xref: /linux/sound/usb/line6/driver.c (revision a6021aa24f6417416d93318bbfa022ab229c33c8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Line 6 Linux USB driver
4  *
5  * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.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 <line6@grabner-graz.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 = kzalloc(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 	unsigned long flags;
290 	int done;
291 
292 	if (urb->status == -ESHUTDOWN)
293 		return;
294 
295 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
296 		spin_lock_irqsave(&line6->line6midi->lock, flags);
297 		done =
298 			line6_midibuf_write(mb, urb->transfer_buffer, urb->actual_length);
299 
300 		if (done < urb->actual_length) {
301 			line6_midibuf_ignore(mb, done);
302 			dev_dbg(line6->ifcdev, "%d %d buffer overflow - message skipped\n",
303 				done, urb->actual_length);
304 		}
305 		spin_unlock_irqrestore(&line6->line6midi->lock, flags);
306 
307 		for (;;) {
308 			spin_lock_irqsave(&line6->line6midi->lock, flags);
309 			done =
310 				line6_midibuf_read(mb, line6->buffer_message,
311 						   LINE6_MIDI_MESSAGE_MAXLEN,
312 						   LINE6_MIDIBUF_READ_RX);
313 			spin_unlock_irqrestore(&line6->line6midi->lock, flags);
314 
315 			if (done <= 0)
316 				break;
317 
318 			line6->message_length = done;
319 			line6_midi_receive(line6, line6->buffer_message, done);
320 
321 			if (line6->process_message)
322 				line6->process_message(line6);
323 		}
324 	} else {
325 		line6->buffer_message = urb->transfer_buffer;
326 		line6->message_length = urb->actual_length;
327 		if (line6->process_message)
328 			line6->process_message(line6);
329 		line6->buffer_message = NULL;
330 	}
331 
332 	line6_start_listen(line6);
333 }
334 
335 #define LINE6_READ_WRITE_STATUS_DELAY 2  /* milliseconds */
336 #define LINE6_READ_WRITE_MAX_RETRIES 50
337 
338 /*
339 	Read data from device.
340 */
341 int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
342 		    unsigned datalen)
343 {
344 	struct usb_device *usbdev = line6->usbdev;
345 	int ret;
346 	u8 len;
347 	unsigned count;
348 
349 	if (address > 0xffff || datalen > 0xff)
350 		return -EINVAL;
351 
352 	/* query the serial number: */
353 	ret = usb_control_msg_send(usbdev, 0, 0x67,
354 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
355 				   (datalen << 8) | 0x21, address, NULL, 0,
356 				   LINE6_TIMEOUT, GFP_KERNEL);
357 	if (ret) {
358 		dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
359 		goto exit;
360 	}
361 
362 	/* Wait for data length. We'll get 0xff until length arrives. */
363 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
364 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
365 
366 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
367 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
368 					   0x0012, 0x0000, &len, 1,
369 					   LINE6_TIMEOUT, GFP_KERNEL);
370 		if (ret) {
371 			dev_err(line6->ifcdev,
372 				"receive length failed (error %d)\n", ret);
373 			goto exit;
374 		}
375 
376 		if (len != 0xff)
377 			break;
378 	}
379 
380 	ret = -EIO;
381 	if (len == 0xff) {
382 		dev_err(line6->ifcdev, "read failed after %d retries\n",
383 			count);
384 		goto exit;
385 	} else if (len != datalen) {
386 		/* should be equal or something went wrong */
387 		dev_err(line6->ifcdev,
388 			"length mismatch (expected %d, got %d)\n",
389 			(int)datalen, len);
390 		goto exit;
391 	}
392 
393 	/* receive the result: */
394 	ret = usb_control_msg_recv(usbdev, 0, 0x67,
395 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
396 				   0x0013, 0x0000, data, datalen, LINE6_TIMEOUT,
397 				   GFP_KERNEL);
398 	if (ret)
399 		dev_err(line6->ifcdev, "read failed (error %d)\n", ret);
400 
401 exit:
402 	return ret;
403 }
404 EXPORT_SYMBOL_GPL(line6_read_data);
405 
406 /*
407 	Write data to device.
408 */
409 int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
410 		     unsigned datalen)
411 {
412 	struct usb_device *usbdev = line6->usbdev;
413 	int ret;
414 	unsigned char *status;
415 	int count;
416 
417 	if (address > 0xffff || datalen > 0xffff)
418 		return -EINVAL;
419 
420 	status = kmalloc(1, GFP_KERNEL);
421 	if (!status)
422 		return -ENOMEM;
423 
424 	ret = usb_control_msg_send(usbdev, 0, 0x67,
425 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
426 				   0x0022, address, data, datalen, LINE6_TIMEOUT,
427 				   GFP_KERNEL);
428 	if (ret) {
429 		dev_err(line6->ifcdev,
430 			"write request failed (error %d)\n", ret);
431 		goto exit;
432 	}
433 
434 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
435 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
436 
437 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
438 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
439 					   0x0012, 0x0000, status, 1, LINE6_TIMEOUT,
440 					   GFP_KERNEL);
441 		if (ret) {
442 			dev_err(line6->ifcdev,
443 				"receiving status failed (error %d)\n", ret);
444 			goto exit;
445 		}
446 
447 		if (*status != 0xff)
448 			break;
449 	}
450 
451 	if (*status == 0xff) {
452 		dev_err(line6->ifcdev, "write failed after %d retries\n",
453 			count);
454 		ret = -EIO;
455 	} else if (*status != 0) {
456 		dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
457 		ret = -EIO;
458 	}
459 exit:
460 	kfree(status);
461 	return ret;
462 }
463 EXPORT_SYMBOL_GPL(line6_write_data);
464 
465 /*
466 	Read Line 6 device serial number.
467 	(POD, TonePort, GuitarPort)
468 */
469 int line6_read_serial_number(struct usb_line6 *line6, u32 *serial_number)
470 {
471 	return line6_read_data(line6, 0x80d0, serial_number,
472 			       sizeof(*serial_number));
473 }
474 EXPORT_SYMBOL_GPL(line6_read_serial_number);
475 
476 /*
477 	Card destructor.
478 */
479 static void line6_destruct(struct snd_card *card)
480 {
481 	struct usb_line6 *line6 = card->private_data;
482 	struct usb_device *usbdev = line6->usbdev;
483 
484 	/* Free buffer memory first. We cannot depend on the existence of private
485 	 * data from the (podhd) module, it may be gone already during this call
486 	 */
487 	kfree(line6->buffer_message);
488 
489 	kfree(line6->buffer_listen);
490 
491 	/* then free URBs: */
492 	usb_free_urb(line6->urb_listen);
493 	line6->urb_listen = NULL;
494 
495 	/* decrement reference counters: */
496 	usb_put_dev(usbdev);
497 }
498 
499 static void line6_get_usb_properties(struct usb_line6 *line6)
500 {
501 	struct usb_device *usbdev = line6->usbdev;
502 	const struct line6_properties *properties = line6->properties;
503 	int pipe;
504 	struct usb_host_endpoint *ep = NULL;
505 
506 	if (properties->capabilities & LINE6_CAP_CONTROL) {
507 		if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
508 			pipe = usb_rcvintpipe(line6->usbdev,
509 				line6->properties->ep_ctrl_r);
510 		} else {
511 			pipe = usb_rcvbulkpipe(line6->usbdev,
512 				line6->properties->ep_ctrl_r);
513 		}
514 		ep = usbdev->ep_in[usb_pipeendpoint(pipe)];
515 	}
516 
517 	/* Control data transfer properties */
518 	if (ep) {
519 		line6->interval = ep->desc.bInterval;
520 		line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
521 	} else {
522 		if (properties->capabilities & LINE6_CAP_CONTROL) {
523 			dev_err(line6->ifcdev,
524 				"endpoint not available, using fallback values");
525 		}
526 		line6->interval = LINE6_FALLBACK_INTERVAL;
527 		line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
528 	}
529 
530 	/* Isochronous transfer properties */
531 	if (usbdev->speed == USB_SPEED_LOW) {
532 		line6->intervals_per_second = USB_LOW_INTERVALS_PER_SECOND;
533 		line6->iso_buffers = USB_LOW_ISO_BUFFERS;
534 	} else {
535 		line6->intervals_per_second = USB_HIGH_INTERVALS_PER_SECOND;
536 		line6->iso_buffers = USB_HIGH_ISO_BUFFERS;
537 	}
538 }
539 
540 /* Enable buffering of incoming messages, flush the buffer */
541 static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file)
542 {
543 	struct usb_line6 *line6 = hw->private_data;
544 
545 	/* NOTE: hwdep layer provides atomicity here */
546 
547 	line6->messages.active = 1;
548 	line6->messages.nonblock = file->f_flags & O_NONBLOCK ? 1 : 0;
549 
550 	return 0;
551 }
552 
553 /* Stop buffering */
554 static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
555 {
556 	struct usb_line6 *line6 = hw->private_data;
557 
558 	line6->messages.active = 0;
559 
560 	return 0;
561 }
562 
563 /* Read from circular buffer, return to user */
564 static long
565 line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
566 					loff_t *offset)
567 {
568 	struct usb_line6 *line6 = hwdep->private_data;
569 	long rv = 0;
570 	unsigned int out_count;
571 
572 	if (mutex_lock_interruptible(&line6->messages.read_lock))
573 		return -ERESTARTSYS;
574 
575 	while (kfifo_len(&line6->messages.fifo) == 0) {
576 		mutex_unlock(&line6->messages.read_lock);
577 
578 		if (line6->messages.nonblock)
579 			return -EAGAIN;
580 
581 		rv = wait_event_interruptible(
582 			line6->messages.wait_queue,
583 			kfifo_len(&line6->messages.fifo) != 0);
584 		if (rv < 0)
585 			return rv;
586 
587 		if (mutex_lock_interruptible(&line6->messages.read_lock))
588 			return -ERESTARTSYS;
589 	}
590 
591 	if (kfifo_peek_len(&line6->messages.fifo) > count) {
592 		/* Buffer too small; allow re-read of the current item... */
593 		rv = -EINVAL;
594 	} else {
595 		rv = kfifo_to_user(&line6->messages.fifo, buf, count, &out_count);
596 		if (rv == 0)
597 			rv = out_count;
598 	}
599 
600 	mutex_unlock(&line6->messages.read_lock);
601 	return rv;
602 }
603 
604 /* Write directly (no buffering) to device by user*/
605 static long
606 line6_hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
607 					loff_t *offset)
608 {
609 	struct usb_line6 *line6 = hwdep->private_data;
610 	int rv;
611 	char *data_copy;
612 
613 	if (count > line6->max_packet_size * LINE6_RAW_MESSAGES_MAXCOUNT) {
614 		/* This is an arbitrary limit - still better than nothing... */
615 		return -EINVAL;
616 	}
617 
618 	data_copy = memdup_user(data, count);
619 	if (IS_ERR(data_copy))
620 		return PTR_ERR(data_copy);
621 
622 	rv = line6_send_raw_message(line6, data_copy, count);
623 
624 	kfree(data_copy);
625 	return rv;
626 }
627 
628 static __poll_t
629 line6_hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
630 {
631 	__poll_t rv;
632 	struct usb_line6 *line6 = hwdep->private_data;
633 
634 	poll_wait(file, &line6->messages.wait_queue, wait);
635 
636 	mutex_lock(&line6->messages.read_lock);
637 	rv = kfifo_len(&line6->messages.fifo) == 0 ? 0 : EPOLLIN | EPOLLRDNORM;
638 	mutex_unlock(&line6->messages.read_lock);
639 
640 	return rv;
641 }
642 
643 static const struct snd_hwdep_ops hwdep_ops = {
644 	.open    = line6_hwdep_open,
645 	.release = line6_hwdep_release,
646 	.read    = line6_hwdep_read,
647 	.write   = line6_hwdep_write,
648 	.poll    = line6_hwdep_poll,
649 };
650 
651 /* Insert into circular buffer */
652 static void line6_hwdep_push_message(struct usb_line6 *line6)
653 {
654 	if (!line6->messages.active)
655 		return;
656 
657 	if (kfifo_avail(&line6->messages.fifo) >= line6->message_length) {
658 		/* No race condition here, there's only one writer */
659 		kfifo_in(&line6->messages.fifo,
660 			line6->buffer_message, line6->message_length);
661 	} /* else TODO: signal overflow */
662 
663 	wake_up_interruptible(&line6->messages.wait_queue);
664 }
665 
666 static int line6_hwdep_init(struct usb_line6 *line6)
667 {
668 	int err;
669 	struct snd_hwdep *hwdep;
670 
671 	/* TODO: usb_driver_claim_interface(); */
672 	line6->process_message = line6_hwdep_push_message;
673 	line6->messages.active = 0;
674 	init_waitqueue_head(&line6->messages.wait_queue);
675 	mutex_init(&line6->messages.read_lock);
676 	INIT_KFIFO(line6->messages.fifo);
677 
678 	err = snd_hwdep_new(line6->card, "config", 0, &hwdep);
679 	if (err < 0)
680 		goto end;
681 	strcpy(hwdep->name, "config");
682 	hwdep->iface = SNDRV_HWDEP_IFACE_LINE6;
683 	hwdep->ops = hwdep_ops;
684 	hwdep->private_data = line6;
685 	hwdep->exclusive = true;
686 
687 end:
688 	return err;
689 }
690 
691 static int line6_init_cap_control(struct usb_line6 *line6)
692 {
693 	int ret;
694 
695 	/* initialize USB buffers: */
696 	line6->buffer_listen = kzalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
697 	if (!line6->buffer_listen)
698 		return -ENOMEM;
699 
700 	line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
701 	if (!line6->urb_listen)
702 		return -ENOMEM;
703 
704 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
705 		line6->buffer_message = kzalloc(LINE6_MIDI_MESSAGE_MAXLEN, GFP_KERNEL);
706 		if (!line6->buffer_message)
707 			return -ENOMEM;
708 
709 		ret = line6_init_midi(line6);
710 		if (ret < 0)
711 			return ret;
712 	} else {
713 		ret = line6_hwdep_init(line6);
714 		if (ret < 0)
715 			return ret;
716 	}
717 
718 	ret = line6_start_listen(line6);
719 	if (ret < 0) {
720 		dev_err(line6->ifcdev, "cannot start listening: %d\n", ret);
721 		return ret;
722 	}
723 
724 	return 0;
725 }
726 
727 static void line6_startup_work(struct work_struct *work)
728 {
729 	struct usb_line6 *line6 =
730 		container_of(work, struct usb_line6, startup_work.work);
731 
732 	if (line6->startup)
733 		line6->startup(line6);
734 }
735 
736 /*
737 	Probe USB device.
738 */
739 int line6_probe(struct usb_interface *interface,
740 		const struct usb_device_id *id,
741 		const char *driver_name,
742 		const struct line6_properties *properties,
743 		int (*private_init)(struct usb_line6 *, const struct usb_device_id *id),
744 		size_t data_size)
745 {
746 	struct usb_device *usbdev = interface_to_usbdev(interface);
747 	struct snd_card *card;
748 	struct usb_line6 *line6;
749 	int interface_number;
750 	int ret;
751 
752 	if (WARN_ON(data_size < sizeof(*line6)))
753 		return -EINVAL;
754 
755 	/* we don't handle multiple configurations */
756 	if (usbdev->descriptor.bNumConfigurations != 1)
757 		return -ENODEV;
758 
759 	ret = snd_card_new(&interface->dev,
760 			   SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
761 			   THIS_MODULE, data_size, &card);
762 	if (ret < 0)
763 		return ret;
764 
765 	/* store basic data: */
766 	line6 = card->private_data;
767 	line6->card = card;
768 	line6->properties = properties;
769 	line6->usbdev = usbdev;
770 	line6->ifcdev = &interface->dev;
771 	INIT_DELAYED_WORK(&line6->startup_work, line6_startup_work);
772 
773 	strcpy(card->id, properties->id);
774 	strcpy(card->driver, driver_name);
775 	strcpy(card->shortname, properties->name);
776 	sprintf(card->longname, "Line 6 %s at USB %s", properties->name,
777 		dev_name(line6->ifcdev));
778 	card->private_free = line6_destruct;
779 
780 	usb_set_intfdata(interface, line6);
781 
782 	/* increment reference counters: */
783 	usb_get_dev(usbdev);
784 
785 	/* initialize device info: */
786 	dev_info(&interface->dev, "Line 6 %s found\n", properties->name);
787 
788 	/* query interface number */
789 	interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
790 
791 	/* TODO reserves the bus bandwidth even without actual transfer */
792 	ret = usb_set_interface(usbdev, interface_number,
793 				properties->altsetting);
794 	if (ret < 0) {
795 		dev_err(&interface->dev, "set_interface failed\n");
796 		goto error;
797 	}
798 
799 	line6_get_usb_properties(line6);
800 
801 	if (properties->capabilities & LINE6_CAP_CONTROL) {
802 		ret = line6_init_cap_control(line6);
803 		if (ret < 0)
804 			goto error;
805 	}
806 
807 	/* initialize device data based on device: */
808 	ret = private_init(line6, id);
809 	if (ret < 0)
810 		goto error;
811 
812 	/* creation of additional special files should go here */
813 
814 	dev_info(&interface->dev, "Line 6 %s now attached\n",
815 		 properties->name);
816 
817 	return 0;
818 
819  error:
820 	/* we can call disconnect callback here because no close-sync is
821 	 * needed yet at this point
822 	 */
823 	line6_disconnect(interface);
824 	return ret;
825 }
826 EXPORT_SYMBOL_GPL(line6_probe);
827 
828 /*
829 	Line 6 device disconnected.
830 */
831 void line6_disconnect(struct usb_interface *interface)
832 {
833 	struct usb_line6 *line6 = usb_get_intfdata(interface);
834 	struct usb_device *usbdev = interface_to_usbdev(interface);
835 
836 	if (!line6)
837 		return;
838 
839 	if (WARN_ON(usbdev != line6->usbdev))
840 		return;
841 
842 	cancel_delayed_work_sync(&line6->startup_work);
843 
844 	if (line6->urb_listen != NULL)
845 		line6_stop_listen(line6);
846 
847 	snd_card_disconnect(line6->card);
848 	if (line6->line6pcm)
849 		line6_pcm_disconnect(line6->line6pcm);
850 	if (line6->disconnect)
851 		line6->disconnect(line6);
852 
853 	dev_info(&interface->dev, "Line 6 %s now disconnected\n",
854 		 line6->properties->name);
855 
856 	/* make sure the device isn't destructed twice: */
857 	usb_set_intfdata(interface, NULL);
858 
859 	snd_card_free_when_closed(line6->card);
860 }
861 EXPORT_SYMBOL_GPL(line6_disconnect);
862 
863 #ifdef CONFIG_PM
864 
865 /*
866 	Suspend Line 6 device.
867 */
868 int line6_suspend(struct usb_interface *interface, pm_message_t message)
869 {
870 	struct usb_line6 *line6 = usb_get_intfdata(interface);
871 	struct snd_line6_pcm *line6pcm = line6->line6pcm;
872 
873 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D3hot);
874 
875 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
876 		line6_stop_listen(line6);
877 
878 	if (line6pcm != NULL)
879 		line6pcm->flags = 0;
880 
881 	return 0;
882 }
883 EXPORT_SYMBOL_GPL(line6_suspend);
884 
885 /*
886 	Resume Line 6 device.
887 */
888 int line6_resume(struct usb_interface *interface)
889 {
890 	struct usb_line6 *line6 = usb_get_intfdata(interface);
891 
892 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
893 		line6_start_listen(line6);
894 
895 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D0);
896 	return 0;
897 }
898 EXPORT_SYMBOL_GPL(line6_resume);
899 
900 #endif /* CONFIG_PM */
901 
902 MODULE_AUTHOR(DRIVER_AUTHOR);
903 MODULE_DESCRIPTION(DRIVER_DESC);
904 MODULE_LICENSE("GPL");
905 
906