kernel/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         if (!opened)
  54                 return;
  55         def_tmr.expires = (1) + jiffies;
  56         add_timer(&def_tmr);
  57
  58         if (!tmr_running)
  59                 return;
  60
  61         spin_lock(&lock);
  62         tmr_ctr++;
  63         curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);
  64
  65         if (curr_ticks >= next_event_time) {
  66                 next_event_time = (unsigned long) -1;
  67                 sequencer_timer(0);
  68         }
  69
  70         spin_unlock(&lock);
  71 }
  72
  73 static void
  74 tmr_reset(void)
  75 {
  76         unsigned long   flags;
  77
  78         spin_lock_irqsave(&lock,flags);
  79         tmr_offs = 0;
  80         ticks_offs = 0;
  81         tmr_ctr = 0;
  82         next_event_time = (unsigned long) -1;
  83         prev_event_time = 0;
  84         curr_ticks = 0;
  85         spin_unlock_irqrestore(&lock,flags);
  86 }
  87
  88 static int
  89 def_tmr_open(int dev, int mode)
  90 {
  91         if (opened)
  92                 return -EBUSY;
  93
  94         tmr_reset();
  95         curr_tempo = 60;
  96         curr_timebase = 100;
  97         opened = 1;
  98         {
  99                 def_tmr.expires = (1) + jiffies;
 100                 add_timer(&def_tmr);
 101         }
 102
 103         return 0;
 104 }
 105
 106 static void
 107 def_tmr_close(int dev)
 108 {
 109         opened = tmr_running = 0;
 110         del_timer(&def_tmr);
 111 }
 112
 113 static int
 114 def_tmr_event(int dev, unsigned char *event)
 115 {
 116         unsigned char   cmd = event[1];
 117         unsigned long   parm = *(int *) &event[4];
 118
 119         switch (cmd)
 120           {
 121           case TMR_WAIT_REL:
 122                   parm += prev_event_time;
 123           case TMR_WAIT_ABS:
 124                   if (parm > 0)
 125                     {
 126                             long            time;
 127
 128                             if (parm <= curr_ticks)     /* It's the time */
 129                                     return TIMER_NOT_ARMED;
 130
 131                             time = parm;
 132                             next_event_time = prev_event_time = time;
 133
 134                             return TIMER_ARMED;
 135                     }
 136                   break;
 137
 138           case TMR_START:
 139                   tmr_reset();
 140                   tmr_running = 1;
 141                   break;
 142
 143           case TMR_STOP:
 144                   tmr_running = 0;
 145                   break;
 146
 147           case TMR_CONTINUE:
 148                   tmr_running = 1;
 149                   break;
 150
 151           case TMR_TEMPO:
 152                   if (parm)
 153                     {
 154                             if (parm < 8)
 155                                     parm = 8;
 156                             if (parm > 360)
 157                                     parm = 360;
 158                             tmr_offs = tmr_ctr;
 159                             ticks_offs += tmr2ticks(tmr_ctr);
 160                             tmr_ctr = 0;
 161                             curr_tempo = parm;
 162                     }
 163                   break;
 164
 165           case TMR_ECHO:
 166                   seq_copy_to_input(event, 8);
 167                   break;
 168
 169           default:;
 170           }
 171
 172         return TIMER_NOT_ARMED;
 173 }
 174
 175 static unsigned long
 176 def_tmr_get_time(int dev)
 177 {
 178         if (!opened)
 179                 return 0;
 180
 181         return curr_ticks;
 182 }
 183
 184 /* same as sound_timer.c:timer_ioctl!? */
 185 static int def_tmr_ioctl(int dev, unsigned int cmd, void __user *arg)
 186 {
 187         int __user *p = arg;
 188         int val;
 189
 190         switch (cmd) {
 191         case SNDCTL_TMR_SOURCE:
 192                 return __put_user(TMR_INTERNAL, p);
 193
 194         case SNDCTL_TMR_START:
 195                 tmr_reset();
 196                 tmr_running = 1;
 197                 return 0;
 198
 199         case SNDCTL_TMR_STOP:
 200                 tmr_running = 0;
 201                 return 0;
 202
 203         case SNDCTL_TMR_CONTINUE:
 204                 tmr_running = 1;
 205                 return 0;
 206
 207         case SNDCTL_TMR_TIMEBASE:
 208                 if (__get_user(val, p))
 209                         return -EFAULT;
 210                 if (val) {
 211                         if (val < 1)
 212                                 val = 1;
 213                         if (val > 1000)
 214                                 val = 1000;
 215                         curr_timebase = val;
 216                 }
 217                 return __put_user(curr_timebase, p);
 218
 219         case SNDCTL_TMR_TEMPO:
 220                 if (__get_user(val, p))
 221                         return -EFAULT;
 222                 if (val) {
 223                         if (val < 8)
 224                                 val = 8;
 225                         if (val > 250)
 226                                 val = 250;
 227                         tmr_offs = tmr_ctr;
 228                         ticks_offs += tmr2ticks(tmr_ctr);
 229                         tmr_ctr = 0;
 230                         curr_tempo = val;
 231                         reprogram_timer();
 232                 }
 233                 return __put_user(curr_tempo, p);
 234
 235         case SNDCTL_SEQ_CTRLRATE:
 236                 if (__get_user(val, p))
 237                         return -EFAULT;
 238                 if (val != 0)   /* Can't change */
 239                         return -EINVAL;
 240                 val = ((curr_tempo * curr_timebase) + 30) / 60;
 241                 return __put_user(val, p);
 242
 243         case SNDCTL_SEQ_GETTIME:
 244                 return __put_user(curr_ticks, p);
 245
 246         case SNDCTL_TMR_METRONOME:
 247                 /* NOP */
 248                 break;
 249
 250         default:;
 251         }
 252         return -EINVAL;
 253 }
 254
 255 static void
 256 def_tmr_arm(int dev, long time)
 257 {
 258         if (time < 0)
 259                 time = curr_ticks + 1;
 260         else if (time <= curr_ticks)    /* It's the time */
 261                 return;
 262
 263         next_event_time = prev_event_time = time;
 264
 265         return;
 266 }
 267
 268 struct sound_timer_operations default_sound_timer =
 269 {
 270         .owner          = THIS_MODULE,
 271         .info           = {"System clock", 0},
 272         .priority       = 0,    /* Priority */
 273         .devlink        = 0,    /* Local device link */
 274         .open           = def_tmr_open,
 275         .close          = def_tmr_close,
 276         .event          = def_tmr_event,
 277         .get_time       = def_tmr_get_time,
 278         .ioctl          = def_tmr_ioctl,
 279         .arm_timer      = def_tmr_arm
 280 };