File: /usr/src/linux/drivers/sound/sys_timer.c
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 static volatile int opened = 0, tmr_running = 0;
21 static volatile time_t tmr_offs, tmr_ctr;
22 static volatile unsigned long ticks_offs;
23 static volatile int curr_tempo, curr_timebase;
24 static volatile unsigned long curr_ticks;
25 static volatile unsigned long next_event_time;
26 static unsigned long prev_event_time;
27
28 static void poll_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 return 0;
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 return 0;
188
189 return curr_ticks;
190 }
191
192 /* same as sound_timer.c:timer_ioctl!? */
193 static int def_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 return 0;
205
206 case SNDCTL_TMR_STOP:
207 tmr_running = 0;
208 return 0;
209
210 case SNDCTL_TMR_CONTINUE:
211 tmr_running = 1;
212 return 0;
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 };
288