1 /*
2 * sound/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
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
30 static unsigned long tmr2ticks(int tmr_value)
31 {
32 /*
33 * Convert timer ticks to MIDI ticks
34 */
35
36 unsigned long tmp;
37 unsigned long scale;
38
39 tmp = tmr_value * usecs_per_tmr; /* Convert to usecs */
40 scale = (60 * 1000000) / (curr_tempo * curr_timebase); /* usecs per MIDI tick */
41 return (tmp + (scale / 2)) / scale;
42 }
43
44 void reprogram_timer(void)
45 {
46 unsigned long usecs_per_tick;
47
48 /*
49 * The user is changing the timer rate before setting a timer
50 * slap, bad bad not allowed.
51 */
52
53 if(!tmr)
54 return;
55
56 usecs_per_tick = (60 * 1000000) / (curr_tempo * curr_timebase);
57
58 /*
59 * Don't kill the system by setting too high timer rate
60 */
61 if (usecs_per_tick < 2000)
62 usecs_per_tick = 2000;
63
64 usecs_per_tmr = tmr->tmr_start(tmr->dev, usecs_per_tick);
65 }
66
67 void sound_timer_syncinterval(unsigned int new_usecs)
68 {
69 /*
70 * This routine is called by the hardware level if
71 * the clock frequency has changed for some reason.
72 */
73 tmr_offs = tmr_ctr;
74 ticks_offs += tmr2ticks(tmr_ctr);
75 tmr_ctr = 0;
76 usecs_per_tmr = new_usecs;
77 }
78
79 static void tmr_reset(void)
80 {
81 unsigned long flags;
82
83 save_flags(flags);
84 cli();
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 restore_flags(flags);
92 }
93
94 static int timer_open(int dev, int mode)
95 {
96 if (opened)
97 return -EBUSY;
98 tmr_reset();
99 curr_tempo = 60;
100 curr_timebase = 100;
101 opened = 1;
102 reprogram_timer();
103 return 0;
104 }
105
106 static void timer_close(int dev)
107 {
108 opened = tmr_running = 0;
109 tmr->tmr_disable(tmr->dev);
110 }
111
112 static int timer_event(int dev, unsigned char *event)
113 {
114 unsigned char cmd = event[1];
115 unsigned long parm = *(int *) &event[4];
116
117 switch (cmd)
118 {
119 case TMR_WAIT_REL:
120 parm += prev_event_time;
121 case TMR_WAIT_ABS:
122 if (parm > 0)
123 {
124 long time;
125
126 if (parm <= curr_ticks) /* It's the time */
127 return TIMER_NOT_ARMED;
128 time = parm;
129 next_event_time = prev_event_time = time;
130 return TIMER_ARMED;
131 }
132 break;
133
134 case TMR_START:
135 tmr_reset();
136 tmr_running = 1;
137 reprogram_timer();
138 break;
139
140 case TMR_STOP:
141 tmr_running = 0;
142 break;
143
144 case TMR_CONTINUE:
145 tmr_running = 1;
146 reprogram_timer();
147 break;
148
149 case TMR_TEMPO:
150 if (parm)
151 {
152 if (parm < 8)
153 parm = 8;
154 if (parm > 250)
155 parm = 250;
156 tmr_offs = tmr_ctr;
157 ticks_offs += tmr2ticks(tmr_ctr);
158 tmr_ctr = 0;
159 curr_tempo = parm;
160 reprogram_timer();
161 }
162 break;
163
164 case TMR_ECHO:
165 seq_copy_to_input(event, 8);
166 break;
167
168 default:;
169 }
170 return TIMER_NOT_ARMED;
171 }
172
173 static unsigned long timer_get_time(int dev)
174 {
175 if (!opened)
176 return 0;
177 return curr_ticks;
178 }
179
180 static int timer_ioctl(int dev, unsigned int cmd, caddr_t arg)
181 {
182 int val;
183
184 switch (cmd)
185 {
186 case SNDCTL_TMR_SOURCE:
187 val = TMR_INTERNAL;
188 break;
189
190 case SNDCTL_TMR_START:
191 tmr_reset();
192 tmr_running = 1;
193 return 0;
194
195 case SNDCTL_TMR_STOP:
196 tmr_running = 0;
197 return 0;
198
199 case SNDCTL_TMR_CONTINUE:
200 tmr_running = 1;
201 return 0;
202
203 case SNDCTL_TMR_TIMEBASE:
204 if (get_user(val, (int *)arg))
205 return -EFAULT;
206 if (val)
207 {
208 if (val < 1)
209 val = 1;
210 if (val > 1000)
211 val = 1000;
212 curr_timebase = val;
213 }
214 val = curr_timebase;
215 break;
216
217 case SNDCTL_TMR_TEMPO:
218 if (get_user(val, (int *)arg))
219 return -EFAULT;
220 if (val)
221 {
222 if (val < 8)
223 val = 8;
224 if (val > 250)
225 val = 250;
226 tmr_offs = tmr_ctr;
227 ticks_offs += tmr2ticks(tmr_ctr);
228 tmr_ctr = 0;
229 curr_tempo = val;
230 reprogram_timer();
231 }
232 val = curr_tempo;
233 break;
234
235 case SNDCTL_SEQ_CTRLRATE:
236 if (get_user(val, (int *)arg))
237 return -EFAULT;
238 if (val != 0) /* Can't change */
239 return -EINVAL;
240 val = ((curr_tempo * curr_timebase) + 30) / 60;
241 break;
242
243 case SNDCTL_SEQ_GETTIME:
244 val = curr_ticks;
245 break;
246
247 case SNDCTL_TMR_METRONOME:
248 default:
249 return -EINVAL;
250 }
251 return put_user(val, (int *)arg);
252 }
253
254 static void timer_arm(int dev, long time)
255 {
256 if (time < 0)
257 time = curr_ticks + 1;
258 else if (time <= curr_ticks) /* It's the time */
259 return;
260
261 next_event_time = prev_event_time = time;
262 return;
263 }
264
265 static struct sound_timer_operations sound_timer =
266 {
267 owner: THIS_MODULE,
268 info: {"Sound Timer", 0},
269 priority: 1, /* Priority */
270 devlink: 0, /* Local device link */
271 open: timer_open,
272 close: timer_close,
273 event: timer_event,
274 get_time: timer_get_time,
275 ioctl: timer_ioctl,
276 arm_timer: timer_arm
277 };
278
279 void sound_timer_interrupt(void)
280 {
281 if (!opened)
282 return;
283
284 tmr->tmr_restart(tmr->dev);
285
286 if (!tmr_running)
287 return;
288
289 tmr_ctr++;
290 curr_ticks = ticks_offs + tmr2ticks(tmr_ctr);
291
292 if (curr_ticks >= next_event_time)
293 {
294 next_event_time = (unsigned long) -1;
295 sequencer_timer(0);
296 }
297 }
298
299 void sound_timer_init(struct sound_lowlev_timer *t, char *name)
300 {
301 int n;
302
303 if (initialized)
304 {
305 if (t->priority <= tmr->priority)
306 return; /* There is already a similar or better timer */
307 tmr = t;
308 return;
309 }
310 initialized = 1;
311 tmr = t;
312
313 n = sound_alloc_timerdev();
314 if (n == -1)
315 n = 0; /* Overwrite the system timer */
316 strcpy(sound_timer.info.name, name);
317 sound_timer_devs[n] = &sound_timer;
318 }
319
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