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
tmr2ticks(int tmr_value)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
poll_def_tmr(unsigned long dummy)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
tmr_reset(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
def_tmr_open(int dev,int mode)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
def_tmr_close(int dev)107 def_tmr_close(int dev)
108 {
109 opened = tmr_running = 0;
110 del_timer(&def_tmr);
111 }
112
113 static int
def_tmr_event(int dev,unsigned char * event)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
def_tmr_get_time(int dev)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!? */
def_tmr_ioctl(int dev,unsigned int cmd,void __user * arg)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
def_tmr_arm(int dev,long time)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 };
281