xref: /linux/sound/usb/bcd2000/bcd2000.c (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78) 
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
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
75 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
76 #endif
77 
78 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
79 {
80 	return 0;
81 }
82 
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 */
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 
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 
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 
172 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
173 {
174 	return 0;
175 }
176 
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 */
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 
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 
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 
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 
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 
348 static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
349 						struct usb_interface *interface)
350 {
351 	/* usb_kill_urb not necessary, urb is aborted automatically */
352 
353 	usb_free_urb(bcd2k->midi_out_urb);
354 	usb_free_urb(bcd2k->midi_in_urb);
355 
356 	if (bcd2k->intf) {
357 		usb_set_intfdata(bcd2k->intf, NULL);
358 		bcd2k->intf = NULL;
359 	}
360 }
361 
362 static int bcd2000_probe(struct usb_interface *interface,
363 				const struct usb_device_id *usb_id)
364 {
365 	struct snd_card *card;
366 	struct bcd2000 *bcd2k;
367 	unsigned int card_index;
368 	char usb_path[32];
369 	int err;
370 
371 	mutex_lock(&devices_mutex);
372 
373 	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
374 		if (!test_bit(card_index, devices_used))
375 			break;
376 
377 	if (card_index >= SNDRV_CARDS) {
378 		mutex_unlock(&devices_mutex);
379 		return -ENOENT;
380 	}
381 
382 	err = snd_card_new(&interface->dev, index[card_index], id[card_index],
383 			THIS_MODULE, sizeof(*bcd2k), &card);
384 	if (err < 0) {
385 		mutex_unlock(&devices_mutex);
386 		return err;
387 	}
388 
389 	bcd2k = card->private_data;
390 	bcd2k->dev = interface_to_usbdev(interface);
391 	bcd2k->card = card;
392 	bcd2k->card_index = card_index;
393 	bcd2k->intf = interface;
394 
395 	snd_card_set_dev(card, &interface->dev);
396 
397 	strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
398 	strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
399 	usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
400 	snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
401 		    "Behringer BCD2000 at %s",
402 			usb_path);
403 
404 	err = bcd2000_init_midi(bcd2k);
405 	if (err < 0)
406 		goto probe_error;
407 
408 	err = snd_card_register(card);
409 	if (err < 0)
410 		goto probe_error;
411 
412 	usb_set_intfdata(interface, bcd2k);
413 	set_bit(card_index, devices_used);
414 
415 	mutex_unlock(&devices_mutex);
416 	return 0;
417 
418 probe_error:
419 	dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
420 	bcd2000_free_usb_related_resources(bcd2k, interface);
421 	snd_card_free(card);
422 	mutex_unlock(&devices_mutex);
423 	return err;
424 }
425 
426 static void bcd2000_disconnect(struct usb_interface *interface)
427 {
428 	struct bcd2000 *bcd2k = usb_get_intfdata(interface);
429 
430 	if (!bcd2k)
431 		return;
432 
433 	mutex_lock(&devices_mutex);
434 
435 	/* make sure that userspace cannot create new requests */
436 	snd_card_disconnect(bcd2k->card);
437 
438 	bcd2000_free_usb_related_resources(bcd2k, interface);
439 
440 	clear_bit(bcd2k->card_index, devices_used);
441 
442 	snd_card_free_when_closed(bcd2k->card);
443 
444 	mutex_unlock(&devices_mutex);
445 }
446 
447 static struct usb_driver bcd2000_driver = {
448 	.name =		"snd-bcd2000",
449 	.probe =	bcd2000_probe,
450 	.disconnect =	bcd2000_disconnect,
451 	.id_table =	id_table,
452 };
453 
454 module_usb_driver(bcd2000_driver);
455 
456 MODULE_DEVICE_TABLE(usb, id_table);
457 MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
458 MODULE_DESCRIPTION("Behringer BCD2000 driver");
459 MODULE_LICENSE("GPL");
460