive owner - no more instances */
0033 #define SNDRV_TIMER_IFLG_EARLY_EVENT 0x00000080 /* write early event to the poll queue */
0034
0035 #define SNDRV_TIMER_FLG_CHANGE  0x00000001
0036 #define SNDRV_TIMER_FLG_RESCHED 0x00000002  /* need reschedule */
0037
0038 struct snd_timer;
0039
0040 struct snd_timer_hardware {
0041     /* -- must be filled with low-level driver */
0042     unsigned int flags;     /* various flags */
0043     unsigned long resolution;   /* average timer resolution for one tick in nsec */
0044     unsigned long resolution_min;   /* minimal resolution */
0045     unsigned long resolution_max;   /* maximal resolution */
0046     unsigned long ticks;        /* max timer ticks per interrupt */
0047     /* -- low-level functions -- */
0048     int (*open) (struct snd_timer * timer);
0049     int (*close) (struct snd_timer * timer);
0050     unsigned long (*c_resolution) (struct snd_timer * timer);
0051     int (*start) (struct snd_timer * timer);
0052     int (*stop) (struct snd_timer * timer);
0053     int (*set_period) (struct snd_timer * timer, unsigned long period_num, unsigned long period_den);
0054     int (*precise_resolution) (struct snd_timer * timer, unsigned long *num, unsigned long *den);
0055 };
0056
0057 struct snd_timer {
0058     int tmr_class;
0059     struct snd_card *card;
0060     struct module *module;
0061     int tmr_device;
0062     int tmr_subdevice;
0063     char id[64];
0064     char name[80];
0065     unsigned int flags;
0066     int running;            /* running instances */
0067     unsigned long sticks;       /* schedule ticks */
0068     void *private_data;
0069     void (*private_free) (struct snd_timer *timer);
0070     struct snd_timer_hardware hw;
0071     spinlock_t lock;
0072     struct list_head device_list;
0073     struct list_head open_list_head;
0074     struct list_head active_list_head;
0075     struct list_head ack_list_head;
0076     struct list_head sack_list_head; /* slow ack list head */
0077     struct work_struct task_work;
0078     int max_instances;  /* upper limit of timer instances */
0079     int num_instances;  /* current number of timer instances */
0080 };
0081
0082 struct snd_timer_instance {
0083     struct snd_timer *timer;
0084     char *owner;
0085     unsigned int flags;
0086     void *private_data;
0087     void (*private_free) (struct snd_timer_instance *ti);
0088     void (*callback) (struct snd_timer_instance *timeri,
0089               unsigned long ticks, unsigned long resolution);
0090     void (*ccallback) (struct snd_timer_instance * timeri,
0091                int event,
0092                struct timespec64 * tstamp,
0093                unsigned long resolution);
0094     void (*disconnect)(struct snd_timer_instance *timeri);
0095     void *callback_data;
0096     unsigned long ticks;        /* auto-load ticks when expired */
0097     unsigned long cticks;       /* current ticks */
0098     unsigned long pticks;       /* accumulated ticks for callback */
0099     unsigned long resolution;   /* current resolution for work */
0100     unsigned long lost;     /* lost ticks */
0101     int slave_class;
0102     unsigned int slave_id;
0103     struct list_head open_list;
0104     struct list_head active_list;
0105     struct list_head ack_list;
0106     struct list_head slave_list_head;
0107     struct list_head slave_active_head;
0108     struct snd_timer_instance *master;
0109 };
0110
0111 /*
0112  *  Registering
0113  */
0114
0115 int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
0116 void snd_timer_notify(struct snd_timer *timer, int event, struct timespec64 *tstamp);
0117 int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
0118 int snd_timer_global_free(struct snd_timer *timer);
0119 int snd_timer_global_register(struct snd_timer *timer);
0120
0121 struct snd_timer_instance *snd_timer_instance_new(const char *owner);
0122 void snd_timer_instance_free(struct snd_timer_instance *timeri);
0123 int snd_timer_open(struct snd_timer_instance *timeri, struct snd_timer_id *tid, unsigned int slave_id);
0124 void snd_timer_close(struct snd_timer_instance *timeri);
0125 unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
0126 int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
0127 int snd_timer_stop(struct snd_timer_instance *timeri);
0128 int snd_timer_continue(struct snd_timer_instance *timeri);
0129 int snd_timer_pause(struct snd_timer_instance *timeri);
0130
0131 void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);
0132
0133 #endif /* __SOUND_TIMER_H */