sound/oss/sound_timer.c

   1 /*
   2  * sound/oss/sound_timer.c
   3  */
   4 /*
   5  * Copyright (C) by Hannu Savolainen 1993-1997
   6  *
   7  * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
   8  * Version 2 (June 1991). See the "COPYING" file distributed with this software
   9  * for more info.
  10  */
  11 /*
  12  * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
  13  */
  14 #include <linux/string.h>
  15 #include <linux/spinlock.h>
  16
  17 #include "sound_config.h"
  18
  19 static volatile int initialized, opened, tmr_running;
  20 static volatile time_t tmr_offs, tmr_ctr;
  21 static volatile unsigned long ticks_offs;
  22 static volatile int curr_tempo, curr_timebase;
  23 static volatile unsigned long curr_ticks;
  24 static volatile unsigned long next_event_time;
  25 static unsigned long prev_event_time;
  26 static volatile unsigned long usecs_per_tmr;    /* Length of the current interval */
  27
  28 static struct sound_lowlev_timer *tmr;
  29 static DEFINE_SPINLOCK(lock);
  30
  31 static unsigned long tmr2ticks(int tmr_value)
  32 {
  33         /*
  34          *    Convert timer ticks to MIDI ticks
  35          */
  36
  37         unsigned long tmp;
  38         unsigned long scale;
  39
  40         tmp = tmr_value * usecs_per_tmr;        /* Convert to usecs */
  41         scale = (60 * 1000000) / (curr_tempo * curr_timebase);  /* usecs per MIDI tick */
  42         return (tmp + (scale / 2)) / scale;
  43 }
  44
  45 void reprogram_timer(void)
  46 {
  47         unsigned long   usecs_per_tick;
  48
  49         /*
  50          *      The user is changing the timer rate before setting a timer
  51          *      slap, bad bad not allowed.
  52          */
  53
  54         if(!tmr)
  55                 return;
  56
  57         usecs_per_tick = (60 * 1000000) / (curr_tempo * curr_timebase);
  58
  59         /*
  60          * Don't kill the system by setting too high timer rate
  61          */
  62         if (usecs_per_tick < 2000)
  63                 usecs_per_tick = 2000;
  64
  65         usecs_per_tmr = tmr->tmr_start(tmr->dev, usecs_per_tick);
  66 }
  67
  68 void sound_timer_syncinterval(unsigned int new_usecs)
  69 {
  70         /*
  71          *    This routine is called by the hardware level if
  72          *      the clock frequency has changed for some reason.
  73          */
  74         tmr_offs = tmr_ctr;
  75         ticks_offs += tmr2ticks(tmr_ctr);
  76         tmr_ctr = 0;
  77         usecs_per_tmr = new_usecs;
  78 }
  79 EXPORT_SYMBOL(sound_timer_syncinterval);
  80
  81 static void tmr_reset(void)
  82 {
  83         unsigned long   flags;
  84
  85         spin_lock_irqsave(&lock,flags);
  86         tmr_offs = 0;
  87         ticks_offs = 0;
  88         tmr_ctr = 0;
  89         next_event_time = (unsigned long) -1;
  90         prev_event_time = 0;
  91         curr_ticks = 0;
  92         spin_unlock_irqrestore(&lock,flags);
  93 }
  94
  95 static int timer_open(int dev, int mode)
  96 {
  97         if (opened)
  98                 return -EBUSY;
  99         tmr_reset();
 100         curr_tempo = 60;
 101         curr_timebase = 100;
 102         opened = 1;
 103         reprogram_timer();
 104         return 0;
 105 }
 106
 107 static void timer_close(int dev)
 108 {
 109         opened = tmr_running = 0;
 110         tmr->tmr_disable(tmr->dev);
 111 }
 112
 113 static int timer_event(int dev, unsigned char *event)
 114 {
 115         unsigned char cmd = event[1];
 116         unsigned long parm = *(int *) &event[4];
 117
 118         switch (cmd)
 119         {
 120                 case TMR_WAIT_REL:
 121                         parm += prev_event_time;
 122                 case TMR_WAIT_ABS:
 123                         if (parm > 0)
 124                         {
 125                                 long time;
 126
 127                                 if (parm <= curr_ticks) /* It's the time */
 128                                         return TIMER_NOT_ARMED;
 129                                 time = parm;
 130                                 next_event_time = prev_event_time = time;
 131                                 return TIMER_ARMED;
 132                         }
 133                         break;
 134
 135                 case TMR_START:
 136                         tmr_reset();
 137                         tmr_running = 1;
 138                         reprogram_timer();
 139                         break;
 140
 141                 case TMR_STOP:
 142                         tmr_running = 0;
 143                         break;
 144
 145                 case TMR_CONTINUE:
 146                         tmr_running = 1;
 147                         reprogram_timer();
 148                         break;
 149
 150                 case TMR_TEMPO:
 151                         if (parm)
 152                         {
 153                                 if (parm < 8)
 154                                         parm = 8;
 155                                 if (parm > 250)
 156                                         parm = 250;
 157                                 tmr_offs = tmr_ctr;
 158                                 ticks_offs += tmr2ticks(tmr_ctr);
 159                                 tmr_ctr = 0;
 160                                 curr_tempo = parm;
 161                                 reprogram_timer();
 162                         }
 163                         break;
 164
 165                 case TMR_ECHO:
 166                         seq_copy_to_input(event, 8);
 167                         break;
 168
 169                 default:;
 170         }
 171         return TIMER_NOT_ARMED;
 172 }
 173
 174 static unsigned long timer_get_time(int dev)
 175 {
 176         if (!opened)
 177                 return 0;
 178         return curr_ticks;
 179 }
 180
 181 static int timer_ioctl(int dev, unsigned int cmd, void __user *arg)
 182 {
 183         int __user *p = arg;
 184         int val;
 185
 186         switch (cmd)
 187         {
 188                 case SNDCTL_TMR_SOURCE:
 189                         val = TMR_INTERNAL;
 190                         break;
 191
 192                 case SNDCTL_TMR_START:
 193                         tmr_reset();
 194                         tmr_running = 1;
 195                         return 0;
 196
 197                 case SNDCTL_TMR_STOP:
 198                         tmr_running = 0;
 199                         return 0;
 200
 201                 case SNDCTL_TMR_CONTINUE:
 202                         tmr_running = 1;
 203                         return 0;
 204
 205                 case SNDCTL_TMR_TIMEBASE:
 206                         if (get_user(val, p))
 207                                 return -EFAULT;
 208                         if (val)
 209                         {
 210                                 if (val < 1)
 211                                         val = 1;
 212                                 if (val > 1000)
 213                                         val = 1000;
 214                                 curr_timebase = val;
 215                         }
 216                         val = curr_timebase;
 217                         break;
 218
 219                 case SNDCTL_TMR_TEMPO:
 220                         if (get_user(val, p))
 221                                 return -EFAULT;
 222                         if (val)
 223                         {
 224                                 if (val < 8)
 225                                         val = 8;
 226                                 if (val > 250)
 227                                         val = 250;
 228                                 tmr_offs = tmr_ctr;
 229                                 ticks_offs += tmr2ticks(tmr_ctr);
 230                                 tmr_ctr = 0;
 231                                 curr_tempo = val;
 232                                 reprogram_timer();
 233                         }
 234                         val = curr_tempo;
 235                         break;
 236
 237                 case SNDCTL_SEQ_CTRLRATE:
 238                         if (get_user(val, p))
 239                                 return -EFAULT;
 240                         if (val != 0)   /* Can't change */
 241                                 return -EINVAL;
 242                         val = ((curr_tempo * curr_timebase) + 30) / 60;
 243                         break;
 244
 245                 case SNDCTL_SEQ_GETTIME:
 246                         val = curr_ticks;
 247                         break;
 248
 249                 case SNDCTL_TMR_METRONOME:
 250                 default:
 251                         return -EINVAL;
 252         }
 253         return put_user(val, p);
 254 }
 255
 256 static void timer_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         return;
 265 }
 266
 267 static struct sound_timer_operations sound_timer =
 268 {
 269         .owner          = THIS_MODULE,
 270         .info           = {"Sound Timer", 0},
 271         .priority       = 1,    /* Priority */
 272         .devlink        = 0,    /* Local device link */
 273         .open           = timer_open,
 274         .close          = timer_close,
 275         .event          = timer_event,
 276         .get_time       = timer_get_time,
 277         .ioctl          = timer_ioctl,
 278         .arm_timer      = timer_arm
 279 };
 280
 281 void sound_timer_interrupt(void)
 282 {
 283         unsigned long flags;
 284
 285         if (!opened)
 286                 return;
 287
 288         tmr->tmr_restart(tmr->dev);
 289
 290         if (!tmr_running)
 291                 return;
 292
 293         spin_lock_irqsave(&lock,flags);
 294         tmr_ctr++;
 295         curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);
 296
 297         if (curr_ticks >= next_event_time)
 298         {
 299                 next_event_time = (unsigned long) -1;
 300                 sequencer_timer(0);
 301         }
 302         spin_unlock_irqrestore(&lock,flags);
 303 }
 304 EXPORT_SYMBOL(sound_timer_interrupt);
 305
 306 void  sound_timer_init(struct sound_lowlev_timer *t, char *name)
 307 {
 308         int n;
 309
 310         if (initialized)
 311         {
 312                 if (t->priority <= tmr->priority)
 313                         return; /* There is already a similar or better timer */
 314                 tmr = t;
 315                 return;
 316         }
 317         initialized = 1;
 318         tmr = t;
 319
 320         n = sound_alloc_timerdev();
 321         if (n == -1)
 322                 n = 0;          /* Overwrite the system timer */
 323         strcpy(sound_timer.info.name, name);
 324         sound_timer_devs[n] = &sound_timer;
 325 }
 326 EXPORT_SYMBOL(sound_timer_init);
 327