LXR linux/sound/core/seq/oss/seq_oss

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * OSS compatible sequencer driver
   4 *
   5 * Timer control routines
   6 *
   7 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
   8 */
   9
  10#include "seq_oss_timer.h"
  11#include "seq_oss_event.h"
  12#include <sound/seq_oss_legacy.h>
  13#include <linux/slab.h>
  14
  15/*
  16 */
  17#define MIN_OSS_TEMPO           8
  18#define MAX_OSS_TEMPO           360
  19#define MIN_OSS_TIMEBASE        1
  20#define MAX_OSS_TIMEBASE        1000
  21
  22/*
  23 */
  24static void calc_alsa_tempo(struct seq_oss_timer *timer);
  25static int send_timer_event(struct seq_oss_devinfo *dp, int type, int value);
  26
  27
  28/*
  29 * create and register a new timer.
  30 * if queue is not started yet, start it.
  31 */
  32struct seq_oss_timer *
  33snd_seq_oss_timer_new(struct seq_oss_devinfo *dp)
  34{
  35        struct seq_oss_timer *rec;
  36
  37        rec = kzalloc(sizeof(*rec), GFP_KERNEL);
  38        if (rec == NULL)
  39                return NULL;
  40
  41        rec->dp = dp;
  42        rec->cur_tick = 0;
  43        rec->realtime = 0;
  44        rec->running = 0;
  45        rec->oss_tempo = 60;
  46        rec->oss_timebase = 100;
  47        calc_alsa_tempo(rec);
  48
  49        return rec;
  50}
  51
  52
  53/*
  54 * delete timer.
  55 * if no more timer exists, stop the queue.
  56 */
  57void
  58snd_seq_oss_timer_delete(struct seq_oss_timer *rec)
  59{
  60        if (rec) {
  61                snd_seq_oss_timer_stop(rec);
  62                kfree(rec);
  63        }
  64}
  65
  66
  67/*
  68 * process one timing event
  69 * return 1 : event proceseed -- skip this event
  70 *        0 : not a timer event -- enqueue this event
  71 */
  72int
  73snd_seq_oss_process_timer_event(struct seq_oss_timer *rec, union evrec *ev)
  74{
  75        abstime_t parm = ev->t.time;
  76
  77        if (ev->t.code == EV_TIMING) {
  78                switch (ev->t.cmd) {
  79                case TMR_WAIT_REL:
  80                        parm += rec->cur_tick;
  81                        rec->realtime = 0;
  82                        fallthrough;
  83                case TMR_WAIT_ABS:
  84                        if (parm == 0) {
  85                                rec->realtime = 1;
  86                        } else if (parm >= rec->cur_tick) {
  87                                rec->realtime = 0;
  88                                rec->cur_tick = parm;
  89                        }
  90                        return 1;       /* skip this event */
  91                        
  92                case TMR_START:
  93                        snd_seq_oss_timer_start(rec);
  94                        return 1;
  95
  96                }
  97        } else if (ev->s.code == SEQ_WAIT) {
  98                /* time = from 1 to 3 bytes */
  99                parm = (ev->echo >> 8) & 0xffffff;
 100                if (parm > rec->cur_tick) {
 101                        /* set next event time */
 102                        rec->cur_tick = parm;
 103                        rec->realtime = 0;
 104                }
 105                return 1;
 106        }
 107
 108        return 0;
 109}
 110
 111
 112/*
 113 * convert tempo units
 114 */
 115static void
 116calc_alsa_tempo(struct seq_oss_timer *timer)
 117{
 118        timer->tempo = (60 * 1000000) / timer->oss_tempo;
 119        timer->ppq = timer->oss_timebase;
 120}
 121
 122
 123/*
 124 * dispatch a timer event
 125 */
 126static int
 127send_timer_event(struct seq_oss_devinfo *dp, int type, int value)
 128{
 129        struct snd_seq_event ev;
 130
 131        memset(&ev, 0, sizeof(ev));
 132        ev.type = type;
 133        ev.source.client = dp->cseq;
 134        ev.source.port = 0;
 135        ev.dest.client = SNDRV_SEQ_CLIENT_SYSTEM;
 136        ev.dest.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
 137        ev.queue = dp->queue;
 138        ev.data.queue.queue = dp->queue;
 139        ev.data.queue.param.value = value;
 140        return snd_seq_kernel_client_dispatch(dp->cseq, &ev, 1, 0);
 141}
 142
 143/*
 144 * set queue tempo and start queue
 145 */
 146int
 147snd_seq_oss_timer_start(struct seq_oss_timer *timer)
 148{
 149        struct seq_oss_devinfo *dp = timer->dp;
 150        struct snd_seq_queue_tempo tmprec;
 151
 152        if (timer->running)
 153                snd_seq_oss_timer_stop(timer);
 154
 155        memset(&tmprec, 0, sizeof(tmprec));
 156        tmprec.queue = dp->queue;
 157        tmprec.ppq = timer->ppq;
 158        tmprec.tempo = timer->tempo;
 159        snd_seq_set_queue_tempo(dp->cseq, &tmprec);
 160
 161        send_timer_event(dp, SNDRV_SEQ_EVENT_START, 0);
 162        timer->running = 1;
 163        timer->cur_tick = 0;
 164        return 0;
 165}
 166
 167
 168/*
 169 * stop queue
 170 */
 171int
 172snd_seq_oss_timer_stop(struct seq_oss_timer *timer)
 173{
 174        if (! timer->running)
 175                return 0;
 176        send_timer_event(timer->dp, SNDRV_SEQ_EVENT_STOP, 0);
 177        timer->running = 0;
 178        return 0;
 179}
 180
 181
 182/*
 183 * continue queue
 184 */
 185int
 186snd_seq_oss_timer_continue(struct seq_oss_timer *timer)
 187{
 188        if (timer->running)
 189                return 0;
 190        send_timer_event(timer->dp, SNDRV_SEQ_EVENT_CONTINUE, 0);
 191        timer->running = 1;
 192        return 0;
 193}
 194
 195
 196/*
 197 * change queue tempo
 198 */
 199int
 200snd_seq_oss_timer_tempo(struct seq_oss_timer *timer, int value)
 201{
 202        if (value < MIN_OSS_TEMPO)
 203                value = MIN_OSS_TEMPO;
 204        else if (value > MAX_OSS_TEMPO)
 205                value = MAX_OSS_TEMPO;
 206        timer->oss_tempo = value;
 207        calc_alsa_tempo(timer);
 208        if (timer->running)
 209                send_timer_event(timer->dp, SNDRV_SEQ_EVENT_TEMPO, timer->tempo);
 210        return 0;
 211}
 212
 213
 214/*
 215 * ioctls
 216 */
 217int
 218snd_seq_oss_timer_ioctl(struct seq_oss_timer *timer, unsigned int cmd, int __user *arg)
 219{
 220        int value;
 221
 222        if (cmd == SNDCTL_SEQ_CTRLRATE) {
 223                /* if *arg == 0, just return the current rate */
 224                if (get_user(value, arg))
 225                        return -EFAULT;
 226                if (value)
 227                        return -EINVAL;
 228                value = ((timer->oss_tempo * timer->oss_timebase) + 30) / 60;
 229                return put_user(value, arg) ? -EFAULT : 0;
 230        }
 231
 232        if (timer->dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
 233                return 0;
 234
 235        switch (cmd) {
 236        case SNDCTL_TMR_START:
 237                return snd_seq_oss_timer_start(timer);
 238        case SNDCTL_TMR_STOP:
 239                return snd_seq_oss_timer_stop(timer);
 240        case SNDCTL_TMR_CONTINUE:
 241                return snd_seq_oss_timer_continue(timer);
 242        case SNDCTL_TMR_TEMPO:
 243                if (get_user(value, arg))
 244                        return -EFAULT;
 245                return snd_seq_oss_timer_tempo(timer, value);
 246        case SNDCTL_TMR_TIMEBASE:
 247                if (get_user(value, arg))
 248                        return -EFAULT;
 249                if (value < MIN_OSS_TIMEBASE)
 250                        value = MIN_OSS_TIMEBASE;
 251                else if (value > MAX_OSS_TIMEBASE)
 252                        value = MAX_OSS_TIMEBASE;
 253                timer->oss_timebase = value;
 254                calc_alsa_tempo(timer);
 255                return 0;
 256
 257        case SNDCTL_TMR_METRONOME:
 258        case SNDCTL_TMR_SELECT:
 259        case SNDCTL_TMR_SOURCE:
 260                /* not supported */
 261                return 0;
 262        }
 263        return 0;
 264}
 265