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                 def_tmr.expires = (1) + jiffies;
 105                 add_timer(&def_tmr);
 106         }
 107
 108         return 0;
 109 }
 110
 111 static void
 112 def_tmr_close(int dev)
 113 {
 114         opened = tmr_running = 0;
 115         del_timer(&def_tmr);
 116 }
 117
 118 static int
 119 def_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
 180 static unsigned long
 181 def_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!? */
 190 static 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
 260 static void
 261 def_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
 273 struct 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 };