xref: /linux/sound/usb/bcd2000/bcd2000.c (revision a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec) 
1 /*
2  * Behringer BCD2000 driver
3  *
4  *   Copyright (C) 2014 Mario Kicherer (dev@kicherer.org)
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/bitmap.h>
23 #include <linux/usb.h>
24 #include <linux/usb/audio.h>
25 #include <sound/core.h>
26 #include <sound/initval.h>
27 #include <sound/rawmidi.h>
28 
29 #define PREFIX "snd-bcd2000: "
30 #define BUFSIZE 64
31 
32 static struct usb_device_id id_table[] = {
33 	{ USB_DEVICE(0x1397, 0x00bd) },
34 	{ },
35 };
36 
37 static unsigned char device_cmd_prefix[] = {0x03, 0x00};
38 
39 static unsigned char bcd2000_init_sequence[] = {
40 	0x07, 0x00, 0x00, 0x00, 0x78, 0x48, 0x1c, 0x81,
41 	0xc4, 0x00, 0x00, 0x00, 0x5e, 0x53, 0x4a, 0xf7,
42 	0x18, 0xfa, 0x11, 0xff, 0x6c, 0xf3, 0x90, 0xff,
43 	0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
44 	0x18, 0xfa, 0x11, 0xff, 0x14, 0x00, 0x00, 0x00,
45 	0x00, 0x00, 0x00, 0x00, 0xf2, 0x34, 0x4a, 0xf7,
46 	0x18, 0xfa, 0x11, 0xff
47 };
48 
49 struct bcd2000 {
50 	struct usb_device *dev;
51 	struct snd_card *card;
52 	struct usb_interface *intf;
53 	int card_index;
54 
55 	int midi_out_active;
56 	struct snd_rawmidi *rmidi;
57 	struct snd_rawmidi_substream *midi_receive_substream;
58 	struct snd_rawmidi_substream *midi_out_substream;
59 
60 	unsigned char midi_in_buf[BUFSIZE];
61 	unsigned char midi_out_buf[BUFSIZE];
62 
63 	struct urb *midi_out_urb;
64 	struct urb *midi_in_urb;
65 
66 	struct usb_anchor anchor;
67 };
68 
69 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
70 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
71 
72 static DEFINE_MUTEX(devices_mutex);
73 static DECLARE_BITMAP(devices_used, SNDRV_CARDS);
74 static struct usb_driver bcd2000_driver;
75 
76 #ifdef CONFIG_SND_DEBUG
77 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len)
78 {
79 	print_hex_dump(KERN_DEBUG, prefix,
80 			DUMP_PREFIX_NONE, 16, 1,
81 			buf, len, false);
82 }
83 #else
84 static void bcd2000_dump_buffer(const char *prefix, const char *buf, int len) {}
85 #endif
86 
87 static int bcd2000_midi_input_open(struct snd_rawmidi_substream *substream)
88 {
89 	return 0;
90 }
91 
92 static int bcd2000_midi_input_close(struct snd_rawmidi_substream *substream)
93 {
94 	return 0;
95 }
96 
97 /* (de)register midi substream from client */
98 static void bcd2000_midi_input_trigger(struct snd_rawmidi_substream *substream,
99 						int up)
100 {
101 	struct bcd2000 *bcd2k = substream->rmidi->private_data;
102 	bcd2k->midi_receive_substream = up ? substream : NULL;
103 }
104 
105 static void bcd2000_midi_handle_input(struct bcd2000 *bcd2k,
106 				const unsigned char *buf, unsigned int buf_len)
107 {
108 	unsigned int payload_length, tocopy;
109 	struct snd_rawmidi_substream *midi_receive_substream;
110 
111 	midi_receive_substream = ACCESS_ONCE(bcd2k->midi_receive_substream);
112 	if (!midi_receive_substream)
113 		return;
114 
115 	bcd2000_dump_buffer(PREFIX "received from device: ", buf, buf_len);
116 
117 	if (buf_len < 2)
118 		return;
119 
120 	payload_length = buf[0];
121 
122 	/* ignore packets without payload */
123 	if (payload_length == 0)
124 		return;
125 
126 	tocopy = min(payload_length, buf_len-1);
127 
128 	bcd2000_dump_buffer(PREFIX "sending to userspace: ",
129 					&buf[1], tocopy);
130 
131 	snd_rawmidi_receive(midi_receive_substream,
132 					&buf[1], tocopy);
133 }
134 
135 static void bcd2000_midi_send(struct bcd2000 *bcd2k)
136 {
137 	int len, ret;
138 	struct snd_rawmidi_substream *midi_out_substream;
139 
140 	BUILD_BUG_ON(sizeof(device_cmd_prefix) >= BUFSIZE);
141 
142 	midi_out_substream = ACCESS_ONCE(bcd2k->midi_out_substream);
143 	if (!midi_out_substream)
144 		return;
145 
146 	/* copy command prefix bytes */
147 	memcpy(bcd2k->midi_out_buf, device_cmd_prefix,
148 		sizeof(device_cmd_prefix));
149 
150 	/*
151 	 * get MIDI packet and leave space for command prefix
152 	 * and payload length
153 	 */
154 	len = snd_rawmidi_transmit(midi_out_substream,
155 				bcd2k->midi_out_buf + 3, BUFSIZE - 3);
156 
157 	if (len < 0)
158 		dev_err(&bcd2k->dev->dev, "%s: snd_rawmidi_transmit error %d\n",
159 				__func__, len);
160 
161 	if (len <= 0)
162 		return;
163 
164 	/* set payload length */
165 	bcd2k->midi_out_buf[2] = len;
166 	bcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;
167 
168 	bcd2000_dump_buffer(PREFIX "sending to device: ",
169 			bcd2k->midi_out_buf, len+3);
170 
171 	/* send packet to the BCD2000 */
172 	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);
173 	if (ret < 0)
174 		dev_err(&bcd2k->dev->dev, PREFIX
175 			"%s (%p): usb_submit_urb() failed, ret=%d, len=%d\n",
176 			__func__, midi_out_substream, ret, len);
177 	else
178 		bcd2k->midi_out_active = 1;
179 }
180 
181 static int bcd2000_midi_output_open(struct snd_rawmidi_substream *substream)
182 {
183 	return 0;
184 }
185 
186 static int bcd2000_midi_output_close(struct snd_rawmidi_substream *substream)
187 {
188 	struct bcd2000 *bcd2k = substream->rmidi->private_data;
189 
190 	if (bcd2k->midi_out_active) {
191 		usb_kill_urb(bcd2k->midi_out_urb);
192 		bcd2k->midi_out_active = 0;
193 	}
194 
195 	return 0;
196 }
197 
198 /* (de)register midi substream from client */
199 static void bcd2000_midi_output_trigger(struct snd_rawmidi_substream *substream,
200 						int up)
201 {
202 	struct bcd2000 *bcd2k = substream->rmidi->private_data;
203 
204 	if (up) {
205 		bcd2k->midi_out_substream = substream;
206 		/* check if there is data userspace wants to send */
207 		if (!bcd2k->midi_out_active)
208 			bcd2000_midi_send(bcd2k);
209 	} else {
210 		bcd2k->midi_out_substream = NULL;
211 	}
212 }
213 
214 static void bcd2000_output_complete(struct urb *urb)
215 {
216 	struct bcd2000 *bcd2k = urb->context;
217 
218 	bcd2k->midi_out_active = 0;
219 
220 	if (urb->status)
221 		dev_warn(&urb->dev->dev,
222 			PREFIX "output urb->status: %d\n", urb->status);
223 
224 	if (urb->status == -ESHUTDOWN)
225 		return;
226 
227 	/* check if there is more data userspace wants to send */
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 	if (urb->actual_length > 0)
244 		bcd2000_midi_handle_input(bcd2k, urb->transfer_buffer,
245 					urb->actual_length);
246 
247 	/* return URB to device */
248 	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_ATOMIC);
249 	if (ret < 0)
250 		dev_err(&bcd2k->dev->dev, PREFIX
251 			"%s: usb_submit_urb() failed, ret=%d\n",
252 			__func__, ret);
253 }
254 
255 static struct snd_rawmidi_ops bcd2000_midi_output = {
256 	.open =    bcd2000_midi_output_open,
257 	.close =   bcd2000_midi_output_close,
258 	.trigger = bcd2000_midi_output_trigger,
259 };
260 
261 static struct snd_rawmidi_ops bcd2000_midi_input = {
262 	.open =    bcd2000_midi_input_open,
263 	.close =   bcd2000_midi_input_close,
264 	.trigger = bcd2000_midi_input_trigger,
265 };
266 
267 static void bcd2000_init_device(struct bcd2000 *bcd2k)
268 {
269 	int ret;
270 
271 	init_usb_anchor(&bcd2k->anchor);
272 	usb_anchor_urb(bcd2k->midi_out_urb, &bcd2k->anchor);
273 	usb_anchor_urb(bcd2k->midi_in_urb, &bcd2k->anchor);
274 
275 	/* copy init sequence into buffer */
276 	memcpy(bcd2k->midi_out_buf, bcd2000_init_sequence, 52);
277 	bcd2k->midi_out_urb->transfer_buffer_length = 52;
278 
279 	/* submit sequence */
280 	ret = usb_submit_urb(bcd2k->midi_out_urb, GFP_KERNEL);
281 	if (ret < 0)
282 		dev_err(&bcd2k->dev->dev, PREFIX
283 			"%s: usb_submit_urb() out failed, ret=%d: ",
284 			__func__, ret);
285 	else
286 		bcd2k->midi_out_active = 1;
287 
288 	/* pass URB to device to enable button and controller events */
289 	ret = usb_submit_urb(bcd2k->midi_in_urb, GFP_KERNEL);
290 	if (ret < 0)
291 		dev_err(&bcd2k->dev->dev, PREFIX
292 			"%s: usb_submit_urb() in failed, ret=%d: ",
293 			__func__, ret);
294 
295 	/* ensure initialization is finished */
296 	usb_wait_anchor_empty_timeout(&bcd2k->anchor, 1000);
297 }
298 
299 static int bcd2000_init_midi(struct bcd2000 *bcd2k)
300 {
301 	int ret;
302 	struct snd_rawmidi *rmidi;
303 
304 	ret = snd_rawmidi_new(bcd2k->card, bcd2k->card->shortname, 0,
305 					1, /* output */
306 					1, /* input */
307 					&rmidi);
308 
309 	if (ret < 0)
310 		return ret;
311 
312 	strlcpy(rmidi->name, bcd2k->card->shortname, sizeof(rmidi->name));
313 
314 	rmidi->info_flags = SNDRV_RAWMIDI_INFO_DUPLEX;
315 	rmidi->private_data = bcd2k;
316 
317 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
318 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
319 					&bcd2000_midi_output);
320 
321 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
322 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
323 					&bcd2000_midi_input);
324 
325 	bcd2k->rmidi = rmidi;
326 
327 	bcd2k->midi_in_urb = usb_alloc_urb(0, GFP_KERNEL);
328 	bcd2k->midi_out_urb = usb_alloc_urb(0, GFP_KERNEL);
329 
330 	if (!bcd2k->midi_in_urb || !bcd2k->midi_out_urb) {
331 		dev_err(&bcd2k->dev->dev, PREFIX "usb_alloc_urb failed\n");
332 		return -ENOMEM;
333 	}
334 
335 	usb_fill_int_urb(bcd2k->midi_in_urb, bcd2k->dev,
336 				usb_rcvintpipe(bcd2k->dev, 0x81),
337 				bcd2k->midi_in_buf, BUFSIZE,
338 				bcd2000_input_complete, bcd2k, 1);
339 
340 	usb_fill_int_urb(bcd2k->midi_out_urb, bcd2k->dev,
341 				usb_sndintpipe(bcd2k->dev, 0x1),
342 				bcd2k->midi_out_buf, BUFSIZE,
343 				bcd2000_output_complete, bcd2k, 1);
344 
345 	bcd2000_init_device(bcd2k);
346 
347 	return 0;
348 }
349 
350 static void bcd2000_free_usb_related_resources(struct bcd2000 *bcd2k,
351 						struct usb_interface *interface)
352 {
353 	/* usb_kill_urb not necessary, urb is aborted automatically */
354 
355 	usb_free_urb(bcd2k->midi_out_urb);
356 	usb_free_urb(bcd2k->midi_in_urb);
357 
358 	if (bcd2k->intf) {
359 		usb_set_intfdata(bcd2k->intf, NULL);
360 		bcd2k->intf = NULL;
361 	}
362 }
363 
364 static int bcd2000_probe(struct usb_interface *interface,
365 				const struct usb_device_id *usb_id)
366 {
367 	struct snd_card *card;
368 	struct bcd2000 *bcd2k;
369 	unsigned int card_index;
370 	char usb_path[32];
371 	int err;
372 
373 	mutex_lock(&devices_mutex);
374 
375 	for (card_index = 0; card_index < SNDRV_CARDS; ++card_index)
376 		if (!test_bit(card_index, devices_used))
377 			break;
378 
379 	if (card_index >= SNDRV_CARDS) {
380 		mutex_unlock(&devices_mutex);
381 		return -ENOENT;
382 	}
383 
384 	err = snd_card_new(&interface->dev, index[card_index], id[card_index],
385 			THIS_MODULE, sizeof(*bcd2k), &card);
386 	if (err < 0) {
387 		mutex_unlock(&devices_mutex);
388 		return err;
389 	}
390 
391 	bcd2k = card->private_data;
392 	bcd2k->dev = interface_to_usbdev(interface);
393 	bcd2k->card = card;
394 	bcd2k->card_index = card_index;
395 	bcd2k->intf = interface;
396 
397 	snd_card_set_dev(card, &interface->dev);
398 
399 	strncpy(card->driver, "snd-bcd2000", sizeof(card->driver));
400 	strncpy(card->shortname, "BCD2000", sizeof(card->shortname));
401 	usb_make_path(bcd2k->dev, usb_path, sizeof(usb_path));
402 	snprintf(bcd2k->card->longname, sizeof(bcd2k->card->longname),
403 		    "Behringer BCD2000 at %s",
404 			usb_path);
405 
406 	err = bcd2000_init_midi(bcd2k);
407 	if (err < 0)
408 		goto probe_error;
409 
410 	err = snd_card_register(card);
411 	if (err < 0)
412 		goto probe_error;
413 
414 	usb_set_intfdata(interface, bcd2k);
415 	set_bit(card_index, devices_used);
416 
417 	mutex_unlock(&devices_mutex);
418 	return 0;
419 
420 probe_error:
421 	dev_info(&bcd2k->dev->dev, PREFIX "error during probing");
422 	bcd2000_free_usb_related_resources(bcd2k, interface);
423 	snd_card_free(card);
424 	mutex_unlock(&devices_mutex);
425 	return err;
426 }
427 
428 static void bcd2000_disconnect(struct usb_interface *interface)
429 {
430 	struct bcd2000 *bcd2k = usb_get_intfdata(interface);
431 
432 	if (!bcd2k)
433 		return;
434 
435 	mutex_lock(&devices_mutex);
436 
437 	/* make sure that userspace cannot create new requests */
438 	snd_card_disconnect(bcd2k->card);
439 
440 	bcd2000_free_usb_related_resources(bcd2k, interface);
441 
442 	clear_bit(bcd2k->card_index, devices_used);
443 
444 	snd_card_free_when_closed(bcd2k->card);
445 
446 	mutex_unlock(&devices_mutex);
447 }
448 
449 static struct usb_driver bcd2000_driver = {
450 	.name =		"snd-bcd2000",
451 	.probe =	bcd2000_probe,
452 	.disconnect =	bcd2000_disconnect,
453 	.id_table =	id_table,
454 };
455 
456 module_usb_driver(bcd2000_driver);
457 
458 MODULE_DEVICE_TABLE(usb, id_table);
459 MODULE_AUTHOR("Mario Kicherer, dev@kicherer.org");
460 MODULE_DESCRIPTION("Behringer BCD2000 driver");
461 MODULE_LICENSE("GPL");
462