sound/oss/sys_timer.c

   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
  21 static volatile int opened, tmr_running;
  22 static volatile time_t tmr_offs, tmr_ctr;
  23 static volatile unsigned long ticks_offs;
  24 static volatile int curr_tempo, curr_timebase;
  25 static volatile unsigned long curr_ticks;
  26 static volatile unsigned long next_event_time;
  27 static unsigned long prev_event_time;
  28
  29 static void     poll_def_tmr(unsigned long dummy);
  30 static DEFINE_SPINLOCK(lock);
  31 static DEFINE_TIMER(def_tmr, poll_def_tmr, 0, 0);
  32
  33 static unsigned long
  34 tmr2ticks(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
  50 static void
  51 poll_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
  78 static void
  79 tmr_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
  93 static int
  94 def_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
 114 static void
 115 def_tmr_close(int dev)
 116 {
 117         opened = tmr_running = 0;
 118         del_timer(&def_tmr);
 119 }
 120
 121 static int
 122 def_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
 183 static unsigned long
 184 def_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!? */
 193 static 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
 263 static void
 264 def_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
 276 struct 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 };