drivers/sound/sys_timer.c

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 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 staticvolatileint opened =0, tmr_running =0;
 21 staticvolatiletime_t tmr_offs, tmr_ctr;
 22 staticvolatileunsigned long ticks_offs;
 23 staticvolatileint curr_tempo, curr_timebase;
 24 staticvolatileunsigned long curr_ticks;
 25 staticvolatileunsigned long next_event_time;
 26 static unsigned long prev_event_time;
 27
 28 static voidpoll_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 return0;
 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 return0;
 188
 189 return curr_ticks;
 190 }
 191
 192 /* same as sound_timer.c:timer_ioctl!? */
 193 static intdef_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 return0;
 205
 206 case SNDCTL_TMR_STOP:
 207  tmr_running =0;
 208 return0;
 209
 210 case SNDCTL_TMR_CONTINUE:
 211  tmr_running =1;
 212 return0;
 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  owner: THIS_MODULE,
 278  info: {"System clock",0},
 279  priority:0,/* Priority */
 280  devlink:0,/* Local device link */
 281  open: def_tmr_open,
 282  close: def_tmr_close,
 283  event: def_tmr_event,
 284  get_time: def_tmr_get_time,
 285  ioctl: def_tmr_ioctl,
 286  arm_timer: def_tmr_arm
 287 };