xref: /linux/sound/usb/line6/driver.c (revision 0e9b70c1e3623fa110fb6be553e644524228ef60)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Line 6 Linux USB driver
4  *
5  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/export.h>
11 #include <linux/slab.h>
12 #include <linux/usb.h>
13 
14 #include <sound/core.h>
15 #include <sound/initval.h>
16 #include <sound/hwdep.h>
17 
18 #include "capture.h"
19 #include "driver.h"
20 #include "midi.h"
21 #include "playback.h"
22 
23 #define DRIVER_AUTHOR  "Markus Grabner <grabner@icg.tugraz.at>"
24 #define DRIVER_DESC    "Line 6 USB Driver"
25 
26 /*
27 	This is Line 6's MIDI manufacturer ID.
28 */
29 const unsigned char line6_midi_id[3] = {
30 	0x00, 0x01, 0x0c
31 };
32 EXPORT_SYMBOL_GPL(line6_midi_id);
33 
34 /*
35 	Code to request version of POD, Variax interface
36 	(and maybe other devices).
37 */
38 static const char line6_request_version[] = {
39 	0xf0, 0x7e, 0x7f, 0x06, 0x01, 0xf7
40 };
41 
42 /*
43 	 Class for asynchronous messages.
44 */
45 struct message {
46 	struct usb_line6 *line6;
47 	const char *buffer;
48 	int size;
49 	int done;
50 };
51 
52 /*
53 	Forward declarations.
54 */
55 static void line6_data_received(struct urb *urb);
56 static int line6_send_raw_message_async_part(struct message *msg,
57 					     struct urb *urb);
58 
59 /*
60 	Start to listen on endpoint.
61 */
62 static int line6_start_listen(struct usb_line6 *line6)
63 {
64 	int err;
65 
66 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
67 		usb_fill_int_urb(line6->urb_listen, line6->usbdev,
68 			usb_rcvintpipe(line6->usbdev, line6->properties->ep_ctrl_r),
69 			line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
70 			line6_data_received, line6, line6->interval);
71 	} else {
72 		usb_fill_bulk_urb(line6->urb_listen, line6->usbdev,
73 			usb_rcvbulkpipe(line6->usbdev, line6->properties->ep_ctrl_r),
74 			line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
75 			line6_data_received, line6);
76 	}
77 
78 	/* sanity checks of EP before actually submitting */
79 	if (usb_urb_ep_type_check(line6->urb_listen)) {
80 		dev_err(line6->ifcdev, "invalid control EP\n");
81 		return -EINVAL;
82 	}
83 
84 	line6->urb_listen->actual_length = 0;
85 	err = usb_submit_urb(line6->urb_listen, GFP_ATOMIC);
86 	return err;
87 }
88 
89 /*
90 	Stop listening on endpoint.
91 */
92 static void line6_stop_listen(struct usb_line6 *line6)
93 {
94 	usb_kill_urb(line6->urb_listen);
95 }
96 
97 /*
98 	Send raw message in pieces of wMaxPacketSize bytes.
99 */
100 int line6_send_raw_message(struct usb_line6 *line6, const char *buffer,
101 				  int size)
102 {
103 	int i, done = 0;
104 	const struct line6_properties *properties = line6->properties;
105 
106 	for (i = 0; i < size; i += line6->max_packet_size) {
107 		int partial;
108 		const char *frag_buf = buffer + i;
109 		int frag_size = min(line6->max_packet_size, size - i);
110 		int retval;
111 
112 		if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
113 			retval = usb_interrupt_msg(line6->usbdev,
114 						usb_sndintpipe(line6->usbdev, properties->ep_ctrl_w),
115 						(char *)frag_buf, frag_size,
116 						&partial, LINE6_TIMEOUT);
117 		} else {
118 			retval = usb_bulk_msg(line6->usbdev,
119 						usb_sndbulkpipe(line6->usbdev, properties->ep_ctrl_w),
120 						(char *)frag_buf, frag_size,
121 						&partial, LINE6_TIMEOUT);
122 		}
123 
124 		if (retval) {
125 			dev_err(line6->ifcdev,
126 				"usb_bulk_msg failed (%d)\n", retval);
127 			break;
128 		}
129 
130 		done += frag_size;
131 	}
132 
133 	return done;
134 }
135 EXPORT_SYMBOL_GPL(line6_send_raw_message);
136 
137 /*
138 	Notification of completion of asynchronous request transmission.
139 */
140 static void line6_async_request_sent(struct urb *urb)
141 {
142 	struct message *msg = (struct message *)urb->context;
143 
144 	if (msg->done >= msg->size) {
145 		usb_free_urb(urb);
146 		kfree(msg);
147 	} else
148 		line6_send_raw_message_async_part(msg, urb);
149 }
150 
151 /*
152 	Asynchronously send part of a raw message.
153 */
154 static int line6_send_raw_message_async_part(struct message *msg,
155 					     struct urb *urb)
156 {
157 	int retval;
158 	struct usb_line6 *line6 = msg->line6;
159 	int done = msg->done;
160 	int bytes = min(msg->size - done, line6->max_packet_size);
161 
162 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
163 		usb_fill_int_urb(urb, line6->usbdev,
164 			usb_sndintpipe(line6->usbdev, line6->properties->ep_ctrl_w),
165 			(char *)msg->buffer + done, bytes,
166 			line6_async_request_sent, msg, line6->interval);
167 	} else {
168 		usb_fill_bulk_urb(urb, line6->usbdev,
169 			usb_sndbulkpipe(line6->usbdev, line6->properties->ep_ctrl_w),
170 			(char *)msg->buffer + done, bytes,
171 			line6_async_request_sent, msg);
172 	}
173 
174 	msg->done += bytes;
175 
176 	/* sanity checks of EP before actually submitting */
177 	retval = usb_urb_ep_type_check(urb);
178 	if (retval < 0)
179 		goto error;
180 
181 	retval = usb_submit_urb(urb, GFP_ATOMIC);
182 	if (retval < 0)
183 		goto error;
184 
185 	return 0;
186 
187  error:
188 	dev_err(line6->ifcdev, "%s: usb_submit_urb failed (%d)\n",
189 		__func__, retval);
190 	usb_free_urb(urb);
191 	kfree(msg);
192 	return retval;
193 }
194 
195 /*
196 	Asynchronously send raw message.
197 */
198 int line6_send_raw_message_async(struct usb_line6 *line6, const char *buffer,
199 				 int size)
200 {
201 	struct message *msg;
202 	struct urb *urb;
203 
204 	/* create message: */
205 	msg = kmalloc(sizeof(struct message), GFP_ATOMIC);
206 	if (msg == NULL)
207 		return -ENOMEM;
208 
209 	/* create URB: */
210 	urb = usb_alloc_urb(0, GFP_ATOMIC);
211 
212 	if (urb == NULL) {
213 		kfree(msg);
214 		return -ENOMEM;
215 	}
216 
217 	/* set message data: */
218 	msg->line6 = line6;
219 	msg->buffer = buffer;
220 	msg->size = size;
221 	msg->done = 0;
222 
223 	/* start sending: */
224 	return line6_send_raw_message_async_part(msg, urb);
225 }
226 EXPORT_SYMBOL_GPL(line6_send_raw_message_async);
227 
228 /*
229 	Send asynchronous device version request.
230 */
231 int line6_version_request_async(struct usb_line6 *line6)
232 {
233 	char *buffer;
234 	int retval;
235 
236 	buffer = kmemdup(line6_request_version,
237 			sizeof(line6_request_version), GFP_ATOMIC);
238 	if (buffer == NULL)
239 		return -ENOMEM;
240 
241 	retval = line6_send_raw_message_async(line6, buffer,
242 					      sizeof(line6_request_version));
243 	kfree(buffer);
244 	return retval;
245 }
246 EXPORT_SYMBOL_GPL(line6_version_request_async);
247 
248 /*
249 	Send sysex message in pieces of wMaxPacketSize bytes.
250 */
251 int line6_send_sysex_message(struct usb_line6 *line6, const char *buffer,
252 			     int size)
253 {
254 	return line6_send_raw_message(line6, buffer,
255 				      size + SYSEX_EXTRA_SIZE) -
256 	    SYSEX_EXTRA_SIZE;
257 }
258 EXPORT_SYMBOL_GPL(line6_send_sysex_message);
259 
260 /*
261 	Allocate buffer for sysex message and prepare header.
262 	@param code sysex message code
263 	@param size number of bytes between code and sysex end
264 */
265 char *line6_alloc_sysex_buffer(struct usb_line6 *line6, int code1, int code2,
266 			       int size)
267 {
268 	char *buffer = kmalloc(size + SYSEX_EXTRA_SIZE, GFP_ATOMIC);
269 
270 	if (!buffer)
271 		return NULL;
272 
273 	buffer[0] = LINE6_SYSEX_BEGIN;
274 	memcpy(buffer + 1, line6_midi_id, sizeof(line6_midi_id));
275 	buffer[sizeof(line6_midi_id) + 1] = code1;
276 	buffer[sizeof(line6_midi_id) + 2] = code2;
277 	buffer[sizeof(line6_midi_id) + 3 + size] = LINE6_SYSEX_END;
278 	return buffer;
279 }
280 EXPORT_SYMBOL_GPL(line6_alloc_sysex_buffer);
281 
282 /*
283 	Notification of data received from the Line 6 device.
284 */
285 static void line6_data_received(struct urb *urb)
286 {
287 	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
288 	struct midi_buffer *mb = &line6->line6midi->midibuf_in;
289 	int done;
290 
291 	if (urb->status == -ESHUTDOWN)
292 		return;
293 
294 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
295 		done =
296 			line6_midibuf_write(mb, urb->transfer_buffer, urb->actual_length);
297 
298 		if (done < urb->actual_length) {
299 			line6_midibuf_ignore(mb, done);
300 			dev_dbg(line6->ifcdev, "%d %d buffer overflow - message skipped\n",
301 				done, urb->actual_length);
302 		}
303 
304 		for (;;) {
305 			done =
306 				line6_midibuf_read(mb, line6->buffer_message,
307 						   LINE6_MIDI_MESSAGE_MAXLEN,
308 						   LINE6_MIDIBUF_READ_RX);
309 
310 			if (done <= 0)
311 				break;
312 
313 			line6->message_length = done;
314 			line6_midi_receive(line6, line6->buffer_message, done);
315 
316 			if (line6->process_message)
317 				line6->process_message(line6);
318 		}
319 	} else {
320 		line6->buffer_message = urb->transfer_buffer;
321 		line6->message_length = urb->actual_length;
322 		if (line6->process_message)
323 			line6->process_message(line6);
324 		line6->buffer_message = NULL;
325 	}
326 
327 	line6_start_listen(line6);
328 }
329 
330 #define LINE6_READ_WRITE_STATUS_DELAY 2  /* milliseconds */
331 #define LINE6_READ_WRITE_MAX_RETRIES 50
332 
333 /*
334 	Read data from device.
335 */
336 int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
337 		    unsigned datalen)
338 {
339 	struct usb_device *usbdev = line6->usbdev;
340 	int ret;
341 	u8 len;
342 	unsigned count;
343 
344 	if (address > 0xffff || datalen > 0xff)
345 		return -EINVAL;
346 
347 	/* query the serial number: */
348 	ret = usb_control_msg_send(usbdev, 0, 0x67,
349 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
350 				   (datalen << 8) | 0x21, address, NULL, 0,
351 				   LINE6_TIMEOUT, GFP_KERNEL);
352 	if (ret) {
353 		dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
354 		goto exit;
355 	}
356 
357 	/* Wait for data length. We'll get 0xff until length arrives. */
358 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
359 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
360 
361 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
362 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
363 					   0x0012, 0x0000, &len, 1,
364 					   LINE6_TIMEOUT, GFP_KERNEL);
365 		if (ret) {
366 			dev_err(line6->ifcdev,
367 				"receive length failed (error %d)\n", ret);
368 			goto exit;
369 		}
370 
371 		if (len != 0xff)
372 			break;
373 	}
374 
375 	ret = -EIO;
376 	if (len == 0xff) {
377 		dev_err(line6->ifcdev, "read failed after %d retries\n",
378 			count);
379 		goto exit;
380 	} else if (len != datalen) {
381 		/* should be equal or something went wrong */
382 		dev_err(line6->ifcdev,
383 			"length mismatch (expected %d, got %d)\n",
384 			(int)datalen, len);
385 		goto exit;
386 	}
387 
388 	/* receive the result: */
389 	ret = usb_control_msg_recv(usbdev, 0, 0x67,
390 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
391 				   0x0013, 0x0000, data, datalen, LINE6_TIMEOUT,
392 				   GFP_KERNEL);
393 	if (ret)
394 		dev_err(line6->ifcdev, "read failed (error %d)\n", ret);
395 
396 exit:
397 	return ret;
398 }
399 EXPORT_SYMBOL_GPL(line6_read_data);
400 
401 /*
402 	Write data to device.
403 */
404 int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
405 		     unsigned datalen)
406 {
407 	struct usb_device *usbdev = line6->usbdev;
408 	int ret;
409 	unsigned char *status;
410 	int count;
411 
412 	if (address > 0xffff || datalen > 0xffff)
413 		return -EINVAL;
414 
415 	status = kmalloc(1, GFP_KERNEL);
416 	if (!status)
417 		return -ENOMEM;
418 
419 	ret = usb_control_msg_send(usbdev, 0, 0x67,
420 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
421 				   0x0022, address, data, datalen, LINE6_TIMEOUT,
422 				   GFP_KERNEL);
423 	if (ret) {
424 		dev_err(line6->ifcdev,
425 			"write request failed (error %d)\n", ret);
426 		goto exit;
427 	}
428 
429 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
430 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
431 
432 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
433 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
434 					   0x0012, 0x0000, status, 1, LINE6_TIMEOUT,
435 					   GFP_KERNEL);
436 		if (ret) {
437 			dev_err(line6->ifcdev,
438 				"receiving status failed (error %d)\n", ret);
439 			goto exit;
440 		}
441 
442 		if (*status != 0xff)
443 			break;
444 	}
445 
446 	if (*status == 0xff) {
447 		dev_err(line6->ifcdev, "write failed after %d retries\n",
448 			count);
449 		ret = -EIO;
450 	} else if (*status != 0) {
451 		dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
452 		ret = -EIO;
453 	}
454 exit:
455 	kfree(status);
456 	return ret;
457 }
458 EXPORT_SYMBOL_GPL(line6_write_data);
459 
460 /*
461 	Read Line 6 device serial number.
462 	(POD, TonePort, GuitarPort)
463 */
464 int line6_read_serial_number(struct usb_line6 *line6, u32 *serial_number)
465 {
466 	return line6_read_data(line6, 0x80d0, serial_number,
467 			       sizeof(*serial_number));
468 }
469 EXPORT_SYMBOL_GPL(line6_read_serial_number);
470 
471 /*
472 	Card destructor.
473 */
474 static void line6_destruct(struct snd_card *card)
475 {
476 	struct usb_line6 *line6 = card->private_data;
477 	struct usb_device *usbdev = line6->usbdev;
478 
479 	/* Free buffer memory first. We cannot depend on the existence of private
480 	 * data from the (podhd) module, it may be gone already during this call
481 	 */
482 	kfree(line6->buffer_message);
483 
484 	kfree(line6->buffer_listen);
485 
486 	/* then free URBs: */
487 	usb_free_urb(line6->urb_listen);
488 	line6->urb_listen = NULL;
489 
490 	/* decrement reference counters: */
491 	usb_put_dev(usbdev);
492 }
493 
494 static void line6_get_usb_properties(struct usb_line6 *line6)
495 {
496 	struct usb_device *usbdev = line6->usbdev;
497 	const struct line6_properties *properties = line6->properties;
498 	int pipe;
499 	struct usb_host_endpoint *ep = NULL;
500 
501 	if (properties->capabilities & LINE6_CAP_CONTROL) {
502 		if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
503 			pipe = usb_rcvintpipe(line6->usbdev,
504 				line6->properties->ep_ctrl_r);
505 		} else {
506 			pipe = usb_rcvbulkpipe(line6->usbdev,
507 				line6->properties->ep_ctrl_r);
508 		}
509 		ep = usbdev->ep_in[usb_pipeendpoint(pipe)];
510 	}
511 
512 	/* Control data transfer properties */
513 	if (ep) {
514 		line6->interval = ep->desc.bInterval;
515 		line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
516 	} else {
517 		if (properties->capabilities & LINE6_CAP_CONTROL) {
518 			dev_err(line6->ifcdev,
519 				"endpoint not available, using fallback values");
520 		}
521 		line6->interval = LINE6_FALLBACK_INTERVAL;
522 		line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
523 	}
524 
525 	/* Isochronous transfer properties */
526 	if (usbdev->speed == USB_SPEED_LOW) {
527 		line6->intervals_per_second = USB_LOW_INTERVALS_PER_SECOND;
528 		line6->iso_buffers = USB_LOW_ISO_BUFFERS;
529 	} else {
530 		line6->intervals_per_second = USB_HIGH_INTERVALS_PER_SECOND;
531 		line6->iso_buffers = USB_HIGH_ISO_BUFFERS;
532 	}
533 }
534 
535 /* Enable buffering of incoming messages, flush the buffer */
536 static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file)
537 {
538 	struct usb_line6 *line6 = hw->private_data;
539 
540 	/* NOTE: hwdep layer provides atomicity here */
541 
542 	line6->messages.active = 1;
543 	line6->messages.nonblock = file->f_flags & O_NONBLOCK ? 1 : 0;
544 
545 	return 0;
546 }
547 
548 /* Stop buffering */
549 static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
550 {
551 	struct usb_line6 *line6 = hw->private_data;
552 
553 	line6->messages.active = 0;
554 
555 	return 0;
556 }
557 
558 /* Read from circular buffer, return to user */
559 static long
560 line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
561 					loff_t *offset)
562 {
563 	struct usb_line6 *line6 = hwdep->private_data;
564 	long rv = 0;
565 	unsigned int out_count;
566 
567 	if (mutex_lock_interruptible(&line6->messages.read_lock))
568 		return -ERESTARTSYS;
569 
570 	while (kfifo_len(&line6->messages.fifo) == 0) {
571 		mutex_unlock(&line6->messages.read_lock);
572 
573 		if (line6->messages.nonblock)
574 			return -EAGAIN;
575 
576 		rv = wait_event_interruptible(
577 			line6->messages.wait_queue,
578 			kfifo_len(&line6->messages.fifo) != 0);
579 		if (rv < 0)
580 			return rv;
581 
582 		if (mutex_lock_interruptible(&line6->messages.read_lock))
583 			return -ERESTARTSYS;
584 	}
585 
586 	if (kfifo_peek_len(&line6->messages.fifo) > count) {
587 		/* Buffer too small; allow re-read of the current item... */
588 		rv = -EINVAL;
589 	} else {
590 		rv = kfifo_to_user(&line6->messages.fifo, buf, count, &out_count);
591 		if (rv == 0)
592 			rv = out_count;
593 	}
594 
595 	mutex_unlock(&line6->messages.read_lock);
596 	return rv;
597 }
598 
599 /* Write directly (no buffering) to device by user*/
600 static long
601 line6_hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
602 					loff_t *offset)
603 {
604 	struct usb_line6 *line6 = hwdep->private_data;
605 	int rv;
606 	char *data_copy;
607 
608 	if (count > line6->max_packet_size * LINE6_RAW_MESSAGES_MAXCOUNT) {
609 		/* This is an arbitrary limit - still better than nothing... */
610 		return -EINVAL;
611 	}
612 
613 	data_copy = memdup_user(data, count);
614 	if (IS_ERR(data_copy))
615 		return PTR_ERR(data_copy);
616 
617 	rv = line6_send_raw_message(line6, data_copy, count);
618 
619 	kfree(data_copy);
620 	return rv;
621 }
622 
623 static __poll_t
624 line6_hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
625 {
626 	__poll_t rv;
627 	struct usb_line6 *line6 = hwdep->private_data;
628 
629 	poll_wait(file, &line6->messages.wait_queue, wait);
630 
631 	mutex_lock(&line6->messages.read_lock);
632 	rv = kfifo_len(&line6->messages.fifo) == 0 ? 0 : EPOLLIN | EPOLLRDNORM;
633 	mutex_unlock(&line6->messages.read_lock);
634 
635 	return rv;
636 }
637 
638 static const struct snd_hwdep_ops hwdep_ops = {
639 	.open    = line6_hwdep_open,
640 	.release = line6_hwdep_release,
641 	.read    = line6_hwdep_read,
642 	.write   = line6_hwdep_write,
643 	.poll    = line6_hwdep_poll,
644 };
645 
646 /* Insert into circular buffer */
647 static void line6_hwdep_push_message(struct usb_line6 *line6)
648 {
649 	if (!line6->messages.active)
650 		return;
651 
652 	if (kfifo_avail(&line6->messages.fifo) >= line6->message_length) {
653 		/* No race condition here, there's only one writer */
654 		kfifo_in(&line6->messages.fifo,
655 			line6->buffer_message, line6->message_length);
656 	} /* else TODO: signal overflow */
657 
658 	wake_up_interruptible(&line6->messages.wait_queue);
659 }
660 
661 static int line6_hwdep_init(struct usb_line6 *line6)
662 {
663 	int err;
664 	struct snd_hwdep *hwdep;
665 
666 	/* TODO: usb_driver_claim_interface(); */
667 	line6->process_message = line6_hwdep_push_message;
668 	line6->messages.active = 0;
669 	init_waitqueue_head(&line6->messages.wait_queue);
670 	mutex_init(&line6->messages.read_lock);
671 	INIT_KFIFO(line6->messages.fifo);
672 
673 	err = snd_hwdep_new(line6->card, "config", 0, &hwdep);
674 	if (err < 0)
675 		goto end;
676 	strcpy(hwdep->name, "config");
677 	hwdep->iface = SNDRV_HWDEP_IFACE_LINE6;
678 	hwdep->ops = hwdep_ops;
679 	hwdep->private_data = line6;
680 	hwdep->exclusive = true;
681 
682 end:
683 	return err;
684 }
685 
686 static int line6_init_cap_control(struct usb_line6 *line6)
687 {
688 	int ret;
689 
690 	/* initialize USB buffers: */
691 	line6->buffer_listen = kmalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
692 	if (!line6->buffer_listen)
693 		return -ENOMEM;
694 
695 	line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
696 	if (!line6->urb_listen)
697 		return -ENOMEM;
698 
699 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
700 		line6->buffer_message = kmalloc(LINE6_MIDI_MESSAGE_MAXLEN, GFP_KERNEL);
701 		if (!line6->buffer_message)
702 			return -ENOMEM;
703 
704 		ret = line6_init_midi(line6);
705 		if (ret < 0)
706 			return ret;
707 	} else {
708 		ret = line6_hwdep_init(line6);
709 		if (ret < 0)
710 			return ret;
711 	}
712 
713 	ret = line6_start_listen(line6);
714 	if (ret < 0) {
715 		dev_err(line6->ifcdev, "cannot start listening: %d\n", ret);
716 		return ret;
717 	}
718 
719 	return 0;
720 }
721 
722 static void line6_startup_work(struct work_struct *work)
723 {
724 	struct usb_line6 *line6 =
725 		container_of(work, struct usb_line6, startup_work.work);
726 
727 	if (line6->startup)
728 		line6->startup(line6);
729 }
730 
731 /*
732 	Probe USB device.
733 */
734 int line6_probe(struct usb_interface *interface,
735 		const struct usb_device_id *id,
736 		const char *driver_name,
737 		const struct line6_properties *properties,
738 		int (*private_init)(struct usb_line6 *, const struct usb_device_id *id),
739 		size_t data_size)
740 {
741 	struct usb_device *usbdev = interface_to_usbdev(interface);
742 	struct snd_card *card;
743 	struct usb_line6 *line6;
744 	int interface_number;
745 	int ret;
746 
747 	if (WARN_ON(data_size < sizeof(*line6)))
748 		return -EINVAL;
749 
750 	/* we don't handle multiple configurations */
751 	if (usbdev->descriptor.bNumConfigurations != 1)
752 		return -ENODEV;
753 
754 	ret = snd_card_new(&interface->dev,
755 			   SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
756 			   THIS_MODULE, data_size, &card);
757 	if (ret < 0)
758 		return ret;
759 
760 	/* store basic data: */
761 	line6 = card->private_data;
762 	line6->card = card;
763 	line6->properties = properties;
764 	line6->usbdev = usbdev;
765 	line6->ifcdev = &interface->dev;
766 	INIT_DELAYED_WORK(&line6->startup_work, line6_startup_work);
767 
768 	strcpy(card->id, properties->id);
769 	strcpy(card->driver, driver_name);
770 	strcpy(card->shortname, properties->name);
771 	sprintf(card->longname, "Line 6 %s at USB %s", properties->name,
772 		dev_name(line6->ifcdev));
773 	card->private_free = line6_destruct;
774 
775 	usb_set_intfdata(interface, line6);
776 
777 	/* increment reference counters: */
778 	usb_get_dev(usbdev);
779 
780 	/* initialize device info: */
781 	dev_info(&interface->dev, "Line 6 %s found\n", properties->name);
782 
783 	/* query interface number */
784 	interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
785 
786 	/* TODO reserves the bus bandwidth even without actual transfer */
787 	ret = usb_set_interface(usbdev, interface_number,
788 				properties->altsetting);
789 	if (ret < 0) {
790 		dev_err(&interface->dev, "set_interface failed\n");
791 		goto error;
792 	}
793 
794 	line6_get_usb_properties(line6);
795 
796 	if (properties->capabilities & LINE6_CAP_CONTROL) {
797 		ret = line6_init_cap_control(line6);
798 		if (ret < 0)
799 			goto error;
800 	}
801 
802 	/* initialize device data based on device: */
803 	ret = private_init(line6, id);
804 	if (ret < 0)
805 		goto error;
806 
807 	/* creation of additional special files should go here */
808 
809 	dev_info(&interface->dev, "Line 6 %s now attached\n",
810 		 properties->name);
811 
812 	return 0;
813 
814  error:
815 	/* we can call disconnect callback here because no close-sync is
816 	 * needed yet at this point
817 	 */
818 	line6_disconnect(interface);
819 	return ret;
820 }
821 EXPORT_SYMBOL_GPL(line6_probe);
822 
823 /*
824 	Line 6 device disconnected.
825 */
826 void line6_disconnect(struct usb_interface *interface)
827 {
828 	struct usb_line6 *line6 = usb_get_intfdata(interface);
829 	struct usb_device *usbdev = interface_to_usbdev(interface);
830 
831 	if (!line6)
832 		return;
833 
834 	if (WARN_ON(usbdev != line6->usbdev))
835 		return;
836 
837 	cancel_delayed_work_sync(&line6->startup_work);
838 
839 	if (line6->urb_listen != NULL)
840 		line6_stop_listen(line6);
841 
842 	snd_card_disconnect(line6->card);
843 	if (line6->line6pcm)
844 		line6_pcm_disconnect(line6->line6pcm);
845 	if (line6->disconnect)
846 		line6->disconnect(line6);
847 
848 	dev_info(&interface->dev, "Line 6 %s now disconnected\n",
849 		 line6->properties->name);
850 
851 	/* make sure the device isn't destructed twice: */
852 	usb_set_intfdata(interface, NULL);
853 
854 	snd_card_free_when_closed(line6->card);
855 }
856 EXPORT_SYMBOL_GPL(line6_disconnect);
857 
858 #ifdef CONFIG_PM
859 
860 /*
861 	Suspend Line 6 device.
862 */
863 int line6_suspend(struct usb_interface *interface, pm_message_t message)
864 {
865 	struct usb_line6 *line6 = usb_get_intfdata(interface);
866 	struct snd_line6_pcm *line6pcm = line6->line6pcm;
867 
868 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D3hot);
869 
870 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
871 		line6_stop_listen(line6);
872 
873 	if (line6pcm != NULL)
874 		line6pcm->flags = 0;
875 
876 	return 0;
877 }
878 EXPORT_SYMBOL_GPL(line6_suspend);
879 
880 /*
881 	Resume Line 6 device.
882 */
883 int line6_resume(struct usb_interface *interface)
884 {
885 	struct usb_line6 *line6 = usb_get_intfdata(interface);
886 
887 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
888 		line6_start_listen(line6);
889 
890 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D0);
891 	return 0;
892 }
893 EXPORT_SYMBOL_GPL(line6_resume);
894 
895 #endif /* CONFIG_PM */
896 
897 MODULE_AUTHOR(DRIVER_AUTHOR);
898 MODULE_DESCRIPTION(DRIVER_DESC);
899 MODULE_LICENSE("GPL");
900 
901