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                def_tmr.expires = (1) + jiffies;
 105                add_timer(&def_tmr);
 106        };
 107
 108        return 0;
 109}
 110
 111static void
 112def_tmr_close(int dev)
 113{
 114        opened = tmr_running = 0;
 115        del_timer(&def_tmr);
 116}
 117
 118static int
 119def_tmr_event(int dev, unsigned char *event)
 120{
 121        unsigned char   cmd = event[1];
 122        unsigned long   parm = *(int *) &event[4];
 123
 124        switch (cmd)
 125          {
 126          case TMR_WAIT_REL:
 127                  parm += prev_event_time;
 128          case TMR_WAIT_ABS:
 129                  if (parm > 0)
 130                    {
 131                            long            time;
 132
 133                            if (parm <= curr_ticks)     /* It's the time */
 134                                    return TIMER_NOT_ARMED;
 135
 136                            time = parm;
 137                            next_event_time = prev_event_time = time;
 138
 139                            return TIMER_ARMED;
 140                    }
 141                  break;
 142
 143          case TMR_START:
 144                  tmr_reset();
 145                  tmr_running = 1;
 146                  break;
 147
 148          case TMR_STOP:
 149                  tmr_running = 0;
 150                  break;
 151
 152          case TMR_CONTINUE:
 153                  tmr_running = 1;
 154                  break;
 155
 156          case TMR_TEMPO:
 157                  if (parm)
 158                    {
 159                            if (parm < 8)
 160                                    parm = 8;
 161                            if (parm > 360)
 162                                    parm = 360;
 163                            tmr_offs = tmr_ctr;
 164                            ticks_offs += tmr2ticks(tmr_ctr);
 165                            tmr_ctr = 0;
 166                            curr_tempo = parm;
 167                    }
 168                  break;
 169
 170          case TMR_ECHO:
 171                  seq_copy_to_input(event, 8);
 172                  break;
 173
 174          default:;
 175          }
 176
 177        return TIMER_NOT_ARMED;
 178}
 179
 180static unsigned long
 181def_tmr_get_time(int dev)
 182{
 183        if (!opened)
 184                return 0;
 185
 186        return curr_ticks;
 187}
 188
 189/* same as sound_timer.c:timer_ioctl!? */
 190static int def_tmr_ioctl(int dev, unsigned int cmd, void __user *arg)
 191{
 192        int __user *p = arg;
 193        int val;
 194
 195        switch (cmd) {
 196        case SNDCTL_TMR_SOURCE:
 197                return __put_user(TMR_INTERNAL, p);
 198
 199        case SNDCTL_TMR_START:
 200                tmr_reset();
 201                tmr_running = 1;
 202                return 0;
 203
 204        case SNDCTL_TMR_STOP:
 205                tmr_running = 0;
 206                return 0;
 207
 208        case SNDCTL_TMR_CONTINUE:
 209                tmr_running = 1;
 210                return 0;
 211
 212        case SNDCTL_TMR_TIMEBASE:
 213                if (__get_user(val, p))
 214                        return -EFAULT;
 215                if (val) {
 216                        if (val < 1)
 217                                val = 1;
 218                        if (val > 1000)
 219                                val = 1000;
 220                        curr_timebase = val;
 221                }
 222                return __put_user(curr_timebase, p);
 223
 224        case SNDCTL_TMR_TEMPO:
 225                if (__get_user(val, p))
 226                        return -EFAULT;
 227                if (val) {
 228                        if (val < 8)
 229                                val = 8;
 230                        if (val > 250)
 231                                val = 250;
 232                        tmr_offs = tmr_ctr;
 233                        ticks_offs += tmr2ticks(tmr_ctr);
 234                        tmr_ctr = 0;
 235                        curr_tempo = val;
 236                        reprogram_timer();
 237                }
 238                return __put_user(curr_tempo, p);
 239
 240        case SNDCTL_SEQ_CTRLRATE:
 241                if (__get_user(val, p))
 242                        return -EFAULT;
 243                if (val != 0)   /* Can't change */
 244                        return -EINVAL;
 245                val = ((curr_tempo * curr_timebase) + 30) / 60;
 246                return __put_user(val, p);
 247                
 248        case SNDCTL_SEQ_GETTIME:
 249                return __put_user(curr_ticks, p);
 250                
 251        case SNDCTL_TMR_METRONOME:
 252                /* NOP */
 253                break;
 254                
 255        default:;
 256        }
 257        return -EINVAL;
 258}
 259
 260static void
 261def_tmr_arm(int dev, long time)
 262{
 263        if (time < 0)
 264                time = curr_ticks + 1;
 265        else if (time <= curr_ticks)    /* It's the time */
 266                return;
 267
 268        next_event_time = prev_event_time = time;
 269
 270        return;
 271}
 272
 273struct sound_timer_operations default_sound_timer =
 274{
 275        .owner          = THIS_MODULE,
 276        .info           = {"System clock", 0},
 277        .priority       = 0,    /* Priority */
 278        .devlink        = 0,    /* Local device link */
 279        .open           = def_tmr_open,
 280        .close          = def_tmr_close,
 281        .event          = def_tmr_event,
 282        .get_time       = def_tmr_get_time,
 283        .ioctl          = def_tmr_ioctl,
 284        .arm_timer      = def_tmr_arm
 285};
 286
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