drivers/sound/sys_timer.c

   1 /*
   2  * sound/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 "sound_config.h"
  19
  20 static volatile int opened = 0, tmr_running = 0;
  21 static volatile time_t tmr_offs, tmr_ctr;
  22 static volatile unsigned long ticks_offs;
  23 static volatile int curr_tempo, curr_timebase;
  24 static volatile unsigned long curr_ticks;
  25 static volatile unsigned long next_event_time;
  26 static unsigned long prev_event_time;
  27
  28 static void     poll_def_tmr(unsigned long dummy);
  29
  30
  31 static struct timer_list def_tmr =
  32 {function: poll_def_tmr};
  33
  34 static unsigned long
  35 tmr2ticks(int tmr_value)
  36 {
  37         /*
  38          *    Convert timer ticks to MIDI ticks
  39          */
  40
  41         unsigned long tmp;
  42         unsigned long scale;
  43
  44         /* tmr_value (ticks per sec) *
  45            1000000 (usecs per sec) / HZ (ticks per sec) -=> usecs */
  46         tmp = tmr_value * (1000000 / HZ);
  47         scale = (60 * 1000000) / (curr_tempo * curr_timebase);  /* usecs per MIDI tick */
  48         return (tmp + scale / 2) / scale;
  49 }
  50
  51 static void
  52 poll_def_tmr(unsigned long dummy)
  53 {
  54
  55         if (opened)
  56           {
  57
  58                   {
  59                           def_tmr.expires = (1) + jiffies;
  60                           add_timer(&def_tmr);
  61                   };
  62
  63                   if (tmr_running)
  64                     {
  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                     }
  74           }
  75 }
  76
  77 static void
  78 tmr_reset(void)
  79 {
  80         unsigned long   flags;
  81
  82         save_flags(flags);
  83         cli();
  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         restore_flags(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, caddr_t arg)
 194 {
 195         int val;
 196
 197         switch (cmd) {
 198         case SNDCTL_TMR_SOURCE:
 199                 return __put_user(TMR_INTERNAL, (int *)arg);
 200
 201         case SNDCTL_TMR_START:
 202                 tmr_reset();
 203                 tmr_running = 1;
 204                 return 0;
 205
 206         case SNDCTL_TMR_STOP:
 207                 tmr_running = 0;
 208                 return 0;
 209
 210         case SNDCTL_TMR_CONTINUE:
 211                 tmr_running = 1;
 212                 return 0;
 213
 214         case SNDCTL_TMR_TIMEBASE:
 215                 if (__get_user(val, (int *)arg))
 216                         return -EFAULT;
 217                 if (val) {
 218                         if (val < 1)
 219                                 val = 1;
 220                         if (val > 1000)
 221                                 val = 1000;
 222                         curr_timebase = val;
 223                 }
 224                 return __put_user(curr_timebase, (int *)arg);
 225
 226         case SNDCTL_TMR_TEMPO:
 227                 if (__get_user(val, (int *)arg))
 228                         return -EFAULT;
 229                 if (val) {
 230                         if (val < 8)
 231                                 val = 8;
 232                         if (val > 250)
 233                                 val = 250;
 234                         tmr_offs = tmr_ctr;
 235                         ticks_offs += tmr2ticks(tmr_ctr);
 236                         tmr_ctr = 0;
 237                         curr_tempo = val;
 238                         reprogram_timer();
 239                 }
 240                 return __put_user(curr_tempo, (int *)arg);
 241
 242         case SNDCTL_SEQ_CTRLRATE:
 243                 if (__get_user(val, (int *)arg))
 244                         return -EFAULT;
 245                 if (val != 0)   /* Can't change */
 246                         return -EINVAL;
 247                 val = ((curr_tempo * curr_timebase) + 30) / 60;
 248                 return __put_user(val, (int *)arg);
 249
 250         case SNDCTL_SEQ_GETTIME:
 251                 return __put_user(curr_ticks, (int *)arg);
 252
 253         case SNDCTL_TMR_METRONOME:
 254                 /* NOP */
 255                 break;
 256
 257         default:;
 258         }
 259         return -EINVAL;
 260 }
 261
 262 static void
 263 def_tmr_arm(int dev, long time)
 264 {
 265         if (time < 0)
 266                 time = curr_ticks + 1;
 267         else if (time <= curr_ticks)    /* It's the time */
 268                 return;
 269
 270         next_event_time = prev_event_time = time;
 271
 272         return;
 273 }
 274
 275 struct sound_timer_operations default_sound_timer =
 276 {
 277         {"System clock", 0},
 278         0,                      /* Priority */
 279         0,                      /* Local device link */
 280         def_tmr_open,
 281         def_tmr_close,
 282         def_tmr_event,
 283         def_tmr_get_time,
 284         def_tmr_ioctl,
 285         def_tmr_arm
 286 };