xref: /linux/sound/usb/bcd2000/bcd2000.c (revision 4bdee8060d1e4581624e68fbd369b1afb14df4bc) 
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
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
76 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
77 #endif
78 
79 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
80 {
81 	return 0;
82 }
83 
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 */
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 
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 
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 
178 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
179 {
180 	return 0;
181 }
182 
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 */
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 
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 
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 
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 
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 
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 
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 
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 
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