linux/sound/oss/sys_timer.c
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   1/*
   2 * sound/oss/sys_timer.c
   3 *
   4 * The default timer for the Level 2 sequencer interface
   5 * Uses the (1/HZ sec) timer of kernel.
   6 */
   7/*
   8 * Copyright (C) by Hannu Savolainen 1993-1997
   9 *
  10 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
  11 * Version 2 (June 1991). See the "COPYING" file distributed with this software
  12 * for more info.
  13 */
  14/*
  15 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
  16 * Andrew Veliath  : adapted tmr2ticks from level 1 sequencer (avoid overflow)
  17 */
  18#include <linux/spinlock.h>
  19#include "sound_config.h"
  20
  21static volatile int opened, tmr_running;
  22static volatile time_t tmr_offs, tmr_ctr;
  23static volatile unsigned long ticks_offs;
  24static volatile int curr_tempo, curr_timebase;
  25static volatile unsigned long curr_ticks;
  26static volatile unsigned long next_event_time;
  27static unsigned long prev_event_time;
  28
  29static void     poll_def_tmr(unsigned long dummy);
  30static DEFINE_SPINLOCK(lock);
  31static DEFINE_TIMER(def_tmr, poll_def_tmr, 0, 0);
  32
  33static unsigned long
  34tmr2ticks(int tmr_value)
  35{
  36        /*
  37         *    Convert timer ticks to MIDI ticks
  38         */
  39
  40        unsigned long tmp;
  41        unsigned long scale;
  42
  43        /* tmr_value (ticks per sec) *
  44           1000000 (usecs per sec) / HZ (ticks per sec) -=> usecs */
  45        tmp = tmr_value * (1000000 / HZ);
  46        scale = (60 * 1000000) / (curr_tempo * curr_timebase);  /* usecs per MIDI tick */
  47        return (tmp + scale / 2) / scale;
  48}
  49
  50static void
  51poll_def_tmr(unsigned long dummy)
  52{
  53
  54        if (opened)
  55          {
  56
  57                  {
  58                          def_tmr.expires = (1) + jiffies;
  59                          add_timer(&def_tmr);
  60                  };
  61
  62                  if (tmr_running)
  63                    {
  64                                spin_lock(&lock);
  65                            tmr_ctr++;
  66                            curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);
  67
  68                            if (curr_ticks >= next_event_time)
  69                              {
  70                                      next_event_time = (unsigned long) -1;
  71                                      sequencer_timer(0);
  72                              }
  73                                spin_unlock(&lock);
  74                    }
  75          }
  76}
  77
  78static void
  79tmr_reset(void)
  80{
  81        unsigned long   flags;
  82
  83        spin_lock_irqsave(&lock,flags);
  84        tmr_offs = 0;
  85        ticks_offs = 0;
  86        tmr_ctr = 0;
  87        next_event_time = (unsigned long) -1;
  88        prev_event_time = 0;
  89        curr_ticks = 0;
  90        spin_unlock_irqrestore(&lock,flags);
  91}
  92
  93static int
  94def_tmr_open(int dev, int mode)
  95{
  96        if (opened)
  97                return -EBUSY;
  98
  99        tmr_reset();
 100        curr_tempo = 60;
 101        curr_timebase = 100;
 102        opened = 1;
 103
 104        ;
 105
 106        {
 107                def_tmr.expires = (1) + jiffies;
 108                add_timer(&def_tmr);
 109        };
 110
 111        return 0;
 112}
 113
 114static void
 115def_tmr_close(int dev)
 116{
 117        opened = tmr_running = 0;
 118        del_timer(&def_tmr);
 119}
 120
 121static int
 122def_tmr_event(int dev, unsigned char *event)
 123{
 124        unsigned char   cmd = event[1];
 125        unsigned long   parm = *(int *) &event[4];
 126
 127        switch (cmd)
 128          {
 129          case TMR_WAIT_REL:
 130                  parm += prev_event_time;
 131          case TMR_WAIT_ABS:
 132                  if (parm > 0)
 133                    {
 134                            long            time;
 135
 136                            if (parm <= curr_ticks)     /* It's the time */
 137                                    return TIMER_NOT_ARMED;
 138
 139                            time = parm;
 140                            next_event_time = prev_event_time = time;
 141
 142                            return TIMER_ARMED;
 143                    }
 144                  break;
 145
 146          case TMR_START:
 147                  tmr_reset();
 148                  tmr_running = 1;
 149                  break;
 150
 151          case TMR_STOP:
 152                  tmr_running = 0;
 153                  break;
 154
 155          case TMR_CONTINUE:
 156                  tmr_running = 1;
 157                  break;
 158
 159          case TMR_TEMPO:
 160                  if (parm)
 161                    {
 162                            if (parm < 8)
 163                                    parm = 8;
 164                            if (parm > 360)
 165                                    parm = 360;
 166                            tmr_offs = tmr_ctr;
 167                            ticks_offs += tmr2ticks(tmr_ctr);
 168                            tmr_ctr = 0;
 169                            curr_tempo = parm;
 170                    }
 171                  break;
 172
 173          case TMR_ECHO:
 174                  seq_copy_to_input(event, 8);
 175                  break;
 176
 177          default:;
 178          }
 179
 180        return TIMER_NOT_ARMED;
 181}
 182
 183static unsigned long
 184def_tmr_get_time(int dev)
 185{
 186        if (!opened)
 187                return 0;
 188
 189        return curr_ticks;
 190}
 191
 192/* same as sound_timer.c:timer_ioctl!? */
 193static int def_tmr_ioctl(int dev, unsigned int cmd, void __user *arg)
 194{
 195        int __user *p = arg;
 196        int val;
 197
 198        switch (cmd) {
 199        case SNDCTL_TMR_SOURCE:
 200                return __put_user(TMR_INTERNAL, p);
 201
 202        case SNDCTL_TMR_START:
 203                tmr_reset();
 204                tmr_running = 1;
 205                return 0;
 206
 207        case SNDCTL_TMR_STOP:
 208                tmr_running = 0;
 209                return 0;
 210
 211        case SNDCTL_TMR_CONTINUE:
 212                tmr_running = 1;
 213                return 0;
 214
 215        case SNDCTL_TMR_TIMEBASE:
 216                if (__get_user(val, p))
 217                        return -EFAULT;
 218                if (val) {
 219                        if (val < 1)
 220                                val = 1;
 221                        if (val > 1000)
 222                                val = 1000;
 223                        curr_timebase = val;
 224                }
 225                return __put_user(curr_timebase, p);
 226
 227        case SNDCTL_TMR_TEMPO:
 228                if (__get_user(val, p))
 229                        return -EFAULT;
 230                if (val) {
 231                        if (val < 8)
 232                                val = 8;
 233                        if (val > 250)
 234                                val = 250;
 235                        tmr_offs = tmr_ctr;
 236                        ticks_offs += tmr2ticks(tmr_ctr);
 237                        tmr_ctr = 0;
 238                        curr_tempo = val;
 239                        reprogram_timer();
 240                }
 241                return __put_user(curr_tempo, p);
 242
 243        case SNDCTL_SEQ_CTRLRATE:
 244                if (__get_user(val, p))
 245                        return -EFAULT;
 246                if (val != 0)   /* Can't change */
 247                        return -EINVAL;
 248                val = ((curr_tempo * curr_timebase) + 30) / 60;
 249                return __put_user(val, p);
 250                
 251        case SNDCTL_SEQ_GETTIME:
 252                return __put_user(curr_ticks, p);
 253                
 254        case SNDCTL_TMR_METRONOME:
 255                /* NOP */
 256                break;
 257                
 258        default:;
 259        }
 260        return -EINVAL;
 261}
 262
 263static void
 264def_tmr_arm(int dev, long time)
 265{
 266        if (time < 0)
 267                time = curr_ticks + 1;
 268        else if (time <= curr_ticks)    /* It's the time */
 269                return;
 270
 271        next_event_time = prev_event_time = time;
 272
 273        return;
 274}
 275
 276struct sound_timer_operations default_sound_timer =
 277{
 278        .owner          = THIS_MODULE,
 279        .info           = {"System clock", 0},
 280        .priority       = 0,    /* Priority */
 281        .devlink        = 0,    /* Local device link */
 282        .open           = def_tmr_open,
 283        .close          = def_tmr_close,
 284        .event          = def_tmr_event,
 285        .get_time       = def_tmr_get_time,
 286        .ioctl          = def_tmr_ioctl,
 287        .arm_timer      = def_tmr_arm
 288};
 289
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