1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Behringer BCD2000 driver
4 *
5 * Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/init.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/bitmap.h>
14 #include <linux/usb.h>
15 #include <linux/usb/audio.h>
16 #include <sound/core.h>
17 #include <sound/initval.h>
18 #include <sound/rawmidi.h>
19
20 #define PREFIX "snd-bcd2000: "
21 #define BUFSIZE 64
22
23 static const struct usb_device_id id_table[] = {
24 { USB_DEVICE(0x1397, 0x00bd) },
25 { },
26 };
27
28 static const unsigned char device_cmd_prefix[] = {0x03, 0x00};
29
30 static const unsigned char bcd2000_init_sequence[] = {
31 0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
32 0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
33 0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
34 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
35 0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
36 0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
37 0x18, 0xfa, 0x11, 0xff
38 };
39
40 struct bcd2000 {
41 struct usb_device *dev;
42 struct snd_card *card;
43 struct usb_interface *intf;
44 int card_index;
45
46 spinlock_t midi_lock;
47 int midi_out_active;
48 struct snd_rawmidi *rmidi;
49 struct snd_rawmidi_substream *midi_receive_substream;
50 struct snd_rawmidi_substream *midi_out_substream;
51
52 unsigned char midi_in_buf[BUFSIZE];
53 unsigned char midi_out_buf[BUFSIZE];
54
55 struct urb *midi_out_urb;
56 struct urb *midi_in_urb;
57
58 struct usb_anchor anchor;
59 };
60
61 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
62 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
63
64 static DEFINE_MUTEX(devices_mutex);
65 static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
66 static struct usb_driver bcd2000_driver;
67
68 #ifdef CONFIG_SND_DEBUG
bcd2000_dump_buffer(const char * prefix,const char * buf,int len)69 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
70 {
71 print_hex_dump(KERN_DEBUG, prefix,
72 DUMP_PREFIX_NONE, 16, 1,
73 buf, len, false);
74 }
75 #else
bcd2000_dump_buffer(const char * prefix,const char * buf,int len)76 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
77 #endif
78
bcd2000_midi_input_open(struct snd_rawmidi_substream * substream)79 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
80 {
81 return 0;
82 }
83
bcd2000_midi_input_close(struct snd_rawmidi_substream * substream)84 static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
85 {
86 return 0;
87 }
88
89 /* (de)register midi substream from client */
bcd2000_midi_input_trigger(struct snd_rawmidi_substream * substream,int up)90 static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
91 int up)
92 {
93 struct bcd2000 *bcd2k = substream->rmidi->private_data;
94
95 guard(spinlock_irqsave)(&bcd2k->midi_lock);
96 bcd2k->midi_receive_substream = up ? substream : NULL;
97 }
98
bcd2000_midi_handle_input(struct bcd2000 * bcd2k,const unsigned char * buf,unsigned int buf_len)99 static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
100 const unsigned char *buf, unsigned int buf_len)
101 {
102 unsigned int payload_length, tocopy;
103 struct snd_rawmidi_substream *midi_receive_substream;
104
105 midi_receive_substream = READ_ONCE(bcd2k->midi_receive_substream);
106 if (!midi_receive_substream)
107 return;
108
109 bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
110
111 if (buf_len < 2)
112 return;
113
114 payload_length = buf[0];
115
116 /* ignore packets without payload */
117 if (payload_length == 0)
118 return;
119
120 tocopy = min(payload_length, buf_len-1);
121
122 bcd2000_dump_buffer(PREFIX "sending to userspace: ",
123 &buf[1], tocopy);
124
125 snd_rawmidi_receive(midi_receive_substream,
126 &buf[1], tocopy);
127 }
128
bcd2000_midi_send(struct bcd2000 * bcd2k)129 static void bcd2000_midi_send(struct bcd2000 *bcd2k)
130 {
131 int len, ret;
132 struct snd_rawmidi_substream *midi_out_substream;
133
134 BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
135
136 midi_out_substream = READ_ONCE(bcd2k->midi_out_substream);
137 if (!midi_out_substream)
138 return;
139
140 if (!bcd2k->midi_out_urb)
141 return;
142
143 /* copy command prefix bytes */
144 memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
145 sizeof(device_cmd_prefix));
146
147 /*
148 * get MIDI packet and leave space for command prefix
149 * and payload length
150 */
151 len = snd_rawmidi_transmit(midi_out_substream,
152 bcd2k->midi_out_buf + 3, BUFSIZE - 3);
153
154 if (len < 0)
155 dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
156 __func__, len);
157
158 if (len <= 0)
159 return;
160
161 /* set payload length */
162 bcd2k->midi_out_buf[2] = len;
163 bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
164
165 bcd2000_dump_buffer(PREFIX "sending to device: ",
166 bcd2k->midi_out_buf, len+3);
167
168 /* send packet to the BCD2000 */
169 ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
170 if (ret < 0)
171 dev_err(&bcd2k->dev->dev, PREFIX
172 "%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
173 __func__, midi_out_substream, ret, len);
174 else
175 bcd2k->midi_out_active = 1;
176 }
177
bcd2000_midi_output_open(struct snd_rawmidi_substream * substream)178 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
179 {
180 return 0;
181 }
182
bcd2000_midi_output_close(struct snd_rawmidi_substream * substream)183 static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
184 {
185 struct bcd2000 *bcd2k = substream->rmidi->private_data;
186
187 if (bcd2k->midi_out_active && bcd2k->midi_out_urb) {
188 usb_kill_urb(bcd2k->midi_out_urb);
189 bcd2k->midi_out_active = 0;
190 }
191
192 return 0;
193 }
194
195 /* (de)register midi substream from client */
bcd2000_midi_output_trigger(struct snd_rawmidi_substream * substream,int up)196 static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
197 int up)
198 {
199 struct bcd2000 *bcd2k = substream->rmidi->private_data;
200
201 guard(spinlock_irqsave)(&bcd2k->midi_lock);
202
203 if (up) {
204 bcd2k->midi_out_substream = substream;
205 /* check if there is data userspace wants to send */
206 if (!bcd2k->midi_out_active)
207 bcd2000_midi_send(bcd2k);
208 } else {
209 bcd2k->midi_out_substream = NULL;
210 }
211 }
212
bcd2000_output_complete(struct urb * urb)213 static void bcd2000_output_complete(struct urb *urb)
214 {
215 struct bcd2000 *bcd2k = urb->context;
216
217 bcd2k->midi_out_active = 0;
218
219 if (urb->status)
220 dev_warn(&urb->dev->dev,
221 PREFIX "output urb->status: %d\n", urb->status);
222
223 if (urb->status == -ESHUTDOWN)
224 return;
225
226 /* check if there is more data userspace wants to send */
227 guard(spinlock_irqsave)(&bcd2k->midi_lock);
228 bcd2000_midi_send(bcd2k);
229 }
230
bcd2000_input_complete(struct urb * urb)231 static void bcd2000_input_complete(struct urb *urb)
232 {
233 int ret;
234 struct bcd2000 *bcd2k = urb->context;
235
236 if (urb->status)
237 dev_warn(&urb->dev->dev,
238 PREFIX "input urb->status: %i\n", urb->status);
239
240 if (!bcd2k || urb->status == -ESHUTDOWN)
241 return;
242
243 guard(spinlock_irqsave)(&bcd2k->midi_lock);
244
245 if (urb->actual_length > 0)
246 bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
247 urb->actual_length);
248
249 /* return URB to device */
250 ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
251 if (ret < 0)
252 dev_err(&bcd2k->dev->dev, PREFIX
253 "%s: usb_submit_urb() failed, ret=%d\n",
254 __func__, ret);
255 }
256
257 static const struct snd_rawmidi_ops bcd2000_midi_output = {
258 .open = bcd2000_midi_output_open,
259 .close = bcd2000_midi_output_close,
260 .trigger = bcd2000_midi_output_trigger,
261 };
262
263 static const struct snd_rawmidi_ops bcd2000_midi_input = {
264 .open = bcd2000_midi_input_open,
265 .close = bcd2000_midi_input_close,
266 .trigger = bcd2000_midi_input_trigger,
267 };
268
bcd2000_init_device(struct bcd2000 * bcd2k)269 static void bcd2000_init_device(struct bcd2000 *bcd2k)
270 {
271 int ret;
272
273 init_usb_anchor(&bcd2k->anchor);
274 usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
275 usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
276
277 /* copy init sequence into buffer */
278 memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
279 bcd2k->midi_out_urb->transfer_buffer_length = 52;
280
281 /* submit sequence */
282 ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
283 if (ret < 0)
284 dev_err(&bcd2k->dev->dev, PREFIX
285 "%s: usb_submit_urb() out failed, ret=%d: ",
286 __func__, ret);
287 else
288 bcd2k->midi_out_active = 1;
289
290 /* pass URB to device to enable button and controller events */
291 ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
292 if (ret < 0)
293 dev_err(&bcd2k->dev->dev, PREFIX
294 "%s: usb_submit_urb() in failed, ret=%d: ",
295 __func__, ret);
296
297 /* ensure initialization is finished */
298 usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
299 }
300
bcd2000_init_midi(struct bcd2000 * bcd2k)301 static int bcd2000_init_midi(struct bcd2000 *bcd2k)
302 {
303 int ret;
304 struct snd_rawmidi *rmidi;
305
306 ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
307 1, /* output */
308 1, /* input */
309 &rmidi);
310
311 if (ret < 0)
312 return ret;
313
314 strscpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
315
316 rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
317 rmidi->private_data = bcd2k;
318
319 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
320 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
321 &bcd2000_midi_output);
322
323 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
324 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
325 &bcd2000_midi_input);
326
327 bcd2k->rmidi = rmidi;
328
329 bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
330 bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
331
332 if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
333 dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
334 return -ENOMEM;
335 }
336
337 usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
338 usb_rcvintpipe(bcd2k->dev, 0x81),
339 bcd2k->midi_in_buf, BUFSIZE,
340 bcd2000_input_complete, bcd2k, 1);
341
342 usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
343 usb_sndintpipe(bcd2k->dev, 0x1),
344 bcd2k->midi_out_buf, BUFSIZE,
345 bcd2000_output_complete, bcd2k, 1);
346
347 /* sanity checks of EPs before actually submitting */
348 if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
349 usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
350 dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
351 return -EINVAL;
352 }
353
354 bcd2000_init_device(bcd2k);
355
356 return 0;
357 }
358
bcd2000_midi_free(struct bcd2000 * bcd2k,struct urb ** urb_p)359 static void bcd2000_midi_free(struct bcd2000 *bcd2k,
360 struct urb **urb_p)
361 {
362 struct urb *urb = *urb_p;
363
364 if (!urb)
365 return;
366
367 usb_poison_urb(urb);
368 scoped_guard(spinlock_irq, &bcd2k->midi_lock)
369 *urb_p = NULL;
370
371 usb_free_urb(urb);
372 }
373
bcd2000_free_usb_related_resources(struct bcd2000 * bcd2k,struct usb_interface * interface)374 static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
375 struct usb_interface *interface)
376 {
377 bcd2000_midi_free(bcd2k, &bcd2k->midi_out_urb);
378 bcd2000_midi_free(bcd2k, &bcd2k->midi_in_urb);
379
380 if (bcd2k->intf) {
381 usb_set_intfdata(bcd2k->intf, NULL);
382 bcd2k->intf = NULL;
383 }
384 }
385
bcd2000_probe(struct usb_interface * interface,const struct usb_device_id * usb_id)386 static int bcd2000_probe(struct usb_interface *interface,
387 const struct usb_device_id *usb_id)
388 {
389 struct snd_card *card;
390 struct bcd2000 *bcd2k;
391 unsigned int card_index;
392 char usb_path[32];
393 int err;
394
395 guard(mutex)(&devices_mutex);
396
397 for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
398 if (!test_bit(card_index, devices_used))
399 break;
400
401 if (card_index >= SNDRV_CARDS)
402 return -ENOENT;
403
404 err = snd_card_new(&interface->dev, index[card_index], id[card_index],
405 THIS_MODULE, sizeof(*bcd2k), &card);
406 if (err < 0)
407 return err;
408
409 bcd2k = card->private_data;
410 bcd2k->dev = interface_to_usbdev(interface);
411 bcd2k->card = card;
412 bcd2k->card_index = card_index;
413 bcd2k->intf = interface;
414 spin_lock_init(&bcd2k->midi_lock);
415
416 snd_card_set_dev(card, &interface->dev);
417
418 strscpy(card->driver, "snd-bcd2000", sizeof(card->driver));
419 strscpy(card->shortname, "BCD2000", sizeof(card->shortname));
420 usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
421 snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
422 "Behringer BCD2000 at %s",
423 usb_path);
424
425 err = bcd2000_init_midi(bcd2k);
426 if (err < 0)
427 goto probe_error;
428
429 err = snd_card_register(card);
430 if (err < 0)
431 goto probe_error;
432
433 usb_set_intfdata(interface, bcd2k);
434 set_bit(card_index, devices_used);
435
436 return 0;
437
438 probe_error:
439 dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
440 bcd2000_free_usb_related_resources(bcd2k, interface);
441 snd_card_free(card);
442 return err;
443 }
444
bcd2000_disconnect(struct usb_interface * interface)445 static void bcd2000_disconnect(struct usb_interface *interface)
446 {
447 struct bcd2000 *bcd2k = usb_get_intfdata(interface);
448
449 if (!bcd2k)
450 return;
451
452 guard(mutex)(&devices_mutex);
453
454 /* make sure that userspace cannot create new requests */
455 snd_card_disconnect(bcd2k->card);
456
457 bcd2000_free_usb_related_resources(bcd2k, interface);
458
459 clear_bit(bcd2k->card_index, devices_used);
460
461 snd_card_free_when_closed(bcd2k->card);
462 }
463
464 static struct usb_driver bcd2000_driver = {
465 .name = "snd-bcd2000",
466 .probe = bcd2000_probe,
467 .disconnect = bcd2000_disconnect,
468 .id_table = id_table,
469 };
470
471 module_usb_driver(bcd2000_driver);
472
473 MODULE_DEVICE_TABLE(usb, id_table);
474 MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
475 MODULE_DESCRIPTION("Behringer BCD2000 driver");
476 MODULE_LICENSE("GPL");
477