summaryrefslogtreecommitdiff
path: root/sound/usb/bcd2000/bcd2000.c
blob: a6408209d7f1dffd421fedf132a44ae56d61a6dd (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
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
/*
 * Behringer BCD2000 driver
 *
 *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/bitmap.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>

#define PREFIX "snd-bcd2000: "
#define BUFSIZE 64

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x1397, 0x00bd) },
	{ },
};

static unsigned char device_cmd_prefix[] = {0x03, 0x00};

static unsigned char bcd2000_init_sequence[] = {
	0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
	0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
	0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
	0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
	0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
	0x18, 0xfa, 0x11, 0xff
};

struct bcd2000 {
	struct usb_device *dev;
	struct snd_card *card;
	struct usb_interface *intf;
	int card_index;

	int midi_out_active;
	struct snd_rawmidi *rmidi;
	struct snd_rawmidi_substream *midi_receive_substream;
	struct snd_rawmidi_substream *midi_out_substream;

	unsigned char midi_in_buf[BUFSIZE];
	unsigned char midi_out_buf[BUFSIZE];

	struct urb *midi_out_urb;
	struct urb *midi_in_urb;

	struct usb_anchor anchor;
};

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;

static DEFINE_MUTEX(devices_mutex);
static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
static struct usb_driver bcd2000_driver;

#ifdef CONFIG_SND_DEBUG
static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
{
	print_hex_dump(KERN_DEBUG, prefix,
			DUMP_PREFIX_NONE, 16, 1,
			buf, len, false);
}
#else
static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
#endif

static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
{
	return 0;
}

static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
{
	return 0;
}

/* (de)register midi substream from client */
static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
						int up)
{
	struct bcd2000 *bcd2k = substream->rmidi->private_data;
	bcd2k->midi_receive_substream = up ? substream : NULL;
}

static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
				const unsigned char *buf, unsigned int buf_len)
{
	unsigned int payload_length, tocopy;
	struct snd_rawmidi_substream *midi_receive_substream;

	midi_receive_substream = ACCESS_ONCE(bcd2k->midi_receive_substream);
	if (!midi_receive_substream)
		return;

	bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);

	if (buf_len < 2)
		return;

	payload_length = buf[0];

	/* ignore packets without payload */
	if (payload_length == 0)
		return;

	tocopy = min(payload_length, buf_len-1);

	bcd2000_dump_buffer(PREFIX "sending to userspace: ",
					&buf[1], tocopy);

	snd_rawmidi_receive(midi_receive_substream,
					&buf[1], tocopy);
}

static void bcd2000_midi_send(struct bcd2000 *bcd2k)
{
	int len, ret;
	struct snd_rawmidi_substream *midi_out_substream;

	BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);

	midi_out_substream = ACCESS_ONCE(bcd2k->midi_out_substream);
	if (!midi_out_substream)
		return;

	/* copy command prefix bytes */
	memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
		sizeof(device_cmd_prefix));

	/*
	 * get MIDI packet and leave space for command prefix
	 * and payload length
	 */
	len = snd_rawmidi_transmit(midi_out_substream,
				bcd2k->midi_out_buf + 3, BUFSIZE - 3);

	if (len < 0)
		dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
				__func__, len);

	if (len <= 0)
		return;

	/* set payload length */
	bcd2k->midi_out_buf[2] = len;
	bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;

	bcd2000_dump_buffer(PREFIX "sending to device: ",
			bcd2k->midi_out_buf, len+3);

	/* send packet to the BCD2000 */
	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
	if (ret < 0)
		dev_err(&bcd2k->dev->dev, PREFIX
			"%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
			__func__, midi_out_substream, ret, len);
	else
		bcd2k->midi_out_active = 1;
}

static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
{
	return 0;
}

static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
{
	struct bcd2000 *bcd2k = substream->rmidi->private_data;

	if (bcd2k->midi_out_active) {
		usb_kill_urb(bcd2k->midi_out_urb);
		bcd2k->midi_out_active = 0;
	}

	return 0;
}

/* (de)register midi substream from client */
static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
						int up)
{
	struct bcd2000 *bcd2k = substream->rmidi->private_data;

	if (up) {
		bcd2k->midi_out_substream = substream;
		/* check if there is data userspace wants to send */
		if (!bcd2k->midi_out_active)
			bcd2000_midi_send(bcd2k);
	} else {
		bcd2k->midi_out_substream = NULL;
	}
}

static void bcd2000_output_complete(struct urb *urb)
{
	struct bcd2000 *bcd2k = urb->context;

	bcd2k->midi_out_active = 0;

	if (urb->status)
		dev_warn(&urb->dev->dev,
			PREFIX "output urb->status: %d\n", urb->status);

	if (urb->status == -ESHUTDOWN)
		return;

	/* check if there is more data userspace wants to send */
	bcd2000_midi_send(bcd2k);
}

static void bcd2000_input_complete(struct urb *urb)
{
	int ret;
	struct bcd2000 *bcd2k = urb->context;

	if (urb->status)
		dev_warn(&urb->dev->dev,
			PREFIX "input urb->status: %i\n", urb->status);

	if (!bcd2k || urb->status == -ESHUTDOWN)
		return;

	if (urb->actual_length > 0)
		bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
					urb->actual_length);

	/* return URB to device */
	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
	if (ret < 0)
		dev_err(&bcd2k->dev->dev, PREFIX
			"%s: usb_submit_urb() failed, ret=%d\n",
			__func__, ret);
}

static const struct snd_rawmidi_ops bcd2000_midi_output = {
	.open =    bcd2000_midi_output_open,
	.close =   bcd2000_midi_output_close,
	.trigger = bcd2000_midi_output_trigger,
};

static const struct snd_rawmidi_ops bcd2000_midi_input = {
	.open =    bcd2000_midi_input_open,
	.close =   bcd2000_midi_input_close,
	.trigger = bcd2000_midi_input_trigger,
};

static void bcd2000_init_device(struct bcd2000 *bcd2k)
{
	int ret;

	init_usb_anchor(&bcd2k->anchor);
	usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
	usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);

	/* copy init sequence into buffer */
	memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
	bcd2k->midi_out_urb->transfer_buffer_length = 52;

	/* submit sequence */
	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
	if (ret < 0)
		dev_err(&bcd2k->dev->dev, PREFIX
			"%s: usb_submit_urb() out failed, ret=%d: ",
			__func__, ret);
	else
		bcd2k->midi_out_active = 1;

	/* pass URB to device to enable button and controller events */
	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
	if (ret < 0)
		dev_err(&bcd2k->dev->dev, PREFIX
			"%s: usb_submit_urb() in failed, ret=%d: ",
			__func__, ret);

	/* ensure initialization is finished */
	usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
}

static int bcd2000_init_midi(struct bcd2000 *bcd2k)
{
	int ret;
	struct snd_rawmidi *rmidi;

	ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
					1, /* output */
					1, /* input */
					&rmidi);

	if (ret < 0)
		return ret;

	strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));

	rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
	rmidi->private_data = bcd2k;

	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
					&bcd2000_midi_output);

	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
					&bcd2000_midi_input);

	bcd2k->rmidi = rmidi;

	bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
	bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);

	if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
		dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
		return -ENOMEM;
	}

	usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
				usb_rcvintpipe(bcd2k->dev, 0x81),
				bcd2k->midi_in_buf, BUFSIZE,
				bcd2000_input_complete, bcd2k, 1);

	usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
				usb_sndintpipe(bcd2k->dev, 0x1),
				bcd2k->midi_out_buf, BUFSIZE,
				bcd2000_output_complete, bcd2k, 1);

	/* sanity checks of EPs before actually submitting */
	if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
	    usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
		dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
		return -EINVAL;
	}

	bcd2000_init_device(bcd2k);

	return 0;
}

static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
						struct usb_interface *interface)
{
	/* usb_kill_urb not necessary, urb is aborted automatically */

	usb_free_urb(bcd2k->midi_out_urb);
	usb_free_urb(bcd2k->midi_in_urb);

	if (bcd2k->intf) {
		usb_set_intfdata(bcd2k->intf, NULL);
		bcd2k->intf = NULL;
	}
}

static int bcd2000_probe(struct usb_interface *interface,
				const struct usb_device_id *usb_id)
{
	struct snd_card *card;
	struct bcd2000 *bcd2k;
	unsigned int card_index;
	char usb_path[32];
	int err;

	mutex_lock(&devices_mutex);

	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
		if (!test_bit(card_index, devices_used))
			break;

	if (card_index >= SNDRV_CARDS) {
		mutex_unlock(&devices_mutex);
		return -ENOENT;
	}

	err = snd_card_new(&interface->dev, index[card_index], id[card_index],
			THIS_MODULE, sizeof(*bcd2k), &card);
	if (err < 0) {
		mutex_unlock(&devices_mutex);
		return err;
	}

	bcd2k = card->private_data;
	bcd2k->dev = interface_to_usbdev(interface);
	bcd2k->card = card;
	bcd2k->card_index = card_index;
	bcd2k->intf = interface;

	snd_card_set_dev(card, &interface->dev);

	strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
	strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
	usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
	snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
		    "Behringer BCD2000 at %s",
			usb_path);

	err = bcd2000_init_midi(bcd2k);
	if (err < 0)
		goto probe_error;

	err = snd_card_register(card);
	if (err < 0)
		goto probe_error;

	usb_set_intfdata(interface, bcd2k);
	set_bit(card_index, devices_used);

	mutex_unlock(&devices_mutex);
	return 0;

probe_error:
	dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
	bcd2000_free_usb_related_resources(bcd2k, interface);
	snd_card_free(card);
	mutex_unlock(&devices_mutex);
	return err;
}

static void bcd2000_disconnect(struct usb_interface *interface)
{
	struct bcd2000 *bcd2k = usb_get_intfdata(interface);

	if (!bcd2k)
		return;

	mutex_lock(&devices_mutex);

	/* make sure that userspace cannot create new requests */
	snd_card_disconnect(bcd2k->card);

	bcd2000_free_usb_related_resources(bcd2k, interface);

	clear_bit(bcd2k->card_index, devices_used);

	snd_card_free_when_closed(bcd2k->card);

	mutex_unlock(&devices_mutex);
}

static struct usb_driver bcd2000_driver = {
	.name =		"snd-bcd2000",
	.probe =	bcd2000_probe,
	.disconnect =	bcd2000_disconnect,
	.id_table =	id_table,
};

module_usb_driver(bcd2000_driver);

MODULE_DEVICE_TABLE(usb, id_table);
MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
MODULE_DESCRIPTION("Behringer BCD2000 driver");
MODULE_LICENSE("GPL");