1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * message.c - synchronous message handling
4 *
5 * Released under the GPLv2 only.
6 */
7
8 #include <linux/pci.h> /* for scatterlist macros */
9 #include <linux/usb.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/mm.h>
13 #include <linux/timer.h>
14 #include <linux/ctype.h>
15 #include <linux/nls.h>
16 #include <linux/device.h>
17 #include <linux/scatterlist.h>
18 #include <linux/usb/cdc.h>
19 #include <linux/usb/quirks.h>
20 #include <linux/usb/hcd.h> /* for usbcore internals */
21 #include <linux/usb/of.h>
22 #include <asm/byteorder.h>
23
24 #include "usb.h"
25
26 static void cancel_async_set_config(struct usb_device *udev);
27
28 struct api_context {
29 struct completion done;
30 int status;
31 };
32
33 static void usb_api_blocking_completion(struct urb *urb)
34 {
35 struct api_context *ctx = urb->context;
36
37 ctx->status = urb->status;
38 complete(&ctx->done);
39 }
40
41
42 /*
43 * Starts urb and waits for completion or timeout. Note that this call
44 * is NOT interruptible. Many device driver i/o requests should be
45 * interruptible and therefore these drivers should implement their
46 * own interruptible routines.
47 */
48 static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
49 {
50 struct api_context ctx;
51 unsigned long expire;
52 int retval;
53
54 init_completion(&ctx.done);
55 urb->context = &ctx;
56 urb->actual_length = 0;
57 retval = usb_submit_urb(urb, GFP_NOIO);
58 if (unlikely(retval))
59 goto out;
60
61 expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
62 if (!wait_for_completion_timeout(&ctx.done, expire)) {
63 usb_kill_urb(urb);
64 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
65
66 dev_dbg(&urb->dev->dev,
67 "%s timed out on ep%d%s len=%u/%u\n",
68 current->comm,
69 usb_endpoint_num(&urb->ep->desc),
70 usb_urb_dir_in(urb) ? "in" : "out",
71 urb->actual_length,
72 urb->transfer_buffer_length);
73 } else
74 retval = ctx.status;
75 out:
76 if (actual_length)
77 *actual_length = urb->actual_length;
78
79 usb_free_urb(urb);
80 return retval;
81 }
82
83 /*-------------------------------------------------------------------*/
84 /* returns status (negative) or length (positive) */
85 static int usb_internal_control_msg(struct usb_device *usb_dev,
86 unsigned int pipe,
87 struct usb_ctrlrequest *cmd,
88 void *data, int len, int timeout)
89 {
90 struct urb *urb;
91 int retv;
92 int length;
93
94 urb = usb_alloc_urb(0, GFP_NOIO);
95 if (!urb)
96 return -ENOMEM;
97
98 usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
99 len, usb_api_blocking_completion, NULL);
100
101 retv = usb_start_wait_urb(urb, timeout, &length);
102 if (retv < 0)
103 return retv;
104 else
105 return length;
106 }
107
108 /**
109 * usb_control_msg - Builds a control urb, sends it off and waits for completion
110 * @dev: pointer to the usb device to send the message to
111 * @pipe: endpoint "pipe" to send the message to
112 * @request: USB message request value
113 * @requesttype: USB message request type value
114 * @value: USB message value
115 * @index: USB message index value
116 * @data: pointer to the data to send
117 * @size: length in bytes of the data to send
118 * @timeout: time in msecs to wait for the message to complete before timing
119 * out (if 0 the wait is forever)
120 *
121 * Context: !in_interrupt ()
122 *
123 * This function sends a simple control message to a specified endpoint and
124 * waits for the message to complete, or timeout.
125 *
126 * Don't use this function from within an interrupt context. If you need
127 * an asynchronous message, or need to send a message from within interrupt
128 * context, use usb_submit_urb(). If a thread in your driver uses this call,
129 * make sure your disconnect() method can wait for it to complete. Since you
130 * don't have a handle on the URB used, you can't cancel the request.
131 *
132 * Return: If successful, the number of bytes transferred. Otherwise, a negative
133 * error number.
134 */
135 int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
136 __u8 requesttype, __u16 value, __u16 index, void *data,
137 __u16 size, int timeout)
138 {
139 struct usb_ctrlrequest *dr;
140 int ret;
141
142 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
143 if (!dr)
144 return -ENOMEM;
145
146 dr->bRequestType = requesttype;
147 dr->bRequest = request;
148 dr->wValue = cpu_to_le16(value);
149 dr->wIndex = cpu_to_le16(index);
150 dr->wLength = cpu_to_le16(size);
151
152 ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
153
154 /* Linger a bit, prior to the next control message. */
155 if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
156 msleep(200);
157
158 kfree(dr);
159
160 return ret;
161 }
162 EXPORT_SYMBOL_GPL(usb_control_msg);
163
164 /**
165 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
166 * @usb_dev: pointer to the usb device to send the message to
167 * @pipe: endpoint "pipe" to send the message to
168 * @data: pointer to the data to send
169 * @len: length in bytes of the data to send
170 * @actual_length: pointer to a location to put the actual length transferred
171 * in bytes
172 * @timeout: time in msecs to wait for the message to complete before
173 * timing out (if 0 the wait is forever)
174 *
175 * Context: !in_interrupt ()
176 *
177 * This function sends a simple interrupt message to a specified endpoint and
178 * waits for the message to complete, or timeout.
179 *
180 * Don't use this function from within an interrupt context. If you need
181 * an asynchronous message, or need to send a message from within interrupt
182 * context, use usb_submit_urb() If a thread in your driver uses this call,
183 * make sure your disconnect() method can wait for it to complete. Since you
184 * don't have a handle on the URB used, you can't cancel the request.
185 *
186 * Return:
187 * If successful, 0. Otherwise a negative error number. The number of actual
188 * bytes transferred will be stored in the @actual_length parameter.
189 */
190 int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
191 void *data, int len, int *actual_length, int timeout)
192 {
193 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
194 }
195 EXPORT_SYMBOL_GPL(usb_interrupt_msg);
196
197 /**
198 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
199 * @usb_dev: pointer to the usb device to send the message to
200 * @pipe: endpoint "pipe" to send the message to
201 * @data: pointer to the data to send
202 * @len: length in bytes of the data to send
203 * @actual_length: pointer to a location to put the actual length transferred
204 * in bytes
205 * @timeout: time in msecs to wait for the message to complete before
206 * timing out (if 0 the wait is forever)
207 *
208 * Context: !in_interrupt ()
209 *
210 * This function sends a simple bulk message to a specified endpoint
211 * and waits for the message to complete, or timeout.
212 *
213 * Don't use this function from within an interrupt context. If you need
214 * an asynchronous message, or need to send a message from within interrupt
215 * context, use usb_submit_urb() If a thread in your driver uses this call,
216 * make sure your disconnect() method can wait for it to complete. Since you
217 * don't have a handle on the URB used, you can't cancel the request.
218 *
219 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
220 * users are forced to abuse this routine by using it to submit URBs for
221 * interrupt endpoints. We will take the liberty of creating an interrupt URB
222 * (with the default interval) if the target is an interrupt endpoint.
223 *
224 * Return:
225 * If successful, 0. Otherwise a negative error number. The number of actual
226 * bytes transferred will be stored in the @actual_length parameter.
227 *
228 */
229 int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
230 void *data, int len, int *actual_length, int timeout)
231 {
232 struct urb *urb;
233 struct usb_host_endpoint *ep;
234
235 ep = usb_pipe_endpoint(usb_dev, pipe);
236 if (!ep || len < 0)
237 return -EINVAL;
238
239 urb = usb_alloc_urb(0, GFP_KERNEL);
240 if (!urb)
241 return -ENOMEM;
242
243 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
244 USB_ENDPOINT_XFER_INT) {
245 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
246 usb_fill_int_urb(urb, usb_dev, pipe, data, len,
247 usb_api_blocking_completion, NULL,
248 ep->desc.bInterval);
249 } else
250 usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
251 usb_api_blocking_completion, NULL);
252
253 return usb_start_wait_urb(urb, timeout, actual_length);
254 }
255 EXPORT_SYMBOL_GPL(usb_bulk_msg);
256
257 /*-------------------------------------------------------------------*/
258
259 static void sg_clean(struct usb_sg_request *io)
260 {
261 if (io->urbs) {
262 while (io->entries--)
263 usb_free_urb(io->urbs[io->entries]);
264 kfree(io->urbs);
265 io->urbs = NULL;
266 }
267 io->dev = NULL;
268 }
269
270 static void sg_complete(struct urb *urb)
271 {
272 unsigned long flags;
273 struct usb_sg_request *io = urb->context;
274 int status = urb->status;
275
276 spin_lock_irqsave(&io->lock, flags);
277
278 /* In 2.5 we require hcds' endpoint queues not to progress after fault
279 * reports, until the completion callback (this!) returns. That lets
280 * device driver code (like this routine) unlink queued urbs first,
281 * if it needs to, since the HC won't work on them at all. So it's
282 * not possible for page N+1 to overwrite page N, and so on.
283 *
284 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
285 * complete before the HCD can get requests away from hardware,
286 * though never during cleanup after a hard fault.
287 */
288 if (io->status
289 && (io->status != -ECONNRESET
290 || status != -ECONNRESET)
291 && urb->actual_length) {
292 dev_err(io->dev->bus->controller,
293 "dev %s ep%d%s scatterlist error %d/%d\n",
294 io->dev->devpath,
295 usb_endpoint_num(&urb->ep->desc),
296 usb_urb_dir_in(urb) ? "in" : "out",
297 status, io->status);
298 /* BUG (); */
299 }
300
301 if (io->status == 0 && status && status != -ECONNRESET) {
302 int i, found, retval;
303
304 io->status = status;
305
306 /* the previous urbs, and this one, completed already.
307 * unlink pending urbs so they won't rx/tx bad data.
308 * careful: unlink can sometimes be synchronous...
309 */
310 spin_unlock_irqrestore(&io->lock, flags);
311 for (i = 0, found = 0; i < io->entries; i++) {
312 if (!io->urbs[i])
313 continue;
314 if (found) {
315 usb_block_urb(io->urbs[i]);
316 retval = usb_unlink_urb(io->urbs[i]);
317 if (retval != -EINPROGRESS &&
318 retval != -ENODEV &&
319 retval != -EBUSY &&
320 retval != -EIDRM)
321 dev_err(&io->dev->dev,
322 "%s, unlink --> %d\n",
323 __func__, retval);
324 } else if (urb == io->urbs[i])
325 found = 1;
326 }
327 spin_lock_irqsave(&io->lock, flags);
328 }
329
330 /* on the last completion, signal usb_sg_wait() */
331 io->bytes += urb->actual_length;
332 io->count--;
333 if (!io->count)
334 complete(&io->complete);
335
336 spin_unlock_irqrestore(&io->lock, flags);
337 }
338
339
340 /**
341 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
342 * @io: request block being initialized. until usb_sg_wait() returns,
343 * treat this as a pointer to an opaque block of memory,
344 * @dev: the usb device that will send or receive the data
345 * @pipe: endpoint "pipe" used to transfer the data
346 * @period: polling rate for interrupt endpoints, in frames or
347 * (for high speed endpoints) microframes; ignored for bulk
348 * @sg: scatterlist entries
349 * @nents: how many entries in the scatterlist
350 * @length: how many bytes to send from the scatterlist, or zero to
351 * send every byte identified in the list.
352 * @mem_flags: SLAB_* flags affecting memory allocations in this call
353 *
354 * This initializes a scatter/gather request, allocating resources such as
355 * I/O mappings and urb memory (except maybe memory used by USB controller
356 * drivers).
357 *
358 * The request must be issued using usb_sg_wait(), which waits for the I/O to
359 * complete (or to be canceled) and then cleans up all resources allocated by
360 * usb_sg_init().
361 *
362 * The request may be canceled with usb_sg_cancel(), either before or after
363 * usb_sg_wait() is called.
364 *
365 * Return: Zero for success, else a negative errno value.
366 */
367 int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
368 unsigned pipe, unsigned period, struct scatterlist *sg,
369 int nents, size_t length, gfp_t mem_flags)
370 {
371 int i;
372 int urb_flags;
373 int use_sg;
374
375 if (!io || !dev || !sg
376 || usb_pipecontrol(pipe)
377 || usb_pipeisoc(pipe)
378 || nents <= 0)
379 return -EINVAL;
380
381 spin_lock_init(&io->lock);
382 io->dev = dev;
383 io->pipe = pipe;
384
385 if (dev->bus->sg_tablesize > 0) {
386 use_sg = true;
387 io->entries = 1;
388 } else {
389 use_sg = false;
390 io->entries = nents;
391 }
392
393 /* initialize all the urbs we'll use */
394 io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
395 if (!io->urbs)
396 goto nomem;
397
398 urb_flags = URB_NO_INTERRUPT;
399 if (usb_pipein(pipe))
400 urb_flags |= URB_SHORT_NOT_OK;
401
402 for_each_sg(sg, sg, io->entries, i) {
403 struct urb *urb;
404 unsigned len;
405
406 urb = usb_alloc_urb(0, mem_flags);
407 if (!urb) {
408 io->entries = i;
409 goto nomem;
410 }
411 io->urbs[i] = urb;
412
413 urb->dev = NULL;
414 urb->pipe = pipe;
415 urb->interval = period;
416 urb->transfer_flags = urb_flags;
417 urb->complete = sg_complete;
418 urb->context = io;
419 urb->sg = sg;
420
421 if (use_sg) {
422 /* There is no single transfer buffer */
423 urb->transfer_buffer = NULL;
424 urb->num_sgs = nents;
425
426 /* A length of zero means transfer the whole sg list */
427 len = length;
428 if (len == 0) {
429 struct scatterlist *sg2;
430 int j;
431
432 for_each_sg(sg, sg2, nents, j)
433 len += sg2->length;
434 }
435 } else {
436 /*
437 * Some systems can't use DMA; they use PIO instead.
438 * For their sakes, transfer_buffer is set whenever
439 * possible.
440 */
441 if (!PageHighMem(sg_page(sg)))
442 urb->transfer_buffer = sg_virt(sg);
443 else
444 urb->transfer_buffer = NULL;
445
446 len = sg->length;
447 if (length) {
448 len = min_t(size_t, len, length);
449 length -= len;
450 if (length == 0)
451 io->entries = i + 1;
452 }
453 }
454 urb->transfer_buffer_length = len;
455 }
456 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
457
458 /* transaction state */
459 io->count = io->entries;
460 io->status = 0;
461 io->bytes = 0;
462 init_completion(&io->complete);
463 return 0;
464
465 nomem:
466 sg_clean(io);
467 return -ENOMEM;
468 }
469 EXPORT_SYMBOL_GPL(usb_sg_init);
470
471 /**
472 * usb_sg_wait - synchronously execute scatter/gather request
473 * @io: request block handle, as initialized with usb_sg_init().
474 * some fields become accessible when this call returns.
475 * Context: !in_interrupt ()
476 *
477 * This function blocks until the specified I/O operation completes. It
478 * leverages the grouping of the related I/O requests to get good transfer
479 * rates, by queueing the requests. At higher speeds, such queuing can
480 * significantly improve USB throughput.
481 *
482 * There are three kinds of completion for this function.
483 *
484 * (1) success, where io->status is zero. The number of io->bytes
485 * transferred is as requested.
486 * (2) error, where io->status is a negative errno value. The number
487 * of io->bytes transferred before the error is usually less
488 * than requested, and can be nonzero.
489 * (3) cancellation, a type of error with status -ECONNRESET that
490 * is initiated by usb_sg_cancel().
491 *
492 * When this function returns, all memory allocated through usb_sg_init() or
493 * this call will have been freed. The request block parameter may still be
494 * passed to usb_sg_cancel(), or it may be freed. It could also be
495 * reinitialized and then reused.
496 *
497 * Data Transfer Rates:
498 *
499 * Bulk transfers are valid for full or high speed endpoints.
500 * The best full speed data rate is 19 packets of 64 bytes each
501 * per frame, or 1216 bytes per millisecond.
502 * The best high speed data rate is 13 packets of 512 bytes each
503 * per microframe, or 52 KBytes per millisecond.
504 *
505 * The reason to use interrupt transfers through this API would most likely
506 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
507 * could be transferred. That capability is less useful for low or full
508 * speed interrupt endpoints, which allow at most one packet per millisecond,
509 * of at most 8 or 64 bytes (respectively).
510 *
511 * It is not necessary to call this function to reserve bandwidth for devices
512 * under an xHCI host controller, as the bandwidth is reserved when the
513 * configuration or interface alt setting is selected.
514 */
515 void usb_sg_wait(struct usb_sg_request *io)
516 {
517 int i;
518 int entries = io->entries;
519
520 /* queue the urbs. */
521 spin_lock_irq(&io->lock);
522 i = 0;
523 while (i < entries && !io->status) {
524 int retval;
525
526 io->urbs[i]->dev = io->dev;
527 spin_unlock_irq(&io->lock);
528
529 retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
530
531 switch (retval) {
532 /* maybe we retrying will recover */
533 case -ENXIO: /* hc didn't queue this one */
534 case -EAGAIN:
535 case -ENOMEM:
536 retval = 0;
537 yield();
538 break;
539
540 /* no error? continue immediately.
541 *
542 * NOTE: to work better with UHCI (4K I/O buffer may
543 * need 3K of TDs) it may be good to limit how many
544 * URBs are queued at once; N milliseconds?
545 */
546 case 0:
547 ++i;
548 cpu_relax();
549 break;
550
551 /* fail any uncompleted urbs */
552 default:
553 io->urbs[i]->status = retval;
554 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
555 __func__, retval);
556 usb_sg_cancel(io);
557 }
558 spin_lock_irq(&io->lock);
559 if (retval && (io->status == 0 || io->status == -ECONNRESET))
560 io->status = retval;
561 }
562 io->count -= entries - i;
563 if (io->count == 0)
564 complete(&io->complete);
565 spin_unlock_irq(&io->lock);
566
567 /* OK, yes, this could be packaged as non-blocking.
568 * So could the submit loop above ... but it's easier to
569 * solve neither problem than to solve both!
570 */
571 wait_for_completion(&io->complete);
572
573 sg_clean(io);
574 }
575 EXPORT_SYMBOL_GPL(usb_sg_wait);
576
577 /**
578 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
579 * @io: request block, initialized with usb_sg_init()
580 *
581 * This stops a request after it has been started by usb_sg_wait().
582 * It can also prevents one initialized by usb_sg_init() from starting,
583 * so that call just frees resources allocated to the request.
584 */
585 void usb_sg_cancel(struct usb_sg_request *io)
586 {
587 unsigned long flags;
588 int i, retval;
589
590 spin_lock_irqsave(&io->lock, flags);
591 if (io->status || io->count == 0) {
592 spin_unlock_irqrestore(&io->lock, flags);
593 return;
594 }
595 /* shut everything down */
596 io->status = -ECONNRESET;
597 io->count++; /* Keep the request alive until we're done */
598 spin_unlock_irqrestore(&io->lock, flags);
599
600 for (i = io->entries - 1; i >= 0; --i) {
601 usb_block_urb(io->urbs[i]);
602
603 retval = usb_unlink_urb(io->urbs[i]);
604 if (retval != -EINPROGRESS
605 && retval != -ENODEV
606 && retval != -EBUSY
607 && retval != -EIDRM)
608 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
609 __func__, retval);
610 }
611
612 spin_lock_irqsave(&io->lock, flags);
613 io->count--;
614 if (!io->count)
615 complete(&io->complete);
616 spin_unlock_irqrestore(&io->lock, flags);
617 }
618 EXPORT_SYMBOL_GPL(usb_sg_cancel);
619
620 /*-------------------------------------------------------------------*/
621
622 /**
623 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
624 * @dev: the device whose descriptor is being retrieved
625 * @type: the descriptor type (USB_DT_*)
626 * @index: the number of the descriptor
627 * @buf: where to put the descriptor
628 * @size: how big is "buf"?
629 * Context: !in_interrupt ()
630 *
631 * Gets a USB descriptor. Convenience functions exist to simplify
632 * getting some types of descriptors. Use
633 * usb_get_string() or usb_string() for USB_DT_STRING.
634 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
635 * are part of the device structure.
636 * In addition to a number of USB-standard descriptors, some
637 * devices also use class-specific or vendor-specific descriptors.
638 *
639 * This call is synchronous, and may not be used in an interrupt context.
640 *
641 * Return: The number of bytes received on success, or else the status code
642 * returned by the underlying usb_control_msg() call.
643 */
644 int usb_get_descriptor(struct usb_device *dev, unsigned char type,
645 unsigned char index, void *buf, int size)
646 {
647 int i;
648 int result;
649
650 memset(buf, 0, size); /* Make sure we parse really received data */
651
652 for (i = 0; i < 3; ++i) {
653 /* retry on length 0 or error; some devices are flakey */
654 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
655 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
656 (type << 8) + index, 0, buf, size,
657 USB_CTRL_GET_TIMEOUT);
658 if (result <= 0 && result != -ETIMEDOUT)
659 continue;
660 if (result > 1 && ((u8 *)buf)[1] != type) {
661 result = -ENODATA;
662 continue;
663 }
664 break;
665 }
666 return result;
667 }
668 EXPORT_SYMBOL_GPL(usb_get_descriptor);
669
670 /**
671 * usb_get_string - gets a string descriptor
672 * @dev: the device whose string descriptor is being retrieved
673 * @langid: code for language chosen (from string descriptor zero)
674 * @index: the number of the descriptor
675 * @buf: where to put the string
676 * @size: how big is "buf"?
677 * Context: !in_interrupt ()
678 *
679 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
680 * in little-endian byte order).
681 * The usb_string() function will often be a convenient way to turn
682 * these strings into kernel-printable form.
683 *
684 * Strings may be referenced in device, configuration, interface, or other
685 * descriptors, and could also be used in vendor-specific ways.
686 *
687 * This call is synchronous, and may not be used in an interrupt context.
688 *
689 * Return: The number of bytes received on success, or else the status code
690 * returned by the underlying usb_control_msg() call.
691 */
692 static int usb_get_string(struct usb_device *dev, unsigned short langid,
693 unsigned char index, void *buf, int size)
694 {
695 int i;
696 int result;
697
698 for (i = 0; i < 3; ++i) {
699 /* retry on length 0 or stall; some devices are flakey */
700 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
701 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
702 (USB_DT_STRING << 8) + index, langid, buf, size,
703 USB_CTRL_GET_TIMEOUT);
704 if (result == 0 || result == -EPIPE)
705 continue;
706 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
707 result = -ENODATA;
708 continue;
709 }
710 break;
711 }
712 return result;
713 }
714
715 static void usb_try_string_workarounds(unsigned char *buf, int *length)
716 {
717 int newlength, oldlength = *length;
718
719 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
720 if (!isprint(buf[newlength]) || buf[newlength + 1])
721 break;
722
723 if (newlength > 2) {
724 buf[0] = newlength;
725 *length = newlength;
726 }
727 }
728
729 static int usb_string_sub(struct usb_device *dev, unsigned int langid,
730 unsigned int index, unsigned char *buf)
731 {
732 int rc;
733
734 /* Try to read the string descriptor by asking for the maximum
735 * possible number of bytes */
736 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
737 rc = -EIO;
738 else
739 rc = usb_get_string(dev, langid, index, buf, 255);
740
741 /* If that failed try to read the descriptor length, then
742 * ask for just that many bytes */
743 if (rc < 2) {
744 rc = usb_get_string(dev, langid, index, buf, 2);
745 if (rc == 2)
746 rc = usb_get_string(dev, langid, index, buf, buf[0]);
747 }
748
749 if (rc >= 2) {
750 if (!buf[0] && !buf[1])
751 usb_try_string_workarounds(buf, &rc);
752
753 /* There might be extra junk at the end of the descriptor */
754 if (buf[0] < rc)
755 rc = buf[0];
756
757 rc = rc - (rc & 1); /* force a multiple of two */
758 }
759
760 if (rc < 2)
761 rc = (rc < 0 ? rc : -EINVAL);
762
763 return rc;
764 }
765
766 static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
767 {
768 int err;
769
770 if (dev->have_langid)
771 return 0;
772
773 if (dev->string_langid < 0)
774 return -EPIPE;
775
776 err = usb_string_sub(dev, 0, 0, tbuf);
777
778 /* If the string was reported but is malformed, default to english
779 * (0x0409) */
780 if (err == -ENODATA || (err > 0 && err < 4)) {
781 dev->string_langid = 0x0409;
782 dev->have_langid = 1;
783 dev_err(&dev->dev,
784 "language id specifier not provided by device, defaulting to English\n");
785 return 0;
786 }
787
788 /* In case of all other errors, we assume the device is not able to
789 * deal with strings at all. Set string_langid to -1 in order to
790 * prevent any string to be retrieved from the device */
791 if (err < 0) {
792 dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
793 err);
794 dev->string_langid = -1;
795 return -EPIPE;
796 }
797
798 /* always use the first langid listed */
799 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
800 dev->have_langid = 1;
801 dev_dbg(&dev->dev, "default language 0x%04x\n",
802 dev->string_langid);
803 return 0;
804 }
805
806 /**
807 * usb_string - returns UTF-8 version of a string descriptor
808 * @dev: the device whose string descriptor is being retrieved
809 * @index: the number of the descriptor
810 * @buf: where to put the string
811 * @size: how big is "buf"?
812 * Context: !in_interrupt ()
813 *
814 * This converts the UTF-16LE encoded strings returned by devices, from
815 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
816 * that are more usable in most kernel contexts. Note that this function
817 * chooses strings in the first language supported by the device.
818 *
819 * This call is synchronous, and may not be used in an interrupt context.
820 *
821 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
822 */
823 int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
824 {
825 unsigned char *tbuf;
826 int err;
827
828 if (dev->state == USB_STATE_SUSPENDED)
829 return -EHOSTUNREACH;
830 if (size <= 0 || !buf)
831 return -EINVAL;
832 buf[0] = 0;
833 if (index <= 0 || index >= 256)
834 return -EINVAL;
835 tbuf = kmalloc(256, GFP_NOIO);
836 if (!tbuf)
837 return -ENOMEM;
838
839 err = usb_get_langid(dev, tbuf);
840 if (err < 0)
841 goto errout;
842
843 err = usb_string_sub(dev, dev->string_langid, index, tbuf);
844 if (err < 0)
845 goto errout;
846
847 size--; /* leave room for trailing NULL char in output buffer */
848 err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
849 UTF16_LITTLE_ENDIAN, buf, size);
850 buf[err] = 0;
851
852 if (tbuf[1] != USB_DT_STRING)
853 dev_dbg(&dev->dev,
854 "wrong descriptor type %02x for string %d (\"%s\")\n",
855 tbuf[1], index, buf);
856
857 errout:
858 kfree(tbuf);
859 return err;
860 }
861 EXPORT_SYMBOL_GPL(usb_string);
862
863 /* one UTF-8-encoded 16-bit character has at most three bytes */
864 #define MAX_USB_STRING_SIZE (127 * 3 + 1)
865
866 /**
867 * usb_cache_string - read a string descriptor and cache it for later use
868 * @udev: the device whose string descriptor is being read
869 * @index: the descriptor index
870 *
871 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
872 * or %NULL if the index is 0 or the string could not be read.
873 */
874 char *usb_cache_string(struct usb_device *udev, int index)
875 {
876 char *buf;
877 char *smallbuf = NULL;
878 int len;
879
880 if (index <= 0)
881 return NULL;
882
883 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
884 if (buf) {
885 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
886 if (len > 0) {
887 smallbuf = kmalloc(++len, GFP_NOIO);
888 if (!smallbuf)
889 return buf;
890 memcpy(smallbuf, buf, len);
891 }
892 kfree(buf);
893 }
894 return smallbuf;
895 }
896
897 /*
898 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
899 * @dev: the device whose device descriptor is being updated
900 * @size: how much of the descriptor to read
901 * Context: !in_interrupt ()
902 *
903 * Updates the copy of the device descriptor stored in the device structure,
904 * which dedicates space for this purpose.
905 *
906 * Not exported, only for use by the core. If drivers really want to read
907 * the device descriptor directly, they can call usb_get_descriptor() with
908 * type = USB_DT_DEVICE and index = 0.
909 *
910 * This call is synchronous, and may not be used in an interrupt context.
911 *
912 * Return: The number of bytes received on success, or else the status code
913 * returned by the underlying usb_control_msg() call.
914 */
915 int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
916 {
917 struct usb_device_descriptor *desc;
918 int ret;
919
920 if (size > sizeof(*desc))
921 return -EINVAL;
922 desc = kmalloc(sizeof(*desc), GFP_NOIO);
923 if (!desc)
924 return -ENOMEM;
925
926 ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
927 if (ret >= 0)
928 memcpy(&dev->descriptor, desc, size);
929 kfree(desc);
930 return ret;
931 }
932
933 /*
934 * usb_set_isoch_delay - informs the device of the packet transmit delay
935 * @dev: the device whose delay is to be informed
936 * Context: !in_interrupt()
937 *
938 * Since this is an optional request, we don't bother if it fails.
939 */
940 int usb_set_isoch_delay(struct usb_device *dev)
941 {
942 /* skip hub devices */
943 if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
944 return 0;
945
946 /* skip non-SS/non-SSP devices */
947 if (dev->speed < USB_SPEED_SUPER)
948 return 0;
949
950 return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
951 USB_REQ_SET_ISOCH_DELAY,
952 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
953 dev->hub_delay, 0, NULL, 0,
954 USB_CTRL_SET_TIMEOUT);
955 }
956
957 /**
958 * usb_get_status - issues a GET_STATUS call
959 * @dev: the device whose status is being checked
960 * @recip: USB_RECIP_*; for device, interface, or endpoint
961 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
962 * @target: zero (for device), else interface or endpoint number
963 * @data: pointer to two bytes of bitmap data
964 * Context: !in_interrupt ()
965 *
966 * Returns device, interface, or endpoint status. Normally only of
967 * interest to see if the device is self powered, or has enabled the
968 * remote wakeup facility; or whether a bulk or interrupt endpoint
969 * is halted ("stalled").
970 *
971 * Bits in these status bitmaps are set using the SET_FEATURE request,
972 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
973 * function should be used to clear halt ("stall") status.
974 *
975 * This call is synchronous, and may not be used in an interrupt context.
976 *
977 * Returns 0 and the status value in *@data (in host byte order) on success,
978 * or else the status code from the underlying usb_control_msg() call.
979 */
980 int usb_get_status(struct usb_device *dev, int recip, int type, int target,
981 void *data)
982 {
983 int ret;
984 void *status;
985 int length;
986
987 switch (type) {
988 case USB_STATUS_TYPE_STANDARD:
989 length = 2;
990 break;
991 case USB_STATUS_TYPE_PTM:
992 if (recip != USB_RECIP_DEVICE)
993 return -EINVAL;
994
995 length = 4;
996 break;
997 default:
998 return -EINVAL;
999 }
1000
1001 status = kmalloc(length, GFP_KERNEL);
1002 if (!status)
1003 return -ENOMEM;
1004
1005 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1006 USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1007 target, status, length, USB_CTRL_GET_TIMEOUT);
1008
1009 switch (ret) {
1010 case 4:
1011 if (type != USB_STATUS_TYPE_PTM) {
1012 ret = -EIO;
1013 break;
1014 }
1015
1016 *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1017 ret = 0;
1018 break;
1019 case 2:
1020 if (type != USB_STATUS_TYPE_STANDARD) {
1021 ret = -EIO;
1022 break;
1023 }
1024
1025 *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1026 ret = 0;
1027 break;
1028 default:
1029 ret = -EIO;
1030 }
1031
1032 kfree(status);
1033 return ret;
1034 }
1035 EXPORT_SYMBOL_GPL(usb_get_status);
1036
1037 /**
1038 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1039 * @dev: device whose endpoint is halted
1040 * @pipe: endpoint "pipe" being cleared
1041 * Context: !in_interrupt ()
1042 *
1043 * This is used to clear halt conditions for bulk and interrupt endpoints,
1044 * as reported by URB completion status. Endpoints that are halted are
1045 * sometimes referred to as being "stalled". Such endpoints are unable
1046 * to transmit or receive data until the halt status is cleared. Any URBs
1047 * queued for such an endpoint should normally be unlinked by the driver
1048 * before clearing the halt condition, as described in sections 5.7.5
1049 * and 5.8.5 of the USB 2.0 spec.
1050 *
1051 * Note that control and isochronous endpoints don't halt, although control
1052 * endpoints report "protocol stall" (for unsupported requests) using the
1053 * same status code used to report a true stall.
1054 *
1055 * This call is synchronous, and may not be used in an interrupt context.
1056 *
1057 * Return: Zero on success, or else the status code returned by the
1058 * underlying usb_control_msg() call.
1059 */
1060 int usb_clear_halt(struct usb_device *dev, int pipe)
1061 {
1062 int result;
1063 int endp = usb_pipeendpoint(pipe);
1064
1065 if (usb_pipein(pipe))
1066 endp |= USB_DIR_IN;
1067
1068 /* we don't care if it wasn't halted first. in fact some devices
1069 * (like some ibmcam model 1 units) seem to expect hosts to make
1070 * this request for iso endpoints, which can't halt!
1071 */
1072 result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1073 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1074 USB_ENDPOINT_HALT, endp, NULL, 0,
1075 USB_CTRL_SET_TIMEOUT);
1076
1077 /* don't un-halt or force to DATA0 except on success */
1078 if (result < 0)
1079 return result;
1080
1081 /* NOTE: seems like Microsoft and Apple don't bother verifying
1082 * the clear "took", so some devices could lock up if you check...
1083 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1084 *
1085 * NOTE: make sure the logic here doesn't diverge much from
1086 * the copy in usb-storage, for as long as we need two copies.
1087 */
1088
1089 usb_reset_endpoint(dev, endp);
1090
1091 return 0;
1092 }
1093 EXPORT_SYMBOL_GPL(usb_clear_halt);
1094
1095 static int create_intf_ep_devs(struct usb_interface *intf)
1096 {
1097 struct usb_device *udev = interface_to_usbdev(intf);
1098 struct usb_host_interface *alt = intf->cur_altsetting;
1099 int i;
1100
1101 if (intf->ep_devs_created || intf->unregistering)
1102 return 0;
1103
1104 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1105 (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1106 intf->ep_devs_created = 1;
1107 return 0;
1108 }
1109
1110 static void remove_intf_ep_devs(struct usb_interface *intf)
1111 {
1112 struct usb_host_interface *alt = intf->cur_altsetting;
1113 int i;
1114
1115 if (!intf->ep_devs_created)
1116 return;
1117
1118 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1119 usb_remove_ep_devs(&alt->endpoint[i]);
1120 intf->ep_devs_created = 0;
1121 }
1122
1123 /**
1124 * usb_disable_endpoint -- Disable an endpoint by address
1125 * @dev: the device whose endpoint is being disabled
1126 * @epaddr: the endpoint's address. Endpoint number for output,
1127 * endpoint number + USB_DIR_IN for input
1128 * @reset_hardware: flag to erase any endpoint state stored in the
1129 * controller hardware
1130 *
1131 * Disables the endpoint for URB submission and nukes all pending URBs.
1132 * If @reset_hardware is set then also deallocates hcd/hardware state
1133 * for the endpoint.
1134 */
1135 void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1136 bool reset_hardware)
1137 {
1138 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1139 struct usb_host_endpoint *ep;
1140
1141 if (!dev)
1142 return;
1143
1144 if (usb_endpoint_out(epaddr)) {
1145 ep = dev->ep_out[epnum];
1146 if (reset_hardware && epnum != 0)
1147 dev->ep_out[epnum] = NULL;
1148 } else {
1149 ep = dev->ep_in[epnum];
1150 if (reset_hardware && epnum != 0)
1151 dev->ep_in[epnum] = NULL;
1152 }
1153 if (ep) {
1154 ep->enabled = 0;
1155 usb_hcd_flush_endpoint(dev, ep);
1156 if (reset_hardware)
1157 usb_hcd_disable_endpoint(dev, ep);
1158 }
1159 }
1160
1161 /**
1162 * usb_reset_endpoint - Reset an endpoint's state.
1163 * @dev: the device whose endpoint is to be reset
1164 * @epaddr: the endpoint's address. Endpoint number for output,
1165 * endpoint number + USB_DIR_IN for input
1166 *
1167 * Resets any host-side endpoint state such as the toggle bit,
1168 * sequence number or current window.
1169 */
1170 void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1171 {
1172 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1173 struct usb_host_endpoint *ep;
1174
1175 if (usb_endpoint_out(epaddr))
1176 ep = dev->ep_out[epnum];
1177 else
1178 ep = dev->ep_in[epnum];
1179 if (ep)
1180 usb_hcd_reset_endpoint(dev, ep);
1181 }
1182 EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1183
1184
1185 /**
1186 * usb_disable_interface -- Disable all endpoints for an interface
1187 * @dev: the device whose interface is being disabled
1188 * @intf: pointer to the interface descriptor
1189 * @reset_hardware: flag to erase any endpoint state stored in the
1190 * controller hardware
1191 *
1192 * Disables all the endpoints for the interface's current altsetting.
1193 */
1194 void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1195 bool reset_hardware)
1196 {
1197 struct usb_host_interface *alt = intf->cur_altsetting;
1198 int i;
1199
1200 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1201 usb_disable_endpoint(dev,
1202 alt->endpoint[i].desc.bEndpointAddress,
1203 reset_hardware);
1204 }
1205 }
1206
1207 /**
1208 * usb_disable_device - Disable all the endpoints for a USB device
1209 * @dev: the device whose endpoints are being disabled
1210 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1211 *
1212 * Disables all the device's endpoints, potentially including endpoint 0.
1213 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1214 * pending urbs) and usbcore state for the interfaces, so that usbcore
1215 * must usb_set_configuration() before any interfaces could be used.
1216 */
1217 void usb_disable_device(struct usb_device *dev, int skip_ep0)
1218 {
1219 int i;
1220 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1221
1222 /* getting rid of interfaces will disconnect
1223 * any drivers bound to them (a key side effect)
1224 */
1225 if (dev->actconfig) {
1226 /*
1227 * FIXME: In order to avoid self-deadlock involving the
1228 * bandwidth_mutex, we have to mark all the interfaces
1229 * before unregistering any of them.
1230 */
1231 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1232 dev->actconfig->interface[i]->unregistering = 1;
1233
1234 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1235 struct usb_interface *interface;
1236
1237 /* remove this interface if it has been registered */
1238 interface = dev->actconfig->interface[i];
1239 if (!device_is_registered(&interface->dev))
1240 continue;
1241 dev_dbg(&dev->dev, "unregistering interface %s\n",
1242 dev_name(&interface->dev));
1243 remove_intf_ep_devs(interface);
1244 device_del(&interface->dev);
1245 }
1246
1247 /* Now that the interfaces are unbound, nobody should
1248 * try to access them.
1249 */
1250 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1251 put_device(&dev->actconfig->interface[i]->dev);
1252 dev->actconfig->interface[i] = NULL;
1253 }
1254
1255 usb_disable_usb2_hardware_lpm(dev);
1256 usb_unlocked_disable_lpm(dev);
1257 usb_disable_ltm(dev);
1258
1259 dev->actconfig = NULL;
1260 if (dev->state == USB_STATE_CONFIGURED)
1261 usb_set_device_state(dev, USB_STATE_ADDRESS);
1262 }
1263
1264 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1265 skip_ep0 ? "non-ep0" : "all");
1266 if (hcd->driver->check_bandwidth) {
1267 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1268 for (i = skip_ep0; i < 16; ++i) {
1269 usb_disable_endpoint(dev, i, false);
1270 usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1271 }
1272 /* Remove endpoints from the host controller internal state */
1273 mutex_lock(hcd->bandwidth_mutex);
1274 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1275 mutex_unlock(hcd->bandwidth_mutex);
1276 /* Second pass: remove endpoint pointers */
1277 }
1278 for (i = skip_ep0; i < 16; ++i) {
1279 usb_disable_endpoint(dev, i, true);
1280 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1281 }
1282 }
1283
1284 /**
1285 * usb_enable_endpoint - Enable an endpoint for USB communications
1286 * @dev: the device whose interface is being enabled
1287 * @ep: the endpoint
1288 * @reset_ep: flag to reset the endpoint state
1289 *
1290 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1291 * For control endpoints, both the input and output sides are handled.
1292 */
1293 void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1294 bool reset_ep)
1295 {
1296 int epnum = usb_endpoint_num(&ep->desc);
1297 int is_out = usb_endpoint_dir_out(&ep->desc);
1298 int is_control = usb_endpoint_xfer_control(&ep->desc);
1299
1300 if (reset_ep)
1301 usb_hcd_reset_endpoint(dev, ep);
1302 if (is_out || is_control)
1303 dev->ep_out[epnum] = ep;
1304 if (!is_out || is_control)
1305 dev->ep_in[epnum] = ep;
1306 ep->enabled = 1;
1307 }
1308
1309 /**
1310 * usb_enable_interface - Enable all the endpoints for an interface
1311 * @dev: the device whose interface is being enabled
1312 * @intf: pointer to the interface descriptor
1313 * @reset_eps: flag to reset the endpoints' state
1314 *
1315 * Enables all the endpoints for the interface's current altsetting.
1316 */
1317 void usb_enable_interface(struct usb_device *dev,
1318 struct usb_interface *intf, bool reset_eps)
1319 {
1320 struct usb_host_interface *alt = intf->cur_altsetting;
1321 int i;
1322
1323 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1324 usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1325 }
1326
1327 /**
1328 * usb_set_interface - Makes a particular alternate setting be current
1329 * @dev: the device whose interface is being updated
1330 * @interface: the interface being updated
1331 * @alternate: the setting being chosen.
1332 * Context: !in_interrupt ()
1333 *
1334 * This is used to enable data transfers on interfaces that may not
1335 * be enabled by default. Not all devices support such configurability.
1336 * Only the driver bound to an interface may change its setting.
1337 *
1338 * Within any given configuration, each interface may have several
1339 * alternative settings. These are often used to control levels of
1340 * bandwidth consumption. For example, the default setting for a high
1341 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1342 * while interrupt transfers of up to 3KBytes per microframe are legal.
1343 * Also, isochronous endpoints may never be part of an
1344 * interface's default setting. To access such bandwidth, alternate
1345 * interface settings must be made current.
1346 *
1347 * Note that in the Linux USB subsystem, bandwidth associated with
1348 * an endpoint in a given alternate setting is not reserved until an URB
1349 * is submitted that needs that bandwidth. Some other operating systems
1350 * allocate bandwidth early, when a configuration is chosen.
1351 *
1352 * xHCI reserves bandwidth and configures the alternate setting in
1353 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1354 * may be disabled. Drivers cannot rely on any particular alternate
1355 * setting being in effect after a failure.
1356 *
1357 * This call is synchronous, and may not be used in an interrupt context.
1358 * Also, drivers must not change altsettings while urbs are scheduled for
1359 * endpoints in that interface; all such urbs must first be completed
1360 * (perhaps forced by unlinking).
1361 *
1362 * Return: Zero on success, or else the status code returned by the
1363 * underlying usb_control_msg() call.
1364 */
1365 int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1366 {
1367 struct usb_interface *iface;
1368 struct usb_host_interface *alt;
1369 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1370 int i, ret, manual = 0;
1371 unsigned int epaddr;
1372 unsigned int pipe;
1373
1374 if (dev->state == USB_STATE_SUSPENDED)
1375 return -EHOSTUNREACH;
1376
1377 iface = usb_ifnum_to_if(dev, interface);
1378 if (!iface) {
1379 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1380 interface);
1381 return -EINVAL;
1382 }
1383 if (iface->unregistering)
1384 return -ENODEV;
1385
1386 alt = usb_altnum_to_altsetting(iface, alternate);
1387 if (!alt) {
1388 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1389 alternate);
1390 return -EINVAL;
1391 }
1392 /*
1393 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1394 * including freeing dropped endpoint ring buffers.
1395 * Make sure the interface endpoints are flushed before that
1396 */
1397 usb_disable_interface(dev, iface, false);
1398
1399 /* Make sure we have enough bandwidth for this alternate interface.
1400 * Remove the current alt setting and add the new alt setting.
1401 */
1402 mutex_lock(hcd->bandwidth_mutex);
1403 /* Disable LPM, and re-enable it once the new alt setting is installed,
1404 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1405 */
1406 if (usb_disable_lpm(dev)) {
1407 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1408 mutex_unlock(hcd->bandwidth_mutex);
1409 return -ENOMEM;
1410 }
1411 /* Changing alt-setting also frees any allocated streams */
1412 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1413 iface->cur_altsetting->endpoint[i].streams = 0;
1414
1415 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1416 if (ret < 0) {
1417 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1418 alternate);
1419 usb_enable_lpm(dev);
1420 mutex_unlock(hcd->bandwidth_mutex);
1421 return ret;
1422 }
1423
1424 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1425 ret = -EPIPE;
1426 else
1427 ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1428 USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
1429 alternate, interface, NULL, 0, 5000);
1430
1431 /* 9.4.10 says devices don't need this and are free to STALL the
1432 * request if the interface only has one alternate setting.
1433 */
1434 if (ret == -EPIPE && iface->num_altsetting == 1) {
1435 dev_dbg(&dev->dev,
1436 "manual set_interface for iface %d, alt %d\n",
1437 interface, alternate);
1438 manual = 1;
1439 } else if (ret < 0) {
1440 /* Re-instate the old alt setting */
1441 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1442 usb_enable_lpm(dev);
1443 mutex_unlock(hcd->bandwidth_mutex);
1444 return ret;
1445 }
1446 mutex_unlock(hcd->bandwidth_mutex);
1447
1448 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1449 * when they implement async or easily-killable versions of this or
1450 * other "should-be-internal" functions (like clear_halt).
1451 * should hcd+usbcore postprocess control requests?
1452 */
1453
1454 /* prevent submissions using previous endpoint settings */
1455 if (iface->cur_altsetting != alt) {
1456 remove_intf_ep_devs(iface);
1457 usb_remove_sysfs_intf_files(iface);
1458 }
1459 usb_disable_interface(dev, iface, true);
1460
1461 iface->cur_altsetting = alt;
1462
1463 /* Now that the interface is installed, re-enable LPM. */
1464 usb_unlocked_enable_lpm(dev);
1465
1466 /* If the interface only has one altsetting and the device didn't
1467 * accept the request, we attempt to carry out the equivalent action
1468 * by manually clearing the HALT feature for each endpoint in the
1469 * new altsetting.
1470 */
1471 if (manual) {
1472 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1473 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1474 pipe = __create_pipe(dev,
1475 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1476 (usb_endpoint_out(epaddr) ?
1477 USB_DIR_OUT : USB_DIR_IN);
1478
1479 usb_clear_halt(dev, pipe);
1480 }
1481 }
1482
1483 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1484 *
1485 * Note:
1486 * Despite EP0 is always present in all interfaces/AS, the list of
1487 * endpoints from the descriptor does not contain EP0. Due to its
1488 * omnipresence one might expect EP0 being considered "affected" by
1489 * any SetInterface request and hence assume toggles need to be reset.
1490 * However, EP0 toggles are re-synced for every individual transfer
1491 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1492 * (Likewise, EP0 never "halts" on well designed devices.)
1493 */
1494 usb_enable_interface(dev, iface, true);
1495 if (device_is_registered(&iface->dev)) {
1496 usb_create_sysfs_intf_files(iface);
1497 create_intf_ep_devs(iface);
1498 }
1499 return 0;
1500 }
1501 EXPORT_SYMBOL_GPL(usb_set_interface);
1502
1503 /**
1504 * usb_reset_configuration - lightweight device reset
1505 * @dev: the device whose configuration is being reset
1506 *
1507 * This issues a standard SET_CONFIGURATION request to the device using
1508 * the current configuration. The effect is to reset most USB-related
1509 * state in the device, including interface altsettings (reset to zero),
1510 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1511 * endpoints). Other usbcore state is unchanged, including bindings of
1512 * usb device drivers to interfaces.
1513 *
1514 * Because this affects multiple interfaces, avoid using this with composite
1515 * (multi-interface) devices. Instead, the driver for each interface may
1516 * use usb_set_interface() on the interfaces it claims. Be careful though;
1517 * some devices don't support the SET_INTERFACE request, and others won't
1518 * reset all the interface state (notably endpoint state). Resetting the whole
1519 * configuration would affect other drivers' interfaces.
1520 *
1521 * The caller must own the device lock.
1522 *
1523 * Return: Zero on success, else a negative error code.
1524 */
1525 int usb_reset_configuration(struct usb_device *dev)
1526 {
1527 int i, retval;
1528 struct usb_host_config *config;
1529 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1530
1531 if (dev->state == USB_STATE_SUSPENDED)
1532 return -EHOSTUNREACH;
1533
1534 /* caller must have locked the device and must own
1535 * the usb bus readlock (so driver bindings are stable);
1536 * calls during probe() are fine
1537 */
1538
1539 for (i = 1; i < 16; ++i) {
1540 usb_disable_endpoint(dev, i, true);
1541 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1542 }
1543
1544 config = dev->actconfig;
1545 retval = 0;
1546 mutex_lock(hcd->bandwidth_mutex);
1547 /* Disable LPM, and re-enable it once the configuration is reset, so
1548 * that the xHCI driver can recalculate the U1/U2 timeouts.
1549 */
1550 if (usb_disable_lpm(dev)) {
1551 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1552 mutex_unlock(hcd->bandwidth_mutex);
1553 return -ENOMEM;
1554 }
1555 /* Make sure we have enough bandwidth for each alternate setting 0 */
1556 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1557 struct usb_interface *intf = config->interface[i];
1558 struct usb_host_interface *alt;
1559
1560 alt = usb_altnum_to_altsetting(intf, 0);
1561 if (!alt)
1562 alt = &intf->altsetting[0];
1563 if (alt != intf->cur_altsetting)
1564 retval = usb_hcd_alloc_bandwidth(dev, NULL,
1565 intf->cur_altsetting, alt);
1566 if (retval < 0)
1567 break;
1568 }
1569 /* If not, reinstate the old alternate settings */
1570 if (retval < 0) {
1571 reset_old_alts:
1572 for (i--; i >= 0; i--) {
1573 struct usb_interface *intf = config->interface[i];
1574 struct usb_host_interface *alt;
1575
1576 alt = usb_altnum_to_altsetting(intf, 0);
1577 if (!alt)
1578 alt = &intf->altsetting[0];
1579 if (alt != intf->cur_altsetting)
1580 usb_hcd_alloc_bandwidth(dev, NULL,
1581 alt, intf->cur_altsetting);
1582 }
1583 usb_enable_lpm(dev);
1584 mutex_unlock(hcd->bandwidth_mutex);
1585 return retval;
1586 }
1587 retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1588 USB_REQ_SET_CONFIGURATION, 0,
1589 config->desc.bConfigurationValue, 0,
1590 NULL, 0, USB_CTRL_SET_TIMEOUT);
1591 if (retval < 0)
1592 goto reset_old_alts;
1593 mutex_unlock(hcd->bandwidth_mutex);
1594
1595 /* re-init hc/hcd interface/endpoint state */
1596 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1597 struct usb_interface *intf = config->interface[i];
1598 struct usb_host_interface *alt;
1599
1600 alt = usb_altnum_to_altsetting(intf, 0);
1601
1602 /* No altsetting 0? We'll assume the first altsetting.
1603 * We could use a GetInterface call, but if a device is
1604 * so non-compliant that it doesn't have altsetting 0
1605 * then I wouldn't trust its reply anyway.
1606 */
1607 if (!alt)
1608 alt = &intf->altsetting[0];
1609
1610 if (alt != intf->cur_altsetting) {
1611 remove_intf_ep_devs(intf);
1612 usb_remove_sysfs_intf_files(intf);
1613 }
1614 intf->cur_altsetting = alt;
1615 usb_enable_interface(dev, intf, true);
1616 if (device_is_registered(&intf->dev)) {
1617 usb_create_sysfs_intf_files(intf);
1618 create_intf_ep_devs(intf);
1619 }
1620 }
1621 /* Now that the interfaces are installed, re-enable LPM. */
1622 usb_unlocked_enable_lpm(dev);
1623 return 0;
1624 }
1625 EXPORT_SYMBOL_GPL(usb_reset_configuration);
1626
1627 static void usb_release_interface(struct device *dev)
1628 {
1629 struct usb_interface *intf = to_usb_interface(dev);
1630 struct usb_interface_cache *intfc =
1631 altsetting_to_usb_interface_cache(intf->altsetting);
1632
1633 kref_put(&intfc->ref, usb_release_interface_cache);
1634 usb_put_dev(interface_to_usbdev(intf));
1635 of_node_put(dev->of_node);
1636 kfree(intf);
1637 }
1638
1639 /*
1640 * usb_deauthorize_interface - deauthorize an USB interface
1641 *
1642 * @intf: USB interface structure
1643 */
1644 void usb_deauthorize_interface(struct usb_interface *intf)
1645 {
1646 struct device *dev = &intf->dev;
1647
1648 device_lock(dev->parent);
1649
1650 if (intf->authorized) {
1651 device_lock(dev);
1652 intf->authorized = 0;
1653 device_unlock(dev);
1654
1655 usb_forced_unbind_intf(intf);
1656 }
1657
1658 device_unlock(dev->parent);
1659 }
1660
1661 /*
1662 * usb_authorize_interface - authorize an USB interface
1663 *
1664 * @intf: USB interface structure
1665 */
1666 void usb_authorize_interface(struct usb_interface *intf)
1667 {
1668 struct device *dev = &intf->dev;
1669
1670 if (!intf->authorized) {
1671 device_lock(dev);
1672 intf->authorized = 1; /* authorize interface */
1673 device_unlock(dev);
1674 }
1675 }
1676
1677 static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1678 {
1679 struct usb_device *usb_dev;
1680 struct usb_interface *intf;
1681 struct usb_host_interface *alt;
1682
1683 intf = to_usb_interface(dev);
1684 usb_dev = interface_to_usbdev(intf);
1685 alt = intf->cur_altsetting;
1686
1687 if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1688 alt->desc.bInterfaceClass,
1689 alt->desc.bInterfaceSubClass,
1690 alt->desc.bInterfaceProtocol))
1691 return -ENOMEM;
1692
1693 if (add_uevent_var(env,
1694 "MODALIAS=usb:"
1695 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1696 le16_to_cpu(usb_dev->descriptor.idVendor),
1697 le16_to_cpu(usb_dev->descriptor.idProduct),
1698 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1699 usb_dev->descriptor.bDeviceClass,
1700 usb_dev->descriptor.bDeviceSubClass,
1701 usb_dev->descriptor.bDeviceProtocol,
1702 alt->desc.bInterfaceClass,
1703 alt->desc.bInterfaceSubClass,
1704 alt->desc.bInterfaceProtocol,
1705 alt->desc.bInterfaceNumber))
1706 return -ENOMEM;
1707
1708 return 0;
1709 }
1710
1711 struct device_type usb_if_device_type = {
1712 .name = "usb_interface",
1713 .release = usb_release_interface,
1714 .uevent = usb_if_uevent,
1715 };
1716
1717 static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1718 struct usb_host_config *config,
1719 u8 inum)
1720 {
1721 struct usb_interface_assoc_descriptor *retval = NULL;
1722 struct usb_interface_assoc_descriptor *intf_assoc;
1723 int first_intf;
1724 int last_intf;
1725 int i;
1726
1727 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1728 intf_assoc = config->intf_assoc[i];
1729 if (intf_assoc->bInterfaceCount == 0)
1730 continue;
1731
1732 first_intf = intf_assoc->bFirstInterface;
1733 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1734 if (inum >= first_intf && inum <= last_intf) {
1735 if (!retval)
1736 retval = intf_assoc;
1737 else
1738 dev_err(&dev->dev, "Interface #%d referenced"
1739 " by multiple IADs\n", inum);
1740 }
1741 }
1742
1743 return retval;
1744 }
1745
1746
1747 /*
1748 * Internal function to queue a device reset
1749 * See usb_queue_reset_device() for more details
1750 */
1751 static void __usb_queue_reset_device(struct work_struct *ws)
1752 {
1753 int rc;
1754 struct usb_interface *iface =
1755 container_of(ws, struct usb_interface, reset_ws);
1756 struct usb_device *udev = interface_to_usbdev(iface);
1757
1758 rc = usb_lock_device_for_reset(udev, iface);
1759 if (rc >= 0) {
1760 usb_reset_device(udev);
1761 usb_unlock_device(udev);
1762 }
1763 usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */
1764 }
1765
1766
1767 /*
1768 * usb_set_configuration - Makes a particular device setting be current
1769 * @dev: the device whose configuration is being updated
1770 * @configuration: the configuration being chosen.
1771 * Context: !in_interrupt(), caller owns the device lock
1772 *
1773 * This is used to enable non-default device modes. Not all devices
1774 * use this kind of configurability; many devices only have one
1775 * configuration.
1776 *
1777 * @configuration is the value of the configuration to be installed.
1778 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1779 * must be non-zero; a value of zero indicates that the device in
1780 * unconfigured. However some devices erroneously use 0 as one of their
1781 * configuration values. To help manage such devices, this routine will
1782 * accept @configuration = -1 as indicating the device should be put in
1783 * an unconfigured state.
1784 *
1785 * USB device configurations may affect Linux interoperability,
1786 * power consumption and the functionality available. For example,
1787 * the default configuration is limited to using 100mA of bus power,
1788 * so that when certain device functionality requires more power,
1789 * and the device is bus powered, that functionality should be in some
1790 * non-default device configuration. Other device modes may also be
1791 * reflected as configuration options, such as whether two ISDN
1792 * channels are available independently; and choosing between open
1793 * standard device protocols (like CDC) or proprietary ones.
1794 *
1795 * Note that a non-authorized device (dev->authorized == 0) will only
1796 * be put in unconfigured mode.
1797 *
1798 * Note that USB has an additional level of device configurability,
1799 * associated with interfaces. That configurability is accessed using
1800 * usb_set_interface().
1801 *
1802 * This call is synchronous. The calling context must be able to sleep,
1803 * must own the device lock, and must not hold the driver model's USB
1804 * bus mutex; usb interface driver probe() methods cannot use this routine.
1805 *
1806 * Returns zero on success, or else the status code returned by the
1807 * underlying call that failed. On successful completion, each interface
1808 * in the original device configuration has been destroyed, and each one
1809 * in the new configuration has been probed by all relevant usb device
1810 * drivers currently known to the kernel.
1811 */
1812 int usb_set_configuration(struct usb_device *dev, int configuration)
1813 {
1814 int i, ret;
1815 struct usb_host_config *cp = NULL;
1816 struct usb_interface **new_interfaces = NULL;
1817 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1818 int n, nintf;
1819
1820 if (dev->authorized == 0 || configuration == -1)
1821 configuration = 0;
1822 else {
1823 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1824 if (dev->config[i].desc.bConfigurationValue ==
1825 configuration) {
1826 cp = &dev->config[i];
1827 break;
1828 }
1829 }
1830 }
1831 if ((!cp && configuration != 0))
1832 return -EINVAL;
1833
1834 /* The USB spec says configuration 0 means unconfigured.
1835 * But if a device includes a configuration numbered 0,
1836 * we will accept it as a correctly configured state.
1837 * Use -1 if you really want to unconfigure the device.
1838 */
1839 if (cp && configuration == 0)
1840 dev_warn(&dev->dev, "config 0 descriptor??\n");
1841
1842 /* Allocate memory for new interfaces before doing anything else,
1843 * so that if we run out then nothing will have changed. */
1844 n = nintf = 0;
1845 if (cp) {
1846 nintf = cp->desc.bNumInterfaces;
1847 new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
1848 GFP_NOIO);
1849 if (!new_interfaces)
1850 return -ENOMEM;
1851
1852 for (; n < nintf; ++n) {
1853 new_interfaces[n] = kzalloc(
1854 sizeof(struct usb_interface),
1855 GFP_NOIO);
1856 if (!new_interfaces[n]) {
1857 ret = -ENOMEM;
1858 free_interfaces:
1859 while (--n >= 0)
1860 kfree(new_interfaces[n]);
1861 kfree(new_interfaces);
1862 return ret;
1863 }
1864 }
1865
1866 i = dev->bus_mA - usb_get_max_power(dev, cp);
1867 if (i < 0)
1868 dev_warn(&dev->dev, "new config #%d exceeds power "
1869 "limit by %dmA\n",
1870 configuration, -i);
1871 }
1872
1873 /* Wake up the device so we can send it the Set-Config request */
1874 ret = usb_autoresume_device(dev);
1875 if (ret)
1876 goto free_interfaces;
1877
1878 /* if it's already configured, clear out old state first.
1879 * getting rid of old interfaces means unbinding their drivers.
1880 */
1881 if (dev->state != USB_STATE_ADDRESS)
1882 usb_disable_device(dev, 1); /* Skip ep0 */
1883
1884 /* Get rid of pending async Set-Config requests for this device */
1885 cancel_async_set_config(dev);
1886
1887 /* Make sure we have bandwidth (and available HCD resources) for this
1888 * configuration. Remove endpoints from the schedule if we're dropping
1889 * this configuration to set configuration 0. After this point, the
1890 * host controller will not allow submissions to dropped endpoints. If
1891 * this call fails, the device state is unchanged.
1892 */
1893 mutex_lock(hcd->bandwidth_mutex);
1894 /* Disable LPM, and re-enable it once the new configuration is
1895 * installed, so that the xHCI driver can recalculate the U1/U2
1896 * timeouts.
1897 */
1898 if (dev->actconfig && usb_disable_lpm(dev)) {
1899 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1900 mutex_unlock(hcd->bandwidth_mutex);
1901 ret = -ENOMEM;
1902 goto free_interfaces;
1903 }
1904 ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
1905 if (ret < 0) {
1906 if (dev->actconfig)
1907 usb_enable_lpm(dev);
1908 mutex_unlock(hcd->bandwidth_mutex);
1909 usb_autosuspend_device(dev);
1910 goto free_interfaces;
1911 }
1912
1913 /*
1914 * Initialize the new interface structures and the
1915 * hc/hcd/usbcore interface/endpoint state.
1916 */
1917 for (i = 0; i < nintf; ++i) {
1918 struct usb_interface_cache *intfc;
1919 struct usb_interface *intf;
1920 struct usb_host_interface *alt;
1921 u8 ifnum;
1922
1923 cp->interface[i] = intf = new_interfaces[i];
1924 intfc = cp->intf_cache[i];
1925 intf->altsetting = intfc->altsetting;
1926 intf->num_altsetting = intfc->num_altsetting;
1927 intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
1928 kref_get(&intfc->ref);
1929
1930 alt = usb_altnum_to_altsetting(intf, 0);
1931
1932 /* No altsetting 0? We'll assume the first altsetting.
1933 * We could use a GetInterface call, but if a device is
1934 * so non-compliant that it doesn't have altsetting 0
1935 * then I wouldn't trust its reply anyway.
1936 */
1937 if (!alt)
1938 alt = &intf->altsetting[0];
1939
1940 ifnum = alt->desc.bInterfaceNumber;
1941 intf->intf_assoc = find_iad(dev, cp, ifnum);
1942 intf->cur_altsetting = alt;
1943 usb_enable_interface(dev, intf, true);
1944 intf->dev.parent = &dev->dev;
1945 if (usb_of_has_combined_node(dev)) {
1946 device_set_of_node_from_dev(&intf->dev, &dev->dev);
1947 } else {
1948 intf->dev.of_node = usb_of_get_interface_node(dev,
1949 configuration, ifnum);
1950 }
1951 intf->dev.driver = NULL;
1952 intf->dev.bus = &usb_bus_type;
1953 intf->dev.type = &usb_if_device_type;
1954 intf->dev.groups = usb_interface_groups;
1955 /*
1956 * Please refer to usb_alloc_dev() to see why we set
1957 * dma_mask and dma_pfn_offset.
1958 */
1959 intf->dev.dma_mask = dev->dev.dma_mask;
1960 intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset;
1961 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
1962 intf->minor = -1;
1963 device_initialize(&intf->dev);
1964 pm_runtime_no_callbacks(&intf->dev);
1965 dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
1966 dev->devpath, configuration, ifnum);
1967 usb_get_dev(dev);
1968 }
1969 kfree(new_interfaces);
1970
1971 ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1972 USB_REQ_SET_CONFIGURATION, 0, configuration, 0,
1973 NULL, 0, USB_CTRL_SET_TIMEOUT);
1974 if (ret < 0 && cp) {
1975 /*
1976 * All the old state is gone, so what else can we do?
1977 * The device is probably useless now anyway.
1978 */
1979 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1980 for (i = 0; i < nintf; ++i) {
1981 usb_disable_interface(dev, cp->interface[i], true);
1982 put_device(&cp->interface[i]->dev);
1983 cp->interface[i] = NULL;
1984 }
1985 cp = NULL;
1986 }
1987
1988 dev->actconfig = cp;
1989 mutex_unlock(hcd->bandwidth_mutex);
1990
1991 if (!cp) {
1992 usb_set_device_state(dev, USB_STATE_ADDRESS);
1993
1994 /* Leave LPM disabled while the device is unconfigured. */
1995 usb_autosuspend_device(dev);
1996 return ret;
1997 }
1998 usb_set_device_state(dev, USB_STATE_CONFIGURED);
1999
2000 if (cp->string == NULL &&
2001 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2002 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2003
2004 /* Now that the interfaces are installed, re-enable LPM. */
2005 usb_unlocked_enable_lpm(dev);
2006 /* Enable LTM if it was turned off by usb_disable_device. */
2007 usb_enable_ltm(dev);
2008
2009 /* Now that all the interfaces are set up, register them
2010 * to trigger binding of drivers to interfaces. probe()
2011 * routines may install different altsettings and may
2012 * claim() any interfaces not yet bound. Many class drivers
2013 * need that: CDC, audio, video, etc.
2014 */
2015 for (i = 0; i < nintf; ++i) {
2016 struct usb_interface *intf = cp->interface[i];
2017
2018 if (intf->dev.of_node &&
2019 !of_device_is_available(intf->dev.of_node)) {
2020 dev_info(&dev->dev, "skipping disabled interface %d\n",
2021 intf->cur_altsetting->desc.bInterfaceNumber);
2022 continue;
2023 }
2024
2025 dev_dbg(&dev->dev,
2026 "adding %s (config #%d, interface %d)\n",
2027 dev_name(&intf->dev), configuration,
2028 intf->cur_altsetting->desc.bInterfaceNumber);
2029 device_enable_async_suspend(&intf->dev);
2030 ret = device_add(&intf->dev);
2031 if (ret != 0) {
2032 dev_err(&dev->dev, "device_add(%s) --> %d\n",
2033 dev_name(&intf->dev), ret);
2034 continue;
2035 }
2036 create_intf_ep_devs(intf);
2037 }
2038
2039 usb_autosuspend_device(dev);
2040 return 0;
2041 }
2042 EXPORT_SYMBOL_GPL(usb_set_configuration);
2043
2044 static LIST_HEAD(set_config_list);
2045 static DEFINE_SPINLOCK(set_config_lock);
2046
2047 struct set_config_request {
2048 struct usb_device *udev;
2049 int config;
2050 struct work_struct work;
2051 struct list_head node;
2052 };
2053
2054 /* Worker routine for usb_driver_set_configuration() */
2055 static void driver_set_config_work(struct work_struct *work)
2056 {
2057 struct set_config_request *req =
2058 container_of(work, struct set_config_request, work);
2059 struct usb_device *udev = req->udev;
2060
2061 usb_lock_device(udev);
2062 spin_lock(&set_config_lock);
2063 list_del(&req->node);
2064 spin_unlock(&set_config_lock);
2065
2066 if (req->config >= -1) /* Is req still valid? */
2067 usb_set_configuration(udev, req->config);
2068 usb_unlock_device(udev);
2069 usb_put_dev(udev);
2070 kfree(req);
2071 }
2072
2073 /* Cancel pending Set-Config requests for a device whose configuration
2074 * was just changed
2075 */
2076 static void cancel_async_set_config(struct usb_device *udev)
2077 {
2078 struct set_config_request *req;
2079
2080 spin_lock(&set_config_lock);
2081 list_for_each_entry(req, &set_config_list, node) {
2082 if (req->udev == udev)
2083 req->config = -999; /* Mark as cancelled */
2084 }
2085 spin_unlock(&set_config_lock);
2086 }
2087
2088 /**
2089 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2090 * @udev: the device whose configuration is being updated
2091 * @config: the configuration being chosen.
2092 * Context: In process context, must be able to sleep
2093 *
2094 * Device interface drivers are not allowed to change device configurations.
2095 * This is because changing configurations will destroy the interface the
2096 * driver is bound to and create new ones; it would be like a floppy-disk
2097 * driver telling the computer to replace the floppy-disk drive with a
2098 * tape drive!
2099 *
2100 * Still, in certain specialized circumstances the need may arise. This
2101 * routine gets around the normal restrictions by using a work thread to
2102 * submit the change-config request.
2103 *
2104 * Return: 0 if the request was successfully queued, error code otherwise.
2105 * The caller has no way to know whether the queued request will eventually
2106 * succeed.
2107 */
2108 int usb_driver_set_configuration(struct usb_device *udev, int config)
2109 {
2110 struct set_config_request *req;
2111
2112 req = kmalloc(sizeof(*req), GFP_KERNEL);
2113 if (!req)
2114 return -ENOMEM;
2115 req->udev = udev;
2116 req->config = config;
2117 INIT_WORK(&req->work, driver_set_config_work);
2118
2119 spin_lock(&set_config_lock);
2120 list_add(&req->node, &set_config_list);
2121 spin_unlock(&set_config_lock);
2122
2123 usb_get_dev(udev);
2124 schedule_work(&req->work);
2125 return 0;
2126 }
2127 EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2128
2129 /**
2130 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2131 * @hdr: the place to put the results of the parsing
2132 * @intf: the interface for which parsing is requested
2133 * @buffer: pointer to the extra headers to be parsed
2134 * @buflen: length of the extra headers
2135 *
2136 * This evaluates the extra headers present in CDC devices which
2137 * bind the interfaces for data and control and provide details
2138 * about the capabilities of the device.
2139 *
2140 * Return: number of descriptors parsed or -EINVAL
2141 * if the header is contradictory beyond salvage
2142 */
2143
2144 int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2145 struct usb_interface *intf,
2146 u8 *buffer,
2147 int buflen)
2148 {
2149 /* duplicates are ignored */
2150 struct usb_cdc_union_desc *union_header = NULL;
2151
2152 /* duplicates are not tolerated */
2153 struct usb_cdc_header_desc *header = NULL;
2154 struct usb_cdc_ether_desc *ether = NULL;
2155 struct usb_cdc_mdlm_detail_desc *detail = NULL;
2156 struct usb_cdc_mdlm_desc *desc = NULL;
2157
2158 unsigned int elength;
2159 int cnt = 0;
2160
2161 memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2162 hdr->phonet_magic_present = false;
2163 while (buflen > 0) {
2164 elength = buffer[0];
2165 if (!elength) {
2166 dev_err(&intf->dev, "skipping garbage byte\n");
2167 elength = 1;
2168 goto next_desc;
2169 }
2170 if ((buflen < elength) || (elength < 3)) {
2171 dev_err(&intf->dev, "invalid descriptor buffer length\n");
2172 break;
2173 }
2174 if (buffer[1] != USB_DT_CS_INTERFACE) {
2175 dev_err(&intf->dev, "skipping garbage\n");
2176 goto next_desc;
2177 }
2178
2179 switch (buffer[2]) {
2180 case USB_CDC_UNION_TYPE: /* we've found it */
2181 if (elength < sizeof(struct usb_cdc_union_desc))
2182 goto next_desc;
2183 if (union_header) {
2184 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2185 goto next_desc;
2186 }
2187 union_header = (struct usb_cdc_union_desc *)buffer;
2188 break;
2189 case USB_CDC_COUNTRY_TYPE:
2190 if (elength < sizeof(struct usb_cdc_country_functional_desc))
2191 goto next_desc;
2192 hdr->usb_cdc_country_functional_desc =
2193 (struct usb_cdc_country_functional_desc *)buffer;
2194 break;
2195 case USB_CDC_HEADER_TYPE:
2196 if (elength != sizeof(struct usb_cdc_header_desc))
2197 goto next_desc;
2198 if (header)
2199 return -EINVAL;
2200 header = (struct usb_cdc_header_desc *)buffer;
2201 break;
2202 case USB_CDC_ACM_TYPE:
2203 if (elength < sizeof(struct usb_cdc_acm_descriptor))
2204 goto next_desc;
2205 hdr->usb_cdc_acm_descriptor =
2206 (struct usb_cdc_acm_descriptor *)buffer;
2207 break;
2208 case USB_CDC_ETHERNET_TYPE:
2209 if (elength != sizeof(struct usb_cdc_ether_desc))
2210 goto next_desc;
2211 if (ether)
2212 return -EINVAL;
2213 ether = (struct usb_cdc_ether_desc *)buffer;
2214 break;
2215 case USB_CDC_CALL_MANAGEMENT_TYPE:
2216 if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2217 goto next_desc;
2218 hdr->usb_cdc_call_mgmt_descriptor =
2219 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2220 break;
2221 case USB_CDC_DMM_TYPE:
2222 if (elength < sizeof(struct usb_cdc_dmm_desc))
2223 goto next_desc;
2224 hdr->usb_cdc_dmm_desc =
2225 (struct usb_cdc_dmm_desc *)buffer;
2226 break;
2227 case USB_CDC_MDLM_TYPE:
2228 if (elength < sizeof(struct usb_cdc_mdlm_desc))
2229 goto next_desc;
2230 if (desc)
2231 return -EINVAL;
2232 desc = (struct usb_cdc_mdlm_desc *)buffer;
2233 break;
2234 case USB_CDC_MDLM_DETAIL_TYPE:
2235 if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2236 goto next_desc;
2237 if (detail)
2238 return -EINVAL;
2239 detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2240 break;
2241 case USB_CDC_NCM_TYPE:
2242 if (elength < sizeof(struct usb_cdc_ncm_desc))
2243 goto next_desc;
2244 hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2245 break;
2246 case USB_CDC_MBIM_TYPE:
2247 if (elength < sizeof(struct usb_cdc_mbim_desc))
2248 goto next_desc;
2249
2250 hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2251 break;
2252 case USB_CDC_MBIM_EXTENDED_TYPE:
2253 if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2254 break;
2255 hdr->usb_cdc_mbim_extended_desc =
2256 (struct usb_cdc_mbim_extended_desc *)buffer;
2257 break;
2258 case CDC_PHONET_MAGIC_NUMBER:
2259 hdr->phonet_magic_present = true;
2260 break;
2261 default:
2262 /*
2263 * there are LOTS more CDC descriptors that
2264 * could legitimately be found here.
2265 */
2266 dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2267 buffer[2], elength);
2268 goto next_desc;
2269 }
2270 cnt++;
2271 next_desc:
2272 buflen -= elength;
2273 buffer += elength;
2274 }
2275 hdr->usb_cdc_union_desc = union_header;
2276 hdr->usb_cdc_header_desc = header;
2277 hdr->usb_cdc_mdlm_detail_desc = detail;
2278 hdr->usb_cdc_mdlm_desc = desc;
2279 hdr->usb_cdc_ether_desc = ether;
2280 return cnt;
2281 }
2282
2283 EXPORT_SYMBOL(cdc_parse_cdc_header);