Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/sound/oss/midibuf.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 8956 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * sound/midibuf.c |
3 | * |
4 | * Device file manager for /dev/midi# |
5 | */ |
6 | /* |
7 | * Copyright (C) by Hannu Savolainen 1993-1997 |
8 | * |
9 | * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL) |
10 | * Version 2 (June 1991). See the "COPYING" file distributed with this software |
11 | * for more info. |
12 | */ |
13 | /* |
14 | * Thomas Sailer : ioctl code reworked (vmalloc/vfree removed) |
15 | */ |
16 | #include <linux/stddef.h> |
17 | #include <linux/kmod.h> |
18 | #include <linux/spinlock.h> |
19 | #define MIDIBUF_C |
20 | |
21 | #include "sound_config.h" |
22 | |
23 | |
24 | /* |
25 | * Don't make MAX_QUEUE_SIZE larger than 4000 |
26 | */ |
27 | |
28 | #define MAX_QUEUE_SIZE 4000 |
29 | |
30 | static wait_queue_head_t midi_sleeper[MAX_MIDI_DEV]; |
31 | static wait_queue_head_t input_sleeper[MAX_MIDI_DEV]; |
32 | |
33 | struct midi_buf |
34 | { |
35 | int len, head, tail; |
36 | unsigned char queue[MAX_QUEUE_SIZE]; |
37 | }; |
38 | |
39 | struct midi_parms |
40 | { |
41 | long prech_timeout; /* |
42 | * Timeout before the first ch |
43 | */ |
44 | }; |
45 | |
46 | static struct midi_buf *midi_out_buf[MAX_MIDI_DEV] = {NULL}; |
47 | static struct midi_buf *midi_in_buf[MAX_MIDI_DEV] = {NULL}; |
48 | static struct midi_parms parms[MAX_MIDI_DEV]; |
49 | |
50 | static void midi_poll(unsigned long dummy); |
51 | |
52 | |
53 | static struct timer_list poll_timer = TIMER_INITIALIZER(midi_poll, 0, 0); |
54 | |
55 | static volatile int open_devs; |
56 | static DEFINE_SPINLOCK(lock); |
57 | |
58 | #define DATA_AVAIL(q) (q->len) |
59 | #define SPACE_AVAIL(q) (MAX_QUEUE_SIZE - q->len) |
60 | |
61 | #define QUEUE_BYTE(q, data) \ |
62 | if (SPACE_AVAIL(q)) \ |
63 | { \ |
64 | unsigned long flags; \ |
65 | spin_lock_irqsave(&lock, flags); \ |
66 | q->queue[q->tail] = (data); \ |
67 | q->len++; q->tail = (q->tail+1) % MAX_QUEUE_SIZE; \ |
68 | spin_unlock_irqrestore(&lock, flags); \ |
69 | } |
70 | |
71 | #define REMOVE_BYTE(q, data) \ |
72 | if (DATA_AVAIL(q)) \ |
73 | { \ |
74 | unsigned long flags; \ |
75 | spin_lock_irqsave(&lock, flags); \ |
76 | data = q->queue[q->head]; \ |
77 | q->len--; q->head = (q->head+1) % MAX_QUEUE_SIZE; \ |
78 | spin_unlock_irqrestore(&lock, flags); \ |
79 | } |
80 | |
81 | static void drain_midi_queue(int dev) |
82 | { |
83 | |
84 | /* |
85 | * Give the Midi driver time to drain its output queues |
86 | */ |
87 | |
88 | if (midi_devs[dev]->buffer_status != NULL) |
89 | while (!signal_pending(current) && midi_devs[dev]->buffer_status(dev)) |
90 | interruptible_sleep_on_timeout(&midi_sleeper[dev], |
91 | HZ/10); |
92 | } |
93 | |
94 | static void midi_input_intr(int dev, unsigned char data) |
95 | { |
96 | if (midi_in_buf[dev] == NULL) |
97 | return; |
98 | |
99 | if (data == 0xfe) /* |
100 | * Active sensing |
101 | */ |
102 | return; /* |
103 | * Ignore |
104 | */ |
105 | |
106 | if (SPACE_AVAIL(midi_in_buf[dev])) { |
107 | QUEUE_BYTE(midi_in_buf[dev], data); |
108 | wake_up(&input_sleeper[dev]); |
109 | } |
110 | } |
111 | |
112 | static void midi_output_intr(int dev) |
113 | { |
114 | /* |
115 | * Currently NOP |
116 | */ |
117 | } |
118 | |
119 | static void midi_poll(unsigned long dummy) |
120 | { |
121 | unsigned long flags; |
122 | int dev; |
123 | |
124 | spin_lock_irqsave(&lock, flags); |
125 | if (open_devs) |
126 | { |
127 | for (dev = 0; dev < num_midis; dev++) |
128 | if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL) |
129 | { |
130 | int ok = 1; |
131 | |
132 | while (DATA_AVAIL(midi_out_buf[dev]) && ok) |
133 | { |
134 | int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head]; |
135 | |
136 | spin_unlock_irqrestore(&lock,flags);/* Give some time to others */ |
137 | ok = midi_devs[dev]->outputc(dev, c); |
138 | spin_lock_irqsave(&lock, flags); |
139 | midi_out_buf[dev]->head = (midi_out_buf[dev]->head + 1) % MAX_QUEUE_SIZE; |
140 | midi_out_buf[dev]->len--; |
141 | } |
142 | |
143 | if (DATA_AVAIL(midi_out_buf[dev]) < 100) |
144 | wake_up(&midi_sleeper[dev]); |
145 | } |
146 | poll_timer.expires = (1) + jiffies; |
147 | add_timer(&poll_timer); |
148 | /* |
149 | * Come back later |
150 | */ |
151 | } |
152 | spin_unlock_irqrestore(&lock, flags); |
153 | } |
154 | |
155 | int MIDIbuf_open(int dev, struct file *file) |
156 | { |
157 | int mode, err; |
158 | |
159 | dev = dev >> 4; |
160 | mode = translate_mode(file); |
161 | |
162 | if (num_midis > MAX_MIDI_DEV) |
163 | { |
164 | printk(KERN_ERR "midi: Too many midi interfaces\n"); |
165 | num_midis = MAX_MIDI_DEV; |
166 | } |
167 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) |
168 | return -ENXIO; |
169 | /* |
170 | * Interrupts disabled. Be careful |
171 | */ |
172 | |
173 | module_put(midi_devs[dev]->owner); |
174 | |
175 | if ((err = midi_devs[dev]->open(dev, mode, |
176 | midi_input_intr, midi_output_intr)) < 0) |
177 | return err; |
178 | |
179 | parms[dev].prech_timeout = MAX_SCHEDULE_TIMEOUT; |
180 | midi_in_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf)); |
181 | |
182 | if (midi_in_buf[dev] == NULL) |
183 | { |
184 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); |
185 | midi_devs[dev]->close(dev); |
186 | return -EIO; |
187 | } |
188 | midi_in_buf[dev]->len = midi_in_buf[dev]->head = midi_in_buf[dev]->tail = 0; |
189 | |
190 | midi_out_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf)); |
191 | |
192 | if (midi_out_buf[dev] == NULL) |
193 | { |
194 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); |
195 | midi_devs[dev]->close(dev); |
196 | vfree(midi_in_buf[dev]); |
197 | midi_in_buf[dev] = NULL; |
198 | return -EIO; |
199 | } |
200 | midi_out_buf[dev]->len = midi_out_buf[dev]->head = midi_out_buf[dev]->tail = 0; |
201 | open_devs++; |
202 | |
203 | init_waitqueue_head(&midi_sleeper[dev]); |
204 | init_waitqueue_head(&input_sleeper[dev]); |
205 | |
206 | if (open_devs < 2) /* This was first open */ |
207 | { |
208 | poll_timer.expires = 1 + jiffies; |
209 | add_timer(&poll_timer); /* Start polling */ |
210 | } |
211 | return err; |
212 | } |
213 | |
214 | void MIDIbuf_release(int dev, struct file *file) |
215 | { |
216 | int mode; |
217 | |
218 | dev = dev >> 4; |
219 | mode = translate_mode(file); |
220 | |
221 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) |
222 | return; |
223 | |
224 | /* |
225 | * Wait until the queue is empty |
226 | */ |
227 | |
228 | if (mode != OPEN_READ) |
229 | { |
230 | midi_devs[dev]->outputc(dev, 0xfe); /* |
231 | * Active sensing to shut the |
232 | * devices |
233 | */ |
234 | |
235 | while (!signal_pending(current) && DATA_AVAIL(midi_out_buf[dev])) |
236 | interruptible_sleep_on(&midi_sleeper[dev]); |
237 | /* |
238 | * Sync |
239 | */ |
240 | |
241 | drain_midi_queue(dev); /* |
242 | * Ensure the output queues are empty |
243 | */ |
244 | } |
245 | |
246 | midi_devs[dev]->close(dev); |
247 | |
248 | open_devs--; |
249 | if (open_devs == 0) |
250 | del_timer_sync(&poll_timer); |
251 | vfree(midi_in_buf[dev]); |
252 | vfree(midi_out_buf[dev]); |
253 | midi_in_buf[dev] = NULL; |
254 | midi_out_buf[dev] = NULL; |
255 | |
256 | module_put(midi_devs[dev]->owner); |
257 | } |
258 | |
259 | int MIDIbuf_write(int dev, struct file *file, const char __user *buf, int count) |
260 | { |
261 | int c, n, i; |
262 | unsigned char tmp_data; |
263 | |
264 | dev = dev >> 4; |
265 | |
266 | if (!count) |
267 | return 0; |
268 | |
269 | c = 0; |
270 | |
271 | while (c < count) |
272 | { |
273 | n = SPACE_AVAIL(midi_out_buf[dev]); |
274 | |
275 | if (n == 0) { /* |
276 | * No space just now. |
277 | */ |
278 | |
279 | if (file->f_flags & O_NONBLOCK) { |
280 | c = -EAGAIN; |
281 | goto out; |
282 | } |
283 | |
284 | interruptible_sleep_on(&midi_sleeper[dev]); |
285 | if (signal_pending(current)) |
286 | { |
287 | c = -EINTR; |
288 | goto out; |
289 | } |
290 | n = SPACE_AVAIL(midi_out_buf[dev]); |
291 | } |
292 | if (n > (count - c)) |
293 | n = count - c; |
294 | |
295 | for (i = 0; i < n; i++) |
296 | { |
297 | /* BROKE BROKE BROKE - CANT DO THIS WITH CLI !! */ |
298 | /* yes, think the same, so I removed the cli() brackets |
299 | QUEUE_BYTE is protected against interrupts */ |
300 | if (copy_from_user((char *) &tmp_data, &(buf)[c], 1)) { |
301 | c = -EFAULT; |
302 | goto out; |
303 | } |
304 | QUEUE_BYTE(midi_out_buf[dev], tmp_data); |
305 | c++; |
306 | } |
307 | } |
308 | out: |
309 | return c; |
310 | } |
311 | |
312 | |
313 | int MIDIbuf_read(int dev, struct file *file, char __user *buf, int count) |
314 | { |
315 | int n, c = 0; |
316 | unsigned char tmp_data; |
317 | |
318 | dev = dev >> 4; |
319 | |
320 | if (!DATA_AVAIL(midi_in_buf[dev])) { /* |
321 | * No data yet, wait |
322 | */ |
323 | if (file->f_flags & O_NONBLOCK) { |
324 | c = -EAGAIN; |
325 | goto out; |
326 | } |
327 | interruptible_sleep_on_timeout(&input_sleeper[dev], |
328 | parms[dev].prech_timeout); |
329 | |
330 | if (signal_pending(current)) |
331 | c = -EINTR; /* The user is getting restless */ |
332 | } |
333 | if (c == 0 && DATA_AVAIL(midi_in_buf[dev])) /* |
334 | * Got some bytes |
335 | */ |
336 | { |
337 | n = DATA_AVAIL(midi_in_buf[dev]); |
338 | if (n > count) |
339 | n = count; |
340 | c = 0; |
341 | |
342 | while (c < n) |
343 | { |
344 | char *fixit; |
345 | REMOVE_BYTE(midi_in_buf[dev], tmp_data); |
346 | fixit = (char *) &tmp_data; |
347 | /* BROKE BROKE BROKE */ |
348 | /* yes removed the cli() brackets again |
349 | should q->len,tail&head be atomic_t? */ |
350 | if (copy_to_user(&(buf)[c], fixit, 1)) { |
351 | c = -EFAULT; |
352 | goto out; |
353 | } |
354 | c++; |
355 | } |
356 | } |
357 | out: |
358 | return c; |
359 | } |
360 | |
361 | int MIDIbuf_ioctl(int dev, struct file *file, |
362 | unsigned int cmd, void __user *arg) |
363 | { |
364 | int val; |
365 | |
366 | dev = dev >> 4; |
367 | |
368 | if (((cmd >> 8) & 0xff) == 'C') |
369 | { |
370 | if (midi_devs[dev]->coproc) /* Coprocessor ioctl */ |
371 | return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0); |
372 | /* printk("/dev/midi%d: No coprocessor for this device\n", dev);*/ |
373 | return -ENXIO; |
374 | } |
375 | else |
376 | { |
377 | switch (cmd) |
378 | { |
379 | case SNDCTL_MIDI_PRETIME: |
380 | if (get_user(val, (int __user *)arg)) |
381 | return -EFAULT; |
382 | if (val < 0) |
383 | val = 0; |
384 | val = (HZ * val) / 10; |
385 | parms[dev].prech_timeout = val; |
386 | return put_user(val, (int __user *)arg); |
387 | |
388 | default: |
389 | if (!midi_devs[dev]->ioctl) |
390 | return -EINVAL; |
391 | return midi_devs[dev]->ioctl(dev, cmd, arg); |
392 | } |
393 | } |
394 | } |
395 | |
396 | /* No kernel lock - fine */ |
397 | unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait) |
398 | { |
399 | unsigned int mask = 0; |
400 | |
401 | dev = dev >> 4; |
402 | |
403 | /* input */ |
404 | poll_wait(file, &input_sleeper[dev], wait); |
405 | if (DATA_AVAIL(midi_in_buf[dev])) |
406 | mask |= POLLIN | POLLRDNORM; |
407 | |
408 | /* output */ |
409 | poll_wait(file, &midi_sleeper[dev], wait); |
410 | if (!SPACE_AVAIL(midi_out_buf[dev])) |
411 | mask |= POLLOUT | POLLWRNORM; |
412 | |
413 | return mask; |
414 | } |
415 | |
416 | |
417 | void MIDIbuf_init(void) |
418 | { |
419 | /* drag in midi_syms.o */ |
420 | { |
421 | extern char midi_syms_symbol; |
422 | midi_syms_symbol = 0; |
423 | } |
424 | } |
425 | |
426 | int MIDIbuf_avail(int dev) |
427 | { |
428 | if (midi_in_buf[dev]) |
429 | return DATA_AVAIL (midi_in_buf[dev]); |
430 | return 0; |
431 | } |