xref: /openbmc/linux/sound/usb/line6/driver.c (revision dd1431e5)
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 * HZ);
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 * HZ);
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 
309 			if (done <= 0)
310 				break;
311 
312 			line6->message_length = done;
313 			line6_midi_receive(line6, line6->buffer_message, done);
314 
315 			if (line6->process_message)
316 				line6->process_message(line6);
317 		}
318 	} else {
319 		line6->buffer_message = urb->transfer_buffer;
320 		line6->message_length = urb->actual_length;
321 		if (line6->process_message)
322 			line6->process_message(line6);
323 		line6->buffer_message = NULL;
324 	}
325 
326 	line6_start_listen(line6);
327 }
328 
329 #define LINE6_READ_WRITE_STATUS_DELAY 2  /* milliseconds */
330 #define LINE6_READ_WRITE_MAX_RETRIES 50
331 
332 /*
333 	Read data from device.
334 */
335 int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
336 		    unsigned datalen)
337 {
338 	struct usb_device *usbdev = line6->usbdev;
339 	int ret;
340 	u8 len;
341 	unsigned count;
342 
343 	if (address > 0xffff || datalen > 0xff)
344 		return -EINVAL;
345 
346 	/* query the serial number: */
347 	ret = usb_control_msg_send(usbdev, 0, 0x67,
348 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
349 				   (datalen << 8) | 0x21, address, NULL, 0,
350 				   LINE6_TIMEOUT * HZ, GFP_KERNEL);
351 	if (ret) {
352 		dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
353 		goto exit;
354 	}
355 
356 	/* Wait for data length. We'll get 0xff until length arrives. */
357 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
358 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
359 
360 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
361 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
362 					   0x0012, 0x0000, &len, 1,
363 					   LINE6_TIMEOUT * HZ, GFP_KERNEL);
364 		if (ret) {
365 			dev_err(line6->ifcdev,
366 				"receive length failed (error %d)\n", ret);
367 			goto exit;
368 		}
369 
370 		if (len != 0xff)
371 			break;
372 	}
373 
374 	ret = -EIO;
375 	if (len == 0xff) {
376 		dev_err(line6->ifcdev, "read failed after %d retries\n",
377 			count);
378 		goto exit;
379 	} else if (len != datalen) {
380 		/* should be equal or something went wrong */
381 		dev_err(line6->ifcdev,
382 			"length mismatch (expected %d, got %d)\n",
383 			(int)datalen, len);
384 		goto exit;
385 	}
386 
387 	/* receive the result: */
388 	ret = usb_control_msg_recv(usbdev, 0, 0x67,
389 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
390 				   0x0013, 0x0000, data, datalen, LINE6_TIMEOUT * HZ,
391 				   GFP_KERNEL);
392 	if (ret)
393 		dev_err(line6->ifcdev, "read failed (error %d)\n", ret);
394 
395 exit:
396 	return ret;
397 }
398 EXPORT_SYMBOL_GPL(line6_read_data);
399 
400 /*
401 	Write data to device.
402 */
403 int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
404 		     unsigned datalen)
405 {
406 	struct usb_device *usbdev = line6->usbdev;
407 	int ret;
408 	unsigned char *status;
409 	int count;
410 
411 	if (address > 0xffff || datalen > 0xffff)
412 		return -EINVAL;
413 
414 	status = kmalloc(1, GFP_KERNEL);
415 	if (!status)
416 		return -ENOMEM;
417 
418 	ret = usb_control_msg_send(usbdev, 0, 0x67,
419 				   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
420 				   0x0022, address, data, datalen, LINE6_TIMEOUT * HZ,
421 				   GFP_KERNEL);
422 	if (ret) {
423 		dev_err(line6->ifcdev,
424 			"write request failed (error %d)\n", ret);
425 		goto exit;
426 	}
427 
428 	for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
429 		mdelay(LINE6_READ_WRITE_STATUS_DELAY);
430 
431 		ret = usb_control_msg_recv(usbdev, 0, 0x67,
432 					   USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
433 					   0x0012, 0x0000, status, 1, LINE6_TIMEOUT * HZ,
434 					   GFP_KERNEL);
435 		if (ret) {
436 			dev_err(line6->ifcdev,
437 				"receiving status failed (error %d)\n", ret);
438 			goto exit;
439 		}
440 
441 		if (*status != 0xff)
442 			break;
443 	}
444 
445 	if (*status == 0xff) {
446 		dev_err(line6->ifcdev, "write failed after %d retries\n",
447 			count);
448 		ret = -EIO;
449 	} else if (*status != 0) {
450 		dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
451 		ret = -EIO;
452 	}
453 exit:
454 	kfree(status);
455 	return ret;
456 }
457 EXPORT_SYMBOL_GPL(line6_write_data);
458 
459 /*
460 	Read Line 6 device serial number.
461 	(POD, TonePort, GuitarPort)
462 */
463 int line6_read_serial_number(struct usb_line6 *line6, u32 *serial_number)
464 {
465 	return line6_read_data(line6, 0x80d0, serial_number,
466 			       sizeof(*serial_number));
467 }
468 EXPORT_SYMBOL_GPL(line6_read_serial_number);
469 
470 /*
471 	Card destructor.
472 */
473 static void line6_destruct(struct snd_card *card)
474 {
475 	struct usb_line6 *line6 = card->private_data;
476 	struct usb_device *usbdev = line6->usbdev;
477 
478 	/* Free buffer memory first. We cannot depend on the existence of private
479 	 * data from the (podhd) module, it may be gone already during this call
480 	 */
481 	kfree(line6->buffer_message);
482 
483 	kfree(line6->buffer_listen);
484 
485 	/* then free URBs: */
486 	usb_free_urb(line6->urb_listen);
487 	line6->urb_listen = NULL;
488 
489 	/* decrement reference counters: */
490 	usb_put_dev(usbdev);
491 }
492 
493 static void line6_get_usb_properties(struct usb_line6 *line6)
494 {
495 	struct usb_device *usbdev = line6->usbdev;
496 	const struct line6_properties *properties = line6->properties;
497 	int pipe;
498 	struct usb_host_endpoint *ep = NULL;
499 
500 	if (properties->capabilities & LINE6_CAP_CONTROL) {
501 		if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
502 			pipe = usb_rcvintpipe(line6->usbdev,
503 				line6->properties->ep_ctrl_r);
504 		} else {
505 			pipe = usb_rcvbulkpipe(line6->usbdev,
506 				line6->properties->ep_ctrl_r);
507 		}
508 		ep = usbdev->ep_in[usb_pipeendpoint(pipe)];
509 	}
510 
511 	/* Control data transfer properties */
512 	if (ep) {
513 		line6->interval = ep->desc.bInterval;
514 		line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
515 	} else {
516 		if (properties->capabilities & LINE6_CAP_CONTROL) {
517 			dev_err(line6->ifcdev,
518 				"endpoint not available, using fallback values");
519 		}
520 		line6->interval = LINE6_FALLBACK_INTERVAL;
521 		line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
522 	}
523 
524 	/* Isochronous transfer properties */
525 	if (usbdev->speed == USB_SPEED_LOW) {
526 		line6->intervals_per_second = USB_LOW_INTERVALS_PER_SECOND;
527 		line6->iso_buffers = USB_LOW_ISO_BUFFERS;
528 	} else {
529 		line6->intervals_per_second = USB_HIGH_INTERVALS_PER_SECOND;
530 		line6->iso_buffers = USB_HIGH_ISO_BUFFERS;
531 	}
532 }
533 
534 /* Enable buffering of incoming messages, flush the buffer */
535 static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file)
536 {
537 	struct usb_line6 *line6 = hw->private_data;
538 
539 	/* NOTE: hwdep layer provides atomicity here */
540 
541 	line6->messages.active = 1;
542 	line6->messages.nonblock = file->f_flags & O_NONBLOCK ? 1 : 0;
543 
544 	return 0;
545 }
546 
547 /* Stop buffering */
548 static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
549 {
550 	struct usb_line6 *line6 = hw->private_data;
551 
552 	line6->messages.active = 0;
553 
554 	return 0;
555 }
556 
557 /* Read from circular buffer, return to user */
558 static long
559 line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
560 					loff_t *offset)
561 {
562 	struct usb_line6 *line6 = hwdep->private_data;
563 	long rv = 0;
564 	unsigned int out_count;
565 
566 	if (mutex_lock_interruptible(&line6->messages.read_lock))
567 		return -ERESTARTSYS;
568 
569 	while (kfifo_len(&line6->messages.fifo) == 0) {
570 		mutex_unlock(&line6->messages.read_lock);
571 
572 		if (line6->messages.nonblock)
573 			return -EAGAIN;
574 
575 		rv = wait_event_interruptible(
576 			line6->messages.wait_queue,
577 			kfifo_len(&line6->messages.fifo) != 0);
578 		if (rv < 0)
579 			return rv;
580 
581 		if (mutex_lock_interruptible(&line6->messages.read_lock))
582 			return -ERESTARTSYS;
583 	}
584 
585 	if (kfifo_peek_len(&line6->messages.fifo) > count) {
586 		/* Buffer too small; allow re-read of the current item... */
587 		rv = -EINVAL;
588 	} else {
589 		rv = kfifo_to_user(&line6->messages.fifo, buf, count, &out_count);
590 		if (rv == 0)
591 			rv = out_count;
592 	}
593 
594 	mutex_unlock(&line6->messages.read_lock);
595 	return rv;
596 }
597 
598 /* Write directly (no buffering) to device by user*/
599 static long
600 line6_hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
601 					loff_t *offset)
602 {
603 	struct usb_line6 *line6 = hwdep->private_data;
604 	int rv;
605 	char *data_copy;
606 
607 	if (count > line6->max_packet_size * LINE6_RAW_MESSAGES_MAXCOUNT) {
608 		/* This is an arbitrary limit - still better than nothing... */
609 		return -EINVAL;
610 	}
611 
612 	data_copy = memdup_user(data, count);
613 	if (IS_ERR(data_copy))
614 		return PTR_ERR(data_copy);
615 
616 	rv = line6_send_raw_message(line6, data_copy, count);
617 
618 	kfree(data_copy);
619 	return rv;
620 }
621 
622 static __poll_t
623 line6_hwdep_poll(struct snd_hwdep *hwdep, struct file *file, poll_table *wait)
624 {
625 	__poll_t rv;
626 	struct usb_line6 *line6 = hwdep->private_data;
627 
628 	poll_wait(file, &line6->messages.wait_queue, wait);
629 
630 	mutex_lock(&line6->messages.read_lock);
631 	rv = kfifo_len(&line6->messages.fifo) == 0 ? 0 : EPOLLIN | EPOLLRDNORM;
632 	mutex_unlock(&line6->messages.read_lock);
633 
634 	return rv;
635 }
636 
637 static const struct snd_hwdep_ops hwdep_ops = {
638 	.open    = line6_hwdep_open,
639 	.release = line6_hwdep_release,
640 	.read    = line6_hwdep_read,
641 	.write   = line6_hwdep_write,
642 	.poll    = line6_hwdep_poll,
643 };
644 
645 /* Insert into circular buffer */
646 static void line6_hwdep_push_message(struct usb_line6 *line6)
647 {
648 	if (!line6->messages.active)
649 		return;
650 
651 	if (kfifo_avail(&line6->messages.fifo) >= line6->message_length) {
652 		/* No race condition here, there's only one writer */
653 		kfifo_in(&line6->messages.fifo,
654 			line6->buffer_message, line6->message_length);
655 	} /* else TODO: signal overflow */
656 
657 	wake_up_interruptible(&line6->messages.wait_queue);
658 }
659 
660 static int line6_hwdep_init(struct usb_line6 *line6)
661 {
662 	int err;
663 	struct snd_hwdep *hwdep;
664 
665 	/* TODO: usb_driver_claim_interface(); */
666 	line6->process_message = line6_hwdep_push_message;
667 	line6->messages.active = 0;
668 	init_waitqueue_head(&line6->messages.wait_queue);
669 	mutex_init(&line6->messages.read_lock);
670 	INIT_KFIFO(line6->messages.fifo);
671 
672 	err = snd_hwdep_new(line6->card, "config", 0, &hwdep);
673 	if (err < 0)
674 		goto end;
675 	strcpy(hwdep->name, "config");
676 	hwdep->iface = SNDRV_HWDEP_IFACE_LINE6;
677 	hwdep->ops = hwdep_ops;
678 	hwdep->private_data = line6;
679 	hwdep->exclusive = true;
680 
681 end:
682 	return err;
683 }
684 
685 static int line6_init_cap_control(struct usb_line6 *line6)
686 {
687 	int ret;
688 
689 	/* initialize USB buffers: */
690 	line6->buffer_listen = kmalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
691 	if (!line6->buffer_listen)
692 		return -ENOMEM;
693 
694 	line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
695 	if (!line6->urb_listen)
696 		return -ENOMEM;
697 
698 	if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
699 		line6->buffer_message = kmalloc(LINE6_MIDI_MESSAGE_MAXLEN, GFP_KERNEL);
700 		if (!line6->buffer_message)
701 			return -ENOMEM;
702 
703 		ret = line6_init_midi(line6);
704 		if (ret < 0)
705 			return ret;
706 	} else {
707 		ret = line6_hwdep_init(line6);
708 		if (ret < 0)
709 			return ret;
710 	}
711 
712 	ret = line6_start_listen(line6);
713 	if (ret < 0) {
714 		dev_err(line6->ifcdev, "cannot start listening: %d\n", ret);
715 		return ret;
716 	}
717 
718 	return 0;
719 }
720 
721 static void line6_startup_work(struct work_struct *work)
722 {
723 	struct usb_line6 *line6 =
724 		container_of(work, struct usb_line6, startup_work.work);
725 
726 	if (line6->startup)
727 		line6->startup(line6);
728 }
729 
730 /*
731 	Probe USB device.
732 */
733 int line6_probe(struct usb_interface *interface,
734 		const struct usb_device_id *id,
735 		const char *driver_name,
736 		const struct line6_properties *properties,
737 		int (*private_init)(struct usb_line6 *, const struct usb_device_id *id),
738 		size_t data_size)
739 {
740 	struct usb_device *usbdev = interface_to_usbdev(interface);
741 	struct snd_card *card;
742 	struct usb_line6 *line6;
743 	int interface_number;
744 	int ret;
745 
746 	if (WARN_ON(data_size < sizeof(*line6)))
747 		return -EINVAL;
748 
749 	/* we don't handle multiple configurations */
750 	if (usbdev->descriptor.bNumConfigurations != 1)
751 		return -ENODEV;
752 
753 	ret = snd_card_new(&interface->dev,
754 			   SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
755 			   THIS_MODULE, data_size, &card);
756 	if (ret < 0)
757 		return ret;
758 
759 	/* store basic data: */
760 	line6 = card->private_data;
761 	line6->card = card;
762 	line6->properties = properties;
763 	line6->usbdev = usbdev;
764 	line6->ifcdev = &interface->dev;
765 	INIT_DELAYED_WORK(&line6->startup_work, line6_startup_work);
766 
767 	strcpy(card->id, properties->id);
768 	strcpy(card->driver, driver_name);
769 	strcpy(card->shortname, properties->name);
770 	sprintf(card->longname, "Line 6 %s at USB %s", properties->name,
771 		dev_name(line6->ifcdev));
772 	card->private_free = line6_destruct;
773 
774 	usb_set_intfdata(interface, line6);
775 
776 	/* increment reference counters: */
777 	usb_get_dev(usbdev);
778 
779 	/* initialize device info: */
780 	dev_info(&interface->dev, "Line 6 %s found\n", properties->name);
781 
782 	/* query interface number */
783 	interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
784 
785 	/* TODO reserves the bus bandwidth even without actual transfer */
786 	ret = usb_set_interface(usbdev, interface_number,
787 				properties->altsetting);
788 	if (ret < 0) {
789 		dev_err(&interface->dev, "set_interface failed\n");
790 		goto error;
791 	}
792 
793 	line6_get_usb_properties(line6);
794 
795 	if (properties->capabilities & LINE6_CAP_CONTROL) {
796 		ret = line6_init_cap_control(line6);
797 		if (ret < 0)
798 			goto error;
799 	}
800 
801 	/* initialize device data based on device: */
802 	ret = private_init(line6, id);
803 	if (ret < 0)
804 		goto error;
805 
806 	/* creation of additional special files should go here */
807 
808 	dev_info(&interface->dev, "Line 6 %s now attached\n",
809 		 properties->name);
810 
811 	return 0;
812 
813  error:
814 	/* we can call disconnect callback here because no close-sync is
815 	 * needed yet at this point
816 	 */
817 	line6_disconnect(interface);
818 	return ret;
819 }
820 EXPORT_SYMBOL_GPL(line6_probe);
821 
822 /*
823 	Line 6 device disconnected.
824 */
825 void line6_disconnect(struct usb_interface *interface)
826 {
827 	struct usb_line6 *line6 = usb_get_intfdata(interface);
828 	struct usb_device *usbdev = interface_to_usbdev(interface);
829 
830 	if (!line6)
831 		return;
832 
833 	if (WARN_ON(usbdev != line6->usbdev))
834 		return;
835 
836 	cancel_delayed_work_sync(&line6->startup_work);
837 
838 	if (line6->urb_listen != NULL)
839 		line6_stop_listen(line6);
840 
841 	snd_card_disconnect(line6->card);
842 	if (line6->line6pcm)
843 		line6_pcm_disconnect(line6->line6pcm);
844 	if (line6->disconnect)
845 		line6->disconnect(line6);
846 
847 	dev_info(&interface->dev, "Line 6 %s now disconnected\n",
848 		 line6->properties->name);
849 
850 	/* make sure the device isn't destructed twice: */
851 	usb_set_intfdata(interface, NULL);
852 
853 	snd_card_free_when_closed(line6->card);
854 }
855 EXPORT_SYMBOL_GPL(line6_disconnect);
856 
857 #ifdef CONFIG_PM
858 
859 /*
860 	Suspend Line 6 device.
861 */
862 int line6_suspend(struct usb_interface *interface, pm_message_t message)
863 {
864 	struct usb_line6 *line6 = usb_get_intfdata(interface);
865 	struct snd_line6_pcm *line6pcm = line6->line6pcm;
866 
867 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D3hot);
868 
869 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
870 		line6_stop_listen(line6);
871 
872 	if (line6pcm != NULL)
873 		line6pcm->flags = 0;
874 
875 	return 0;
876 }
877 EXPORT_SYMBOL_GPL(line6_suspend);
878 
879 /*
880 	Resume Line 6 device.
881 */
882 int line6_resume(struct usb_interface *interface)
883 {
884 	struct usb_line6 *line6 = usb_get_intfdata(interface);
885 
886 	if (line6->properties->capabilities & LINE6_CAP_CONTROL)
887 		line6_start_listen(line6);
888 
889 	snd_power_change_state(line6->card, SNDRV_CTL_POWER_D0);
890 	return 0;
891 }
892 EXPORT_SYMBOL_GPL(line6_resume);
893 
894 #endif /* CONFIG_PM */
895 
896 MODULE_AUTHOR(DRIVER_AUTHOR);
897 MODULE_DESCRIPTION(DRIVER_DESC);
898 MODULE_LICENSE("GPL");
899 
900