aboutsummaryrefslogtreecommitdiffstats
path: root/sound/oss/midibuf.c
blob: 782b3b84dac68ccd036c52ee3533336f243ac15b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
/*
 * sound/oss/midibuf.c
 *
 * Device file manager for /dev/midi#
 */
/*
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 */
/*
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 */
#include <linux/stddef.h>
#include <linux/kmod.h>
#include <linux/spinlock.h>
#define MIDIBUF_C

#include "sound_config.h"


/*
 * Don't make MAX_QUEUE_SIZE larger than 4000
 */

#define MAX_QUEUE_SIZE	4000

static wait_queue_head_t midi_sleeper[MAX_MIDI_DEV];
static wait_queue_head_t input_sleeper[MAX_MIDI_DEV];

struct midi_buf
{
	int len, head, tail;
	unsigned char queue[MAX_QUEUE_SIZE];
};

struct midi_parms
{
	long prech_timeout;	/*
				 * Timeout before the first ch
				 */
};

static struct midi_buf *midi_out_buf[MAX_MIDI_DEV] = {NULL};
static struct midi_buf *midi_in_buf[MAX_MIDI_DEV] = {NULL};
static struct midi_parms parms[MAX_MIDI_DEV];

static void midi_poll(unsigned long dummy);


static DEFINE_TIMER(poll_timer, midi_poll, 0, 0);

static volatile int open_devs;
static DEFINE_SPINLOCK(lock);

#define DATA_AVAIL(q) (q->len)
#define SPACE_AVAIL(q) (MAX_QUEUE_SIZE - q->len)

#define QUEUE_BYTE(q, data) \
	if (SPACE_AVAIL(q)) \
	{ \
	  unsigned long flags; \
	  spin_lock_irqsave(&lock, flags); \
	  q->queue[q->tail] = (data); \
	  q->len++; q->tail = (q->tail+1) % MAX_QUEUE_SIZE; \
	  spin_unlock_irqrestore(&lock, flags); \
	}

#define REMOVE_BYTE(q, data) \
	if (DATA_AVAIL(q)) \
	{ \
	  unsigned long flags; \
	  spin_lock_irqsave(&lock, flags); \
	  data = q->queue[q->head]; \
	  q->len--; q->head = (q->head+1) % MAX_QUEUE_SIZE; \
	  spin_unlock_irqrestore(&lock, flags); \
	}

static void drain_midi_queue(int dev)
{

	/*
	 * Give the Midi driver time to drain its output queues
	 */

	if (midi_devs[dev]->buffer_status != NULL)
		while (!signal_pending(current) && midi_devs[dev]->buffer_status(dev)) 
			interruptible_sleep_on_timeout(&midi_sleeper[dev],
						       HZ/10);
}

static void midi_input_intr(int dev, unsigned char data)
{
	if (midi_in_buf[dev] == NULL)
		return;

	if (data == 0xfe)	/*
				 * Active sensing
				 */
		return;		/*
				 * Ignore
				 */

	if (SPACE_AVAIL(midi_in_buf[dev])) {
		QUEUE_BYTE(midi_in_buf[dev], data);
		wake_up(&input_sleeper[dev]);
	}
}

static void midi_output_intr(int dev)
{
	/*
	 * Currently NOP
	 */
}

static void midi_poll(unsigned long dummy)
{
	unsigned long   flags;
	int             dev;

	spin_lock_irqsave(&lock, flags);
	if (open_devs)
	{
		for (dev = 0; dev < num_midis; dev++)
			if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL)
			{
				while (DATA_AVAIL(midi_out_buf[dev]))
				{
					int ok;
					int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head];

					spin_unlock_irqrestore(&lock,flags);/* Give some time to others */
					ok = midi_devs[dev]->outputc(dev, c);
					spin_lock_irqsave(&lock, flags);
					if (!ok)
						break;
					midi_out_buf[dev]->head = (midi_out_buf[dev]->head + 1) % MAX_QUEUE_SIZE;
					midi_out_buf[dev]->len--;
				}

				if (DATA_AVAIL(midi_out_buf[dev]) < 100)
					wake_up(&midi_sleeper[dev]);
			}
		poll_timer.expires = (1) + jiffies;
		add_timer(&poll_timer);
		/*
		 * Come back later
		 */
	}
	spin_unlock_irqrestore(&lock, flags);
}

int MIDIbuf_open(int dev, struct file *file)
{
	int mode, err;

	dev = dev >> 4;
	mode = translate_mode(file);

	if (num_midis > MAX_MIDI_DEV)
	{
		printk(KERN_ERR "midi: Too many midi interfaces\n");
		num_midis = MAX_MIDI_DEV;
	}
	if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL)
		  return -ENXIO;
	/*
	 *    Interrupts disabled. Be careful
	 */

	module_put(midi_devs[dev]->owner);

	if ((err = midi_devs[dev]->open(dev, mode,
				 midi_input_intr, midi_output_intr)) < 0)
		return err;

	parms[dev].prech_timeout = MAX_SCHEDULE_TIMEOUT;
	midi_in_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf));

	if (midi_in_buf[dev] == NULL)
	{
		printk(KERN_WARNING "midi: Can't allocate buffer\n");
		midi_devs[dev]->close(dev);
		return -EIO;
	}
	midi_in_buf[dev]->len = midi_in_buf[dev]->head = midi_in_buf[dev]->tail = 0;

	midi_out_buf[dev] = (struct midi_buf *) vmalloc(sizeof(struct midi_buf));

	if (midi_out_buf[dev] == NULL)
	{
		printk(KERN_WARNING "midi: Can't allocate buffer\n");
		midi_devs[dev]->close(dev);
		vfree(midi_in_buf[dev]);
		midi_in_buf[dev] = NULL;
		return -EIO;
	}
	midi_out_buf[dev]->len = midi_out_buf[dev]->head = midi_out_buf[dev]->tail = 0;
	open_devs++;

	init_waitqueue_head(&midi_sleeper[dev]);
	init_waitqueue_head(&input_sleeper[dev]);

	if (open_devs < 2)	/* This was first open */
	{
		poll_timer.expires = 1 + jiffies;
		add_timer(&poll_timer);	/* Start polling */
	}
	return err;
}

void MIDIbuf_release(int dev, struct file *file)
{
	int mode;

	dev = dev >> 4;
	mode = translate_mode(file);

	if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL)
		return;

	/*
	 * Wait until the queue is empty
	 */

	if (mode != OPEN_READ)
	{
		midi_devs[dev]->outputc(dev, 0xfe);	/*
							   * Active sensing to shut the
							   * devices
							 */

		while (!signal_pending(current) && DATA_AVAIL(midi_out_buf[dev]))
			  interruptible_sleep_on(&midi_sleeper[dev]);
		/*
		 *	Sync
		 */

		drain_midi_queue(dev);	/*
					 * Ensure the output queues are empty
					 */
	}

	midi_devs[dev]->close(dev);

	open_devs--;
	if (open_devs == 0)
		del_timer_sync(&poll_timer);
	vfree(midi_in_buf[dev]);
	vfree(midi_out_buf[dev]);
	midi_in_buf[dev] = NULL;
	midi_out_buf[dev] = NULL;

	module_put(midi_devs[dev]->owner);
}

int MIDIbuf_write(int dev, struct file *file, const char __user *buf, int count)
{
	int c, n, i;
	unsigned char tmp_data;

	dev = dev >> 4;

	if (!count)
		return 0;

	c = 0;

	while (c < count)
	{
		n = SPACE_AVAIL(midi_out_buf[dev]);

		if (n == 0) {	/*
				 * No space just now.
				 */

			if (file->f_flags & O_NONBLOCK) {
				c = -EAGAIN;
				goto out;
			}

			interruptible_sleep_on(&midi_sleeper[dev]);
			if (signal_pending(current)) 
			{
				c = -EINTR;
				goto out;
			}
			n = SPACE_AVAIL(midi_out_buf[dev]);
		}
		if (n > (count - c))
			n = count - c;

		for (i = 0; i < n; i++)
		{
			/* BROKE BROKE BROKE - CANT DO THIS WITH CLI !! */
			/* yes, think the same, so I removed the cli() brackets 
				QUEUE_BYTE is protected against interrupts */
			if (copy_from_user((char *) &tmp_data, &(buf)[c], 1)) {
				c = -EFAULT;
				goto out;
			}
			QUEUE_BYTE(midi_out_buf[dev], tmp_data);
			c++;
		}
	}
out:
	return c;
}


int MIDIbuf_read(int dev, struct file *file, char __user *buf, int count)
{
	int n, c = 0;
	unsigned char tmp_data;

	dev = dev >> 4;

	if (!DATA_AVAIL(midi_in_buf[dev])) {	/*
						 * No data yet, wait
						 */
 		if (file->f_flags & O_NONBLOCK) {
 			c = -EAGAIN;
			goto out;
 		}
		interruptible_sleep_on_timeout(&input_sleeper[dev],
					       parms[dev].prech_timeout);

		if (signal_pending(current))
			c = -EINTR;	/* The user is getting restless */
	}
	if (c == 0 && DATA_AVAIL(midi_in_buf[dev]))	/*
							 * Got some bytes
							 */
	{
		n = DATA_AVAIL(midi_in_buf[dev]);
		if (n > count)
			n = count;
		c = 0;

		while (c < n)
		{
			char *fixit;
			REMOVE_BYTE(midi_in_buf[dev], tmp_data);
			fixit = (char *) &tmp_data;
			/* BROKE BROKE BROKE */
			/* yes removed the cli() brackets again
			 should q->len,tail&head be atomic_t? */
			if (copy_to_user(&(buf)[c], fixit, 1)) {
				c = -EFAULT;
				goto out;
			}
			c++;
		}
	}
out:
	return c;
}

int MIDIbuf_ioctl(int dev, struct file *file,
		  unsigned int cmd, void __user *arg)
{
	int val;

	dev = dev >> 4;
	
	if (((cmd >> 8) & 0xff) == 'C') 
	{
		if (midi_devs[dev]->coproc)	/* Coprocessor ioctl */
			return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0);
/*		printk("/dev/midi%d: No coprocessor for this device\n", dev);*/
		return -ENXIO;
	}
	else
	{
		switch (cmd) 
		{
			case SNDCTL_MIDI_PRETIME:
				if (get_user(val, (int __user *)arg))
					return -EFAULT;
				if (val < 0)
					val = 0;
				val = (HZ * val) / 10;
				parms[dev].prech_timeout = val;
				return put_user(val, (int __user *)arg);
			
			default:
				if (!midi_devs[dev]->ioctl)
					return -EINVAL;
				return midi_devs[dev]->ioctl(dev, cmd, arg);
		}
	}
}

/* No kernel lock - fine */
unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait)
{
	unsigned int mask = 0;

	dev = dev >> 4;

	/* input */
	poll_wait(file, &input_sleeper[dev], wait);
	if (DATA_AVAIL(midi_in_buf[dev]))
		mask |= POLLIN | POLLRDNORM;

	/* output */
	poll_wait(file, &midi_sleeper[dev], wait);
	if (!SPACE_AVAIL(midi_out_buf[dev]))
		mask |= POLLOUT | POLLWRNORM;
	
	return mask;
}


int MIDIbuf_avail(int dev)
{
	if (midi_in_buf[dev])
		return DATA_AVAIL (midi_in_buf[dev]);
	return 0;
}
EXPORT_SYMBOL(MIDIbuf_avail);