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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/acpi.h>
9#include <linux/pci.h> /* for scatterlist macros */
10#include <linux/usb.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/mm.h>
14#include <linux/timer.h>
15#include <linux/ctype.h>
16#include <linux/nls.h>
17#include <linux/device.h>
18#include <linux/scatterlist.h>
19#include <linux/usb/cdc.h>
20#include <linux/usb/quirks.h>
21#include <linux/usb/hcd.h> /* for usbcore internals */
22#include <linux/usb/of.h>
23#include <asm/byteorder.h>
24
25#include "usb.h"
26
27static void cancel_async_set_config(struct usb_device *udev);
28
29struct api_context {
30 struct completion done;
31 int status;
32};
33
34static void usb_api_blocking_completion(struct urb *urb)
35{
36 struct api_context *ctx = urb->context;
37
38 ctx->status = urb->status;
39 complete(&ctx->done);
40}
41
42
43/*
44 * Starts urb and waits for completion or timeout. Note that this call
45 * is NOT interruptible. Many device driver i/o requests should be
46 * interruptible and therefore these drivers should implement their
47 * own interruptible routines.
48 */
49static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
50{
51 struct api_context ctx;
52 unsigned long expire;
53 int retval;
54
55 init_completion(&ctx.done);
56 urb->context = &ctx;
57 urb->actual_length = 0;
58 retval = usb_submit_urb(urb, GFP_NOIO);
59 if (unlikely(retval))
60 goto out;
61
62 expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
63 if (!wait_for_completion_timeout(&ctx.done, expire)) {
64 usb_kill_urb(urb);
65 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
66
67 dev_dbg(&urb->dev->dev,
68 "%s timed out on ep%d%s len=%u/%u\n",
69 current->comm,
70 usb_endpoint_num(&urb->ep->desc),
71 usb_urb_dir_in(urb) ? "in" : "out",
72 urb->actual_length,
73 urb->transfer_buffer_length);
74 } else
75 retval = ctx.status;
76out:
77 if (actual_length)
78 *actual_length = urb->actual_length;
79
80 usb_free_urb(urb);
81 return retval;
82}
83
84/*-------------------------------------------------------------------*/
85/* returns status (negative) or length (positive) */
86static int usb_internal_control_msg(struct usb_device *usb_dev,
87 unsigned int pipe,
88 struct usb_ctrlrequest *cmd,
89 void *data, int len, int timeout)
90{
91 struct urb *urb;
92 int retv;
93 int length;
94
95 urb = usb_alloc_urb(0, GFP_NOIO);
96 if (!urb)
97 return -ENOMEM;
98
99 usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
100 len, usb_api_blocking_completion, NULL);
101
102 retv = usb_start_wait_urb(urb, timeout, &length);
103 if (retv < 0)
104 return retv;
105 else
106 return length;
107}
108
109/**
110 * usb_control_msg - Builds a control urb, sends it off and waits for completion
111 * @dev: pointer to the usb device to send the message to
112 * @pipe: endpoint "pipe" to send the message to
113 * @request: USB message request value
114 * @requesttype: USB message request type value
115 * @value: USB message value
116 * @index: USB message index value
117 * @data: pointer to the data to send
118 * @size: length in bytes of the data to send
119 * @timeout: time in msecs to wait for the message to complete before timing
120 * out (if 0 the wait is forever)
121 *
122 * Context: task context, might sleep.
123 *
124 * This function sends a simple control message to a specified endpoint and
125 * waits for the message to complete, or timeout.
126 *
127 * Don't use this function from within an interrupt context. If you need
128 * an asynchronous message, or need to send a message from within interrupt
129 * context, use usb_submit_urb(). If a thread in your driver uses this call,
130 * make sure your disconnect() method can wait for it to complete. Since you
131 * don't have a handle on the URB used, you can't cancel the request.
132 *
133 * Return: If successful, the number of bytes transferred. Otherwise, a negative
134 * error number.
135 */
136int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
137 __u8 requesttype, __u16 value, __u16 index, void *data,
138 __u16 size, int timeout)
139{
140 struct usb_ctrlrequest *dr;
141 int ret;
142
143 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
144 if (!dr)
145 return -ENOMEM;
146
147 dr->bRequestType = requesttype;
148 dr->bRequest = request;
149 dr->wValue = cpu_to_le16(value);
150 dr->wIndex = cpu_to_le16(index);
151 dr->wLength = cpu_to_le16(size);
152
153 ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
154
155 /* Linger a bit, prior to the next control message. */
156 if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
157 msleep(200);
158
159 kfree(dr);
160
161 return ret;
162}
163EXPORT_SYMBOL_GPL(usb_control_msg);
164
165/**
166 * usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
167 * @dev: pointer to the usb device to send the message to
168 * @endpoint: endpoint to send the message to
169 * @request: USB message request value
170 * @requesttype: USB message request type value
171 * @value: USB message value
172 * @index: USB message index value
173 * @driver_data: pointer to the data to send
174 * @size: length in bytes of the data to send
175 * @timeout: time in msecs to wait for the message to complete before timing
176 * out (if 0 the wait is forever)
177 * @memflags: the flags for memory allocation for buffers
178 *
179 * Context: !in_interrupt ()
180 *
181 * This function sends a control message to a specified endpoint that is not
182 * expected to fill in a response (i.e. a "send message") and waits for the
183 * message to complete, or timeout.
184 *
185 * Do not use this function from within an interrupt context. If you need
186 * an asynchronous message, or need to send a message from within interrupt
187 * context, use usb_submit_urb(). If a thread in your driver uses this call,
188 * make sure your disconnect() method can wait for it to complete. Since you
189 * don't have a handle on the URB used, you can't cancel the request.
190 *
191 * The data pointer can be made to a reference on the stack, or anywhere else,
192 * as it will not be modified at all. This does not have the restriction that
193 * usb_control_msg() has where the data pointer must be to dynamically allocated
194 * memory (i.e. memory that can be successfully DMAed to a device).
195 *
196 * Return: If successful, 0 is returned, Otherwise, a negative error number.
197 */
198int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
199 __u8 requesttype, __u16 value, __u16 index,
200 const void *driver_data, __u16 size, int timeout,
201 gfp_t memflags)
202{
203 unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
204 int ret;
205 u8 *data = NULL;
206
207 if (size) {
208 data = kmemdup(driver_data, size, memflags);
209 if (!data)
210 return -ENOMEM;
211 }
212
213 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
214 data, size, timeout);
215 kfree(data);
216
217 if (ret < 0)
218 return ret;
219
220 return 0;
221}
222EXPORT_SYMBOL_GPL(usb_control_msg_send);
223
224/**
225 * usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
226 * @dev: pointer to the usb device to send the message to
227 * @endpoint: endpoint to send the message to
228 * @request: USB message request value
229 * @requesttype: USB message request type value
230 * @value: USB message value
231 * @index: USB message index value
232 * @driver_data: pointer to the data to be filled in by the message
233 * @size: length in bytes of the data to be received
234 * @timeout: time in msecs to wait for the message to complete before timing
235 * out (if 0 the wait is forever)
236 * @memflags: the flags for memory allocation for buffers
237 *
238 * Context: !in_interrupt ()
239 *
240 * This function sends a control message to a specified endpoint that is
241 * expected to fill in a response (i.e. a "receive message") and waits for the
242 * message to complete, or timeout.
243 *
244 * Do not use this function from within an interrupt context. If you need
245 * an asynchronous message, or need to send a message from within interrupt
246 * context, use usb_submit_urb(). If a thread in your driver uses this call,
247 * make sure your disconnect() method can wait for it to complete. Since you
248 * don't have a handle on the URB used, you can't cancel the request.
249 *
250 * The data pointer can be made to a reference on the stack, or anywhere else
251 * that can be successfully written to. This function does not have the
252 * restriction that usb_control_msg() has where the data pointer must be to
253 * dynamically allocated memory (i.e. memory that can be successfully DMAed to a
254 * device).
255 *
256 * The "whole" message must be properly received from the device in order for
257 * this function to be successful. If a device returns less than the expected
258 * amount of data, then the function will fail. Do not use this for messages
259 * where a variable amount of data might be returned.
260 *
261 * Return: If successful, 0 is returned, Otherwise, a negative error number.
262 */
263int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
264 __u8 requesttype, __u16 value, __u16 index,
265 void *driver_data, __u16 size, int timeout,
266 gfp_t memflags)
267{
268 unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
269 int ret;
270 u8 *data;
271
272 if (!size || !driver_data)
273 return -EINVAL;
274
275 data = kmalloc(size, memflags);
276 if (!data)
277 return -ENOMEM;
278
279 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
280 data, size, timeout);
281
282 if (ret < 0)
283 goto exit;
284
285 if (ret == size) {
286 memcpy(driver_data, data, size);
287 ret = 0;
288 } else {
289 ret = -EREMOTEIO;
290 }
291
292exit:
293 kfree(data);
294 return ret;
295}
296EXPORT_SYMBOL_GPL(usb_control_msg_recv);
297
298/**
299 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
300 * @usb_dev: pointer to the usb device to send the message to
301 * @pipe: endpoint "pipe" to send the message to
302 * @data: pointer to the data to send
303 * @len: length in bytes of the data to send
304 * @actual_length: pointer to a location to put the actual length transferred
305 * in bytes
306 * @timeout: time in msecs to wait for the message to complete before
307 * timing out (if 0 the wait is forever)
308 *
309 * Context: task context, might sleep.
310 *
311 * This function sends a simple interrupt message to a specified endpoint and
312 * waits for the message to complete, or timeout.
313 *
314 * Don't use this function from within an interrupt context. If you need
315 * an asynchronous message, or need to send a message from within interrupt
316 * context, use usb_submit_urb() If a thread in your driver uses this call,
317 * make sure your disconnect() method can wait for it to complete. Since you
318 * don't have a handle on the URB used, you can't cancel the request.
319 *
320 * Return:
321 * If successful, 0. Otherwise a negative error number. The number of actual
322 * bytes transferred will be stored in the @actual_length parameter.
323 */
324int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
325 void *data, int len, int *actual_length, int timeout)
326{
327 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
328}
329EXPORT_SYMBOL_GPL(usb_interrupt_msg);
330
331/**
332 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
333 * @usb_dev: pointer to the usb device to send the message to
334 * @pipe: endpoint "pipe" to send the message to
335 * @data: pointer to the data to send
336 * @len: length in bytes of the data to send
337 * @actual_length: pointer to a location to put the actual length transferred
338 * in bytes
339 * @timeout: time in msecs to wait for the message to complete before
340 * timing out (if 0 the wait is forever)
341 *
342 * Context: task context, might sleep.
343 *
344 * This function sends a simple bulk message to a specified endpoint
345 * and waits for the message to complete, or timeout.
346 *
347 * Don't use this function from within an interrupt context. If you need
348 * an asynchronous message, or need to send a message from within interrupt
349 * context, use usb_submit_urb() If a thread in your driver uses this call,
350 * make sure your disconnect() method can wait for it to complete. Since you
351 * don't have a handle on the URB used, you can't cancel the request.
352 *
353 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
354 * users are forced to abuse this routine by using it to submit URBs for
355 * interrupt endpoints. We will take the liberty of creating an interrupt URB
356 * (with the default interval) if the target is an interrupt endpoint.
357 *
358 * Return:
359 * If successful, 0. Otherwise a negative error number. The number of actual
360 * bytes transferred will be stored in the @actual_length parameter.
361 *
362 */
363int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
364 void *data, int len, int *actual_length, int timeout)
365{
366 struct urb *urb;
367 struct usb_host_endpoint *ep;
368
369 ep = usb_pipe_endpoint(usb_dev, pipe);
370 if (!ep || len < 0)
371 return -EINVAL;
372
373 urb = usb_alloc_urb(0, GFP_KERNEL);
374 if (!urb)
375 return -ENOMEM;
376
377 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
378 USB_ENDPOINT_XFER_INT) {
379 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
380 usb_fill_int_urb(urb, usb_dev, pipe, data, len,
381 usb_api_blocking_completion, NULL,
382 ep->desc.bInterval);
383 } else
384 usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
385 usb_api_blocking_completion, NULL);
386
387 return usb_start_wait_urb(urb, timeout, actual_length);
388}
389EXPORT_SYMBOL_GPL(usb_bulk_msg);
390
391/*-------------------------------------------------------------------*/
392
393static void sg_clean(struct usb_sg_request *io)
394{
395 if (io->urbs) {
396 while (io->entries--)
397 usb_free_urb(io->urbs[io->entries]);
398 kfree(io->urbs);
399 io->urbs = NULL;
400 }
401 io->dev = NULL;
402}
403
404static void sg_complete(struct urb *urb)
405{
406 unsigned long flags;
407 struct usb_sg_request *io = urb->context;
408 int status = urb->status;
409
410 spin_lock_irqsave(&io->lock, flags);
411
412 /* In 2.5 we require hcds' endpoint queues not to progress after fault
413 * reports, until the completion callback (this!) returns. That lets
414 * device driver code (like this routine) unlink queued urbs first,
415 * if it needs to, since the HC won't work on them at all. So it's
416 * not possible for page N+1 to overwrite page N, and so on.
417 *
418 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
419 * complete before the HCD can get requests away from hardware,
420 * though never during cleanup after a hard fault.
421 */
422 if (io->status
423 && (io->status != -ECONNRESET
424 || status != -ECONNRESET)
425 && urb->actual_length) {
426 dev_err(io->dev->bus->controller,
427 "dev %s ep%d%s scatterlist error %d/%d\n",
428 io->dev->devpath,
429 usb_endpoint_num(&urb->ep->desc),
430 usb_urb_dir_in(urb) ? "in" : "out",
431 status, io->status);
432 /* BUG (); */
433 }
434
435 if (io->status == 0 && status && status != -ECONNRESET) {
436 int i, found, retval;
437
438 io->status = status;
439
440 /* the previous urbs, and this one, completed already.
441 * unlink pending urbs so they won't rx/tx bad data.
442 * careful: unlink can sometimes be synchronous...
443 */
444 spin_unlock_irqrestore(&io->lock, flags);
445 for (i = 0, found = 0; i < io->entries; i++) {
446 if (!io->urbs[i])
447 continue;
448 if (found) {
449 usb_block_urb(io->urbs[i]);
450 retval = usb_unlink_urb(io->urbs[i]);
451 if (retval != -EINPROGRESS &&
452 retval != -ENODEV &&
453 retval != -EBUSY &&
454 retval != -EIDRM)
455 dev_err(&io->dev->dev,
456 "%s, unlink --> %d\n",
457 __func__, retval);
458 } else if (urb == io->urbs[i])
459 found = 1;
460 }
461 spin_lock_irqsave(&io->lock, flags);
462 }
463
464 /* on the last completion, signal usb_sg_wait() */
465 io->bytes += urb->actual_length;
466 io->count--;
467 if (!io->count)
468 complete(&io->complete);
469
470 spin_unlock_irqrestore(&io->lock, flags);
471}
472
473
474/**
475 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
476 * @io: request block being initialized. until usb_sg_wait() returns,
477 * treat this as a pointer to an opaque block of memory,
478 * @dev: the usb device that will send or receive the data
479 * @pipe: endpoint "pipe" used to transfer the data
480 * @period: polling rate for interrupt endpoints, in frames or
481 * (for high speed endpoints) microframes; ignored for bulk
482 * @sg: scatterlist entries
483 * @nents: how many entries in the scatterlist
484 * @length: how many bytes to send from the scatterlist, or zero to
485 * send every byte identified in the list.
486 * @mem_flags: SLAB_* flags affecting memory allocations in this call
487 *
488 * This initializes a scatter/gather request, allocating resources such as
489 * I/O mappings and urb memory (except maybe memory used by USB controller
490 * drivers).
491 *
492 * The request must be issued using usb_sg_wait(), which waits for the I/O to
493 * complete (or to be canceled) and then cleans up all resources allocated by
494 * usb_sg_init().
495 *
496 * The request may be canceled with usb_sg_cancel(), either before or after
497 * usb_sg_wait() is called.
498 *
499 * Return: Zero for success, else a negative errno value.
500 */
501int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
502 unsigned pipe, unsigned period, struct scatterlist *sg,
503 int nents, size_t length, gfp_t mem_flags)
504{
505 int i;
506 int urb_flags;
507 int use_sg;
508
509 if (!io || !dev || !sg
510 || usb_pipecontrol(pipe)
511 || usb_pipeisoc(pipe)
512 || nents <= 0)
513 return -EINVAL;
514
515 spin_lock_init(&io->lock);
516 io->dev = dev;
517 io->pipe = pipe;
518
519 if (dev->bus->sg_tablesize > 0) {
520 use_sg = true;
521 io->entries = 1;
522 } else {
523 use_sg = false;
524 io->entries = nents;
525 }
526
527 /* initialize all the urbs we'll use */
528 io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
529 if (!io->urbs)
530 goto nomem;
531
532 urb_flags = URB_NO_INTERRUPT;
533 if (usb_pipein(pipe))
534 urb_flags |= URB_SHORT_NOT_OK;
535
536 for_each_sg(sg, sg, io->entries, i) {
537 struct urb *urb;
538 unsigned len;
539
540 urb = usb_alloc_urb(0, mem_flags);
541 if (!urb) {
542 io->entries = i;
543 goto nomem;
544 }
545 io->urbs[i] = urb;
546
547 urb->dev = NULL;
548 urb->pipe = pipe;
549 urb->interval = period;
550 urb->transfer_flags = urb_flags;
551 urb->complete = sg_complete;
552 urb->context = io;
553 urb->sg = sg;
554
555 if (use_sg) {
556 /* There is no single transfer buffer */
557 urb->transfer_buffer = NULL;
558 urb->num_sgs = nents;
559
560 /* A length of zero means transfer the whole sg list */
561 len = length;
562 if (len == 0) {
563 struct scatterlist *sg2;
564 int j;
565
566 for_each_sg(sg, sg2, nents, j)
567 len += sg2->length;
568 }
569 } else {
570 /*
571 * Some systems can't use DMA; they use PIO instead.
572 * For their sakes, transfer_buffer is set whenever
573 * possible.
574 */
575 if (!PageHighMem(sg_page(sg)))
576 urb->transfer_buffer = sg_virt(sg);
577 else
578 urb->transfer_buffer = NULL;
579
580 len = sg->length;
581 if (length) {
582 len = min_t(size_t, len, length);
583 length -= len;
584 if (length == 0)
585 io->entries = i + 1;
586 }
587 }
588 urb->transfer_buffer_length = len;
589 }
590 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
591
592 /* transaction state */
593 io->count = io->entries;
594 io->status = 0;
595 io->bytes = 0;
596 init_completion(&io->complete);
597 return 0;
598
599nomem:
600 sg_clean(io);
601 return -ENOMEM;
602}
603EXPORT_SYMBOL_GPL(usb_sg_init);
604
605/**
606 * usb_sg_wait - synchronously execute scatter/gather request
607 * @io: request block handle, as initialized with usb_sg_init().
608 * some fields become accessible when this call returns.
609 *
610 * Context: task context, might sleep.
611 *
612 * This function blocks until the specified I/O operation completes. It
613 * leverages the grouping of the related I/O requests to get good transfer
614 * rates, by queueing the requests. At higher speeds, such queuing can
615 * significantly improve USB throughput.
616 *
617 * There are three kinds of completion for this function.
618 *
619 * (1) success, where io->status is zero. The number of io->bytes
620 * transferred is as requested.
621 * (2) error, where io->status is a negative errno value. The number
622 * of io->bytes transferred before the error is usually less
623 * than requested, and can be nonzero.
624 * (3) cancellation, a type of error with status -ECONNRESET that
625 * is initiated by usb_sg_cancel().
626 *
627 * When this function returns, all memory allocated through usb_sg_init() or
628 * this call will have been freed. The request block parameter may still be
629 * passed to usb_sg_cancel(), or it may be freed. It could also be
630 * reinitialized and then reused.
631 *
632 * Data Transfer Rates:
633 *
634 * Bulk transfers are valid for full or high speed endpoints.
635 * The best full speed data rate is 19 packets of 64 bytes each
636 * per frame, or 1216 bytes per millisecond.
637 * The best high speed data rate is 13 packets of 512 bytes each
638 * per microframe, or 52 KBytes per millisecond.
639 *
640 * The reason to use interrupt transfers through this API would most likely
641 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
642 * could be transferred. That capability is less useful for low or full
643 * speed interrupt endpoints, which allow at most one packet per millisecond,
644 * of at most 8 or 64 bytes (respectively).
645 *
646 * It is not necessary to call this function to reserve bandwidth for devices
647 * under an xHCI host controller, as the bandwidth is reserved when the
648 * configuration or interface alt setting is selected.
649 */
650void usb_sg_wait(struct usb_sg_request *io)
651{
652 int i;
653 int entries = io->entries;
654
655 /* queue the urbs. */
656 spin_lock_irq(&io->lock);
657 i = 0;
658 while (i < entries && !io->status) {
659 int retval;
660
661 io->urbs[i]->dev = io->dev;
662 spin_unlock_irq(&io->lock);
663
664 retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
665
666 switch (retval) {
667 /* maybe we retrying will recover */
668 case -ENXIO: /* hc didn't queue this one */
669 case -EAGAIN:
670 case -ENOMEM:
671 retval = 0;
672 yield();
673 break;
674
675 /* no error? continue immediately.
676 *
677 * NOTE: to work better with UHCI (4K I/O buffer may
678 * need 3K of TDs) it may be good to limit how many
679 * URBs are queued at once; N milliseconds?
680 */
681 case 0:
682 ++i;
683 cpu_relax();
684 break;
685
686 /* fail any uncompleted urbs */
687 default:
688 io->urbs[i]->status = retval;
689 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
690 __func__, retval);
691 usb_sg_cancel(io);
692 }
693 spin_lock_irq(&io->lock);
694 if (retval && (io->status == 0 || io->status == -ECONNRESET))
695 io->status = retval;
696 }
697 io->count -= entries - i;
698 if (io->count == 0)
699 complete(&io->complete);
700 spin_unlock_irq(&io->lock);
701
702 /* OK, yes, this could be packaged as non-blocking.
703 * So could the submit loop above ... but it's easier to
704 * solve neither problem than to solve both!
705 */
706 wait_for_completion(&io->complete);
707
708 sg_clean(io);
709}
710EXPORT_SYMBOL_GPL(usb_sg_wait);
711
712/**
713 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
714 * @io: request block, initialized with usb_sg_init()
715 *
716 * This stops a request after it has been started by usb_sg_wait().
717 * It can also prevents one initialized by usb_sg_init() from starting,
718 * so that call just frees resources allocated to the request.
719 */
720void usb_sg_cancel(struct usb_sg_request *io)
721{
722 unsigned long flags;
723 int i, retval;
724
725 spin_lock_irqsave(&io->lock, flags);
726 if (io->status || io->count == 0) {
727 spin_unlock_irqrestore(&io->lock, flags);
728 return;
729 }
730 /* shut everything down */
731 io->status = -ECONNRESET;
732 io->count++; /* Keep the request alive until we're done */
733 spin_unlock_irqrestore(&io->lock, flags);
734
735 for (i = io->entries - 1; i >= 0; --i) {
736 usb_block_urb(io->urbs[i]);
737
738 retval = usb_unlink_urb(io->urbs[i]);
739 if (retval != -EINPROGRESS
740 && retval != -ENODEV
741 && retval != -EBUSY
742 && retval != -EIDRM)
743 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
744 __func__, retval);
745 }
746
747 spin_lock_irqsave(&io->lock, flags);
748 io->count--;
749 if (!io->count)
750 complete(&io->complete);
751 spin_unlock_irqrestore(&io->lock, flags);
752}
753EXPORT_SYMBOL_GPL(usb_sg_cancel);
754
755/*-------------------------------------------------------------------*/
756
757/**
758 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
759 * @dev: the device whose descriptor is being retrieved
760 * @type: the descriptor type (USB_DT_*)
761 * @index: the number of the descriptor
762 * @buf: where to put the descriptor
763 * @size: how big is "buf"?
764 *
765 * Context: task context, might sleep.
766 *
767 * Gets a USB descriptor. Convenience functions exist to simplify
768 * getting some types of descriptors. Use
769 * usb_get_string() or usb_string() for USB_DT_STRING.
770 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
771 * are part of the device structure.
772 * In addition to a number of USB-standard descriptors, some
773 * devices also use class-specific or vendor-specific descriptors.
774 *
775 * This call is synchronous, and may not be used in an interrupt context.
776 *
777 * Return: The number of bytes received on success, or else the status code
778 * returned by the underlying usb_control_msg() call.
779 */
780int usb_get_descriptor(struct usb_device *dev, unsigned char type,
781 unsigned char index, void *buf, int size)
782{
783 int i;
784 int result;
785
786 if (size <= 0) /* No point in asking for no data */
787 return -EINVAL;
788
789 memset(buf, 0, size); /* Make sure we parse really received data */
790
791 for (i = 0; i < 3; ++i) {
792 /* retry on length 0 or error; some devices are flakey */
793 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
794 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
795 (type << 8) + index, 0, buf, size,
796 USB_CTRL_GET_TIMEOUT);
797 if (result <= 0 && result != -ETIMEDOUT)
798 continue;
799 if (result > 1 && ((u8 *)buf)[1] != type) {
800 result = -ENODATA;
801 continue;
802 }
803 break;
804 }
805 return result;
806}
807EXPORT_SYMBOL_GPL(usb_get_descriptor);
808
809/**
810 * usb_get_string - gets a string descriptor
811 * @dev: the device whose string descriptor is being retrieved
812 * @langid: code for language chosen (from string descriptor zero)
813 * @index: the number of the descriptor
814 * @buf: where to put the string
815 * @size: how big is "buf"?
816 *
817 * Context: task context, might sleep.
818 *
819 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
820 * in little-endian byte order).
821 * The usb_string() function will often be a convenient way to turn
822 * these strings into kernel-printable form.
823 *
824 * Strings may be referenced in device, configuration, interface, or other
825 * descriptors, and could also be used in vendor-specific ways.
826 *
827 * This call is synchronous, and may not be used in an interrupt context.
828 *
829 * Return: The number of bytes received on success, or else the status code
830 * returned by the underlying usb_control_msg() call.
831 */
832static int usb_get_string(struct usb_device *dev, unsigned short langid,
833 unsigned char index, void *buf, int size)
834{
835 int i;
836 int result;
837
838 if (size <= 0) /* No point in asking for no data */
839 return -EINVAL;
840
841 for (i = 0; i < 3; ++i) {
842 /* retry on length 0 or stall; some devices are flakey */
843 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
844 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
845 (USB_DT_STRING << 8) + index, langid, buf, size,
846 USB_CTRL_GET_TIMEOUT);
847 if (result == 0 || result == -EPIPE)
848 continue;
849 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
850 result = -ENODATA;
851 continue;
852 }
853 break;
854 }
855 return result;
856}
857
858static void usb_try_string_workarounds(unsigned char *buf, int *length)
859{
860 int newlength, oldlength = *length;
861
862 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
863 if (!isprint(buf[newlength]) || buf[newlength + 1])
864 break;
865
866 if (newlength > 2) {
867 buf[0] = newlength;
868 *length = newlength;
869 }
870}
871
872static int usb_string_sub(struct usb_device *dev, unsigned int langid,
873 unsigned int index, unsigned char *buf)
874{
875 int rc;
876
877 /* Try to read the string descriptor by asking for the maximum
878 * possible number of bytes */
879 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
880 rc = -EIO;
881 else
882 rc = usb_get_string(dev, langid, index, buf, 255);
883
884 /* If that failed try to read the descriptor length, then
885 * ask for just that many bytes */
886 if (rc < 2) {
887 rc = usb_get_string(dev, langid, index, buf, 2);
888 if (rc == 2)
889 rc = usb_get_string(dev, langid, index, buf, buf[0]);
890 }
891
892 if (rc >= 2) {
893 if (!buf[0] && !buf[1])
894 usb_try_string_workarounds(buf, &rc);
895
896 /* There might be extra junk at the end of the descriptor */
897 if (buf[0] < rc)
898 rc = buf[0];
899
900 rc = rc - (rc & 1); /* force a multiple of two */
901 }
902
903 if (rc < 2)
904 rc = (rc < 0 ? rc : -EINVAL);
905
906 return rc;
907}
908
909static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
910{
911 int err;
912
913 if (dev->have_langid)
914 return 0;
915
916 if (dev->string_langid < 0)
917 return -EPIPE;
918
919 err = usb_string_sub(dev, 0, 0, tbuf);
920
921 /* If the string was reported but is malformed, default to english
922 * (0x0409) */
923 if (err == -ENODATA || (err > 0 && err < 4)) {
924 dev->string_langid = 0x0409;
925 dev->have_langid = 1;
926 dev_err(&dev->dev,
927 "language id specifier not provided by device, defaulting to English\n");
928 return 0;
929 }
930
931 /* In case of all other errors, we assume the device is not able to
932 * deal with strings at all. Set string_langid to -1 in order to
933 * prevent any string to be retrieved from the device */
934 if (err < 0) {
935 dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
936 err);
937 dev->string_langid = -1;
938 return -EPIPE;
939 }
940
941 /* always use the first langid listed */
942 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
943 dev->have_langid = 1;
944 dev_dbg(&dev->dev, "default language 0x%04x\n",
945 dev->string_langid);
946 return 0;
947}
948
949/**
950 * usb_string - returns UTF-8 version of a string descriptor
951 * @dev: the device whose string descriptor is being retrieved
952 * @index: the number of the descriptor
953 * @buf: where to put the string
954 * @size: how big is "buf"?
955 *
956 * Context: task context, might sleep.
957 *
958 * This converts the UTF-16LE encoded strings returned by devices, from
959 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
960 * that are more usable in most kernel contexts. Note that this function
961 * chooses strings in the first language supported by the device.
962 *
963 * This call is synchronous, and may not be used in an interrupt context.
964 *
965 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
966 */
967int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
968{
969 unsigned char *tbuf;
970 int err;
971
972 if (dev->state == USB_STATE_SUSPENDED)
973 return -EHOSTUNREACH;
974 if (size <= 0 || !buf)
975 return -EINVAL;
976 buf[0] = 0;
977 if (index <= 0 || index >= 256)
978 return -EINVAL;
979 tbuf = kmalloc(256, GFP_NOIO);
980 if (!tbuf)
981 return -ENOMEM;
982
983 err = usb_get_langid(dev, tbuf);
984 if (err < 0)
985 goto errout;
986
987 err = usb_string_sub(dev, dev->string_langid, index, tbuf);
988 if (err < 0)
989 goto errout;
990
991 size--; /* leave room for trailing NULL char in output buffer */
992 err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
993 UTF16_LITTLE_ENDIAN, buf, size);
994 buf[err] = 0;
995
996 if (tbuf[1] != USB_DT_STRING)
997 dev_dbg(&dev->dev,
998 "wrong descriptor type %02x for string %d (\"%s\")\n",
999 tbuf[1], index, buf);
1000
1001 errout:
1002 kfree(tbuf);
1003 return err;
1004}
1005EXPORT_SYMBOL_GPL(usb_string);
1006
1007/* one UTF-8-encoded 16-bit character has at most three bytes */
1008#define MAX_USB_STRING_SIZE (127 * 3 + 1)
1009
1010/**
1011 * usb_cache_string - read a string descriptor and cache it for later use
1012 * @udev: the device whose string descriptor is being read
1013 * @index: the descriptor index
1014 *
1015 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1016 * or %NULL if the index is 0 or the string could not be read.
1017 */
1018char *usb_cache_string(struct usb_device *udev, int index)
1019{
1020 char *buf;
1021 char *smallbuf = NULL;
1022 int len;
1023
1024 if (index <= 0)
1025 return NULL;
1026
1027 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1028 if (buf) {
1029 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1030 if (len > 0) {
1031 smallbuf = kmalloc(++len, GFP_NOIO);
1032 if (!smallbuf)
1033 return buf;
1034 memcpy(smallbuf, buf, len);
1035 }
1036 kfree(buf);
1037 }
1038 return smallbuf;
1039}
1040EXPORT_SYMBOL_GPL(usb_cache_string);
1041
1042/*
1043 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
1044 * @dev: the device whose device descriptor is being updated
1045 * @size: how much of the descriptor to read
1046 *
1047 * Context: task context, might sleep.
1048 *
1049 * Updates the copy of the device descriptor stored in the device structure,
1050 * which dedicates space for this purpose.
1051 *
1052 * Not exported, only for use by the core. If drivers really want to read
1053 * the device descriptor directly, they can call usb_get_descriptor() with
1054 * type = USB_DT_DEVICE and index = 0.
1055 *
1056 * This call is synchronous, and may not be used in an interrupt context.
1057 *
1058 * Return: The number of bytes received on success, or else the status code
1059 * returned by the underlying usb_control_msg() call.
1060 */
1061int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
1062{
1063 struct usb_device_descriptor *desc;
1064 int ret;
1065
1066 if (size > sizeof(*desc))
1067 return -EINVAL;
1068 desc = kmalloc(sizeof(*desc), GFP_NOIO);
1069 if (!desc)
1070 return -ENOMEM;
1071
1072 ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
1073 if (ret >= 0)
1074 memcpy(&dev->descriptor, desc, size);
1075 kfree(desc);
1076 return ret;
1077}
1078
1079/*
1080 * usb_set_isoch_delay - informs the device of the packet transmit delay
1081 * @dev: the device whose delay is to be informed
1082 * Context: task context, might sleep
1083 *
1084 * Since this is an optional request, we don't bother if it fails.
1085 */
1086int usb_set_isoch_delay(struct usb_device *dev)
1087{
1088 /* skip hub devices */
1089 if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1090 return 0;
1091
1092 /* skip non-SS/non-SSP devices */
1093 if (dev->speed < USB_SPEED_SUPER)
1094 return 0;
1095
1096 return usb_control_msg_send(dev, 0,
1097 USB_REQ_SET_ISOCH_DELAY,
1098 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1099 dev->hub_delay, 0, NULL, 0,
1100 USB_CTRL_SET_TIMEOUT,
1101 GFP_NOIO);
1102}
1103
1104/**
1105 * usb_get_status - issues a GET_STATUS call
1106 * @dev: the device whose status is being checked
1107 * @recip: USB_RECIP_*; for device, interface, or endpoint
1108 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
1109 * @target: zero (for device), else interface or endpoint number
1110 * @data: pointer to two bytes of bitmap data
1111 *
1112 * Context: task context, might sleep.
1113 *
1114 * Returns device, interface, or endpoint status. Normally only of
1115 * interest to see if the device is self powered, or has enabled the
1116 * remote wakeup facility; or whether a bulk or interrupt endpoint
1117 * is halted ("stalled").
1118 *
1119 * Bits in these status bitmaps are set using the SET_FEATURE request,
1120 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
1121 * function should be used to clear halt ("stall") status.
1122 *
1123 * This call is synchronous, and may not be used in an interrupt context.
1124 *
1125 * Returns 0 and the status value in *@data (in host byte order) on success,
1126 * or else the status code from the underlying usb_control_msg() call.
1127 */
1128int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1129 void *data)
1130{
1131 int ret;
1132 void *status;
1133 int length;
1134
1135 switch (type) {
1136 case USB_STATUS_TYPE_STANDARD:
1137 length = 2;
1138 break;
1139 case USB_STATUS_TYPE_PTM:
1140 if (recip != USB_RECIP_DEVICE)
1141 return -EINVAL;
1142
1143 length = 4;
1144 break;
1145 default:
1146 return -EINVAL;
1147 }
1148
1149 status = kmalloc(length, GFP_KERNEL);
1150 if (!status)
1151 return -ENOMEM;
1152
1153 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1154 USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1155 target, status, length, USB_CTRL_GET_TIMEOUT);
1156
1157 switch (ret) {
1158 case 4:
1159 if (type != USB_STATUS_TYPE_PTM) {
1160 ret = -EIO;
1161 break;
1162 }
1163
1164 *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1165 ret = 0;
1166 break;
1167 case 2:
1168 if (type != USB_STATUS_TYPE_STANDARD) {
1169 ret = -EIO;
1170 break;
1171 }
1172
1173 *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1174 ret = 0;
1175 break;
1176 default:
1177 ret = -EIO;
1178 }
1179
1180 kfree(status);
1181 return ret;
1182}
1183EXPORT_SYMBOL_GPL(usb_get_status);
1184
1185/**
1186 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1187 * @dev: device whose endpoint is halted
1188 * @pipe: endpoint "pipe" being cleared
1189 *
1190 * Context: task context, might sleep.
1191 *
1192 * This is used to clear halt conditions for bulk and interrupt endpoints,
1193 * as reported by URB completion status. Endpoints that are halted are
1194 * sometimes referred to as being "stalled". Such endpoints are unable
1195 * to transmit or receive data until the halt status is cleared. Any URBs
1196 * queued for such an endpoint should normally be unlinked by the driver
1197 * before clearing the halt condition, as described in sections 5.7.5
1198 * and 5.8.5 of the USB 2.0 spec.
1199 *
1200 * Note that control and isochronous endpoints don't halt, although control
1201 * endpoints report "protocol stall" (for unsupported requests) using the
1202 * same status code used to report a true stall.
1203 *
1204 * This call is synchronous, and may not be used in an interrupt context.
1205 *
1206 * Return: Zero on success, or else the status code returned by the
1207 * underlying usb_control_msg() call.
1208 */
1209int usb_clear_halt(struct usb_device *dev, int pipe)
1210{
1211 int result;
1212 int endp = usb_pipeendpoint(pipe);
1213
1214 if (usb_pipein(pipe))
1215 endp |= USB_DIR_IN;
1216
1217 /* we don't care if it wasn't halted first. in fact some devices
1218 * (like some ibmcam model 1 units) seem to expect hosts to make
1219 * this request for iso endpoints, which can't halt!
1220 */
1221 result = usb_control_msg_send(dev, 0,
1222 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1223 USB_ENDPOINT_HALT, endp, NULL, 0,
1224 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1225
1226 /* don't un-halt or force to DATA0 except on success */
1227 if (result)
1228 return result;
1229
1230 /* NOTE: seems like Microsoft and Apple don't bother verifying
1231 * the clear "took", so some devices could lock up if you check...
1232 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1233 *
1234 * NOTE: make sure the logic here doesn't diverge much from
1235 * the copy in usb-storage, for as long as we need two copies.
1236 */
1237
1238 usb_reset_endpoint(dev, endp);
1239
1240 return 0;
1241}
1242EXPORT_SYMBOL_GPL(usb_clear_halt);
1243
1244static int create_intf_ep_devs(struct usb_interface *intf)
1245{
1246 struct usb_device *udev = interface_to_usbdev(intf);
1247 struct usb_host_interface *alt = intf->cur_altsetting;
1248 int i;
1249
1250 if (intf->ep_devs_created || intf->unregistering)
1251 return 0;
1252
1253 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1254 (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1255 intf->ep_devs_created = 1;
1256 return 0;
1257}
1258
1259static void remove_intf_ep_devs(struct usb_interface *intf)
1260{
1261 struct usb_host_interface *alt = intf->cur_altsetting;
1262 int i;
1263
1264 if (!intf->ep_devs_created)
1265 return;
1266
1267 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1268 usb_remove_ep_devs(&alt->endpoint[i]);
1269 intf->ep_devs_created = 0;
1270}
1271
1272/**
1273 * usb_disable_endpoint -- Disable an endpoint by address
1274 * @dev: the device whose endpoint is being disabled
1275 * @epaddr: the endpoint's address. Endpoint number for output,
1276 * endpoint number + USB_DIR_IN for input
1277 * @reset_hardware: flag to erase any endpoint state stored in the
1278 * controller hardware
1279 *
1280 * Disables the endpoint for URB submission and nukes all pending URBs.
1281 * If @reset_hardware is set then also deallocates hcd/hardware state
1282 * for the endpoint.
1283 */
1284void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1285 bool reset_hardware)
1286{
1287 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1288 struct usb_host_endpoint *ep;
1289
1290 if (!dev)
1291 return;
1292
1293 if (usb_endpoint_out(epaddr)) {
1294 ep = dev->ep_out[epnum];
1295 if (reset_hardware && epnum != 0)
1296 dev->ep_out[epnum] = NULL;
1297 } else {
1298 ep = dev->ep_in[epnum];
1299 if (reset_hardware && epnum != 0)
1300 dev->ep_in[epnum] = NULL;
1301 }
1302 if (ep) {
1303 ep->enabled = 0;
1304 usb_hcd_flush_endpoint(dev, ep);
1305 if (reset_hardware)
1306 usb_hcd_disable_endpoint(dev, ep);
1307 }
1308}
1309
1310/**
1311 * usb_reset_endpoint - Reset an endpoint's state.
1312 * @dev: the device whose endpoint is to be reset
1313 * @epaddr: the endpoint's address. Endpoint number for output,
1314 * endpoint number + USB_DIR_IN for input
1315 *
1316 * Resets any host-side endpoint state such as the toggle bit,
1317 * sequence number or current window.
1318 */
1319void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1320{
1321 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1322 struct usb_host_endpoint *ep;
1323
1324 if (usb_endpoint_out(epaddr))
1325 ep = dev->ep_out[epnum];
1326 else
1327 ep = dev->ep_in[epnum];
1328 if (ep)
1329 usb_hcd_reset_endpoint(dev, ep);
1330}
1331EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1332
1333
1334/**
1335 * usb_disable_interface -- Disable all endpoints for an interface
1336 * @dev: the device whose interface is being disabled
1337 * @intf: pointer to the interface descriptor
1338 * @reset_hardware: flag to erase any endpoint state stored in the
1339 * controller hardware
1340 *
1341 * Disables all the endpoints for the interface's current altsetting.
1342 */
1343void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1344 bool reset_hardware)
1345{
1346 struct usb_host_interface *alt = intf->cur_altsetting;
1347 int i;
1348
1349 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1350 usb_disable_endpoint(dev,
1351 alt->endpoint[i].desc.bEndpointAddress,
1352 reset_hardware);
1353 }
1354}
1355
1356/*
1357 * usb_disable_device_endpoints -- Disable all endpoints for a device
1358 * @dev: the device whose endpoints are being disabled
1359 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1360 */
1361static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1362{
1363 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1364 int i;
1365
1366 if (hcd->driver->check_bandwidth) {
1367 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1368 for (i = skip_ep0; i < 16; ++i) {
1369 usb_disable_endpoint(dev, i, false);
1370 usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1371 }
1372 /* Remove endpoints from the host controller internal state */
1373 mutex_lock(hcd->bandwidth_mutex);
1374 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1375 mutex_unlock(hcd->bandwidth_mutex);
1376 }
1377 /* Second pass: remove endpoint pointers */
1378 for (i = skip_ep0; i < 16; ++i) {
1379 usb_disable_endpoint(dev, i, true);
1380 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1381 }
1382}
1383
1384/**
1385 * usb_disable_device - Disable all the endpoints for a USB device
1386 * @dev: the device whose endpoints are being disabled
1387 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1388 *
1389 * Disables all the device's endpoints, potentially including endpoint 0.
1390 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1391 * pending urbs) and usbcore state for the interfaces, so that usbcore
1392 * must usb_set_configuration() before any interfaces could be used.
1393 */
1394void usb_disable_device(struct usb_device *dev, int skip_ep0)
1395{
1396 int i;
1397
1398 /* getting rid of interfaces will disconnect
1399 * any drivers bound to them (a key side effect)
1400 */
1401 if (dev->actconfig) {
1402 /*
1403 * FIXME: In order to avoid self-deadlock involving the
1404 * bandwidth_mutex, we have to mark all the interfaces
1405 * before unregistering any of them.
1406 */
1407 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1408 dev->actconfig->interface[i]->unregistering = 1;
1409
1410 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1411 struct usb_interface *interface;
1412
1413 /* remove this interface if it has been registered */
1414 interface = dev->actconfig->interface[i];
1415 if (!device_is_registered(&interface->dev))
1416 continue;
1417 dev_dbg(&dev->dev, "unregistering interface %s\n",
1418 dev_name(&interface->dev));
1419 remove_intf_ep_devs(interface);
1420 device_del(&interface->dev);
1421 }
1422
1423 /* Now that the interfaces are unbound, nobody should
1424 * try to access them.
1425 */
1426 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1427 put_device(&dev->actconfig->interface[i]->dev);
1428 dev->actconfig->interface[i] = NULL;
1429 }
1430
1431 usb_disable_usb2_hardware_lpm(dev);
1432 usb_unlocked_disable_lpm(dev);
1433 usb_disable_ltm(dev);
1434
1435 dev->actconfig = NULL;
1436 if (dev->state == USB_STATE_CONFIGURED)
1437 usb_set_device_state(dev, USB_STATE_ADDRESS);
1438 }
1439
1440 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1441 skip_ep0 ? "non-ep0" : "all");
1442
1443 usb_disable_device_endpoints(dev, skip_ep0);
1444}
1445
1446/**
1447 * usb_enable_endpoint - Enable an endpoint for USB communications
1448 * @dev: the device whose interface is being enabled
1449 * @ep: the endpoint
1450 * @reset_ep: flag to reset the endpoint state
1451 *
1452 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1453 * For control endpoints, both the input and output sides are handled.
1454 */
1455void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1456 bool reset_ep)
1457{
1458 int epnum = usb_endpoint_num(&ep->desc);
1459 int is_out = usb_endpoint_dir_out(&ep->desc);
1460 int is_control = usb_endpoint_xfer_control(&ep->desc);
1461
1462 if (reset_ep)
1463 usb_hcd_reset_endpoint(dev, ep);
1464 if (is_out || is_control)
1465 dev->ep_out[epnum] = ep;
1466 if (!is_out || is_control)
1467 dev->ep_in[epnum] = ep;
1468 ep->enabled = 1;
1469}
1470
1471/**
1472 * usb_enable_interface - Enable all the endpoints for an interface
1473 * @dev: the device whose interface is being enabled
1474 * @intf: pointer to the interface descriptor
1475 * @reset_eps: flag to reset the endpoints' state
1476 *
1477 * Enables all the endpoints for the interface's current altsetting.
1478 */
1479void usb_enable_interface(struct usb_device *dev,
1480 struct usb_interface *intf, bool reset_eps)
1481{
1482 struct usb_host_interface *alt = intf->cur_altsetting;
1483 int i;
1484
1485 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1486 usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1487}
1488
1489/**
1490 * usb_set_interface - Makes a particular alternate setting be current
1491 * @dev: the device whose interface is being updated
1492 * @interface: the interface being updated
1493 * @alternate: the setting being chosen.
1494 *
1495 * Context: task context, might sleep.
1496 *
1497 * This is used to enable data transfers on interfaces that may not
1498 * be enabled by default. Not all devices support such configurability.
1499 * Only the driver bound to an interface may change its setting.
1500 *
1501 * Within any given configuration, each interface may have several
1502 * alternative settings. These are often used to control levels of
1503 * bandwidth consumption. For example, the default setting for a high
1504 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1505 * while interrupt transfers of up to 3KBytes per microframe are legal.
1506 * Also, isochronous endpoints may never be part of an
1507 * interface's default setting. To access such bandwidth, alternate
1508 * interface settings must be made current.
1509 *
1510 * Note that in the Linux USB subsystem, bandwidth associated with
1511 * an endpoint in a given alternate setting is not reserved until an URB
1512 * is submitted that needs that bandwidth. Some other operating systems
1513 * allocate bandwidth early, when a configuration is chosen.
1514 *
1515 * xHCI reserves bandwidth and configures the alternate setting in
1516 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1517 * may be disabled. Drivers cannot rely on any particular alternate
1518 * setting being in effect after a failure.
1519 *
1520 * This call is synchronous, and may not be used in an interrupt context.
1521 * Also, drivers must not change altsettings while urbs are scheduled for
1522 * endpoints in that interface; all such urbs must first be completed
1523 * (perhaps forced by unlinking).
1524 *
1525 * Return: Zero on success, or else the status code returned by the
1526 * underlying usb_control_msg() call.
1527 */
1528int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1529{
1530 struct usb_interface *iface;
1531 struct usb_host_interface *alt;
1532 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1533 int i, ret, manual = 0;
1534 unsigned int epaddr;
1535 unsigned int pipe;
1536
1537 if (dev->state == USB_STATE_SUSPENDED)
1538 return -EHOSTUNREACH;
1539
1540 iface = usb_ifnum_to_if(dev, interface);
1541 if (!iface) {
1542 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1543 interface);
1544 return -EINVAL;
1545 }
1546 if (iface->unregistering)
1547 return -ENODEV;
1548
1549 alt = usb_altnum_to_altsetting(iface, alternate);
1550 if (!alt) {
1551 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1552 alternate);
1553 return -EINVAL;
1554 }
1555 /*
1556 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1557 * including freeing dropped endpoint ring buffers.
1558 * Make sure the interface endpoints are flushed before that
1559 */
1560 usb_disable_interface(dev, iface, false);
1561
1562 /* Make sure we have enough bandwidth for this alternate interface.
1563 * Remove the current alt setting and add the new alt setting.
1564 */
1565 mutex_lock(hcd->bandwidth_mutex);
1566 /* Disable LPM, and re-enable it once the new alt setting is installed,
1567 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1568 */
1569 if (usb_disable_lpm(dev)) {
1570 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1571 mutex_unlock(hcd->bandwidth_mutex);
1572 return -ENOMEM;
1573 }
1574 /* Changing alt-setting also frees any allocated streams */
1575 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1576 iface->cur_altsetting->endpoint[i].streams = 0;
1577
1578 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1579 if (ret < 0) {
1580 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1581 alternate);
1582 usb_enable_lpm(dev);
1583 mutex_unlock(hcd->bandwidth_mutex);
1584 return ret;
1585 }
1586
1587 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1588 ret = -EPIPE;
1589 else
1590 ret = usb_control_msg_send(dev, 0,
1591 USB_REQ_SET_INTERFACE,
1592 USB_RECIP_INTERFACE, alternate,
1593 interface, NULL, 0, 5000,
1594 GFP_NOIO);
1595
1596 /* 9.4.10 says devices don't need this and are free to STALL the
1597 * request if the interface only has one alternate setting.
1598 */
1599 if (ret == -EPIPE && iface->num_altsetting == 1) {
1600 dev_dbg(&dev->dev,
1601 "manual set_interface for iface %d, alt %d\n",
1602 interface, alternate);
1603 manual = 1;
1604 } else if (ret) {
1605 /* Re-instate the old alt setting */
1606 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1607 usb_enable_lpm(dev);
1608 mutex_unlock(hcd->bandwidth_mutex);
1609 return ret;
1610 }
1611 mutex_unlock(hcd->bandwidth_mutex);
1612
1613 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1614 * when they implement async or easily-killable versions of this or
1615 * other "should-be-internal" functions (like clear_halt).
1616 * should hcd+usbcore postprocess control requests?
1617 */
1618
1619 /* prevent submissions using previous endpoint settings */
1620 if (iface->cur_altsetting != alt) {
1621 remove_intf_ep_devs(iface);
1622 usb_remove_sysfs_intf_files(iface);
1623 }
1624 usb_disable_interface(dev, iface, true);
1625
1626 iface->cur_altsetting = alt;
1627
1628 /* Now that the interface is installed, re-enable LPM. */
1629 usb_unlocked_enable_lpm(dev);
1630
1631 /* If the interface only has one altsetting and the device didn't
1632 * accept the request, we attempt to carry out the equivalent action
1633 * by manually clearing the HALT feature for each endpoint in the
1634 * new altsetting.
1635 */
1636 if (manual) {
1637 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1638 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1639 pipe = __create_pipe(dev,
1640 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1641 (usb_endpoint_out(epaddr) ?
1642 USB_DIR_OUT : USB_DIR_IN);
1643
1644 usb_clear_halt(dev, pipe);
1645 }
1646 }
1647
1648 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1649 *
1650 * Note:
1651 * Despite EP0 is always present in all interfaces/AS, the list of
1652 * endpoints from the descriptor does not contain EP0. Due to its
1653 * omnipresence one might expect EP0 being considered "affected" by
1654 * any SetInterface request and hence assume toggles need to be reset.
1655 * However, EP0 toggles are re-synced for every individual transfer
1656 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1657 * (Likewise, EP0 never "halts" on well designed devices.)
1658 */
1659 usb_enable_interface(dev, iface, true);
1660 if (device_is_registered(&iface->dev)) {
1661 usb_create_sysfs_intf_files(iface);
1662 create_intf_ep_devs(iface);
1663 }
1664 return 0;
1665}
1666EXPORT_SYMBOL_GPL(usb_set_interface);
1667
1668/**
1669 * usb_reset_configuration - lightweight device reset
1670 * @dev: the device whose configuration is being reset
1671 *
1672 * This issues a standard SET_CONFIGURATION request to the device using
1673 * the current configuration. The effect is to reset most USB-related
1674 * state in the device, including interface altsettings (reset to zero),
1675 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1676 * endpoints). Other usbcore state is unchanged, including bindings of
1677 * usb device drivers to interfaces.
1678 *
1679 * Because this affects multiple interfaces, avoid using this with composite
1680 * (multi-interface) devices. Instead, the driver for each interface may
1681 * use usb_set_interface() on the interfaces it claims. Be careful though;
1682 * some devices don't support the SET_INTERFACE request, and others won't
1683 * reset all the interface state (notably endpoint state). Resetting the whole
1684 * configuration would affect other drivers' interfaces.
1685 *
1686 * The caller must own the device lock.
1687 *
1688 * Return: Zero on success, else a negative error code.
1689 *
1690 * If this routine fails the device will probably be in an unusable state
1691 * with endpoints disabled, and interfaces only partially enabled.
1692 */
1693int usb_reset_configuration(struct usb_device *dev)
1694{
1695 int i, retval;
1696 struct usb_host_config *config;
1697 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1698
1699 if (dev->state == USB_STATE_SUSPENDED)
1700 return -EHOSTUNREACH;
1701
1702 /* caller must have locked the device and must own
1703 * the usb bus readlock (so driver bindings are stable);
1704 * calls during probe() are fine
1705 */
1706
1707 usb_disable_device_endpoints(dev, 1); /* skip ep0*/
1708
1709 config = dev->actconfig;
1710 retval = 0;
1711 mutex_lock(hcd->bandwidth_mutex);
1712 /* Disable LPM, and re-enable it once the configuration is reset, so
1713 * that the xHCI driver can recalculate the U1/U2 timeouts.
1714 */
1715 if (usb_disable_lpm(dev)) {
1716 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1717 mutex_unlock(hcd->bandwidth_mutex);
1718 return -ENOMEM;
1719 }
1720
1721 /* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1722 retval = usb_hcd_alloc_bandwidth(dev, config, NULL, NULL);
1723 if (retval < 0) {
1724 usb_enable_lpm(dev);
1725 mutex_unlock(hcd->bandwidth_mutex);
1726 return retval;
1727 }
1728 retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1729 config->desc.bConfigurationValue, 0,
1730 NULL, 0, USB_CTRL_SET_TIMEOUT,
1731 GFP_NOIO);
1732 if (retval) {
1733 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1734 usb_enable_lpm(dev);
1735 mutex_unlock(hcd->bandwidth_mutex);
1736 return retval;
1737 }
1738 mutex_unlock(hcd->bandwidth_mutex);
1739
1740 /* re-init hc/hcd interface/endpoint state */
1741 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1742 struct usb_interface *intf = config->interface[i];
1743 struct usb_host_interface *alt;
1744
1745 alt = usb_altnum_to_altsetting(intf, 0);
1746
1747 /* No altsetting 0? We'll assume the first altsetting.
1748 * We could use a GetInterface call, but if a device is
1749 * so non-compliant that it doesn't have altsetting 0
1750 * then I wouldn't trust its reply anyway.
1751 */
1752 if (!alt)
1753 alt = &intf->altsetting[0];
1754
1755 if (alt != intf->cur_altsetting) {
1756 remove_intf_ep_devs(intf);
1757 usb_remove_sysfs_intf_files(intf);
1758 }
1759 intf->cur_altsetting = alt;
1760 usb_enable_interface(dev, intf, true);
1761 if (device_is_registered(&intf->dev)) {
1762 usb_create_sysfs_intf_files(intf);
1763 create_intf_ep_devs(intf);
1764 }
1765 }
1766 /* Now that the interfaces are installed, re-enable LPM. */
1767 usb_unlocked_enable_lpm(dev);
1768 return 0;
1769}
1770EXPORT_SYMBOL_GPL(usb_reset_configuration);
1771
1772static void usb_release_interface(struct device *dev)
1773{
1774 struct usb_interface *intf = to_usb_interface(dev);
1775 struct usb_interface_cache *intfc =
1776 altsetting_to_usb_interface_cache(intf->altsetting);
1777
1778 kref_put(&intfc->ref, usb_release_interface_cache);
1779 usb_put_dev(interface_to_usbdev(intf));
1780 of_node_put(dev->of_node);
1781 kfree(intf);
1782}
1783
1784/*
1785 * usb_deauthorize_interface - deauthorize an USB interface
1786 *
1787 * @intf: USB interface structure
1788 */
1789void usb_deauthorize_interface(struct usb_interface *intf)
1790{
1791 struct device *dev = &intf->dev;
1792
1793 device_lock(dev->parent);
1794
1795 if (intf->authorized) {
1796 device_lock(dev);
1797 intf->authorized = 0;
1798 device_unlock(dev);
1799
1800 usb_forced_unbind_intf(intf);
1801 }
1802
1803 device_unlock(dev->parent);
1804}
1805
1806/*
1807 * usb_authorize_interface - authorize an USB interface
1808 *
1809 * @intf: USB interface structure
1810 */
1811void usb_authorize_interface(struct usb_interface *intf)
1812{
1813 struct device *dev = &intf->dev;
1814
1815 if (!intf->authorized) {
1816 device_lock(dev);
1817 intf->authorized = 1; /* authorize interface */
1818 device_unlock(dev);
1819 }
1820}
1821
1822static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1823{
1824 struct usb_device *usb_dev;
1825 struct usb_interface *intf;
1826 struct usb_host_interface *alt;
1827
1828 intf = to_usb_interface(dev);
1829 usb_dev = interface_to_usbdev(intf);
1830 alt = intf->cur_altsetting;
1831
1832 if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1833 alt->desc.bInterfaceClass,
1834 alt->desc.bInterfaceSubClass,
1835 alt->desc.bInterfaceProtocol))
1836 return -ENOMEM;
1837
1838 if (add_uevent_var(env,
1839 "MODALIAS=usb:"
1840 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1841 le16_to_cpu(usb_dev->descriptor.idVendor),
1842 le16_to_cpu(usb_dev->descriptor.idProduct),
1843 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1844 usb_dev->descriptor.bDeviceClass,
1845 usb_dev->descriptor.bDeviceSubClass,
1846 usb_dev->descriptor.bDeviceProtocol,
1847 alt->desc.bInterfaceClass,
1848 alt->desc.bInterfaceSubClass,
1849 alt->desc.bInterfaceProtocol,
1850 alt->desc.bInterfaceNumber))
1851 return -ENOMEM;
1852
1853 return 0;
1854}
1855
1856struct device_type usb_if_device_type = {
1857 .name = "usb_interface",
1858 .release = usb_release_interface,
1859 .uevent = usb_if_uevent,
1860};
1861
1862static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1863 struct usb_host_config *config,
1864 u8 inum)
1865{
1866 struct usb_interface_assoc_descriptor *retval = NULL;
1867 struct usb_interface_assoc_descriptor *intf_assoc;
1868 int first_intf;
1869 int last_intf;
1870 int i;
1871
1872 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1873 intf_assoc = config->intf_assoc[i];
1874 if (intf_assoc->bInterfaceCount == 0)
1875 continue;
1876
1877 first_intf = intf_assoc->bFirstInterface;
1878 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1879 if (inum >= first_intf && inum <= last_intf) {
1880 if (!retval)
1881 retval = intf_assoc;
1882 else
1883 dev_err(&dev->dev, "Interface #%d referenced"
1884 " by multiple IADs\n", inum);
1885 }
1886 }
1887
1888 return retval;
1889}
1890
1891
1892/*
1893 * Internal function to queue a device reset
1894 * See usb_queue_reset_device() for more details
1895 */
1896static void __usb_queue_reset_device(struct work_struct *ws)
1897{
1898 int rc;
1899 struct usb_interface *iface =
1900 container_of(ws, struct usb_interface, reset_ws);
1901 struct usb_device *udev = interface_to_usbdev(iface);
1902
1903 rc = usb_lock_device_for_reset(udev, iface);
1904 if (rc >= 0) {
1905 usb_reset_device(udev);
1906 usb_unlock_device(udev);
1907 }
1908 usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */
1909}
1910
1911
1912/*
1913 * usb_set_configuration - Makes a particular device setting be current
1914 * @dev: the device whose configuration is being updated
1915 * @configuration: the configuration being chosen.
1916 *
1917 * Context: task context, might sleep. Caller holds device lock.
1918 *
1919 * This is used to enable non-default device modes. Not all devices
1920 * use this kind of configurability; many devices only have one
1921 * configuration.
1922 *
1923 * @configuration is the value of the configuration to be installed.
1924 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1925 * must be non-zero; a value of zero indicates that the device in
1926 * unconfigured. However some devices erroneously use 0 as one of their
1927 * configuration values. To help manage such devices, this routine will
1928 * accept @configuration = -1 as indicating the device should be put in
1929 * an unconfigured state.
1930 *
1931 * USB device configurations may affect Linux interoperability,
1932 * power consumption and the functionality available. For example,
1933 * the default configuration is limited to using 100mA of bus power,
1934 * so that when certain device functionality requires more power,
1935 * and the device is bus powered, that functionality should be in some
1936 * non-default device configuration. Other device modes may also be
1937 * reflected as configuration options, such as whether two ISDN
1938 * channels are available independently; and choosing between open
1939 * standard device protocols (like CDC) or proprietary ones.
1940 *
1941 * Note that a non-authorized device (dev->authorized == 0) will only
1942 * be put in unconfigured mode.
1943 *
1944 * Note that USB has an additional level of device configurability,
1945 * associated with interfaces. That configurability is accessed using
1946 * usb_set_interface().
1947 *
1948 * This call is synchronous. The calling context must be able to sleep,
1949 * must own the device lock, and must not hold the driver model's USB
1950 * bus mutex; usb interface driver probe() methods cannot use this routine.
1951 *
1952 * Returns zero on success, or else the status code returned by the
1953 * underlying call that failed. On successful completion, each interface
1954 * in the original device configuration has been destroyed, and each one
1955 * in the new configuration has been probed by all relevant usb device
1956 * drivers currently known to the kernel.
1957 */
1958int usb_set_configuration(struct usb_device *dev, int configuration)
1959{
1960 int i, ret;
1961 struct usb_host_config *cp = NULL;
1962 struct usb_interface **new_interfaces = NULL;
1963 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1964 int n, nintf;
1965
1966 if (dev->authorized == 0 || configuration == -1)
1967 configuration = 0;
1968 else {
1969 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1970 if (dev->config[i].desc.bConfigurationValue ==
1971 configuration) {
1972 cp = &dev->config[i];
1973 break;
1974 }
1975 }
1976 }
1977 if ((!cp && configuration != 0))
1978 return -EINVAL;
1979
1980 /* The USB spec says configuration 0 means unconfigured.
1981 * But if a device includes a configuration numbered 0,
1982 * we will accept it as a correctly configured state.
1983 * Use -1 if you really want to unconfigure the device.
1984 */
1985 if (cp && configuration == 0)
1986 dev_warn(&dev->dev, "config 0 descriptor??\n");
1987
1988 /* Allocate memory for new interfaces before doing anything else,
1989 * so that if we run out then nothing will have changed. */
1990 n = nintf = 0;
1991 if (cp) {
1992 nintf = cp->desc.bNumInterfaces;
1993 new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
1994 GFP_NOIO);
1995 if (!new_interfaces)
1996 return -ENOMEM;
1997
1998 for (; n < nintf; ++n) {
1999 new_interfaces[n] = kzalloc(
2000 sizeof(struct usb_interface),
2001 GFP_NOIO);
2002 if (!new_interfaces[n]) {
2003 ret = -ENOMEM;
2004free_interfaces:
2005 while (--n >= 0)
2006 kfree(new_interfaces[n]);
2007 kfree(new_interfaces);
2008 return ret;
2009 }
2010 }
2011
2012 i = dev->bus_mA - usb_get_max_power(dev, cp);
2013 if (i < 0)
2014 dev_warn(&dev->dev, "new config #%d exceeds power "
2015 "limit by %dmA\n",
2016 configuration, -i);
2017 }
2018
2019 /* Wake up the device so we can send it the Set-Config request */
2020 ret = usb_autoresume_device(dev);
2021 if (ret)
2022 goto free_interfaces;
2023
2024 /* if it's already configured, clear out old state first.
2025 * getting rid of old interfaces means unbinding their drivers.
2026 */
2027 if (dev->state != USB_STATE_ADDRESS)
2028 usb_disable_device(dev, 1); /* Skip ep0 */
2029
2030 /* Get rid of pending async Set-Config requests for this device */
2031 cancel_async_set_config(dev);
2032
2033 /* Make sure we have bandwidth (and available HCD resources) for this
2034 * configuration. Remove endpoints from the schedule if we're dropping
2035 * this configuration to set configuration 0. After this point, the
2036 * host controller will not allow submissions to dropped endpoints. If
2037 * this call fails, the device state is unchanged.
2038 */
2039 mutex_lock(hcd->bandwidth_mutex);
2040 /* Disable LPM, and re-enable it once the new configuration is
2041 * installed, so that the xHCI driver can recalculate the U1/U2
2042 * timeouts.
2043 */
2044 if (dev->actconfig && usb_disable_lpm(dev)) {
2045 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2046 mutex_unlock(hcd->bandwidth_mutex);
2047 ret = -ENOMEM;
2048 goto free_interfaces;
2049 }
2050 ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
2051 if (ret < 0) {
2052 if (dev->actconfig)
2053 usb_enable_lpm(dev);
2054 mutex_unlock(hcd->bandwidth_mutex);
2055 usb_autosuspend_device(dev);
2056 goto free_interfaces;
2057 }
2058
2059 /*
2060 * Initialize the new interface structures and the
2061 * hc/hcd/usbcore interface/endpoint state.
2062 */
2063 for (i = 0; i < nintf; ++i) {
2064 struct usb_interface_cache *intfc;
2065 struct usb_interface *intf;
2066 struct usb_host_interface *alt;
2067 u8 ifnum;
2068
2069 cp->interface[i] = intf = new_interfaces[i];
2070 intfc = cp->intf_cache[i];
2071 intf->altsetting = intfc->altsetting;
2072 intf->num_altsetting = intfc->num_altsetting;
2073 intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2074 kref_get(&intfc->ref);
2075
2076 alt = usb_altnum_to_altsetting(intf, 0);
2077
2078 /* No altsetting 0? We'll assume the first altsetting.
2079 * We could use a GetInterface call, but if a device is
2080 * so non-compliant that it doesn't have altsetting 0
2081 * then I wouldn't trust its reply anyway.
2082 */
2083 if (!alt)
2084 alt = &intf->altsetting[0];
2085
2086 ifnum = alt->desc.bInterfaceNumber;
2087 intf->intf_assoc = find_iad(dev, cp, ifnum);
2088 intf->cur_altsetting = alt;
2089 usb_enable_interface(dev, intf, true);
2090 intf->dev.parent = &dev->dev;
2091 if (usb_of_has_combined_node(dev)) {
2092 device_set_of_node_from_dev(&intf->dev, &dev->dev);
2093 } else {
2094 intf->dev.of_node = usb_of_get_interface_node(dev,
2095 configuration, ifnum);
2096 }
2097 ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2098 intf->dev.driver = NULL;
2099 intf->dev.bus = &usb_bus_type;
2100 intf->dev.type = &usb_if_device_type;
2101 intf->dev.groups = usb_interface_groups;
2102 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2103 intf->minor = -1;
2104 device_initialize(&intf->dev);
2105 pm_runtime_no_callbacks(&intf->dev);
2106 dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
2107 dev->devpath, configuration, ifnum);
2108 usb_get_dev(dev);
2109 }
2110 kfree(new_interfaces);
2111
2112 ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2113 configuration, 0, NULL, 0,
2114 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2115 if (ret && cp) {
2116 /*
2117 * All the old state is gone, so what else can we do?
2118 * The device is probably useless now anyway.
2119 */
2120 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
2121 for (i = 0; i < nintf; ++i) {
2122 usb_disable_interface(dev, cp->interface[i], true);
2123 put_device(&cp->interface[i]->dev);
2124 cp->interface[i] = NULL;
2125 }
2126 cp = NULL;
2127 }
2128
2129 dev->actconfig = cp;
2130 mutex_unlock(hcd->bandwidth_mutex);
2131
2132 if (!cp) {
2133 usb_set_device_state(dev, USB_STATE_ADDRESS);
2134
2135 /* Leave LPM disabled while the device is unconfigured. */
2136 usb_autosuspend_device(dev);
2137 return ret;
2138 }
2139 usb_set_device_state(dev, USB_STATE_CONFIGURED);
2140
2141 if (cp->string == NULL &&
2142 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2143 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2144
2145 /* Now that the interfaces are installed, re-enable LPM. */
2146 usb_unlocked_enable_lpm(dev);
2147 /* Enable LTM if it was turned off by usb_disable_device. */
2148 usb_enable_ltm(dev);
2149
2150 /* Now that all the interfaces are set up, register them
2151 * to trigger binding of drivers to interfaces. probe()
2152 * routines may install different altsettings and may
2153 * claim() any interfaces not yet bound. Many class drivers
2154 * need that: CDC, audio, video, etc.
2155 */
2156 for (i = 0; i < nintf; ++i) {
2157 struct usb_interface *intf = cp->interface[i];
2158
2159 if (intf->dev.of_node &&
2160 !of_device_is_available(intf->dev.of_node)) {
2161 dev_info(&dev->dev, "skipping disabled interface %d\n",
2162 intf->cur_altsetting->desc.bInterfaceNumber);
2163 continue;
2164 }
2165
2166 dev_dbg(&dev->dev,
2167 "adding %s (config #%d, interface %d)\n",
2168 dev_name(&intf->dev), configuration,
2169 intf->cur_altsetting->desc.bInterfaceNumber);
2170 device_enable_async_suspend(&intf->dev);
2171 ret = device_add(&intf->dev);
2172 if (ret != 0) {
2173 dev_err(&dev->dev, "device_add(%s) --> %d\n",
2174 dev_name(&intf->dev), ret);
2175 continue;
2176 }
2177 create_intf_ep_devs(intf);
2178 }
2179
2180 usb_autosuspend_device(dev);
2181 return 0;
2182}
2183EXPORT_SYMBOL_GPL(usb_set_configuration);
2184
2185static LIST_HEAD(set_config_list);
2186static DEFINE_SPINLOCK(set_config_lock);
2187
2188struct set_config_request {
2189 struct usb_device *udev;
2190 int config;
2191 struct work_struct work;
2192 struct list_head node;
2193};
2194
2195/* Worker routine for usb_driver_set_configuration() */
2196static void driver_set_config_work(struct work_struct *work)
2197{
2198 struct set_config_request *req =
2199 container_of(work, struct set_config_request, work);
2200 struct usb_device *udev = req->udev;
2201
2202 usb_lock_device(udev);
2203 spin_lock(&set_config_lock);
2204 list_del(&req->node);
2205 spin_unlock(&set_config_lock);
2206
2207 if (req->config >= -1) /* Is req still valid? */
2208 usb_set_configuration(udev, req->config);
2209 usb_unlock_device(udev);
2210 usb_put_dev(udev);
2211 kfree(req);
2212}
2213
2214/* Cancel pending Set-Config requests for a device whose configuration
2215 * was just changed
2216 */
2217static void cancel_async_set_config(struct usb_device *udev)
2218{
2219 struct set_config_request *req;
2220
2221 spin_lock(&set_config_lock);
2222 list_for_each_entry(req, &set_config_list, node) {
2223 if (req->udev == udev)
2224 req->config = -999; /* Mark as cancelled */
2225 }
2226 spin_unlock(&set_config_lock);
2227}
2228
2229/**
2230 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2231 * @udev: the device whose configuration is being updated
2232 * @config: the configuration being chosen.
2233 * Context: In process context, must be able to sleep
2234 *
2235 * Device interface drivers are not allowed to change device configurations.
2236 * This is because changing configurations will destroy the interface the
2237 * driver is bound to and create new ones; it would be like a floppy-disk
2238 * driver telling the computer to replace the floppy-disk drive with a
2239 * tape drive!
2240 *
2241 * Still, in certain specialized circumstances the need may arise. This
2242 * routine gets around the normal restrictions by using a work thread to
2243 * submit the change-config request.
2244 *
2245 * Return: 0 if the request was successfully queued, error code otherwise.
2246 * The caller has no way to know whether the queued request will eventually
2247 * succeed.
2248 */
2249int usb_driver_set_configuration(struct usb_device *udev, int config)
2250{
2251 struct set_config_request *req;
2252
2253 req = kmalloc(sizeof(*req), GFP_KERNEL);
2254 if (!req)
2255 return -ENOMEM;
2256 req->udev = udev;
2257 req->config = config;
2258 INIT_WORK(&req->work, driver_set_config_work);
2259
2260 spin_lock(&set_config_lock);
2261 list_add(&req->node, &set_config_list);
2262 spin_unlock(&set_config_lock);
2263
2264 usb_get_dev(udev);
2265 schedule_work(&req->work);
2266 return 0;
2267}
2268EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2269
2270/**
2271 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2272 * @hdr: the place to put the results of the parsing
2273 * @intf: the interface for which parsing is requested
2274 * @buffer: pointer to the extra headers to be parsed
2275 * @buflen: length of the extra headers
2276 *
2277 * This evaluates the extra headers present in CDC devices which
2278 * bind the interfaces for data and control and provide details
2279 * about the capabilities of the device.
2280 *
2281 * Return: number of descriptors parsed or -EINVAL
2282 * if the header is contradictory beyond salvage
2283 */
2284
2285int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2286 struct usb_interface *intf,
2287 u8 *buffer,
2288 int buflen)
2289{
2290 /* duplicates are ignored */
2291 struct usb_cdc_union_desc *union_header = NULL;
2292
2293 /* duplicates are not tolerated */
2294 struct usb_cdc_header_desc *header = NULL;
2295 struct usb_cdc_ether_desc *ether = NULL;
2296 struct usb_cdc_mdlm_detail_desc *detail = NULL;
2297 struct usb_cdc_mdlm_desc *desc = NULL;
2298
2299 unsigned int elength;
2300 int cnt = 0;
2301
2302 memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2303 hdr->phonet_magic_present = false;
2304 while (buflen > 0) {
2305 elength = buffer[0];
2306 if (!elength) {
2307 dev_err(&intf->dev, "skipping garbage byte\n");
2308 elength = 1;
2309 goto next_desc;
2310 }
2311 if ((buflen < elength) || (elength < 3)) {
2312 dev_err(&intf->dev, "invalid descriptor buffer length\n");
2313 break;
2314 }
2315 if (buffer[1] != USB_DT_CS_INTERFACE) {
2316 dev_err(&intf->dev, "skipping garbage\n");
2317 goto next_desc;
2318 }
2319
2320 switch (buffer[2]) {
2321 case USB_CDC_UNION_TYPE: /* we've found it */
2322 if (elength < sizeof(struct usb_cdc_union_desc))
2323 goto next_desc;
2324 if (union_header) {
2325 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2326 goto next_desc;
2327 }
2328 union_header = (struct usb_cdc_union_desc *)buffer;
2329 break;
2330 case USB_CDC_COUNTRY_TYPE:
2331 if (elength < sizeof(struct usb_cdc_country_functional_desc))
2332 goto next_desc;
2333 hdr->usb_cdc_country_functional_desc =
2334 (struct usb_cdc_country_functional_desc *)buffer;
2335 break;
2336 case USB_CDC_HEADER_TYPE:
2337 if (elength != sizeof(struct usb_cdc_header_desc))
2338 goto next_desc;
2339 if (header)
2340 return -EINVAL;
2341 header = (struct usb_cdc_header_desc *)buffer;
2342 break;
2343 case USB_CDC_ACM_TYPE:
2344 if (elength < sizeof(struct usb_cdc_acm_descriptor))
2345 goto next_desc;
2346 hdr->usb_cdc_acm_descriptor =
2347 (struct usb_cdc_acm_descriptor *)buffer;
2348 break;
2349 case USB_CDC_ETHERNET_TYPE:
2350 if (elength != sizeof(struct usb_cdc_ether_desc))
2351 goto next_desc;
2352 if (ether)
2353 return -EINVAL;
2354 ether = (struct usb_cdc_ether_desc *)buffer;
2355 break;
2356 case USB_CDC_CALL_MANAGEMENT_TYPE:
2357 if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2358 goto next_desc;
2359 hdr->usb_cdc_call_mgmt_descriptor =
2360 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2361 break;
2362 case USB_CDC_DMM_TYPE:
2363 if (elength < sizeof(struct usb_cdc_dmm_desc))
2364 goto next_desc;
2365 hdr->usb_cdc_dmm_desc =
2366 (struct usb_cdc_dmm_desc *)buffer;
2367 break;
2368 case USB_CDC_MDLM_TYPE:
2369 if (elength < sizeof(struct usb_cdc_mdlm_desc))
2370 goto next_desc;
2371 if (desc)
2372 return -EINVAL;
2373 desc = (struct usb_cdc_mdlm_desc *)buffer;
2374 break;
2375 case USB_CDC_MDLM_DETAIL_TYPE:
2376 if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2377 goto next_desc;
2378 if (detail)
2379 return -EINVAL;
2380 detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2381 break;
2382 case USB_CDC_NCM_TYPE:
2383 if (elength < sizeof(struct usb_cdc_ncm_desc))
2384 goto next_desc;
2385 hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2386 break;
2387 case USB_CDC_MBIM_TYPE:
2388 if (elength < sizeof(struct usb_cdc_mbim_desc))
2389 goto next_desc;
2390
2391 hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2392 break;
2393 case USB_CDC_MBIM_EXTENDED_TYPE:
2394 if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2395 break;
2396 hdr->usb_cdc_mbim_extended_desc =
2397 (struct usb_cdc_mbim_extended_desc *)buffer;
2398 break;
2399 case CDC_PHONET_MAGIC_NUMBER:
2400 hdr->phonet_magic_present = true;
2401 break;
2402 default:
2403 /*
2404 * there are LOTS more CDC descriptors that
2405 * could legitimately be found here.
2406 */
2407 dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2408 buffer[2], elength);
2409 goto next_desc;
2410 }
2411 cnt++;
2412next_desc:
2413 buflen -= elength;
2414 buffer += elength;
2415 }
2416 hdr->usb_cdc_union_desc = union_header;
2417 hdr->usb_cdc_header_desc = header;
2418 hdr->usb_cdc_mdlm_detail_desc = detail;
2419 hdr->usb_cdc_mdlm_desc = desc;
2420 hdr->usb_cdc_ether_desc = ether;
2421 return cnt;
2422}
2423
2424EXPORT_SYMBOL(cdc_parse_cdc_header);
1/*
2 * message.c - synchronous message handling
3 */
4
5#include <linux/pci.h> /* for scatterlist macros */
6#include <linux/usb.h>
7#include <linux/module.h>
8#include <linux/slab.h>
9#include <linux/init.h>
10#include <linux/mm.h>
11#include <linux/timer.h>
12#include <linux/ctype.h>
13#include <linux/nls.h>
14#include <linux/device.h>
15#include <linux/scatterlist.h>
16#include <linux/usb/quirks.h>
17#include <linux/usb/hcd.h> /* for usbcore internals */
18#include <asm/byteorder.h>
19
20#include "usb.h"
21
22static void cancel_async_set_config(struct usb_device *udev);
23
24struct api_context {
25 struct completion done;
26 int status;
27};
28
29static void usb_api_blocking_completion(struct urb *urb)
30{
31 struct api_context *ctx = urb->context;
32
33 ctx->status = urb->status;
34 complete(&ctx->done);
35}
36
37
38/*
39 * Starts urb and waits for completion or timeout. Note that this call
40 * is NOT interruptible. Many device driver i/o requests should be
41 * interruptible and therefore these drivers should implement their
42 * own interruptible routines.
43 */
44static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
45{
46 struct api_context ctx;
47 unsigned long expire;
48 int retval;
49
50 init_completion(&ctx.done);
51 urb->context = &ctx;
52 urb->actual_length = 0;
53 retval = usb_submit_urb(urb, GFP_NOIO);
54 if (unlikely(retval))
55 goto out;
56
57 expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
58 if (!wait_for_completion_timeout(&ctx.done, expire)) {
59 usb_kill_urb(urb);
60 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
61
62 dev_dbg(&urb->dev->dev,
63 "%s timed out on ep%d%s len=%u/%u\n",
64 current->comm,
65 usb_endpoint_num(&urb->ep->desc),
66 usb_urb_dir_in(urb) ? "in" : "out",
67 urb->actual_length,
68 urb->transfer_buffer_length);
69 } else
70 retval = ctx.status;
71out:
72 if (actual_length)
73 *actual_length = urb->actual_length;
74
75 usb_free_urb(urb);
76 return retval;
77}
78
79/*-------------------------------------------------------------------*/
80/* returns status (negative) or length (positive) */
81static int usb_internal_control_msg(struct usb_device *usb_dev,
82 unsigned int pipe,
83 struct usb_ctrlrequest *cmd,
84 void *data, int len, int timeout)
85{
86 struct urb *urb;
87 int retv;
88 int length;
89
90 urb = usb_alloc_urb(0, GFP_NOIO);
91 if (!urb)
92 return -ENOMEM;
93
94 usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
95 len, usb_api_blocking_completion, NULL);
96
97 retv = usb_start_wait_urb(urb, timeout, &length);
98 if (retv < 0)
99 return retv;
100 else
101 return length;
102}
103
104/**
105 * usb_control_msg - Builds a control urb, sends it off and waits for completion
106 * @dev: pointer to the usb device to send the message to
107 * @pipe: endpoint "pipe" to send the message to
108 * @request: USB message request value
109 * @requesttype: USB message request type value
110 * @value: USB message value
111 * @index: USB message index value
112 * @data: pointer to the data to send
113 * @size: length in bytes of the data to send
114 * @timeout: time in msecs to wait for the message to complete before timing
115 * out (if 0 the wait is forever)
116 *
117 * Context: !in_interrupt ()
118 *
119 * This function sends a simple control message to a specified endpoint and
120 * waits for the message to complete, or timeout.
121 *
122 * If successful, it returns the number of bytes transferred, otherwise a
123 * negative error number.
124 *
125 * Don't use this function from within an interrupt context, like a bottom half
126 * handler. If you need an asynchronous message, or need to send a message
127 * from within interrupt context, use usb_submit_urb().
128 * If a thread in your driver uses this call, make sure your disconnect()
129 * method can wait for it to complete. Since you don't have a handle on the
130 * URB used, you can't cancel the request.
131 */
132int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
133 __u8 requesttype, __u16 value, __u16 index, void *data,
134 __u16 size, int timeout)
135{
136 struct usb_ctrlrequest *dr;
137 int ret;
138
139 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
140 if (!dr)
141 return -ENOMEM;
142
143 dr->bRequestType = requesttype;
144 dr->bRequest = request;
145 dr->wValue = cpu_to_le16(value);
146 dr->wIndex = cpu_to_le16(index);
147 dr->wLength = cpu_to_le16(size);
148
149 /* dbg("usb_control_msg"); */
150
151 ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
152
153 kfree(dr);
154
155 return ret;
156}
157EXPORT_SYMBOL_GPL(usb_control_msg);
158
159/**
160 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
161 * @usb_dev: pointer to the usb device to send the message to
162 * @pipe: endpoint "pipe" to send the message to
163 * @data: pointer to the data to send
164 * @len: length in bytes of the data to send
165 * @actual_length: pointer to a location to put the actual length transferred
166 * in bytes
167 * @timeout: time in msecs to wait for the message to complete before
168 * timing out (if 0 the wait is forever)
169 *
170 * Context: !in_interrupt ()
171 *
172 * This function sends a simple interrupt message to a specified endpoint and
173 * waits for the message to complete, or timeout.
174 *
175 * If successful, it returns 0, otherwise a negative error number. The number
176 * of actual bytes transferred will be stored in the actual_length paramater.
177 *
178 * Don't use this function from within an interrupt context, like a bottom half
179 * handler. If you need an asynchronous message, or need to send a message
180 * from within interrupt context, use usb_submit_urb() If a thread in your
181 * driver uses this call, make sure your disconnect() method can wait for it to
182 * complete. Since you don't have a handle on the URB used, you can't cancel
183 * the request.
184 */
185int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
186 void *data, int len, int *actual_length, int timeout)
187{
188 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
189}
190EXPORT_SYMBOL_GPL(usb_interrupt_msg);
191
192/**
193 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
194 * @usb_dev: pointer to the usb device to send the message to
195 * @pipe: endpoint "pipe" to send the message to
196 * @data: pointer to the data to send
197 * @len: length in bytes of the data to send
198 * @actual_length: pointer to a location to put the actual length transferred
199 * in bytes
200 * @timeout: time in msecs to wait for the message to complete before
201 * timing out (if 0 the wait is forever)
202 *
203 * Context: !in_interrupt ()
204 *
205 * This function sends a simple bulk message to a specified endpoint
206 * and waits for the message to complete, or timeout.
207 *
208 * If successful, it returns 0, otherwise a negative error number. The number
209 * of actual bytes transferred will be stored in the actual_length paramater.
210 *
211 * Don't use this function from within an interrupt context, like a bottom half
212 * handler. If you need an asynchronous message, or need to send a message
213 * from within interrupt context, use usb_submit_urb() If a thread in your
214 * driver uses this call, make sure your disconnect() method can wait for it to
215 * complete. Since you don't have a handle on the URB used, you can't cancel
216 * the request.
217 *
218 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
219 * users are forced to abuse this routine by using it to submit URBs for
220 * interrupt endpoints. We will take the liberty of creating an interrupt URB
221 * (with the default interval) if the target is an interrupt endpoint.
222 */
223int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
224 void *data, int len, int *actual_length, int timeout)
225{
226 struct urb *urb;
227 struct usb_host_endpoint *ep;
228
229 ep = usb_pipe_endpoint(usb_dev, pipe);
230 if (!ep || len < 0)
231 return -EINVAL;
232
233 urb = usb_alloc_urb(0, GFP_KERNEL);
234 if (!urb)
235 return -ENOMEM;
236
237 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
238 USB_ENDPOINT_XFER_INT) {
239 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
240 usb_fill_int_urb(urb, usb_dev, pipe, data, len,
241 usb_api_blocking_completion, NULL,
242 ep->desc.bInterval);
243 } else
244 usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
245 usb_api_blocking_completion, NULL);
246
247 return usb_start_wait_urb(urb, timeout, actual_length);
248}
249EXPORT_SYMBOL_GPL(usb_bulk_msg);
250
251/*-------------------------------------------------------------------*/
252
253static void sg_clean(struct usb_sg_request *io)
254{
255 if (io->urbs) {
256 while (io->entries--)
257 usb_free_urb(io->urbs [io->entries]);
258 kfree(io->urbs);
259 io->urbs = NULL;
260 }
261 io->dev = NULL;
262}
263
264static void sg_complete(struct urb *urb)
265{
266 struct usb_sg_request *io = urb->context;
267 int status = urb->status;
268
269 spin_lock(&io->lock);
270
271 /* In 2.5 we require hcds' endpoint queues not to progress after fault
272 * reports, until the completion callback (this!) returns. That lets
273 * device driver code (like this routine) unlink queued urbs first,
274 * if it needs to, since the HC won't work on them at all. So it's
275 * not possible for page N+1 to overwrite page N, and so on.
276 *
277 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
278 * complete before the HCD can get requests away from hardware,
279 * though never during cleanup after a hard fault.
280 */
281 if (io->status
282 && (io->status != -ECONNRESET
283 || status != -ECONNRESET)
284 && urb->actual_length) {
285 dev_err(io->dev->bus->controller,
286 "dev %s ep%d%s scatterlist error %d/%d\n",
287 io->dev->devpath,
288 usb_endpoint_num(&urb->ep->desc),
289 usb_urb_dir_in(urb) ? "in" : "out",
290 status, io->status);
291 /* BUG (); */
292 }
293
294 if (io->status == 0 && status && status != -ECONNRESET) {
295 int i, found, retval;
296
297 io->status = status;
298
299 /* the previous urbs, and this one, completed already.
300 * unlink pending urbs so they won't rx/tx bad data.
301 * careful: unlink can sometimes be synchronous...
302 */
303 spin_unlock(&io->lock);
304 for (i = 0, found = 0; i < io->entries; i++) {
305 if (!io->urbs [i] || !io->urbs [i]->dev)
306 continue;
307 if (found) {
308 retval = usb_unlink_urb(io->urbs [i]);
309 if (retval != -EINPROGRESS &&
310 retval != -ENODEV &&
311 retval != -EBUSY &&
312 retval != -EIDRM)
313 dev_err(&io->dev->dev,
314 "%s, unlink --> %d\n",
315 __func__, retval);
316 } else if (urb == io->urbs [i])
317 found = 1;
318 }
319 spin_lock(&io->lock);
320 }
321
322 /* on the last completion, signal usb_sg_wait() */
323 io->bytes += urb->actual_length;
324 io->count--;
325 if (!io->count)
326 complete(&io->complete);
327
328 spin_unlock(&io->lock);
329}
330
331
332/**
333 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
334 * @io: request block being initialized. until usb_sg_wait() returns,
335 * treat this as a pointer to an opaque block of memory,
336 * @dev: the usb device that will send or receive the data
337 * @pipe: endpoint "pipe" used to transfer the data
338 * @period: polling rate for interrupt endpoints, in frames or
339 * (for high speed endpoints) microframes; ignored for bulk
340 * @sg: scatterlist entries
341 * @nents: how many entries in the scatterlist
342 * @length: how many bytes to send from the scatterlist, or zero to
343 * send every byte identified in the list.
344 * @mem_flags: SLAB_* flags affecting memory allocations in this call
345 *
346 * Returns zero for success, else a negative errno value. This initializes a
347 * scatter/gather request, allocating resources such as I/O mappings and urb
348 * memory (except maybe memory used by USB controller drivers).
349 *
350 * The request must be issued using usb_sg_wait(), which waits for the I/O to
351 * complete (or to be canceled) and then cleans up all resources allocated by
352 * usb_sg_init().
353 *
354 * The request may be canceled with usb_sg_cancel(), either before or after
355 * usb_sg_wait() is called.
356 */
357int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
358 unsigned pipe, unsigned period, struct scatterlist *sg,
359 int nents, size_t length, gfp_t mem_flags)
360{
361 int i;
362 int urb_flags;
363 int use_sg;
364
365 if (!io || !dev || !sg
366 || usb_pipecontrol(pipe)
367 || usb_pipeisoc(pipe)
368 || nents <= 0)
369 return -EINVAL;
370
371 spin_lock_init(&io->lock);
372 io->dev = dev;
373 io->pipe = pipe;
374
375 if (dev->bus->sg_tablesize > 0) {
376 use_sg = true;
377 io->entries = 1;
378 } else {
379 use_sg = false;
380 io->entries = nents;
381 }
382
383 /* initialize all the urbs we'll use */
384 io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
385 if (!io->urbs)
386 goto nomem;
387
388 urb_flags = URB_NO_INTERRUPT;
389 if (usb_pipein(pipe))
390 urb_flags |= URB_SHORT_NOT_OK;
391
392 for_each_sg(sg, sg, io->entries, i) {
393 struct urb *urb;
394 unsigned len;
395
396 urb = usb_alloc_urb(0, mem_flags);
397 if (!urb) {
398 io->entries = i;
399 goto nomem;
400 }
401 io->urbs[i] = urb;
402
403 urb->dev = NULL;
404 urb->pipe = pipe;
405 urb->interval = period;
406 urb->transfer_flags = urb_flags;
407 urb->complete = sg_complete;
408 urb->context = io;
409 urb->sg = sg;
410
411 if (use_sg) {
412 /* There is no single transfer buffer */
413 urb->transfer_buffer = NULL;
414 urb->num_sgs = nents;
415
416 /* A length of zero means transfer the whole sg list */
417 len = length;
418 if (len == 0) {
419 struct scatterlist *sg2;
420 int j;
421
422 for_each_sg(sg, sg2, nents, j)
423 len += sg2->length;
424 }
425 } else {
426 /*
427 * Some systems can't use DMA; they use PIO instead.
428 * For their sakes, transfer_buffer is set whenever
429 * possible.
430 */
431 if (!PageHighMem(sg_page(sg)))
432 urb->transfer_buffer = sg_virt(sg);
433 else
434 urb->transfer_buffer = NULL;
435
436 len = sg->length;
437 if (length) {
438 len = min_t(size_t, len, length);
439 length -= len;
440 if (length == 0)
441 io->entries = i + 1;
442 }
443 }
444 urb->transfer_buffer_length = len;
445 }
446 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
447
448 /* transaction state */
449 io->count = io->entries;
450 io->status = 0;
451 io->bytes = 0;
452 init_completion(&io->complete);
453 return 0;
454
455nomem:
456 sg_clean(io);
457 return -ENOMEM;
458}
459EXPORT_SYMBOL_GPL(usb_sg_init);
460
461/**
462 * usb_sg_wait - synchronously execute scatter/gather request
463 * @io: request block handle, as initialized with usb_sg_init().
464 * some fields become accessible when this call returns.
465 * Context: !in_interrupt ()
466 *
467 * This function blocks until the specified I/O operation completes. It
468 * leverages the grouping of the related I/O requests to get good transfer
469 * rates, by queueing the requests. At higher speeds, such queuing can
470 * significantly improve USB throughput.
471 *
472 * There are three kinds of completion for this function.
473 * (1) success, where io->status is zero. The number of io->bytes
474 * transferred is as requested.
475 * (2) error, where io->status is a negative errno value. The number
476 * of io->bytes transferred before the error is usually less
477 * than requested, and can be nonzero.
478 * (3) cancellation, a type of error with status -ECONNRESET that
479 * is initiated by usb_sg_cancel().
480 *
481 * When this function returns, all memory allocated through usb_sg_init() or
482 * this call will have been freed. The request block parameter may still be
483 * passed to usb_sg_cancel(), or it may be freed. It could also be
484 * reinitialized and then reused.
485 *
486 * Data Transfer Rates:
487 *
488 * Bulk transfers are valid for full or high speed endpoints.
489 * The best full speed data rate is 19 packets of 64 bytes each
490 * per frame, or 1216 bytes per millisecond.
491 * The best high speed data rate is 13 packets of 512 bytes each
492 * per microframe, or 52 KBytes per millisecond.
493 *
494 * The reason to use interrupt transfers through this API would most likely
495 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
496 * could be transferred. That capability is less useful for low or full
497 * speed interrupt endpoints, which allow at most one packet per millisecond,
498 * of at most 8 or 64 bytes (respectively).
499 *
500 * It is not necessary to call this function to reserve bandwidth for devices
501 * under an xHCI host controller, as the bandwidth is reserved when the
502 * configuration or interface alt setting is selected.
503 */
504void usb_sg_wait(struct usb_sg_request *io)
505{
506 int i;
507 int entries = io->entries;
508
509 /* queue the urbs. */
510 spin_lock_irq(&io->lock);
511 i = 0;
512 while (i < entries && !io->status) {
513 int retval;
514
515 io->urbs[i]->dev = io->dev;
516 retval = usb_submit_urb(io->urbs [i], GFP_ATOMIC);
517
518 /* after we submit, let completions or cancelations fire;
519 * we handshake using io->status.
520 */
521 spin_unlock_irq(&io->lock);
522 switch (retval) {
523 /* maybe we retrying will recover */
524 case -ENXIO: /* hc didn't queue this one */
525 case -EAGAIN:
526 case -ENOMEM:
527 retval = 0;
528 yield();
529 break;
530
531 /* no error? continue immediately.
532 *
533 * NOTE: to work better with UHCI (4K I/O buffer may
534 * need 3K of TDs) it may be good to limit how many
535 * URBs are queued at once; N milliseconds?
536 */
537 case 0:
538 ++i;
539 cpu_relax();
540 break;
541
542 /* fail any uncompleted urbs */
543 default:
544 io->urbs[i]->status = retval;
545 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
546 __func__, retval);
547 usb_sg_cancel(io);
548 }
549 spin_lock_irq(&io->lock);
550 if (retval && (io->status == 0 || io->status == -ECONNRESET))
551 io->status = retval;
552 }
553 io->count -= entries - i;
554 if (io->count == 0)
555 complete(&io->complete);
556 spin_unlock_irq(&io->lock);
557
558 /* OK, yes, this could be packaged as non-blocking.
559 * So could the submit loop above ... but it's easier to
560 * solve neither problem than to solve both!
561 */
562 wait_for_completion(&io->complete);
563
564 sg_clean(io);
565}
566EXPORT_SYMBOL_GPL(usb_sg_wait);
567
568/**
569 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
570 * @io: request block, initialized with usb_sg_init()
571 *
572 * This stops a request after it has been started by usb_sg_wait().
573 * It can also prevents one initialized by usb_sg_init() from starting,
574 * so that call just frees resources allocated to the request.
575 */
576void usb_sg_cancel(struct usb_sg_request *io)
577{
578 unsigned long flags;
579
580 spin_lock_irqsave(&io->lock, flags);
581
582 /* shut everything down, if it didn't already */
583 if (!io->status) {
584 int i;
585
586 io->status = -ECONNRESET;
587 spin_unlock(&io->lock);
588 for (i = 0; i < io->entries; i++) {
589 int retval;
590
591 if (!io->urbs [i]->dev)
592 continue;
593 retval = usb_unlink_urb(io->urbs [i]);
594 if (retval != -EINPROGRESS
595 && retval != -ENODEV
596 && retval != -EBUSY
597 && retval != -EIDRM)
598 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
599 __func__, retval);
600 }
601 spin_lock(&io->lock);
602 }
603 spin_unlock_irqrestore(&io->lock, flags);
604}
605EXPORT_SYMBOL_GPL(usb_sg_cancel);
606
607/*-------------------------------------------------------------------*/
608
609/**
610 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
611 * @dev: the device whose descriptor is being retrieved
612 * @type: the descriptor type (USB_DT_*)
613 * @index: the number of the descriptor
614 * @buf: where to put the descriptor
615 * @size: how big is "buf"?
616 * Context: !in_interrupt ()
617 *
618 * Gets a USB descriptor. Convenience functions exist to simplify
619 * getting some types of descriptors. Use
620 * usb_get_string() or usb_string() for USB_DT_STRING.
621 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
622 * are part of the device structure.
623 * In addition to a number of USB-standard descriptors, some
624 * devices also use class-specific or vendor-specific descriptors.
625 *
626 * This call is synchronous, and may not be used in an interrupt context.
627 *
628 * Returns the number of bytes received on success, or else the status code
629 * returned by the underlying usb_control_msg() call.
630 */
631int usb_get_descriptor(struct usb_device *dev, unsigned char type,
632 unsigned char index, void *buf, int size)
633{
634 int i;
635 int result;
636
637 memset(buf, 0, size); /* Make sure we parse really received data */
638
639 for (i = 0; i < 3; ++i) {
640 /* retry on length 0 or error; some devices are flakey */
641 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
642 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
643 (type << 8) + index, 0, buf, size,
644 USB_CTRL_GET_TIMEOUT);
645 if (result <= 0 && result != -ETIMEDOUT)
646 continue;
647 if (result > 1 && ((u8 *)buf)[1] != type) {
648 result = -ENODATA;
649 continue;
650 }
651 break;
652 }
653 return result;
654}
655EXPORT_SYMBOL_GPL(usb_get_descriptor);
656
657/**
658 * usb_get_string - gets a string descriptor
659 * @dev: the device whose string descriptor is being retrieved
660 * @langid: code for language chosen (from string descriptor zero)
661 * @index: the number of the descriptor
662 * @buf: where to put the string
663 * @size: how big is "buf"?
664 * Context: !in_interrupt ()
665 *
666 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
667 * in little-endian byte order).
668 * The usb_string() function will often be a convenient way to turn
669 * these strings into kernel-printable form.
670 *
671 * Strings may be referenced in device, configuration, interface, or other
672 * descriptors, and could also be used in vendor-specific ways.
673 *
674 * This call is synchronous, and may not be used in an interrupt context.
675 *
676 * Returns the number of bytes received on success, or else the status code
677 * returned by the underlying usb_control_msg() call.
678 */
679static int usb_get_string(struct usb_device *dev, unsigned short langid,
680 unsigned char index, void *buf, int size)
681{
682 int i;
683 int result;
684
685 for (i = 0; i < 3; ++i) {
686 /* retry on length 0 or stall; some devices are flakey */
687 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
688 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
689 (USB_DT_STRING << 8) + index, langid, buf, size,
690 USB_CTRL_GET_TIMEOUT);
691 if (result == 0 || result == -EPIPE)
692 continue;
693 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
694 result = -ENODATA;
695 continue;
696 }
697 break;
698 }
699 return result;
700}
701
702static void usb_try_string_workarounds(unsigned char *buf, int *length)
703{
704 int newlength, oldlength = *length;
705
706 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
707 if (!isprint(buf[newlength]) || buf[newlength + 1])
708 break;
709
710 if (newlength > 2) {
711 buf[0] = newlength;
712 *length = newlength;
713 }
714}
715
716static int usb_string_sub(struct usb_device *dev, unsigned int langid,
717 unsigned int index, unsigned char *buf)
718{
719 int rc;
720
721 /* Try to read the string descriptor by asking for the maximum
722 * possible number of bytes */
723 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
724 rc = -EIO;
725 else
726 rc = usb_get_string(dev, langid, index, buf, 255);
727
728 /* If that failed try to read the descriptor length, then
729 * ask for just that many bytes */
730 if (rc < 2) {
731 rc = usb_get_string(dev, langid, index, buf, 2);
732 if (rc == 2)
733 rc = usb_get_string(dev, langid, index, buf, buf[0]);
734 }
735
736 if (rc >= 2) {
737 if (!buf[0] && !buf[1])
738 usb_try_string_workarounds(buf, &rc);
739
740 /* There might be extra junk at the end of the descriptor */
741 if (buf[0] < rc)
742 rc = buf[0];
743
744 rc = rc - (rc & 1); /* force a multiple of two */
745 }
746
747 if (rc < 2)
748 rc = (rc < 0 ? rc : -EINVAL);
749
750 return rc;
751}
752
753static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
754{
755 int err;
756
757 if (dev->have_langid)
758 return 0;
759
760 if (dev->string_langid < 0)
761 return -EPIPE;
762
763 err = usb_string_sub(dev, 0, 0, tbuf);
764
765 /* If the string was reported but is malformed, default to english
766 * (0x0409) */
767 if (err == -ENODATA || (err > 0 && err < 4)) {
768 dev->string_langid = 0x0409;
769 dev->have_langid = 1;
770 dev_err(&dev->dev,
771 "string descriptor 0 malformed (err = %d), "
772 "defaulting to 0x%04x\n",
773 err, dev->string_langid);
774 return 0;
775 }
776
777 /* In case of all other errors, we assume the device is not able to
778 * deal with strings at all. Set string_langid to -1 in order to
779 * prevent any string to be retrieved from the device */
780 if (err < 0) {
781 dev_err(&dev->dev, "string descriptor 0 read error: %d\n",
782 err);
783 dev->string_langid = -1;
784 return -EPIPE;
785 }
786
787 /* always use the first langid listed */
788 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
789 dev->have_langid = 1;
790 dev_dbg(&dev->dev, "default language 0x%04x\n",
791 dev->string_langid);
792 return 0;
793}
794
795/**
796 * usb_string - returns UTF-8 version of a string descriptor
797 * @dev: the device whose string descriptor is being retrieved
798 * @index: the number of the descriptor
799 * @buf: where to put the string
800 * @size: how big is "buf"?
801 * Context: !in_interrupt ()
802 *
803 * This converts the UTF-16LE encoded strings returned by devices, from
804 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
805 * that are more usable in most kernel contexts. Note that this function
806 * chooses strings in the first language supported by the device.
807 *
808 * This call is synchronous, and may not be used in an interrupt context.
809 *
810 * Returns length of the string (>= 0) or usb_control_msg status (< 0).
811 */
812int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
813{
814 unsigned char *tbuf;
815 int err;
816
817 if (dev->state == USB_STATE_SUSPENDED)
818 return -EHOSTUNREACH;
819 if (size <= 0 || !buf || !index)
820 return -EINVAL;
821 buf[0] = 0;
822 tbuf = kmalloc(256, GFP_NOIO);
823 if (!tbuf)
824 return -ENOMEM;
825
826 err = usb_get_langid(dev, tbuf);
827 if (err < 0)
828 goto errout;
829
830 err = usb_string_sub(dev, dev->string_langid, index, tbuf);
831 if (err < 0)
832 goto errout;
833
834 size--; /* leave room for trailing NULL char in output buffer */
835 err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
836 UTF16_LITTLE_ENDIAN, buf, size);
837 buf[err] = 0;
838
839 if (tbuf[1] != USB_DT_STRING)
840 dev_dbg(&dev->dev,
841 "wrong descriptor type %02x for string %d (\"%s\")\n",
842 tbuf[1], index, buf);
843
844 errout:
845 kfree(tbuf);
846 return err;
847}
848EXPORT_SYMBOL_GPL(usb_string);
849
850/* one UTF-8-encoded 16-bit character has at most three bytes */
851#define MAX_USB_STRING_SIZE (127 * 3 + 1)
852
853/**
854 * usb_cache_string - read a string descriptor and cache it for later use
855 * @udev: the device whose string descriptor is being read
856 * @index: the descriptor index
857 *
858 * Returns a pointer to a kmalloc'ed buffer containing the descriptor string,
859 * or NULL if the index is 0 or the string could not be read.
860 */
861char *usb_cache_string(struct usb_device *udev, int index)
862{
863 char *buf;
864 char *smallbuf = NULL;
865 int len;
866
867 if (index <= 0)
868 return NULL;
869
870 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
871 if (buf) {
872 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
873 if (len > 0) {
874 smallbuf = kmalloc(++len, GFP_NOIO);
875 if (!smallbuf)
876 return buf;
877 memcpy(smallbuf, buf, len);
878 }
879 kfree(buf);
880 }
881 return smallbuf;
882}
883
884/*
885 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
886 * @dev: the device whose device descriptor is being updated
887 * @size: how much of the descriptor to read
888 * Context: !in_interrupt ()
889 *
890 * Updates the copy of the device descriptor stored in the device structure,
891 * which dedicates space for this purpose.
892 *
893 * Not exported, only for use by the core. If drivers really want to read
894 * the device descriptor directly, they can call usb_get_descriptor() with
895 * type = USB_DT_DEVICE and index = 0.
896 *
897 * This call is synchronous, and may not be used in an interrupt context.
898 *
899 * Returns the number of bytes received on success, or else the status code
900 * returned by the underlying usb_control_msg() call.
901 */
902int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
903{
904 struct usb_device_descriptor *desc;
905 int ret;
906
907 if (size > sizeof(*desc))
908 return -EINVAL;
909 desc = kmalloc(sizeof(*desc), GFP_NOIO);
910 if (!desc)
911 return -ENOMEM;
912
913 ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
914 if (ret >= 0)
915 memcpy(&dev->descriptor, desc, size);
916 kfree(desc);
917 return ret;
918}
919
920/**
921 * usb_get_status - issues a GET_STATUS call
922 * @dev: the device whose status is being checked
923 * @type: USB_RECIP_*; for device, interface, or endpoint
924 * @target: zero (for device), else interface or endpoint number
925 * @data: pointer to two bytes of bitmap data
926 * Context: !in_interrupt ()
927 *
928 * Returns device, interface, or endpoint status. Normally only of
929 * interest to see if the device is self powered, or has enabled the
930 * remote wakeup facility; or whether a bulk or interrupt endpoint
931 * is halted ("stalled").
932 *
933 * Bits in these status bitmaps are set using the SET_FEATURE request,
934 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
935 * function should be used to clear halt ("stall") status.
936 *
937 * This call is synchronous, and may not be used in an interrupt context.
938 *
939 * Returns the number of bytes received on success, or else the status code
940 * returned by the underlying usb_control_msg() call.
941 */
942int usb_get_status(struct usb_device *dev, int type, int target, void *data)
943{
944 int ret;
945 u16 *status = kmalloc(sizeof(*status), GFP_KERNEL);
946
947 if (!status)
948 return -ENOMEM;
949
950 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
951 USB_REQ_GET_STATUS, USB_DIR_IN | type, 0, target, status,
952 sizeof(*status), USB_CTRL_GET_TIMEOUT);
953
954 *(u16 *)data = *status;
955 kfree(status);
956 return ret;
957}
958EXPORT_SYMBOL_GPL(usb_get_status);
959
960/**
961 * usb_clear_halt - tells device to clear endpoint halt/stall condition
962 * @dev: device whose endpoint is halted
963 * @pipe: endpoint "pipe" being cleared
964 * Context: !in_interrupt ()
965 *
966 * This is used to clear halt conditions for bulk and interrupt endpoints,
967 * as reported by URB completion status. Endpoints that are halted are
968 * sometimes referred to as being "stalled". Such endpoints are unable
969 * to transmit or receive data until the halt status is cleared. Any URBs
970 * queued for such an endpoint should normally be unlinked by the driver
971 * before clearing the halt condition, as described in sections 5.7.5
972 * and 5.8.5 of the USB 2.0 spec.
973 *
974 * Note that control and isochronous endpoints don't halt, although control
975 * endpoints report "protocol stall" (for unsupported requests) using the
976 * same status code used to report a true stall.
977 *
978 * This call is synchronous, and may not be used in an interrupt context.
979 *
980 * Returns zero on success, or else the status code returned by the
981 * underlying usb_control_msg() call.
982 */
983int usb_clear_halt(struct usb_device *dev, int pipe)
984{
985 int result;
986 int endp = usb_pipeendpoint(pipe);
987
988 if (usb_pipein(pipe))
989 endp |= USB_DIR_IN;
990
991 /* we don't care if it wasn't halted first. in fact some devices
992 * (like some ibmcam model 1 units) seem to expect hosts to make
993 * this request for iso endpoints, which can't halt!
994 */
995 result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
996 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
997 USB_ENDPOINT_HALT, endp, NULL, 0,
998 USB_CTRL_SET_TIMEOUT);
999
1000 /* don't un-halt or force to DATA0 except on success */
1001 if (result < 0)
1002 return result;
1003
1004 /* NOTE: seems like Microsoft and Apple don't bother verifying
1005 * the clear "took", so some devices could lock up if you check...
1006 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1007 *
1008 * NOTE: make sure the logic here doesn't diverge much from
1009 * the copy in usb-storage, for as long as we need two copies.
1010 */
1011
1012 usb_reset_endpoint(dev, endp);
1013
1014 return 0;
1015}
1016EXPORT_SYMBOL_GPL(usb_clear_halt);
1017
1018static int create_intf_ep_devs(struct usb_interface *intf)
1019{
1020 struct usb_device *udev = interface_to_usbdev(intf);
1021 struct usb_host_interface *alt = intf->cur_altsetting;
1022 int i;
1023
1024 if (intf->ep_devs_created || intf->unregistering)
1025 return 0;
1026
1027 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1028 (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1029 intf->ep_devs_created = 1;
1030 return 0;
1031}
1032
1033static void remove_intf_ep_devs(struct usb_interface *intf)
1034{
1035 struct usb_host_interface *alt = intf->cur_altsetting;
1036 int i;
1037
1038 if (!intf->ep_devs_created)
1039 return;
1040
1041 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1042 usb_remove_ep_devs(&alt->endpoint[i]);
1043 intf->ep_devs_created = 0;
1044}
1045
1046/**
1047 * usb_disable_endpoint -- Disable an endpoint by address
1048 * @dev: the device whose endpoint is being disabled
1049 * @epaddr: the endpoint's address. Endpoint number for output,
1050 * endpoint number + USB_DIR_IN for input
1051 * @reset_hardware: flag to erase any endpoint state stored in the
1052 * controller hardware
1053 *
1054 * Disables the endpoint for URB submission and nukes all pending URBs.
1055 * If @reset_hardware is set then also deallocates hcd/hardware state
1056 * for the endpoint.
1057 */
1058void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1059 bool reset_hardware)
1060{
1061 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1062 struct usb_host_endpoint *ep;
1063
1064 if (!dev)
1065 return;
1066
1067 if (usb_endpoint_out(epaddr)) {
1068 ep = dev->ep_out[epnum];
1069 if (reset_hardware)
1070 dev->ep_out[epnum] = NULL;
1071 } else {
1072 ep = dev->ep_in[epnum];
1073 if (reset_hardware)
1074 dev->ep_in[epnum] = NULL;
1075 }
1076 if (ep) {
1077 ep->enabled = 0;
1078 usb_hcd_flush_endpoint(dev, ep);
1079 if (reset_hardware)
1080 usb_hcd_disable_endpoint(dev, ep);
1081 }
1082}
1083
1084/**
1085 * usb_reset_endpoint - Reset an endpoint's state.
1086 * @dev: the device whose endpoint is to be reset
1087 * @epaddr: the endpoint's address. Endpoint number for output,
1088 * endpoint number + USB_DIR_IN for input
1089 *
1090 * Resets any host-side endpoint state such as the toggle bit,
1091 * sequence number or current window.
1092 */
1093void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1094{
1095 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1096 struct usb_host_endpoint *ep;
1097
1098 if (usb_endpoint_out(epaddr))
1099 ep = dev->ep_out[epnum];
1100 else
1101 ep = dev->ep_in[epnum];
1102 if (ep)
1103 usb_hcd_reset_endpoint(dev, ep);
1104}
1105EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1106
1107
1108/**
1109 * usb_disable_interface -- Disable all endpoints for an interface
1110 * @dev: the device whose interface is being disabled
1111 * @intf: pointer to the interface descriptor
1112 * @reset_hardware: flag to erase any endpoint state stored in the
1113 * controller hardware
1114 *
1115 * Disables all the endpoints for the interface's current altsetting.
1116 */
1117void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1118 bool reset_hardware)
1119{
1120 struct usb_host_interface *alt = intf->cur_altsetting;
1121 int i;
1122
1123 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1124 usb_disable_endpoint(dev,
1125 alt->endpoint[i].desc.bEndpointAddress,
1126 reset_hardware);
1127 }
1128}
1129
1130/**
1131 * usb_disable_device - Disable all the endpoints for a USB device
1132 * @dev: the device whose endpoints are being disabled
1133 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1134 *
1135 * Disables all the device's endpoints, potentially including endpoint 0.
1136 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1137 * pending urbs) and usbcore state for the interfaces, so that usbcore
1138 * must usb_set_configuration() before any interfaces could be used.
1139 */
1140void usb_disable_device(struct usb_device *dev, int skip_ep0)
1141{
1142 int i;
1143 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1144
1145 /* getting rid of interfaces will disconnect
1146 * any drivers bound to them (a key side effect)
1147 */
1148 if (dev->actconfig) {
1149 /*
1150 * FIXME: In order to avoid self-deadlock involving the
1151 * bandwidth_mutex, we have to mark all the interfaces
1152 * before unregistering any of them.
1153 */
1154 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1155 dev->actconfig->interface[i]->unregistering = 1;
1156
1157 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1158 struct usb_interface *interface;
1159
1160 /* remove this interface if it has been registered */
1161 interface = dev->actconfig->interface[i];
1162 if (!device_is_registered(&interface->dev))
1163 continue;
1164 dev_dbg(&dev->dev, "unregistering interface %s\n",
1165 dev_name(&interface->dev));
1166 remove_intf_ep_devs(interface);
1167 device_del(&interface->dev);
1168 }
1169
1170 /* Now that the interfaces are unbound, nobody should
1171 * try to access them.
1172 */
1173 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1174 put_device(&dev->actconfig->interface[i]->dev);
1175 dev->actconfig->interface[i] = NULL;
1176 }
1177 usb_unlocked_disable_lpm(dev);
1178 dev->actconfig = NULL;
1179 if (dev->state == USB_STATE_CONFIGURED)
1180 usb_set_device_state(dev, USB_STATE_ADDRESS);
1181 }
1182
1183 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1184 skip_ep0 ? "non-ep0" : "all");
1185 if (hcd->driver->check_bandwidth) {
1186 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1187 for (i = skip_ep0; i < 16; ++i) {
1188 usb_disable_endpoint(dev, i, false);
1189 usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1190 }
1191 /* Remove endpoints from the host controller internal state */
1192 mutex_lock(hcd->bandwidth_mutex);
1193 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1194 mutex_unlock(hcd->bandwidth_mutex);
1195 /* Second pass: remove endpoint pointers */
1196 }
1197 for (i = skip_ep0; i < 16; ++i) {
1198 usb_disable_endpoint(dev, i, true);
1199 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1200 }
1201}
1202
1203/**
1204 * usb_enable_endpoint - Enable an endpoint for USB communications
1205 * @dev: the device whose interface is being enabled
1206 * @ep: the endpoint
1207 * @reset_ep: flag to reset the endpoint state
1208 *
1209 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1210 * For control endpoints, both the input and output sides are handled.
1211 */
1212void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1213 bool reset_ep)
1214{
1215 int epnum = usb_endpoint_num(&ep->desc);
1216 int is_out = usb_endpoint_dir_out(&ep->desc);
1217 int is_control = usb_endpoint_xfer_control(&ep->desc);
1218
1219 if (reset_ep)
1220 usb_hcd_reset_endpoint(dev, ep);
1221 if (is_out || is_control)
1222 dev->ep_out[epnum] = ep;
1223 if (!is_out || is_control)
1224 dev->ep_in[epnum] = ep;
1225 ep->enabled = 1;
1226}
1227
1228/**
1229 * usb_enable_interface - Enable all the endpoints for an interface
1230 * @dev: the device whose interface is being enabled
1231 * @intf: pointer to the interface descriptor
1232 * @reset_eps: flag to reset the endpoints' state
1233 *
1234 * Enables all the endpoints for the interface's current altsetting.
1235 */
1236void usb_enable_interface(struct usb_device *dev,
1237 struct usb_interface *intf, bool reset_eps)
1238{
1239 struct usb_host_interface *alt = intf->cur_altsetting;
1240 int i;
1241
1242 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1243 usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1244}
1245
1246/**
1247 * usb_set_interface - Makes a particular alternate setting be current
1248 * @dev: the device whose interface is being updated
1249 * @interface: the interface being updated
1250 * @alternate: the setting being chosen.
1251 * Context: !in_interrupt ()
1252 *
1253 * This is used to enable data transfers on interfaces that may not
1254 * be enabled by default. Not all devices support such configurability.
1255 * Only the driver bound to an interface may change its setting.
1256 *
1257 * Within any given configuration, each interface may have several
1258 * alternative settings. These are often used to control levels of
1259 * bandwidth consumption. For example, the default setting for a high
1260 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1261 * while interrupt transfers of up to 3KBytes per microframe are legal.
1262 * Also, isochronous endpoints may never be part of an
1263 * interface's default setting. To access such bandwidth, alternate
1264 * interface settings must be made current.
1265 *
1266 * Note that in the Linux USB subsystem, bandwidth associated with
1267 * an endpoint in a given alternate setting is not reserved until an URB
1268 * is submitted that needs that bandwidth. Some other operating systems
1269 * allocate bandwidth early, when a configuration is chosen.
1270 *
1271 * This call is synchronous, and may not be used in an interrupt context.
1272 * Also, drivers must not change altsettings while urbs are scheduled for
1273 * endpoints in that interface; all such urbs must first be completed
1274 * (perhaps forced by unlinking).
1275 *
1276 * Returns zero on success, or else the status code returned by the
1277 * underlying usb_control_msg() call.
1278 */
1279int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1280{
1281 struct usb_interface *iface;
1282 struct usb_host_interface *alt;
1283 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1284 int ret;
1285 int manual = 0;
1286 unsigned int epaddr;
1287 unsigned int pipe;
1288
1289 if (dev->state == USB_STATE_SUSPENDED)
1290 return -EHOSTUNREACH;
1291
1292 iface = usb_ifnum_to_if(dev, interface);
1293 if (!iface) {
1294 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1295 interface);
1296 return -EINVAL;
1297 }
1298 if (iface->unregistering)
1299 return -ENODEV;
1300
1301 alt = usb_altnum_to_altsetting(iface, alternate);
1302 if (!alt) {
1303 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1304 alternate);
1305 return -EINVAL;
1306 }
1307
1308 /* Make sure we have enough bandwidth for this alternate interface.
1309 * Remove the current alt setting and add the new alt setting.
1310 */
1311 mutex_lock(hcd->bandwidth_mutex);
1312 /* Disable LPM, and re-enable it once the new alt setting is installed,
1313 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1314 */
1315 if (usb_disable_lpm(dev)) {
1316 dev_err(&iface->dev, "%s Failed to disable LPM\n.", __func__);
1317 mutex_unlock(hcd->bandwidth_mutex);
1318 return -ENOMEM;
1319 }
1320 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1321 if (ret < 0) {
1322 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1323 alternate);
1324 usb_enable_lpm(dev);
1325 mutex_unlock(hcd->bandwidth_mutex);
1326 return ret;
1327 }
1328
1329 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1330 ret = -EPIPE;
1331 else
1332 ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1333 USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
1334 alternate, interface, NULL, 0, 5000);
1335
1336 /* 9.4.10 says devices don't need this and are free to STALL the
1337 * request if the interface only has one alternate setting.
1338 */
1339 if (ret == -EPIPE && iface->num_altsetting == 1) {
1340 dev_dbg(&dev->dev,
1341 "manual set_interface for iface %d, alt %d\n",
1342 interface, alternate);
1343 manual = 1;
1344 } else if (ret < 0) {
1345 /* Re-instate the old alt setting */
1346 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1347 usb_enable_lpm(dev);
1348 mutex_unlock(hcd->bandwidth_mutex);
1349 return ret;
1350 }
1351 mutex_unlock(hcd->bandwidth_mutex);
1352
1353 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1354 * when they implement async or easily-killable versions of this or
1355 * other "should-be-internal" functions (like clear_halt).
1356 * should hcd+usbcore postprocess control requests?
1357 */
1358
1359 /* prevent submissions using previous endpoint settings */
1360 if (iface->cur_altsetting != alt) {
1361 remove_intf_ep_devs(iface);
1362 usb_remove_sysfs_intf_files(iface);
1363 }
1364 usb_disable_interface(dev, iface, true);
1365
1366 iface->cur_altsetting = alt;
1367
1368 /* Now that the interface is installed, re-enable LPM. */
1369 usb_unlocked_enable_lpm(dev);
1370
1371 /* If the interface only has one altsetting and the device didn't
1372 * accept the request, we attempt to carry out the equivalent action
1373 * by manually clearing the HALT feature for each endpoint in the
1374 * new altsetting.
1375 */
1376 if (manual) {
1377 int i;
1378
1379 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1380 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1381 pipe = __create_pipe(dev,
1382 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1383 (usb_endpoint_out(epaddr) ?
1384 USB_DIR_OUT : USB_DIR_IN);
1385
1386 usb_clear_halt(dev, pipe);
1387 }
1388 }
1389
1390 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1391 *
1392 * Note:
1393 * Despite EP0 is always present in all interfaces/AS, the list of
1394 * endpoints from the descriptor does not contain EP0. Due to its
1395 * omnipresence one might expect EP0 being considered "affected" by
1396 * any SetInterface request and hence assume toggles need to be reset.
1397 * However, EP0 toggles are re-synced for every individual transfer
1398 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1399 * (Likewise, EP0 never "halts" on well designed devices.)
1400 */
1401 usb_enable_interface(dev, iface, true);
1402 if (device_is_registered(&iface->dev)) {
1403 usb_create_sysfs_intf_files(iface);
1404 create_intf_ep_devs(iface);
1405 }
1406 return 0;
1407}
1408EXPORT_SYMBOL_GPL(usb_set_interface);
1409
1410/**
1411 * usb_reset_configuration - lightweight device reset
1412 * @dev: the device whose configuration is being reset
1413 *
1414 * This issues a standard SET_CONFIGURATION request to the device using
1415 * the current configuration. The effect is to reset most USB-related
1416 * state in the device, including interface altsettings (reset to zero),
1417 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1418 * endpoints). Other usbcore state is unchanged, including bindings of
1419 * usb device drivers to interfaces.
1420 *
1421 * Because this affects multiple interfaces, avoid using this with composite
1422 * (multi-interface) devices. Instead, the driver for each interface may
1423 * use usb_set_interface() on the interfaces it claims. Be careful though;
1424 * some devices don't support the SET_INTERFACE request, and others won't
1425 * reset all the interface state (notably endpoint state). Resetting the whole
1426 * configuration would affect other drivers' interfaces.
1427 *
1428 * The caller must own the device lock.
1429 *
1430 * Returns zero on success, else a negative error code.
1431 */
1432int usb_reset_configuration(struct usb_device *dev)
1433{
1434 int i, retval;
1435 struct usb_host_config *config;
1436 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1437
1438 if (dev->state == USB_STATE_SUSPENDED)
1439 return -EHOSTUNREACH;
1440
1441 /* caller must have locked the device and must own
1442 * the usb bus readlock (so driver bindings are stable);
1443 * calls during probe() are fine
1444 */
1445
1446 for (i = 1; i < 16; ++i) {
1447 usb_disable_endpoint(dev, i, true);
1448 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1449 }
1450
1451 config = dev->actconfig;
1452 retval = 0;
1453 mutex_lock(hcd->bandwidth_mutex);
1454 /* Disable LPM, and re-enable it once the configuration is reset, so
1455 * that the xHCI driver can recalculate the U1/U2 timeouts.
1456 */
1457 if (usb_disable_lpm(dev)) {
1458 dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
1459 mutex_unlock(hcd->bandwidth_mutex);
1460 return -ENOMEM;
1461 }
1462 /* Make sure we have enough bandwidth for each alternate setting 0 */
1463 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1464 struct usb_interface *intf = config->interface[i];
1465 struct usb_host_interface *alt;
1466
1467 alt = usb_altnum_to_altsetting(intf, 0);
1468 if (!alt)
1469 alt = &intf->altsetting[0];
1470 if (alt != intf->cur_altsetting)
1471 retval = usb_hcd_alloc_bandwidth(dev, NULL,
1472 intf->cur_altsetting, alt);
1473 if (retval < 0)
1474 break;
1475 }
1476 /* If not, reinstate the old alternate settings */
1477 if (retval < 0) {
1478reset_old_alts:
1479 for (i--; i >= 0; i--) {
1480 struct usb_interface *intf = config->interface[i];
1481 struct usb_host_interface *alt;
1482
1483 alt = usb_altnum_to_altsetting(intf, 0);
1484 if (!alt)
1485 alt = &intf->altsetting[0];
1486 if (alt != intf->cur_altsetting)
1487 usb_hcd_alloc_bandwidth(dev, NULL,
1488 alt, intf->cur_altsetting);
1489 }
1490 usb_enable_lpm(dev);
1491 mutex_unlock(hcd->bandwidth_mutex);
1492 return retval;
1493 }
1494 retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1495 USB_REQ_SET_CONFIGURATION, 0,
1496 config->desc.bConfigurationValue, 0,
1497 NULL, 0, USB_CTRL_SET_TIMEOUT);
1498 if (retval < 0)
1499 goto reset_old_alts;
1500 mutex_unlock(hcd->bandwidth_mutex);
1501
1502 /* re-init hc/hcd interface/endpoint state */
1503 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1504 struct usb_interface *intf = config->interface[i];
1505 struct usb_host_interface *alt;
1506
1507 alt = usb_altnum_to_altsetting(intf, 0);
1508
1509 /* No altsetting 0? We'll assume the first altsetting.
1510 * We could use a GetInterface call, but if a device is
1511 * so non-compliant that it doesn't have altsetting 0
1512 * then I wouldn't trust its reply anyway.
1513 */
1514 if (!alt)
1515 alt = &intf->altsetting[0];
1516
1517 if (alt != intf->cur_altsetting) {
1518 remove_intf_ep_devs(intf);
1519 usb_remove_sysfs_intf_files(intf);
1520 }
1521 intf->cur_altsetting = alt;
1522 usb_enable_interface(dev, intf, true);
1523 if (device_is_registered(&intf->dev)) {
1524 usb_create_sysfs_intf_files(intf);
1525 create_intf_ep_devs(intf);
1526 }
1527 }
1528 /* Now that the interfaces are installed, re-enable LPM. */
1529 usb_unlocked_enable_lpm(dev);
1530 return 0;
1531}
1532EXPORT_SYMBOL_GPL(usb_reset_configuration);
1533
1534static void usb_release_interface(struct device *dev)
1535{
1536 struct usb_interface *intf = to_usb_interface(dev);
1537 struct usb_interface_cache *intfc =
1538 altsetting_to_usb_interface_cache(intf->altsetting);
1539
1540 kref_put(&intfc->ref, usb_release_interface_cache);
1541 kfree(intf);
1542}
1543
1544#ifdef CONFIG_HOTPLUG
1545static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1546{
1547 struct usb_device *usb_dev;
1548 struct usb_interface *intf;
1549 struct usb_host_interface *alt;
1550
1551 intf = to_usb_interface(dev);
1552 usb_dev = interface_to_usbdev(intf);
1553 alt = intf->cur_altsetting;
1554
1555 if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1556 alt->desc.bInterfaceClass,
1557 alt->desc.bInterfaceSubClass,
1558 alt->desc.bInterfaceProtocol))
1559 return -ENOMEM;
1560
1561 if (add_uevent_var(env,
1562 "MODALIAS=usb:"
1563 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
1564 le16_to_cpu(usb_dev->descriptor.idVendor),
1565 le16_to_cpu(usb_dev->descriptor.idProduct),
1566 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1567 usb_dev->descriptor.bDeviceClass,
1568 usb_dev->descriptor.bDeviceSubClass,
1569 usb_dev->descriptor.bDeviceProtocol,
1570 alt->desc.bInterfaceClass,
1571 alt->desc.bInterfaceSubClass,
1572 alt->desc.bInterfaceProtocol))
1573 return -ENOMEM;
1574
1575 return 0;
1576}
1577
1578#else
1579
1580static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1581{
1582 return -ENODEV;
1583}
1584#endif /* CONFIG_HOTPLUG */
1585
1586struct device_type usb_if_device_type = {
1587 .name = "usb_interface",
1588 .release = usb_release_interface,
1589 .uevent = usb_if_uevent,
1590};
1591
1592static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1593 struct usb_host_config *config,
1594 u8 inum)
1595{
1596 struct usb_interface_assoc_descriptor *retval = NULL;
1597 struct usb_interface_assoc_descriptor *intf_assoc;
1598 int first_intf;
1599 int last_intf;
1600 int i;
1601
1602 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1603 intf_assoc = config->intf_assoc[i];
1604 if (intf_assoc->bInterfaceCount == 0)
1605 continue;
1606
1607 first_intf = intf_assoc->bFirstInterface;
1608 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1609 if (inum >= first_intf && inum <= last_intf) {
1610 if (!retval)
1611 retval = intf_assoc;
1612 else
1613 dev_err(&dev->dev, "Interface #%d referenced"
1614 " by multiple IADs\n", inum);
1615 }
1616 }
1617
1618 return retval;
1619}
1620
1621
1622/*
1623 * Internal function to queue a device reset
1624 *
1625 * This is initialized into the workstruct in 'struct
1626 * usb_device->reset_ws' that is launched by
1627 * message.c:usb_set_configuration() when initializing each 'struct
1628 * usb_interface'.
1629 *
1630 * It is safe to get the USB device without reference counts because
1631 * the life cycle of @iface is bound to the life cycle of @udev. Then,
1632 * this function will be ran only if @iface is alive (and before
1633 * freeing it any scheduled instances of it will have been cancelled).
1634 *
1635 * We need to set a flag (usb_dev->reset_running) because when we call
1636 * the reset, the interfaces might be unbound. The current interface
1637 * cannot try to remove the queued work as it would cause a deadlock
1638 * (you cannot remove your work from within your executing
1639 * workqueue). This flag lets it know, so that
1640 * usb_cancel_queued_reset() doesn't try to do it.
1641 *
1642 * See usb_queue_reset_device() for more details
1643 */
1644static void __usb_queue_reset_device(struct work_struct *ws)
1645{
1646 int rc;
1647 struct usb_interface *iface =
1648 container_of(ws, struct usb_interface, reset_ws);
1649 struct usb_device *udev = interface_to_usbdev(iface);
1650
1651 rc = usb_lock_device_for_reset(udev, iface);
1652 if (rc >= 0) {
1653 iface->reset_running = 1;
1654 usb_reset_device(udev);
1655 iface->reset_running = 0;
1656 usb_unlock_device(udev);
1657 }
1658}
1659
1660
1661/*
1662 * usb_set_configuration - Makes a particular device setting be current
1663 * @dev: the device whose configuration is being updated
1664 * @configuration: the configuration being chosen.
1665 * Context: !in_interrupt(), caller owns the device lock
1666 *
1667 * This is used to enable non-default device modes. Not all devices
1668 * use this kind of configurability; many devices only have one
1669 * configuration.
1670 *
1671 * @configuration is the value of the configuration to be installed.
1672 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1673 * must be non-zero; a value of zero indicates that the device in
1674 * unconfigured. However some devices erroneously use 0 as one of their
1675 * configuration values. To help manage such devices, this routine will
1676 * accept @configuration = -1 as indicating the device should be put in
1677 * an unconfigured state.
1678 *
1679 * USB device configurations may affect Linux interoperability,
1680 * power consumption and the functionality available. For example,
1681 * the default configuration is limited to using 100mA of bus power,
1682 * so that when certain device functionality requires more power,
1683 * and the device is bus powered, that functionality should be in some
1684 * non-default device configuration. Other device modes may also be
1685 * reflected as configuration options, such as whether two ISDN
1686 * channels are available independently; and choosing between open
1687 * standard device protocols (like CDC) or proprietary ones.
1688 *
1689 * Note that a non-authorized device (dev->authorized == 0) will only
1690 * be put in unconfigured mode.
1691 *
1692 * Note that USB has an additional level of device configurability,
1693 * associated with interfaces. That configurability is accessed using
1694 * usb_set_interface().
1695 *
1696 * This call is synchronous. The calling context must be able to sleep,
1697 * must own the device lock, and must not hold the driver model's USB
1698 * bus mutex; usb interface driver probe() methods cannot use this routine.
1699 *
1700 * Returns zero on success, or else the status code returned by the
1701 * underlying call that failed. On successful completion, each interface
1702 * in the original device configuration has been destroyed, and each one
1703 * in the new configuration has been probed by all relevant usb device
1704 * drivers currently known to the kernel.
1705 */
1706int usb_set_configuration(struct usb_device *dev, int configuration)
1707{
1708 int i, ret;
1709 struct usb_host_config *cp = NULL;
1710 struct usb_interface **new_interfaces = NULL;
1711 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1712 int n, nintf;
1713
1714 if (dev->authorized == 0 || configuration == -1)
1715 configuration = 0;
1716 else {
1717 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1718 if (dev->config[i].desc.bConfigurationValue ==
1719 configuration) {
1720 cp = &dev->config[i];
1721 break;
1722 }
1723 }
1724 }
1725 if ((!cp && configuration != 0))
1726 return -EINVAL;
1727
1728 /* The USB spec says configuration 0 means unconfigured.
1729 * But if a device includes a configuration numbered 0,
1730 * we will accept it as a correctly configured state.
1731 * Use -1 if you really want to unconfigure the device.
1732 */
1733 if (cp && configuration == 0)
1734 dev_warn(&dev->dev, "config 0 descriptor??\n");
1735
1736 /* Allocate memory for new interfaces before doing anything else,
1737 * so that if we run out then nothing will have changed. */
1738 n = nintf = 0;
1739 if (cp) {
1740 nintf = cp->desc.bNumInterfaces;
1741 new_interfaces = kmalloc(nintf * sizeof(*new_interfaces),
1742 GFP_NOIO);
1743 if (!new_interfaces) {
1744 dev_err(&dev->dev, "Out of memory\n");
1745 return -ENOMEM;
1746 }
1747
1748 for (; n < nintf; ++n) {
1749 new_interfaces[n] = kzalloc(
1750 sizeof(struct usb_interface),
1751 GFP_NOIO);
1752 if (!new_interfaces[n]) {
1753 dev_err(&dev->dev, "Out of memory\n");
1754 ret = -ENOMEM;
1755free_interfaces:
1756 while (--n >= 0)
1757 kfree(new_interfaces[n]);
1758 kfree(new_interfaces);
1759 return ret;
1760 }
1761 }
1762
1763 i = dev->bus_mA - cp->desc.bMaxPower * 2;
1764 if (i < 0)
1765 dev_warn(&dev->dev, "new config #%d exceeds power "
1766 "limit by %dmA\n",
1767 configuration, -i);
1768 }
1769
1770 /* Wake up the device so we can send it the Set-Config request */
1771 ret = usb_autoresume_device(dev);
1772 if (ret)
1773 goto free_interfaces;
1774
1775 /* if it's already configured, clear out old state first.
1776 * getting rid of old interfaces means unbinding their drivers.
1777 */
1778 if (dev->state != USB_STATE_ADDRESS)
1779 usb_disable_device(dev, 1); /* Skip ep0 */
1780
1781 /* Get rid of pending async Set-Config requests for this device */
1782 cancel_async_set_config(dev);
1783
1784 /* Make sure we have bandwidth (and available HCD resources) for this
1785 * configuration. Remove endpoints from the schedule if we're dropping
1786 * this configuration to set configuration 0. After this point, the
1787 * host controller will not allow submissions to dropped endpoints. If
1788 * this call fails, the device state is unchanged.
1789 */
1790 mutex_lock(hcd->bandwidth_mutex);
1791 /* Disable LPM, and re-enable it once the new configuration is
1792 * installed, so that the xHCI driver can recalculate the U1/U2
1793 * timeouts.
1794 */
1795 if (dev->actconfig && usb_disable_lpm(dev)) {
1796 dev_err(&dev->dev, "%s Failed to disable LPM\n.", __func__);
1797 mutex_unlock(hcd->bandwidth_mutex);
1798 return -ENOMEM;
1799 }
1800 ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
1801 if (ret < 0) {
1802 if (dev->actconfig)
1803 usb_enable_lpm(dev);
1804 mutex_unlock(hcd->bandwidth_mutex);
1805 usb_autosuspend_device(dev);
1806 goto free_interfaces;
1807 }
1808
1809 ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1810 USB_REQ_SET_CONFIGURATION, 0, configuration, 0,
1811 NULL, 0, USB_CTRL_SET_TIMEOUT);
1812 if (ret < 0) {
1813 /* All the old state is gone, so what else can we do?
1814 * The device is probably useless now anyway.
1815 */
1816 cp = NULL;
1817 }
1818
1819 dev->actconfig = cp;
1820 if (!cp) {
1821 usb_set_device_state(dev, USB_STATE_ADDRESS);
1822 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1823 /* Leave LPM disabled while the device is unconfigured. */
1824 mutex_unlock(hcd->bandwidth_mutex);
1825 usb_autosuspend_device(dev);
1826 goto free_interfaces;
1827 }
1828 mutex_unlock(hcd->bandwidth_mutex);
1829 usb_set_device_state(dev, USB_STATE_CONFIGURED);
1830
1831 /* Initialize the new interface structures and the
1832 * hc/hcd/usbcore interface/endpoint state.
1833 */
1834 for (i = 0; i < nintf; ++i) {
1835 struct usb_interface_cache *intfc;
1836 struct usb_interface *intf;
1837 struct usb_host_interface *alt;
1838
1839 cp->interface[i] = intf = new_interfaces[i];
1840 intfc = cp->intf_cache[i];
1841 intf->altsetting = intfc->altsetting;
1842 intf->num_altsetting = intfc->num_altsetting;
1843 kref_get(&intfc->ref);
1844
1845 alt = usb_altnum_to_altsetting(intf, 0);
1846
1847 /* No altsetting 0? We'll assume the first altsetting.
1848 * We could use a GetInterface call, but if a device is
1849 * so non-compliant that it doesn't have altsetting 0
1850 * then I wouldn't trust its reply anyway.
1851 */
1852 if (!alt)
1853 alt = &intf->altsetting[0];
1854
1855 intf->intf_assoc =
1856 find_iad(dev, cp, alt->desc.bInterfaceNumber);
1857 intf->cur_altsetting = alt;
1858 usb_enable_interface(dev, intf, true);
1859 intf->dev.parent = &dev->dev;
1860 intf->dev.driver = NULL;
1861 intf->dev.bus = &usb_bus_type;
1862 intf->dev.type = &usb_if_device_type;
1863 intf->dev.groups = usb_interface_groups;
1864 intf->dev.dma_mask = dev->dev.dma_mask;
1865 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
1866 intf->minor = -1;
1867 device_initialize(&intf->dev);
1868 pm_runtime_no_callbacks(&intf->dev);
1869 dev_set_name(&intf->dev, "%d-%s:%d.%d",
1870 dev->bus->busnum, dev->devpath,
1871 configuration, alt->desc.bInterfaceNumber);
1872 }
1873 kfree(new_interfaces);
1874
1875 if (cp->string == NULL &&
1876 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
1877 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
1878
1879 /* Now that the interfaces are installed, re-enable LPM. */
1880 usb_unlocked_enable_lpm(dev);
1881
1882 /* Now that all the interfaces are set up, register them
1883 * to trigger binding of drivers to interfaces. probe()
1884 * routines may install different altsettings and may
1885 * claim() any interfaces not yet bound. Many class drivers
1886 * need that: CDC, audio, video, etc.
1887 */
1888 for (i = 0; i < nintf; ++i) {
1889 struct usb_interface *intf = cp->interface[i];
1890
1891 dev_dbg(&dev->dev,
1892 "adding %s (config #%d, interface %d)\n",
1893 dev_name(&intf->dev), configuration,
1894 intf->cur_altsetting->desc.bInterfaceNumber);
1895 device_enable_async_suspend(&intf->dev);
1896 ret = device_add(&intf->dev);
1897 if (ret != 0) {
1898 dev_err(&dev->dev, "device_add(%s) --> %d\n",
1899 dev_name(&intf->dev), ret);
1900 continue;
1901 }
1902 create_intf_ep_devs(intf);
1903 }
1904
1905 usb_autosuspend_device(dev);
1906 return 0;
1907}
1908
1909static LIST_HEAD(set_config_list);
1910static DEFINE_SPINLOCK(set_config_lock);
1911
1912struct set_config_request {
1913 struct usb_device *udev;
1914 int config;
1915 struct work_struct work;
1916 struct list_head node;
1917};
1918
1919/* Worker routine for usb_driver_set_configuration() */
1920static void driver_set_config_work(struct work_struct *work)
1921{
1922 struct set_config_request *req =
1923 container_of(work, struct set_config_request, work);
1924 struct usb_device *udev = req->udev;
1925
1926 usb_lock_device(udev);
1927 spin_lock(&set_config_lock);
1928 list_del(&req->node);
1929 spin_unlock(&set_config_lock);
1930
1931 if (req->config >= -1) /* Is req still valid? */
1932 usb_set_configuration(udev, req->config);
1933 usb_unlock_device(udev);
1934 usb_put_dev(udev);
1935 kfree(req);
1936}
1937
1938/* Cancel pending Set-Config requests for a device whose configuration
1939 * was just changed
1940 */
1941static void cancel_async_set_config(struct usb_device *udev)
1942{
1943 struct set_config_request *req;
1944
1945 spin_lock(&set_config_lock);
1946 list_for_each_entry(req, &set_config_list, node) {
1947 if (req->udev == udev)
1948 req->config = -999; /* Mark as cancelled */
1949 }
1950 spin_unlock(&set_config_lock);
1951}
1952
1953/**
1954 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
1955 * @udev: the device whose configuration is being updated
1956 * @config: the configuration being chosen.
1957 * Context: In process context, must be able to sleep
1958 *
1959 * Device interface drivers are not allowed to change device configurations.
1960 * This is because changing configurations will destroy the interface the
1961 * driver is bound to and create new ones; it would be like a floppy-disk
1962 * driver telling the computer to replace the floppy-disk drive with a
1963 * tape drive!
1964 *
1965 * Still, in certain specialized circumstances the need may arise. This
1966 * routine gets around the normal restrictions by using a work thread to
1967 * submit the change-config request.
1968 *
1969 * Returns 0 if the request was successfully queued, error code otherwise.
1970 * The caller has no way to know whether the queued request will eventually
1971 * succeed.
1972 */
1973int usb_driver_set_configuration(struct usb_device *udev, int config)
1974{
1975 struct set_config_request *req;
1976
1977 req = kmalloc(sizeof(*req), GFP_KERNEL);
1978 if (!req)
1979 return -ENOMEM;
1980 req->udev = udev;
1981 req->config = config;
1982 INIT_WORK(&req->work, driver_set_config_work);
1983
1984 spin_lock(&set_config_lock);
1985 list_add(&req->node, &set_config_list);
1986 spin_unlock(&set_config_lock);
1987
1988 usb_get_dev(udev);
1989 schedule_work(&req->work);
1990 return 0;
1991}
1992EXPORT_SYMBOL_GPL(usb_driver_set_configuration);