sound/oss/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 <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
  32 static struct timer_list def_tmr = TIMER_INITIALIZER(poll_def_tmr, 0, 0);
  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                                 spin_lock(&lock);
  66                             tmr_ctr++;
  67                             curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);
  68
  69                             if (curr_ticks >= next_event_time)
  70                               {
  71                                       next_event_time = (unsigned long) -1;
  72                                       sequencer_timer(0);
  73                               }
  74                                 spin_unlock(&lock);
  75                     }
  76           }
  77 }
  78
  79 static void
  80 tmr_reset(void)
  81 {
  82         unsigned long   flags;
  83
  84         spin_lock_irqsave(&lock,flags);
  85         tmr_offs = 0;
  86         ticks_offs = 0;
  87         tmr_ctr = 0;
  88         next_event_time = (unsigned long) -1;
  89         prev_event_time = 0;
  90         curr_ticks = 0;
  91         spin_unlock_irqrestore(&lock,flags);
  92 }
  93
  94 static int
  95 def_tmr_open(int dev, int mode)
  96 {
  97         if (opened)
  98                 return -EBUSY;
  99
 100         tmr_reset();
 101         curr_tempo = 60;
 102         curr_timebase = 100;
 103         opened = 1;
 104
 105         ;
 106
 107         {
 108                 def_tmr.expires = (1) + jiffies;
 109                 add_timer(&def_tmr);
 110         };
 111
 112         return 0;
 113 }
 114
 115 static void
 116 def_tmr_close(int dev)
 117 {
 118         opened = tmr_running = 0;
 119         del_timer(&def_tmr);
 120 }
 121
 122 static int
 123 def_tmr_event(int dev, unsigned char *event)
 124 {
 125         unsigned char   cmd = event[1];
 126         unsigned long   parm = *(int *) &event[4];
 127
 128         switch (cmd)
 129           {
 130           case TMR_WAIT_REL:
 131                   parm += prev_event_time;
 132           case TMR_WAIT_ABS:
 133                   if (parm > 0)
 134                     {
 135                             long            time;
 136
 137                             if (parm <= curr_ticks)     /* It's the time */
 138                                     return TIMER_NOT_ARMED;
 139
 140                             time = parm;
 141                             next_event_time = prev_event_time = time;
 142
 143                             return TIMER_ARMED;
 144                     }
 145                   break;
 146
 147           case TMR_START:
 148                   tmr_reset();
 149                   tmr_running = 1;
 150                   break;
 151
 152           case TMR_STOP:
 153                   tmr_running = 0;
 154                   break;
 155
 156           case TMR_CONTINUE:
 157                   tmr_running = 1;
 158                   break;
 159
 160           case TMR_TEMPO:
 161                   if (parm)
 162                     {
 163                             if (parm < 8)
 164                                     parm = 8;
 165                             if (parm > 360)
 166                                     parm = 360;
 167                             tmr_offs = tmr_ctr;
 168                             ticks_offs += tmr2ticks(tmr_ctr);
 169                             tmr_ctr = 0;
 170                             curr_tempo = parm;
 171                     }
 172                   break;
 173
 174           case TMR_ECHO:
 175                   seq_copy_to_input(event, 8);
 176                   break;
 177
 178           default:;
 179           }
 180
 181         return TIMER_NOT_ARMED;
 182 }
 183
 184 static unsigned long
 185 def_tmr_get_time(int dev)
 186 {
 187         if (!opened)
 188                 return 0;
 189
 190         return curr_ticks;
 191 }
 192
 193 /* same as sound_timer.c:timer_ioctl!? */
 194 static int def_tmr_ioctl(int dev, unsigned int cmd, void __user *arg)
 195 {
 196         int __user *p = arg;
 197         int val;
 198
 199         switch (cmd) {
 200         case SNDCTL_TMR_SOURCE:
 201                 return __put_user(TMR_INTERNAL, p);
 202
 203         case SNDCTL_TMR_START:
 204                 tmr_reset();
 205                 tmr_running = 1;
 206                 return 0;
 207
 208         case SNDCTL_TMR_STOP:
 209                 tmr_running = 0;
 210                 return 0;
 211
 212         case SNDCTL_TMR_CONTINUE:
 213                 tmr_running = 1;
 214                 return 0;
 215
 216         case SNDCTL_TMR_TIMEBASE:
 217                 if (__get_user(val, p))
 218                         return -EFAULT;
 219                 if (val) {
 220                         if (val < 1)
 221                                 val = 1;
 222                         if (val > 1000)
 223                                 val = 1000;
 224                         curr_timebase = val;
 225                 }
 226                 return __put_user(curr_timebase, p);
 227
 228         case SNDCTL_TMR_TEMPO:
 229                 if (__get_user(val, p))
 230                         return -EFAULT;
 231                 if (val) {
 232                         if (val < 8)
 233                                 val = 8;
 234                         if (val > 250)
 235                                 val = 250;
 236                         tmr_offs = tmr_ctr;
 237                         ticks_offs += tmr2ticks(tmr_ctr);
 238                         tmr_ctr = 0;
 239                         curr_tempo = val;
 240                         reprogram_timer();
 241                 }
 242                 return __put_user(curr_tempo, p);
 243
 244         case SNDCTL_SEQ_CTRLRATE:
 245                 if (__get_user(val, p))
 246                         return -EFAULT;
 247                 if (val != 0)   /* Can't change */
 248                         return -EINVAL;
 249                 val = ((curr_tempo * curr_timebase) + 30) / 60;
 250                 return __put_user(val, p);
 251
 252         case SNDCTL_SEQ_GETTIME:
 253                 return __put_user(curr_ticks, p);
 254
 255         case SNDCTL_TMR_METRONOME:
 256                 /* NOP */
 257                 break;
 258
 259         default:;
 260         }
 261         return -EINVAL;
 262 }
 263
 264 static void
 265 def_tmr_arm(int dev, long time)
 266 {
 267         if (time < 0)
 268                 time = curr_ticks + 1;
 269         else if (time <= curr_ticks)    /* It's the time */
 270                 return;
 271
 272         next_event_time = prev_event_time = time;
 273
 274         return;
 275 }
 276
 277 struct sound_timer_operations default_sound_timer =
 278 {
 279         .owner          = THIS_MODULE,
 280         .info           = {"System clock", 0},
 281         .priority       = 0,    /* Priority */
 282         .devlink        = 0,    /* Local device link */
 283         .open           = def_tmr_open,
 284         .close          = def_tmr_close,
 285         .event          = def_tmr_event,
 286         .get_time       = def_tmr_get_time,
 287         .ioctl          = def_tmr_ioctl,
 288         .arm_timer      = def_tmr_arm
 289 };