1 /*
2 * sound/oss/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 DEFINE_TIMER(poll_timer, 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
drain_midi_queue(int dev)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 wait_event_interruptible_timeout(midi_sleeper[dev],
90 !midi_devs[dev]->buffer_status(dev), HZ/10);
91 }
92
midi_input_intr(int dev,unsigned char data)93 static void midi_input_intr(int dev, unsigned char data)
94 {
95 if (midi_in_buf[dev] == NULL)
96 return;
97
98 if (data == 0xfe) /*
99 * Active sensing
100 */
101 return; /*
102 * Ignore
103 */
104
105 if (SPACE_AVAIL(midi_in_buf[dev])) {
106 QUEUE_BYTE(midi_in_buf[dev], data);
107 wake_up(&input_sleeper[dev]);
108 }
109 }
110
midi_output_intr(int dev)111 static void midi_output_intr(int dev)
112 {
113 /*
114 * Currently NOP
115 */
116 }
117
midi_poll(unsigned long dummy)118 static void midi_poll(unsigned long dummy)
119 {
120 unsigned long flags;
121 int dev;
122
123 spin_lock_irqsave(&lock, flags);
124 if (open_devs)
125 {
126 for (dev = 0; dev < num_midis; dev++)
127 if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL)
128 {
129 while (DATA_AVAIL(midi_out_buf[dev]))
130 {
131 int ok;
132 int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head];
133
134 spin_unlock_irqrestore(&lock,flags);/* Give some time to others */
135 ok = midi_devs[dev]->outputc(dev, c);
136 spin_lock_irqsave(&lock, flags);
137 if (!ok)
138 break;
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
MIDIbuf_open(int dev,struct file * file)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] = 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] = 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
MIDIbuf_release(int dev,struct file * file)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 wait_event_interruptible(midi_sleeper[dev],
236 !DATA_AVAIL(midi_out_buf[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
MIDIbuf_write(int dev,struct file * file,const char __user * buf,int count)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 if (wait_event_interruptible(midi_sleeper[dev],
285 SPACE_AVAIL(midi_out_buf[dev])))
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 - CAN'T 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
MIDIbuf_read(int dev,struct file * file,char __user * buf,int count)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 wait_event_interruptible_timeout(input_sleeper[dev],
328 DATA_AVAIL(midi_in_buf[dev]),
329 parms[dev].prech_timeout);
330
331 if (signal_pending(current))
332 c = -EINTR; /* The user is getting restless */
333 }
334 if (c == 0 && DATA_AVAIL(midi_in_buf[dev])) /*
335 * Got some bytes
336 */
337 {
338 n = DATA_AVAIL(midi_in_buf[dev]);
339 if (n > count)
340 n = count;
341 c = 0;
342
343 while (c < n)
344 {
345 char *fixit;
346 REMOVE_BYTE(midi_in_buf[dev], tmp_data);
347 fixit = (char *) &tmp_data;
348 /* BROKE BROKE BROKE */
349 /* yes removed the cli() brackets again
350 should q->len,tail&head be atomic_t? */
351 if (copy_to_user(&(buf)[c], fixit, 1)) {
352 c = -EFAULT;
353 goto out;
354 }
355 c++;
356 }
357 }
358 out:
359 return c;
360 }
361
MIDIbuf_ioctl(int dev,struct file * file,unsigned int cmd,void __user * arg)362 int MIDIbuf_ioctl(int dev, struct file *file,
363 unsigned int cmd, void __user *arg)
364 {
365 int val;
366
367 dev = dev >> 4;
368
369 if (((cmd >> 8) & 0xff) == 'C')
370 {
371 if (midi_devs[dev]->coproc) /* Coprocessor ioctl */
372 return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0);
373 /* printk("/dev/midi%d: No coprocessor for this device\n", dev);*/
374 return -ENXIO;
375 }
376 else
377 {
378 switch (cmd)
379 {
380 case SNDCTL_MIDI_PRETIME:
381 if (get_user(val, (int __user *)arg))
382 return -EFAULT;
383 if (val < 0)
384 val = 0;
385 val = (HZ * val) / 10;
386 parms[dev].prech_timeout = val;
387 return put_user(val, (int __user *)arg);
388
389 default:
390 if (!midi_devs[dev]->ioctl)
391 return -EINVAL;
392 return midi_devs[dev]->ioctl(dev, cmd, arg);
393 }
394 }
395 }
396
397 /* No kernel lock - fine */
MIDIbuf_poll(int dev,struct file * file,poll_table * wait)398 unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait)
399 {
400 unsigned int mask = 0;
401
402 dev = dev >> 4;
403
404 /* input */
405 poll_wait(file, &input_sleeper[dev], wait);
406 if (DATA_AVAIL(midi_in_buf[dev]))
407 mask |= POLLIN | POLLRDNORM;
408
409 /* output */
410 poll_wait(file, &midi_sleeper[dev], wait);
411 if (!SPACE_AVAIL(midi_out_buf[dev]))
412 mask |= POLLOUT | POLLWRNORM;
413
414 return mask;
415 }
416
417
MIDIbuf_avail(int dev)418 int MIDIbuf_avail(int dev)
419 {
420 if (midi_in_buf[dev])
421 return DATA_AVAIL (midi_in_buf[dev]);
422 return 0;
423 }
424 EXPORT_SYMBOL(MIDIbuf_avail);
425
426