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