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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/of.h>
13#include <linux/slab.h>
14#include <linux/mm.h>
15#include <linux/timer.h>
16#include <linux/ctype.h>
17#include <linux/nls.h>
18#include <linux/device.h>
19#include <linux/scatterlist.h>
20#include <linux/usb/cdc.h>
21#include <linux/usb/quirks.h>
22#include <linux/usb/hcd.h> /* for usbcore internals */
23#include <linux/usb/of.h>
24#include <asm/byteorder.h>
25
26#include "usb.h"
27
28static void cancel_async_set_config(struct usb_device *udev);
29
30struct api_context {
31 struct completion done;
32 int status;
33};
34
35static void usb_api_blocking_completion(struct urb *urb)
36{
37 struct api_context *ctx = urb->context;
38
39 ctx->status = urb->status;
40 complete(&ctx->done);
41}
42
43
44/*
45 * Starts urb and waits for completion or timeout. Note that this call
46 * is NOT interruptible. Many device driver i/o requests should be
47 * interruptible and therefore these drivers should implement their
48 * own interruptible routines.
49 */
50static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
51{
52 struct api_context ctx;
53 unsigned long expire;
54 int retval;
55
56 init_completion(&ctx.done);
57 urb->context = &ctx;
58 urb->actual_length = 0;
59 retval = usb_submit_urb(urb, GFP_NOIO);
60 if (unlikely(retval))
61 goto out;
62
63 expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
64 if (!wait_for_completion_timeout(&ctx.done, expire)) {
65 usb_kill_urb(urb);
66 retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
67
68 dev_dbg(&urb->dev->dev,
69 "%s timed out on ep%d%s len=%u/%u\n",
70 current->comm,
71 usb_endpoint_num(&urb->ep->desc),
72 usb_urb_dir_in(urb) ? "in" : "out",
73 urb->actual_length,
74 urb->transfer_buffer_length);
75 } else
76 retval = ctx.status;
77out:
78 if (actual_length)
79 *actual_length = urb->actual_length;
80
81 usb_free_urb(urb);
82 return retval;
83}
84
85/*-------------------------------------------------------------------*/
86/* returns status (negative) or length (positive) */
87static int usb_internal_control_msg(struct usb_device *usb_dev,
88 unsigned int pipe,
89 struct usb_ctrlrequest *cmd,
90 void *data, int len, int timeout)
91{
92 struct urb *urb;
93 int retv;
94 int length;
95
96 urb = usb_alloc_urb(0, GFP_NOIO);
97 if (!urb)
98 return -ENOMEM;
99
100 usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
101 len, usb_api_blocking_completion, NULL);
102
103 retv = usb_start_wait_urb(urb, timeout, &length);
104 if (retv < 0)
105 return retv;
106 else
107 return length;
108}
109
110/**
111 * usb_control_msg - Builds a control urb, sends it off and waits for completion
112 * @dev: pointer to the usb device to send the message to
113 * @pipe: endpoint "pipe" to send the message to
114 * @request: USB message request value
115 * @requesttype: USB message request type value
116 * @value: USB message value
117 * @index: USB message index value
118 * @data: pointer to the data to send
119 * @size: length in bytes of the data to send
120 * @timeout: time in msecs to wait for the message to complete before timing
121 * out (if 0 the wait is forever)
122 *
123 * Context: task context, might sleep.
124 *
125 * This function sends a simple control message to a specified endpoint and
126 * waits for the message to complete, or timeout.
127 *
128 * Don't use this function from within an interrupt context. If you need
129 * an asynchronous message, or need to send a message from within interrupt
130 * context, use usb_submit_urb(). If a thread in your driver uses this call,
131 * make sure your disconnect() method can wait for it to complete. Since you
132 * don't have a handle on the URB used, you can't cancel the request.
133 *
134 * Return: If successful, the number of bytes transferred. Otherwise, a negative
135 * error number.
136 */
137int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
138 __u8 requesttype, __u16 value, __u16 index, void *data,
139 __u16 size, int timeout)
140{
141 struct usb_ctrlrequest *dr;
142 int ret;
143
144 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
145 if (!dr)
146 return -ENOMEM;
147
148 dr->bRequestType = requesttype;
149 dr->bRequest = request;
150 dr->wValue = cpu_to_le16(value);
151 dr->wIndex = cpu_to_le16(index);
152 dr->wLength = cpu_to_le16(size);
153
154 ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
155
156 /* Linger a bit, prior to the next control message. */
157 if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
158 msleep(200);
159
160 kfree(dr);
161
162 return ret;
163}
164EXPORT_SYMBOL_GPL(usb_control_msg);
165
166/**
167 * usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
168 * @dev: pointer to the usb device to send the message to
169 * @endpoint: endpoint to send the message to
170 * @request: USB message request value
171 * @requesttype: USB message request type value
172 * @value: USB message value
173 * @index: USB message index value
174 * @driver_data: pointer to the data to send
175 * @size: length in bytes of the data to send
176 * @timeout: time in msecs to wait for the message to complete before timing
177 * out (if 0 the wait is forever)
178 * @memflags: the flags for memory allocation for buffers
179 *
180 * Context: !in_interrupt ()
181 *
182 * This function sends a control message to a specified endpoint that is not
183 * expected to fill in a response (i.e. a "send message") and waits for the
184 * message to complete, or timeout.
185 *
186 * Do not use this function from within an interrupt context. If you need
187 * an asynchronous message, or need to send a message from within interrupt
188 * context, use usb_submit_urb(). If a thread in your driver uses this call,
189 * make sure your disconnect() method can wait for it to complete. Since you
190 * don't have a handle on the URB used, you can't cancel the request.
191 *
192 * The data pointer can be made to a reference on the stack, or anywhere else,
193 * as it will not be modified at all. This does not have the restriction that
194 * usb_control_msg() has where the data pointer must be to dynamically allocated
195 * memory (i.e. memory that can be successfully DMAed to a device).
196 *
197 * Return: If successful, 0 is returned, Otherwise, a negative error number.
198 */
199int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
200 __u8 requesttype, __u16 value, __u16 index,
201 const void *driver_data, __u16 size, int timeout,
202 gfp_t memflags)
203{
204 unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
205 int ret;
206 u8 *data = NULL;
207
208 if (size) {
209 data = kmemdup(driver_data, size, memflags);
210 if (!data)
211 return -ENOMEM;
212 }
213
214 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
215 data, size, timeout);
216 kfree(data);
217
218 if (ret < 0)
219 return ret;
220
221 return 0;
222}
223EXPORT_SYMBOL_GPL(usb_control_msg_send);
224
225/**
226 * usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
227 * @dev: pointer to the usb device to send the message to
228 * @endpoint: endpoint to send the message to
229 * @request: USB message request value
230 * @requesttype: USB message request type value
231 * @value: USB message value
232 * @index: USB message index value
233 * @driver_data: pointer to the data to be filled in by the message
234 * @size: length in bytes of the data to be received
235 * @timeout: time in msecs to wait for the message to complete before timing
236 * out (if 0 the wait is forever)
237 * @memflags: the flags for memory allocation for buffers
238 *
239 * Context: !in_interrupt ()
240 *
241 * This function sends a control message to a specified endpoint that is
242 * expected to fill in a response (i.e. a "receive message") and waits for the
243 * message to complete, or timeout.
244 *
245 * Do not use this function from within an interrupt context. If you need
246 * an asynchronous message, or need to send a message from within interrupt
247 * context, use usb_submit_urb(). If a thread in your driver uses this call,
248 * make sure your disconnect() method can wait for it to complete. Since you
249 * don't have a handle on the URB used, you can't cancel the request.
250 *
251 * The data pointer can be made to a reference on the stack, or anywhere else
252 * that can be successfully written to. This function does not have the
253 * restriction that usb_control_msg() has where the data pointer must be to
254 * dynamically allocated memory (i.e. memory that can be successfully DMAed to a
255 * device).
256 *
257 * The "whole" message must be properly received from the device in order for
258 * this function to be successful. If a device returns less than the expected
259 * amount of data, then the function will fail. Do not use this for messages
260 * where a variable amount of data might be returned.
261 *
262 * Return: If successful, 0 is returned, Otherwise, a negative error number.
263 */
264int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
265 __u8 requesttype, __u16 value, __u16 index,
266 void *driver_data, __u16 size, int timeout,
267 gfp_t memflags)
268{
269 unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
270 int ret;
271 u8 *data;
272
273 if (!size || !driver_data)
274 return -EINVAL;
275
276 data = kmalloc(size, memflags);
277 if (!data)
278 return -ENOMEM;
279
280 ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
281 data, size, timeout);
282
283 if (ret < 0)
284 goto exit;
285
286 if (ret == size) {
287 memcpy(driver_data, data, size);
288 ret = 0;
289 } else {
290 ret = -EREMOTEIO;
291 }
292
293exit:
294 kfree(data);
295 return ret;
296}
297EXPORT_SYMBOL_GPL(usb_control_msg_recv);
298
299/**
300 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
301 * @usb_dev: pointer to the usb device to send the message to
302 * @pipe: endpoint "pipe" to send the message to
303 * @data: pointer to the data to send
304 * @len: length in bytes of the data to send
305 * @actual_length: pointer to a location to put the actual length transferred
306 * in bytes
307 * @timeout: time in msecs to wait for the message to complete before
308 * timing out (if 0 the wait is forever)
309 *
310 * Context: task context, might sleep.
311 *
312 * This function sends a simple interrupt message to a specified endpoint and
313 * waits for the message to complete, or timeout.
314 *
315 * Don't use this function from within an interrupt context. If you need
316 * an asynchronous message, or need to send a message from within interrupt
317 * context, use usb_submit_urb() If a thread in your driver uses this call,
318 * make sure your disconnect() method can wait for it to complete. Since you
319 * don't have a handle on the URB used, you can't cancel the request.
320 *
321 * Return:
322 * If successful, 0. Otherwise a negative error number. The number of actual
323 * bytes transferred will be stored in the @actual_length parameter.
324 */
325int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
326 void *data, int len, int *actual_length, int timeout)
327{
328 return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
329}
330EXPORT_SYMBOL_GPL(usb_interrupt_msg);
331
332/**
333 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
334 * @usb_dev: pointer to the usb device to send the message to
335 * @pipe: endpoint "pipe" to send the message to
336 * @data: pointer to the data to send
337 * @len: length in bytes of the data to send
338 * @actual_length: pointer to a location to put the actual length transferred
339 * in bytes
340 * @timeout: time in msecs to wait for the message to complete before
341 * timing out (if 0 the wait is forever)
342 *
343 * Context: task context, might sleep.
344 *
345 * This function sends a simple bulk message to a specified endpoint
346 * and waits for the message to complete, or timeout.
347 *
348 * Don't use this function from within an interrupt context. If you need
349 * an asynchronous message, or need to send a message from within interrupt
350 * context, use usb_submit_urb() If a thread in your driver uses this call,
351 * make sure your disconnect() method can wait for it to complete. Since you
352 * don't have a handle on the URB used, you can't cancel the request.
353 *
354 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
355 * users are forced to abuse this routine by using it to submit URBs for
356 * interrupt endpoints. We will take the liberty of creating an interrupt URB
357 * (with the default interval) if the target is an interrupt endpoint.
358 *
359 * Return:
360 * If successful, 0. Otherwise a negative error number. The number of actual
361 * bytes transferred will be stored in the @actual_length parameter.
362 *
363 */
364int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
365 void *data, int len, int *actual_length, int timeout)
366{
367 struct urb *urb;
368 struct usb_host_endpoint *ep;
369
370 ep = usb_pipe_endpoint(usb_dev, pipe);
371 if (!ep || len < 0)
372 return -EINVAL;
373
374 urb = usb_alloc_urb(0, GFP_KERNEL);
375 if (!urb)
376 return -ENOMEM;
377
378 if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
379 USB_ENDPOINT_XFER_INT) {
380 pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
381 usb_fill_int_urb(urb, usb_dev, pipe, data, len,
382 usb_api_blocking_completion, NULL,
383 ep->desc.bInterval);
384 } else
385 usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
386 usb_api_blocking_completion, NULL);
387
388 return usb_start_wait_urb(urb, timeout, actual_length);
389}
390EXPORT_SYMBOL_GPL(usb_bulk_msg);
391
392/*-------------------------------------------------------------------*/
393
394static void sg_clean(struct usb_sg_request *io)
395{
396 if (io->urbs) {
397 while (io->entries--)
398 usb_free_urb(io->urbs[io->entries]);
399 kfree(io->urbs);
400 io->urbs = NULL;
401 }
402 io->dev = NULL;
403}
404
405static void sg_complete(struct urb *urb)
406{
407 unsigned long flags;
408 struct usb_sg_request *io = urb->context;
409 int status = urb->status;
410
411 spin_lock_irqsave(&io->lock, flags);
412
413 /* In 2.5 we require hcds' endpoint queues not to progress after fault
414 * reports, until the completion callback (this!) returns. That lets
415 * device driver code (like this routine) unlink queued urbs first,
416 * if it needs to, since the HC won't work on them at all. So it's
417 * not possible for page N+1 to overwrite page N, and so on.
418 *
419 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
420 * complete before the HCD can get requests away from hardware,
421 * though never during cleanup after a hard fault.
422 */
423 if (io->status
424 && (io->status != -ECONNRESET
425 || status != -ECONNRESET)
426 && urb->actual_length) {
427 dev_err(io->dev->bus->controller,
428 "dev %s ep%d%s scatterlist error %d/%d\n",
429 io->dev->devpath,
430 usb_endpoint_num(&urb->ep->desc),
431 usb_urb_dir_in(urb) ? "in" : "out",
432 status, io->status);
433 /* BUG (); */
434 }
435
436 if (io->status == 0 && status && status != -ECONNRESET) {
437 int i, found, retval;
438
439 io->status = status;
440
441 /* the previous urbs, and this one, completed already.
442 * unlink pending urbs so they won't rx/tx bad data.
443 * careful: unlink can sometimes be synchronous...
444 */
445 spin_unlock_irqrestore(&io->lock, flags);
446 for (i = 0, found = 0; i < io->entries; i++) {
447 if (!io->urbs[i])
448 continue;
449 if (found) {
450 usb_block_urb(io->urbs[i]);
451 retval = usb_unlink_urb(io->urbs[i]);
452 if (retval != -EINPROGRESS &&
453 retval != -ENODEV &&
454 retval != -EBUSY &&
455 retval != -EIDRM)
456 dev_err(&io->dev->dev,
457 "%s, unlink --> %d\n",
458 __func__, retval);
459 } else if (urb == io->urbs[i])
460 found = 1;
461 }
462 spin_lock_irqsave(&io->lock, flags);
463 }
464
465 /* on the last completion, signal usb_sg_wait() */
466 io->bytes += urb->actual_length;
467 io->count--;
468 if (!io->count)
469 complete(&io->complete);
470
471 spin_unlock_irqrestore(&io->lock, flags);
472}
473
474
475/**
476 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
477 * @io: request block being initialized. until usb_sg_wait() returns,
478 * treat this as a pointer to an opaque block of memory,
479 * @dev: the usb device that will send or receive the data
480 * @pipe: endpoint "pipe" used to transfer the data
481 * @period: polling rate for interrupt endpoints, in frames or
482 * (for high speed endpoints) microframes; ignored for bulk
483 * @sg: scatterlist entries
484 * @nents: how many entries in the scatterlist
485 * @length: how many bytes to send from the scatterlist, or zero to
486 * send every byte identified in the list.
487 * @mem_flags: SLAB_* flags affecting memory allocations in this call
488 *
489 * This initializes a scatter/gather request, allocating resources such as
490 * I/O mappings and urb memory (except maybe memory used by USB controller
491 * drivers).
492 *
493 * The request must be issued using usb_sg_wait(), which waits for the I/O to
494 * complete (or to be canceled) and then cleans up all resources allocated by
495 * usb_sg_init().
496 *
497 * The request may be canceled with usb_sg_cancel(), either before or after
498 * usb_sg_wait() is called.
499 *
500 * Return: Zero for success, else a negative errno value.
501 */
502int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
503 unsigned pipe, unsigned period, struct scatterlist *sg,
504 int nents, size_t length, gfp_t mem_flags)
505{
506 int i;
507 int urb_flags;
508 int use_sg;
509
510 if (!io || !dev || !sg
511 || usb_pipecontrol(pipe)
512 || usb_pipeisoc(pipe)
513 || nents <= 0)
514 return -EINVAL;
515
516 spin_lock_init(&io->lock);
517 io->dev = dev;
518 io->pipe = pipe;
519
520 if (dev->bus->sg_tablesize > 0) {
521 use_sg = true;
522 io->entries = 1;
523 } else {
524 use_sg = false;
525 io->entries = nents;
526 }
527
528 /* initialize all the urbs we'll use */
529 io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
530 if (!io->urbs)
531 goto nomem;
532
533 urb_flags = URB_NO_INTERRUPT;
534 if (usb_pipein(pipe))
535 urb_flags |= URB_SHORT_NOT_OK;
536
537 for_each_sg(sg, sg, io->entries, i) {
538 struct urb *urb;
539 unsigned len;
540
541 urb = usb_alloc_urb(0, mem_flags);
542 if (!urb) {
543 io->entries = i;
544 goto nomem;
545 }
546 io->urbs[i] = urb;
547
548 urb->dev = NULL;
549 urb->pipe = pipe;
550 urb->interval = period;
551 urb->transfer_flags = urb_flags;
552 urb->complete = sg_complete;
553 urb->context = io;
554 urb->sg = sg;
555
556 if (use_sg) {
557 /* There is no single transfer buffer */
558 urb->transfer_buffer = NULL;
559 urb->num_sgs = nents;
560
561 /* A length of zero means transfer the whole sg list */
562 len = length;
563 if (len == 0) {
564 struct scatterlist *sg2;
565 int j;
566
567 for_each_sg(sg, sg2, nents, j)
568 len += sg2->length;
569 }
570 } else {
571 /*
572 * Some systems can't use DMA; they use PIO instead.
573 * For their sakes, transfer_buffer is set whenever
574 * possible.
575 */
576 if (!PageHighMem(sg_page(sg)))
577 urb->transfer_buffer = sg_virt(sg);
578 else
579 urb->transfer_buffer = NULL;
580
581 len = sg->length;
582 if (length) {
583 len = min_t(size_t, len, length);
584 length -= len;
585 if (length == 0)
586 io->entries = i + 1;
587 }
588 }
589 urb->transfer_buffer_length = len;
590 }
591 io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
592
593 /* transaction state */
594 io->count = io->entries;
595 io->status = 0;
596 io->bytes = 0;
597 init_completion(&io->complete);
598 return 0;
599
600nomem:
601 sg_clean(io);
602 return -ENOMEM;
603}
604EXPORT_SYMBOL_GPL(usb_sg_init);
605
606/**
607 * usb_sg_wait - synchronously execute scatter/gather request
608 * @io: request block handle, as initialized with usb_sg_init().
609 * some fields become accessible when this call returns.
610 *
611 * Context: task context, might sleep.
612 *
613 * This function blocks until the specified I/O operation completes. It
614 * leverages the grouping of the related I/O requests to get good transfer
615 * rates, by queueing the requests. At higher speeds, such queuing can
616 * significantly improve USB throughput.
617 *
618 * There are three kinds of completion for this function.
619 *
620 * (1) success, where io->status is zero. The number of io->bytes
621 * transferred is as requested.
622 * (2) error, where io->status is a negative errno value. The number
623 * of io->bytes transferred before the error is usually less
624 * than requested, and can be nonzero.
625 * (3) cancellation, a type of error with status -ECONNRESET that
626 * is initiated by usb_sg_cancel().
627 *
628 * When this function returns, all memory allocated through usb_sg_init() or
629 * this call will have been freed. The request block parameter may still be
630 * passed to usb_sg_cancel(), or it may be freed. It could also be
631 * reinitialized and then reused.
632 *
633 * Data Transfer Rates:
634 *
635 * Bulk transfers are valid for full or high speed endpoints.
636 * The best full speed data rate is 19 packets of 64 bytes each
637 * per frame, or 1216 bytes per millisecond.
638 * The best high speed data rate is 13 packets of 512 bytes each
639 * per microframe, or 52 KBytes per millisecond.
640 *
641 * The reason to use interrupt transfers through this API would most likely
642 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
643 * could be transferred. That capability is less useful for low or full
644 * speed interrupt endpoints, which allow at most one packet per millisecond,
645 * of at most 8 or 64 bytes (respectively).
646 *
647 * It is not necessary to call this function to reserve bandwidth for devices
648 * under an xHCI host controller, as the bandwidth is reserved when the
649 * configuration or interface alt setting is selected.
650 */
651void usb_sg_wait(struct usb_sg_request *io)
652{
653 int i;
654 int entries = io->entries;
655
656 /* queue the urbs. */
657 spin_lock_irq(&io->lock);
658 i = 0;
659 while (i < entries && !io->status) {
660 int retval;
661
662 io->urbs[i]->dev = io->dev;
663 spin_unlock_irq(&io->lock);
664
665 retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
666
667 switch (retval) {
668 /* maybe we retrying will recover */
669 case -ENXIO: /* hc didn't queue this one */
670 case -EAGAIN:
671 case -ENOMEM:
672 retval = 0;
673 yield();
674 break;
675
676 /* no error? continue immediately.
677 *
678 * NOTE: to work better with UHCI (4K I/O buffer may
679 * need 3K of TDs) it may be good to limit how many
680 * URBs are queued at once; N milliseconds?
681 */
682 case 0:
683 ++i;
684 cpu_relax();
685 break;
686
687 /* fail any uncompleted urbs */
688 default:
689 io->urbs[i]->status = retval;
690 dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
691 __func__, retval);
692 usb_sg_cancel(io);
693 }
694 spin_lock_irq(&io->lock);
695 if (retval && (io->status == 0 || io->status == -ECONNRESET))
696 io->status = retval;
697 }
698 io->count -= entries - i;
699 if (io->count == 0)
700 complete(&io->complete);
701 spin_unlock_irq(&io->lock);
702
703 /* OK, yes, this could be packaged as non-blocking.
704 * So could the submit loop above ... but it's easier to
705 * solve neither problem than to solve both!
706 */
707 wait_for_completion(&io->complete);
708
709 sg_clean(io);
710}
711EXPORT_SYMBOL_GPL(usb_sg_wait);
712
713/**
714 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
715 * @io: request block, initialized with usb_sg_init()
716 *
717 * This stops a request after it has been started by usb_sg_wait().
718 * It can also prevents one initialized by usb_sg_init() from starting,
719 * so that call just frees resources allocated to the request.
720 */
721void usb_sg_cancel(struct usb_sg_request *io)
722{
723 unsigned long flags;
724 int i, retval;
725
726 spin_lock_irqsave(&io->lock, flags);
727 if (io->status || io->count == 0) {
728 spin_unlock_irqrestore(&io->lock, flags);
729 return;
730 }
731 /* shut everything down */
732 io->status = -ECONNRESET;
733 io->count++; /* Keep the request alive until we're done */
734 spin_unlock_irqrestore(&io->lock, flags);
735
736 for (i = io->entries - 1; i >= 0; --i) {
737 usb_block_urb(io->urbs[i]);
738
739 retval = usb_unlink_urb(io->urbs[i]);
740 if (retval != -EINPROGRESS
741 && retval != -ENODEV
742 && retval != -EBUSY
743 && retval != -EIDRM)
744 dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
745 __func__, retval);
746 }
747
748 spin_lock_irqsave(&io->lock, flags);
749 io->count--;
750 if (!io->count)
751 complete(&io->complete);
752 spin_unlock_irqrestore(&io->lock, flags);
753}
754EXPORT_SYMBOL_GPL(usb_sg_cancel);
755
756/*-------------------------------------------------------------------*/
757
758/**
759 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
760 * @dev: the device whose descriptor is being retrieved
761 * @type: the descriptor type (USB_DT_*)
762 * @index: the number of the descriptor
763 * @buf: where to put the descriptor
764 * @size: how big is "buf"?
765 *
766 * Context: task context, might sleep.
767 *
768 * Gets a USB descriptor. Convenience functions exist to simplify
769 * getting some types of descriptors. Use
770 * usb_get_string() or usb_string() for USB_DT_STRING.
771 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
772 * are part of the device structure.
773 * In addition to a number of USB-standard descriptors, some
774 * devices also use class-specific or vendor-specific descriptors.
775 *
776 * This call is synchronous, and may not be used in an interrupt context.
777 *
778 * Return: The number of bytes received on success, or else the status code
779 * returned by the underlying usb_control_msg() call.
780 */
781int usb_get_descriptor(struct usb_device *dev, unsigned char type,
782 unsigned char index, void *buf, int size)
783{
784 int i;
785 int result;
786
787 if (size <= 0) /* No point in asking for no data */
788 return -EINVAL;
789
790 memset(buf, 0, size); /* Make sure we parse really received data */
791
792 for (i = 0; i < 3; ++i) {
793 /* retry on length 0 or error; some devices are flakey */
794 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
795 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
796 (type << 8) + index, 0, buf, size,
797 USB_CTRL_GET_TIMEOUT);
798 if (result <= 0 && result != -ETIMEDOUT)
799 continue;
800 if (result > 1 && ((u8 *)buf)[1] != type) {
801 result = -ENODATA;
802 continue;
803 }
804 break;
805 }
806 return result;
807}
808EXPORT_SYMBOL_GPL(usb_get_descriptor);
809
810/**
811 * usb_get_string - gets a string descriptor
812 * @dev: the device whose string descriptor is being retrieved
813 * @langid: code for language chosen (from string descriptor zero)
814 * @index: the number of the descriptor
815 * @buf: where to put the string
816 * @size: how big is "buf"?
817 *
818 * Context: task context, might sleep.
819 *
820 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
821 * in little-endian byte order).
822 * The usb_string() function will often be a convenient way to turn
823 * these strings into kernel-printable form.
824 *
825 * Strings may be referenced in device, configuration, interface, or other
826 * descriptors, and could also be used in vendor-specific ways.
827 *
828 * This call is synchronous, and may not be used in an interrupt context.
829 *
830 * Return: The number of bytes received on success, or else the status code
831 * returned by the underlying usb_control_msg() call.
832 */
833static int usb_get_string(struct usb_device *dev, unsigned short langid,
834 unsigned char index, void *buf, int size)
835{
836 int i;
837 int result;
838
839 if (size <= 0) /* No point in asking for no data */
840 return -EINVAL;
841
842 for (i = 0; i < 3; ++i) {
843 /* retry on length 0 or stall; some devices are flakey */
844 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
845 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
846 (USB_DT_STRING << 8) + index, langid, buf, size,
847 USB_CTRL_GET_TIMEOUT);
848 if (result == 0 || result == -EPIPE)
849 continue;
850 if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
851 result = -ENODATA;
852 continue;
853 }
854 break;
855 }
856 return result;
857}
858
859static void usb_try_string_workarounds(unsigned char *buf, int *length)
860{
861 int newlength, oldlength = *length;
862
863 for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
864 if (!isprint(buf[newlength]) || buf[newlength + 1])
865 break;
866
867 if (newlength > 2) {
868 buf[0] = newlength;
869 *length = newlength;
870 }
871}
872
873static int usb_string_sub(struct usb_device *dev, unsigned int langid,
874 unsigned int index, unsigned char *buf)
875{
876 int rc;
877
878 /* Try to read the string descriptor by asking for the maximum
879 * possible number of bytes */
880 if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
881 rc = -EIO;
882 else
883 rc = usb_get_string(dev, langid, index, buf, 255);
884
885 /* If that failed try to read the descriptor length, then
886 * ask for just that many bytes */
887 if (rc < 2) {
888 rc = usb_get_string(dev, langid, index, buf, 2);
889 if (rc == 2)
890 rc = usb_get_string(dev, langid, index, buf, buf[0]);
891 }
892
893 if (rc >= 2) {
894 if (!buf[0] && !buf[1])
895 usb_try_string_workarounds(buf, &rc);
896
897 /* There might be extra junk at the end of the descriptor */
898 if (buf[0] < rc)
899 rc = buf[0];
900
901 rc = rc - (rc & 1); /* force a multiple of two */
902 }
903
904 if (rc < 2)
905 rc = (rc < 0 ? rc : -EINVAL);
906
907 return rc;
908}
909
910static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
911{
912 int err;
913
914 if (dev->have_langid)
915 return 0;
916
917 if (dev->string_langid < 0)
918 return -EPIPE;
919
920 err = usb_string_sub(dev, 0, 0, tbuf);
921
922 /* If the string was reported but is malformed, default to english
923 * (0x0409) */
924 if (err == -ENODATA || (err > 0 && err < 4)) {
925 dev->string_langid = 0x0409;
926 dev->have_langid = 1;
927 dev_err(&dev->dev,
928 "language id specifier not provided by device, defaulting to English\n");
929 return 0;
930 }
931
932 /* In case of all other errors, we assume the device is not able to
933 * deal with strings at all. Set string_langid to -1 in order to
934 * prevent any string to be retrieved from the device */
935 if (err < 0) {
936 dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
937 err);
938 dev->string_langid = -1;
939 return -EPIPE;
940 }
941
942 /* always use the first langid listed */
943 dev->string_langid = tbuf[2] | (tbuf[3] << 8);
944 dev->have_langid = 1;
945 dev_dbg(&dev->dev, "default language 0x%04x\n",
946 dev->string_langid);
947 return 0;
948}
949
950/**
951 * usb_string - returns UTF-8 version of a string descriptor
952 * @dev: the device whose string descriptor is being retrieved
953 * @index: the number of the descriptor
954 * @buf: where to put the string
955 * @size: how big is "buf"?
956 *
957 * Context: task context, might sleep.
958 *
959 * This converts the UTF-16LE encoded strings returned by devices, from
960 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
961 * that are more usable in most kernel contexts. Note that this function
962 * chooses strings in the first language supported by the device.
963 *
964 * This call is synchronous, and may not be used in an interrupt context.
965 *
966 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
967 */
968int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
969{
970 unsigned char *tbuf;
971 int err;
972
973 if (dev->state == USB_STATE_SUSPENDED)
974 return -EHOSTUNREACH;
975 if (size <= 0 || !buf)
976 return -EINVAL;
977 buf[0] = 0;
978 if (index <= 0 || index >= 256)
979 return -EINVAL;
980 tbuf = kmalloc(256, GFP_NOIO);
981 if (!tbuf)
982 return -ENOMEM;
983
984 err = usb_get_langid(dev, tbuf);
985 if (err < 0)
986 goto errout;
987
988 err = usb_string_sub(dev, dev->string_langid, index, tbuf);
989 if (err < 0)
990 goto errout;
991
992 size--; /* leave room for trailing NULL char in output buffer */
993 err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
994 UTF16_LITTLE_ENDIAN, buf, size);
995 buf[err] = 0;
996
997 if (tbuf[1] != USB_DT_STRING)
998 dev_dbg(&dev->dev,
999 "wrong descriptor type %02x for string %d (\"%s\")\n",
1000 tbuf[1], index, buf);
1001
1002 errout:
1003 kfree(tbuf);
1004 return err;
1005}
1006EXPORT_SYMBOL_GPL(usb_string);
1007
1008/* one UTF-8-encoded 16-bit character has at most three bytes */
1009#define MAX_USB_STRING_SIZE (127 * 3 + 1)
1010
1011/**
1012 * usb_cache_string - read a string descriptor and cache it for later use
1013 * @udev: the device whose string descriptor is being read
1014 * @index: the descriptor index
1015 *
1016 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1017 * or %NULL if the index is 0 or the string could not be read.
1018 */
1019char *usb_cache_string(struct usb_device *udev, int index)
1020{
1021 char *buf;
1022 char *smallbuf = NULL;
1023 int len;
1024
1025 if (index <= 0)
1026 return NULL;
1027
1028 buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1029 if (buf) {
1030 len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1031 if (len > 0) {
1032 smallbuf = kmalloc(++len, GFP_NOIO);
1033 if (!smallbuf)
1034 return buf;
1035 memcpy(smallbuf, buf, len);
1036 }
1037 kfree(buf);
1038 }
1039 return smallbuf;
1040}
1041EXPORT_SYMBOL_GPL(usb_cache_string);
1042
1043/*
1044 * usb_get_device_descriptor - read the device descriptor
1045 * @udev: the device whose device descriptor should be read
1046 *
1047 * Context: task context, might sleep.
1048 *
1049 * Not exported, only for use by the core. If drivers really want to read
1050 * the device descriptor directly, they can call usb_get_descriptor() with
1051 * type = USB_DT_DEVICE and index = 0.
1052 *
1053 * Returns: a pointer to a dynamically allocated usb_device_descriptor
1054 * structure (which the caller must deallocate), or an ERR_PTR value.
1055 */
1056struct usb_device_descriptor *usb_get_device_descriptor(struct usb_device *udev)
1057{
1058 struct usb_device_descriptor *desc;
1059 int ret;
1060
1061 desc = kmalloc(sizeof(*desc), GFP_NOIO);
1062 if (!desc)
1063 return ERR_PTR(-ENOMEM);
1064
1065 ret = usb_get_descriptor(udev, USB_DT_DEVICE, 0, desc, sizeof(*desc));
1066 if (ret == sizeof(*desc))
1067 return desc;
1068
1069 if (ret >= 0)
1070 ret = -EMSGSIZE;
1071 kfree(desc);
1072 return ERR_PTR(ret);
1073}
1074
1075/*
1076 * usb_set_isoch_delay - informs the device of the packet transmit delay
1077 * @dev: the device whose delay is to be informed
1078 * Context: task context, might sleep
1079 *
1080 * Since this is an optional request, we don't bother if it fails.
1081 */
1082int usb_set_isoch_delay(struct usb_device *dev)
1083{
1084 /* skip hub devices */
1085 if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1086 return 0;
1087
1088 /* skip non-SS/non-SSP devices */
1089 if (dev->speed < USB_SPEED_SUPER)
1090 return 0;
1091
1092 return usb_control_msg_send(dev, 0,
1093 USB_REQ_SET_ISOCH_DELAY,
1094 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1095 dev->hub_delay, 0, NULL, 0,
1096 USB_CTRL_SET_TIMEOUT,
1097 GFP_NOIO);
1098}
1099
1100/**
1101 * usb_get_status - issues a GET_STATUS call
1102 * @dev: the device whose status is being checked
1103 * @recip: USB_RECIP_*; for device, interface, or endpoint
1104 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
1105 * @target: zero (for device), else interface or endpoint number
1106 * @data: pointer to two bytes of bitmap data
1107 *
1108 * Context: task context, might sleep.
1109 *
1110 * Returns device, interface, or endpoint status. Normally only of
1111 * interest to see if the device is self powered, or has enabled the
1112 * remote wakeup facility; or whether a bulk or interrupt endpoint
1113 * is halted ("stalled").
1114 *
1115 * Bits in these status bitmaps are set using the SET_FEATURE request,
1116 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
1117 * function should be used to clear halt ("stall") status.
1118 *
1119 * This call is synchronous, and may not be used in an interrupt context.
1120 *
1121 * Returns 0 and the status value in *@data (in host byte order) on success,
1122 * or else the status code from the underlying usb_control_msg() call.
1123 */
1124int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1125 void *data)
1126{
1127 int ret;
1128 void *status;
1129 int length;
1130
1131 switch (type) {
1132 case USB_STATUS_TYPE_STANDARD:
1133 length = 2;
1134 break;
1135 case USB_STATUS_TYPE_PTM:
1136 if (recip != USB_RECIP_DEVICE)
1137 return -EINVAL;
1138
1139 length = 4;
1140 break;
1141 default:
1142 return -EINVAL;
1143 }
1144
1145 status = kmalloc(length, GFP_KERNEL);
1146 if (!status)
1147 return -ENOMEM;
1148
1149 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1150 USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1151 target, status, length, USB_CTRL_GET_TIMEOUT);
1152
1153 switch (ret) {
1154 case 4:
1155 if (type != USB_STATUS_TYPE_PTM) {
1156 ret = -EIO;
1157 break;
1158 }
1159
1160 *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1161 ret = 0;
1162 break;
1163 case 2:
1164 if (type != USB_STATUS_TYPE_STANDARD) {
1165 ret = -EIO;
1166 break;
1167 }
1168
1169 *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1170 ret = 0;
1171 break;
1172 default:
1173 ret = -EIO;
1174 }
1175
1176 kfree(status);
1177 return ret;
1178}
1179EXPORT_SYMBOL_GPL(usb_get_status);
1180
1181/**
1182 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1183 * @dev: device whose endpoint is halted
1184 * @pipe: endpoint "pipe" being cleared
1185 *
1186 * Context: task context, might sleep.
1187 *
1188 * This is used to clear halt conditions for bulk and interrupt endpoints,
1189 * as reported by URB completion status. Endpoints that are halted are
1190 * sometimes referred to as being "stalled". Such endpoints are unable
1191 * to transmit or receive data until the halt status is cleared. Any URBs
1192 * queued for such an endpoint should normally be unlinked by the driver
1193 * before clearing the halt condition, as described in sections 5.7.5
1194 * and 5.8.5 of the USB 2.0 spec.
1195 *
1196 * Note that control and isochronous endpoints don't halt, although control
1197 * endpoints report "protocol stall" (for unsupported requests) using the
1198 * same status code used to report a true stall.
1199 *
1200 * This call is synchronous, and may not be used in an interrupt context.
1201 *
1202 * Return: Zero on success, or else the status code returned by the
1203 * underlying usb_control_msg() call.
1204 */
1205int usb_clear_halt(struct usb_device *dev, int pipe)
1206{
1207 int result;
1208 int endp = usb_pipeendpoint(pipe);
1209
1210 if (usb_pipein(pipe))
1211 endp |= USB_DIR_IN;
1212
1213 /* we don't care if it wasn't halted first. in fact some devices
1214 * (like some ibmcam model 1 units) seem to expect hosts to make
1215 * this request for iso endpoints, which can't halt!
1216 */
1217 result = usb_control_msg_send(dev, 0,
1218 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1219 USB_ENDPOINT_HALT, endp, NULL, 0,
1220 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1221
1222 /* don't un-halt or force to DATA0 except on success */
1223 if (result)
1224 return result;
1225
1226 /* NOTE: seems like Microsoft and Apple don't bother verifying
1227 * the clear "took", so some devices could lock up if you check...
1228 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1229 *
1230 * NOTE: make sure the logic here doesn't diverge much from
1231 * the copy in usb-storage, for as long as we need two copies.
1232 */
1233
1234 usb_reset_endpoint(dev, endp);
1235
1236 return 0;
1237}
1238EXPORT_SYMBOL_GPL(usb_clear_halt);
1239
1240static int create_intf_ep_devs(struct usb_interface *intf)
1241{
1242 struct usb_device *udev = interface_to_usbdev(intf);
1243 struct usb_host_interface *alt = intf->cur_altsetting;
1244 int i;
1245
1246 if (intf->ep_devs_created || intf->unregistering)
1247 return 0;
1248
1249 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1250 (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1251 intf->ep_devs_created = 1;
1252 return 0;
1253}
1254
1255static void remove_intf_ep_devs(struct usb_interface *intf)
1256{
1257 struct usb_host_interface *alt = intf->cur_altsetting;
1258 int i;
1259
1260 if (!intf->ep_devs_created)
1261 return;
1262
1263 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1264 usb_remove_ep_devs(&alt->endpoint[i]);
1265 intf->ep_devs_created = 0;
1266}
1267
1268/**
1269 * usb_disable_endpoint -- Disable an endpoint by address
1270 * @dev: the device whose endpoint is being disabled
1271 * @epaddr: the endpoint's address. Endpoint number for output,
1272 * endpoint number + USB_DIR_IN for input
1273 * @reset_hardware: flag to erase any endpoint state stored in the
1274 * controller hardware
1275 *
1276 * Disables the endpoint for URB submission and nukes all pending URBs.
1277 * If @reset_hardware is set then also deallocates hcd/hardware state
1278 * for the endpoint.
1279 */
1280void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1281 bool reset_hardware)
1282{
1283 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1284 struct usb_host_endpoint *ep;
1285
1286 if (!dev)
1287 return;
1288
1289 if (usb_endpoint_out(epaddr)) {
1290 ep = dev->ep_out[epnum];
1291 if (reset_hardware && epnum != 0)
1292 dev->ep_out[epnum] = NULL;
1293 } else {
1294 ep = dev->ep_in[epnum];
1295 if (reset_hardware && epnum != 0)
1296 dev->ep_in[epnum] = NULL;
1297 }
1298 if (ep) {
1299 ep->enabled = 0;
1300 usb_hcd_flush_endpoint(dev, ep);
1301 if (reset_hardware)
1302 usb_hcd_disable_endpoint(dev, ep);
1303 }
1304}
1305
1306/**
1307 * usb_reset_endpoint - Reset an endpoint's state.
1308 * @dev: the device whose endpoint is to be reset
1309 * @epaddr: the endpoint's address. Endpoint number for output,
1310 * endpoint number + USB_DIR_IN for input
1311 *
1312 * Resets any host-side endpoint state such as the toggle bit,
1313 * sequence number or current window.
1314 */
1315void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1316{
1317 unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1318 struct usb_host_endpoint *ep;
1319
1320 if (usb_endpoint_out(epaddr))
1321 ep = dev->ep_out[epnum];
1322 else
1323 ep = dev->ep_in[epnum];
1324 if (ep)
1325 usb_hcd_reset_endpoint(dev, ep);
1326}
1327EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1328
1329
1330/**
1331 * usb_disable_interface -- Disable all endpoints for an interface
1332 * @dev: the device whose interface is being disabled
1333 * @intf: pointer to the interface descriptor
1334 * @reset_hardware: flag to erase any endpoint state stored in the
1335 * controller hardware
1336 *
1337 * Disables all the endpoints for the interface's current altsetting.
1338 */
1339void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1340 bool reset_hardware)
1341{
1342 struct usb_host_interface *alt = intf->cur_altsetting;
1343 int i;
1344
1345 for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1346 usb_disable_endpoint(dev,
1347 alt->endpoint[i].desc.bEndpointAddress,
1348 reset_hardware);
1349 }
1350}
1351
1352/*
1353 * usb_disable_device_endpoints -- Disable all endpoints for a device
1354 * @dev: the device whose endpoints are being disabled
1355 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1356 */
1357static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1358{
1359 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1360 int i;
1361
1362 if (hcd->driver->check_bandwidth) {
1363 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1364 for (i = skip_ep0; i < 16; ++i) {
1365 usb_disable_endpoint(dev, i, false);
1366 usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1367 }
1368 /* Remove endpoints from the host controller internal state */
1369 mutex_lock(hcd->bandwidth_mutex);
1370 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1371 mutex_unlock(hcd->bandwidth_mutex);
1372 }
1373 /* Second pass: remove endpoint pointers */
1374 for (i = skip_ep0; i < 16; ++i) {
1375 usb_disable_endpoint(dev, i, true);
1376 usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1377 }
1378}
1379
1380/**
1381 * usb_disable_device - Disable all the endpoints for a USB device
1382 * @dev: the device whose endpoints are being disabled
1383 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1384 *
1385 * Disables all the device's endpoints, potentially including endpoint 0.
1386 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1387 * pending urbs) and usbcore state for the interfaces, so that usbcore
1388 * must usb_set_configuration() before any interfaces could be used.
1389 */
1390void usb_disable_device(struct usb_device *dev, int skip_ep0)
1391{
1392 int i;
1393
1394 /* getting rid of interfaces will disconnect
1395 * any drivers bound to them (a key side effect)
1396 */
1397 if (dev->actconfig) {
1398 /*
1399 * FIXME: In order to avoid self-deadlock involving the
1400 * bandwidth_mutex, we have to mark all the interfaces
1401 * before unregistering any of them.
1402 */
1403 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1404 dev->actconfig->interface[i]->unregistering = 1;
1405
1406 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1407 struct usb_interface *interface;
1408
1409 /* remove this interface if it has been registered */
1410 interface = dev->actconfig->interface[i];
1411 if (!device_is_registered(&interface->dev))
1412 continue;
1413 dev_dbg(&dev->dev, "unregistering interface %s\n",
1414 dev_name(&interface->dev));
1415 remove_intf_ep_devs(interface);
1416 device_del(&interface->dev);
1417 }
1418
1419 /* Now that the interfaces are unbound, nobody should
1420 * try to access them.
1421 */
1422 for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1423 put_device(&dev->actconfig->interface[i]->dev);
1424 dev->actconfig->interface[i] = NULL;
1425 }
1426
1427 usb_disable_usb2_hardware_lpm(dev);
1428 usb_unlocked_disable_lpm(dev);
1429 usb_disable_ltm(dev);
1430
1431 dev->actconfig = NULL;
1432 if (dev->state == USB_STATE_CONFIGURED)
1433 usb_set_device_state(dev, USB_STATE_ADDRESS);
1434 }
1435
1436 dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1437 skip_ep0 ? "non-ep0" : "all");
1438
1439 usb_disable_device_endpoints(dev, skip_ep0);
1440}
1441
1442/**
1443 * usb_enable_endpoint - Enable an endpoint for USB communications
1444 * @dev: the device whose interface is being enabled
1445 * @ep: the endpoint
1446 * @reset_ep: flag to reset the endpoint state
1447 *
1448 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1449 * For control endpoints, both the input and output sides are handled.
1450 */
1451void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1452 bool reset_ep)
1453{
1454 int epnum = usb_endpoint_num(&ep->desc);
1455 int is_out = usb_endpoint_dir_out(&ep->desc);
1456 int is_control = usb_endpoint_xfer_control(&ep->desc);
1457
1458 if (reset_ep)
1459 usb_hcd_reset_endpoint(dev, ep);
1460 if (is_out || is_control)
1461 dev->ep_out[epnum] = ep;
1462 if (!is_out || is_control)
1463 dev->ep_in[epnum] = ep;
1464 ep->enabled = 1;
1465}
1466
1467/**
1468 * usb_enable_interface - Enable all the endpoints for an interface
1469 * @dev: the device whose interface is being enabled
1470 * @intf: pointer to the interface descriptor
1471 * @reset_eps: flag to reset the endpoints' state
1472 *
1473 * Enables all the endpoints for the interface's current altsetting.
1474 */
1475void usb_enable_interface(struct usb_device *dev,
1476 struct usb_interface *intf, bool reset_eps)
1477{
1478 struct usb_host_interface *alt = intf->cur_altsetting;
1479 int i;
1480
1481 for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1482 usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1483}
1484
1485/**
1486 * usb_set_interface - Makes a particular alternate setting be current
1487 * @dev: the device whose interface is being updated
1488 * @interface: the interface being updated
1489 * @alternate: the setting being chosen.
1490 *
1491 * Context: task context, might sleep.
1492 *
1493 * This is used to enable data transfers on interfaces that may not
1494 * be enabled by default. Not all devices support such configurability.
1495 * Only the driver bound to an interface may change its setting.
1496 *
1497 * Within any given configuration, each interface may have several
1498 * alternative settings. These are often used to control levels of
1499 * bandwidth consumption. For example, the default setting for a high
1500 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1501 * while interrupt transfers of up to 3KBytes per microframe are legal.
1502 * Also, isochronous endpoints may never be part of an
1503 * interface's default setting. To access such bandwidth, alternate
1504 * interface settings must be made current.
1505 *
1506 * Note that in the Linux USB subsystem, bandwidth associated with
1507 * an endpoint in a given alternate setting is not reserved until an URB
1508 * is submitted that needs that bandwidth. Some other operating systems
1509 * allocate bandwidth early, when a configuration is chosen.
1510 *
1511 * xHCI reserves bandwidth and configures the alternate setting in
1512 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1513 * may be disabled. Drivers cannot rely on any particular alternate
1514 * setting being in effect after a failure.
1515 *
1516 * This call is synchronous, and may not be used in an interrupt context.
1517 * Also, drivers must not change altsettings while urbs are scheduled for
1518 * endpoints in that interface; all such urbs must first be completed
1519 * (perhaps forced by unlinking).
1520 *
1521 * Return: Zero on success, or else the status code returned by the
1522 * underlying usb_control_msg() call.
1523 */
1524int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1525{
1526 struct usb_interface *iface;
1527 struct usb_host_interface *alt;
1528 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1529 int i, ret, manual = 0;
1530 unsigned int epaddr;
1531 unsigned int pipe;
1532
1533 if (dev->state == USB_STATE_SUSPENDED)
1534 return -EHOSTUNREACH;
1535
1536 iface = usb_ifnum_to_if(dev, interface);
1537 if (!iface) {
1538 dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1539 interface);
1540 return -EINVAL;
1541 }
1542 if (iface->unregistering)
1543 return -ENODEV;
1544
1545 alt = usb_altnum_to_altsetting(iface, alternate);
1546 if (!alt) {
1547 dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1548 alternate);
1549 return -EINVAL;
1550 }
1551 /*
1552 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1553 * including freeing dropped endpoint ring buffers.
1554 * Make sure the interface endpoints are flushed before that
1555 */
1556 usb_disable_interface(dev, iface, false);
1557
1558 /* Make sure we have enough bandwidth for this alternate interface.
1559 * Remove the current alt setting and add the new alt setting.
1560 */
1561 mutex_lock(hcd->bandwidth_mutex);
1562 /* Disable LPM, and re-enable it once the new alt setting is installed,
1563 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1564 */
1565 if (usb_disable_lpm(dev)) {
1566 dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1567 mutex_unlock(hcd->bandwidth_mutex);
1568 return -ENOMEM;
1569 }
1570 /* Changing alt-setting also frees any allocated streams */
1571 for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1572 iface->cur_altsetting->endpoint[i].streams = 0;
1573
1574 ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1575 if (ret < 0) {
1576 dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1577 alternate);
1578 usb_enable_lpm(dev);
1579 mutex_unlock(hcd->bandwidth_mutex);
1580 return ret;
1581 }
1582
1583 if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1584 ret = -EPIPE;
1585 else
1586 ret = usb_control_msg_send(dev, 0,
1587 USB_REQ_SET_INTERFACE,
1588 USB_RECIP_INTERFACE, alternate,
1589 interface, NULL, 0, 5000,
1590 GFP_NOIO);
1591
1592 /* 9.4.10 says devices don't need this and are free to STALL the
1593 * request if the interface only has one alternate setting.
1594 */
1595 if (ret == -EPIPE && iface->num_altsetting == 1) {
1596 dev_dbg(&dev->dev,
1597 "manual set_interface for iface %d, alt %d\n",
1598 interface, alternate);
1599 manual = 1;
1600 } else if (ret) {
1601 /* Re-instate the old alt setting */
1602 usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1603 usb_enable_lpm(dev);
1604 mutex_unlock(hcd->bandwidth_mutex);
1605 return ret;
1606 }
1607 mutex_unlock(hcd->bandwidth_mutex);
1608
1609 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1610 * when they implement async or easily-killable versions of this or
1611 * other "should-be-internal" functions (like clear_halt).
1612 * should hcd+usbcore postprocess control requests?
1613 */
1614
1615 /* prevent submissions using previous endpoint settings */
1616 if (iface->cur_altsetting != alt) {
1617 remove_intf_ep_devs(iface);
1618 usb_remove_sysfs_intf_files(iface);
1619 }
1620 usb_disable_interface(dev, iface, true);
1621
1622 iface->cur_altsetting = alt;
1623
1624 /* Now that the interface is installed, re-enable LPM. */
1625 usb_unlocked_enable_lpm(dev);
1626
1627 /* If the interface only has one altsetting and the device didn't
1628 * accept the request, we attempt to carry out the equivalent action
1629 * by manually clearing the HALT feature for each endpoint in the
1630 * new altsetting.
1631 */
1632 if (manual) {
1633 for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1634 epaddr = alt->endpoint[i].desc.bEndpointAddress;
1635 pipe = __create_pipe(dev,
1636 USB_ENDPOINT_NUMBER_MASK & epaddr) |
1637 (usb_endpoint_out(epaddr) ?
1638 USB_DIR_OUT : USB_DIR_IN);
1639
1640 usb_clear_halt(dev, pipe);
1641 }
1642 }
1643
1644 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1645 *
1646 * Note:
1647 * Despite EP0 is always present in all interfaces/AS, the list of
1648 * endpoints from the descriptor does not contain EP0. Due to its
1649 * omnipresence one might expect EP0 being considered "affected" by
1650 * any SetInterface request and hence assume toggles need to be reset.
1651 * However, EP0 toggles are re-synced for every individual transfer
1652 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1653 * (Likewise, EP0 never "halts" on well designed devices.)
1654 */
1655 usb_enable_interface(dev, iface, true);
1656 if (device_is_registered(&iface->dev)) {
1657 usb_create_sysfs_intf_files(iface);
1658 create_intf_ep_devs(iface);
1659 }
1660 return 0;
1661}
1662EXPORT_SYMBOL_GPL(usb_set_interface);
1663
1664/**
1665 * usb_reset_configuration - lightweight device reset
1666 * @dev: the device whose configuration is being reset
1667 *
1668 * This issues a standard SET_CONFIGURATION request to the device using
1669 * the current configuration. The effect is to reset most USB-related
1670 * state in the device, including interface altsettings (reset to zero),
1671 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1672 * endpoints). Other usbcore state is unchanged, including bindings of
1673 * usb device drivers to interfaces.
1674 *
1675 * Because this affects multiple interfaces, avoid using this with composite
1676 * (multi-interface) devices. Instead, the driver for each interface may
1677 * use usb_set_interface() on the interfaces it claims. Be careful though;
1678 * some devices don't support the SET_INTERFACE request, and others won't
1679 * reset all the interface state (notably endpoint state). Resetting the whole
1680 * configuration would affect other drivers' interfaces.
1681 *
1682 * The caller must own the device lock.
1683 *
1684 * Return: Zero on success, else a negative error code.
1685 *
1686 * If this routine fails the device will probably be in an unusable state
1687 * with endpoints disabled, and interfaces only partially enabled.
1688 */
1689int usb_reset_configuration(struct usb_device *dev)
1690{
1691 int i, retval;
1692 struct usb_host_config *config;
1693 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1694
1695 if (dev->state == USB_STATE_SUSPENDED)
1696 return -EHOSTUNREACH;
1697
1698 /* caller must have locked the device and must own
1699 * the usb bus readlock (so driver bindings are stable);
1700 * calls during probe() are fine
1701 */
1702
1703 usb_disable_device_endpoints(dev, 1); /* skip ep0*/
1704
1705 config = dev->actconfig;
1706 retval = 0;
1707 mutex_lock(hcd->bandwidth_mutex);
1708 /* Disable LPM, and re-enable it once the configuration is reset, so
1709 * that the xHCI driver can recalculate the U1/U2 timeouts.
1710 */
1711 if (usb_disable_lpm(dev)) {
1712 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1713 mutex_unlock(hcd->bandwidth_mutex);
1714 return -ENOMEM;
1715 }
1716
1717 /* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1718 retval = usb_hcd_alloc_bandwidth(dev, config, NULL, NULL);
1719 if (retval < 0) {
1720 usb_enable_lpm(dev);
1721 mutex_unlock(hcd->bandwidth_mutex);
1722 return retval;
1723 }
1724 retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1725 config->desc.bConfigurationValue, 0,
1726 NULL, 0, USB_CTRL_SET_TIMEOUT,
1727 GFP_NOIO);
1728 if (retval) {
1729 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1730 usb_enable_lpm(dev);
1731 mutex_unlock(hcd->bandwidth_mutex);
1732 return retval;
1733 }
1734 mutex_unlock(hcd->bandwidth_mutex);
1735
1736 /* re-init hc/hcd interface/endpoint state */
1737 for (i = 0; i < config->desc.bNumInterfaces; i++) {
1738 struct usb_interface *intf = config->interface[i];
1739 struct usb_host_interface *alt;
1740
1741 alt = usb_altnum_to_altsetting(intf, 0);
1742
1743 /* No altsetting 0? We'll assume the first altsetting.
1744 * We could use a GetInterface call, but if a device is
1745 * so non-compliant that it doesn't have altsetting 0
1746 * then I wouldn't trust its reply anyway.
1747 */
1748 if (!alt)
1749 alt = &intf->altsetting[0];
1750
1751 if (alt != intf->cur_altsetting) {
1752 remove_intf_ep_devs(intf);
1753 usb_remove_sysfs_intf_files(intf);
1754 }
1755 intf->cur_altsetting = alt;
1756 usb_enable_interface(dev, intf, true);
1757 if (device_is_registered(&intf->dev)) {
1758 usb_create_sysfs_intf_files(intf);
1759 create_intf_ep_devs(intf);
1760 }
1761 }
1762 /* Now that the interfaces are installed, re-enable LPM. */
1763 usb_unlocked_enable_lpm(dev);
1764 return 0;
1765}
1766EXPORT_SYMBOL_GPL(usb_reset_configuration);
1767
1768static void usb_release_interface(struct device *dev)
1769{
1770 struct usb_interface *intf = to_usb_interface(dev);
1771 struct usb_interface_cache *intfc =
1772 altsetting_to_usb_interface_cache(intf->altsetting);
1773
1774 kref_put(&intfc->ref, usb_release_interface_cache);
1775 usb_put_dev(interface_to_usbdev(intf));
1776 of_node_put(dev->of_node);
1777 kfree(intf);
1778}
1779
1780/*
1781 * usb_deauthorize_interface - deauthorize an USB interface
1782 *
1783 * @intf: USB interface structure
1784 */
1785void usb_deauthorize_interface(struct usb_interface *intf)
1786{
1787 struct device *dev = &intf->dev;
1788
1789 device_lock(dev->parent);
1790
1791 if (intf->authorized) {
1792 device_lock(dev);
1793 intf->authorized = 0;
1794 device_unlock(dev);
1795
1796 usb_forced_unbind_intf(intf);
1797 }
1798
1799 device_unlock(dev->parent);
1800}
1801
1802/*
1803 * usb_authorize_interface - authorize an USB interface
1804 *
1805 * @intf: USB interface structure
1806 */
1807void usb_authorize_interface(struct usb_interface *intf)
1808{
1809 struct device *dev = &intf->dev;
1810
1811 if (!intf->authorized) {
1812 device_lock(dev);
1813 intf->authorized = 1; /* authorize interface */
1814 device_unlock(dev);
1815 }
1816}
1817
1818static int usb_if_uevent(const struct device *dev, struct kobj_uevent_env *env)
1819{
1820 const struct usb_device *usb_dev;
1821 const struct usb_interface *intf;
1822 const struct usb_host_interface *alt;
1823
1824 intf = to_usb_interface(dev);
1825 usb_dev = interface_to_usbdev(intf);
1826 alt = intf->cur_altsetting;
1827
1828 if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1829 alt->desc.bInterfaceClass,
1830 alt->desc.bInterfaceSubClass,
1831 alt->desc.bInterfaceProtocol))
1832 return -ENOMEM;
1833
1834 if (add_uevent_var(env,
1835 "MODALIAS=usb:"
1836 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1837 le16_to_cpu(usb_dev->descriptor.idVendor),
1838 le16_to_cpu(usb_dev->descriptor.idProduct),
1839 le16_to_cpu(usb_dev->descriptor.bcdDevice),
1840 usb_dev->descriptor.bDeviceClass,
1841 usb_dev->descriptor.bDeviceSubClass,
1842 usb_dev->descriptor.bDeviceProtocol,
1843 alt->desc.bInterfaceClass,
1844 alt->desc.bInterfaceSubClass,
1845 alt->desc.bInterfaceProtocol,
1846 alt->desc.bInterfaceNumber))
1847 return -ENOMEM;
1848
1849 return 0;
1850}
1851
1852struct device_type usb_if_device_type = {
1853 .name = "usb_interface",
1854 .release = usb_release_interface,
1855 .uevent = usb_if_uevent,
1856};
1857
1858static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1859 struct usb_host_config *config,
1860 u8 inum)
1861{
1862 struct usb_interface_assoc_descriptor *retval = NULL;
1863 struct usb_interface_assoc_descriptor *intf_assoc;
1864 int first_intf;
1865 int last_intf;
1866 int i;
1867
1868 for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1869 intf_assoc = config->intf_assoc[i];
1870 if (intf_assoc->bInterfaceCount == 0)
1871 continue;
1872
1873 first_intf = intf_assoc->bFirstInterface;
1874 last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1875 if (inum >= first_intf && inum <= last_intf) {
1876 if (!retval)
1877 retval = intf_assoc;
1878 else
1879 dev_err(&dev->dev, "Interface #%d referenced"
1880 " by multiple IADs\n", inum);
1881 }
1882 }
1883
1884 return retval;
1885}
1886
1887
1888/*
1889 * Internal function to queue a device reset
1890 * See usb_queue_reset_device() for more details
1891 */
1892static void __usb_queue_reset_device(struct work_struct *ws)
1893{
1894 int rc;
1895 struct usb_interface *iface =
1896 container_of(ws, struct usb_interface, reset_ws);
1897 struct usb_device *udev = interface_to_usbdev(iface);
1898
1899 rc = usb_lock_device_for_reset(udev, iface);
1900 if (rc >= 0) {
1901 usb_reset_device(udev);
1902 usb_unlock_device(udev);
1903 }
1904 usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */
1905}
1906
1907/*
1908 * Internal function to set the wireless_status sysfs attribute
1909 * See usb_set_wireless_status() for more details
1910 */
1911static void __usb_wireless_status_intf(struct work_struct *ws)
1912{
1913 struct usb_interface *iface =
1914 container_of(ws, struct usb_interface, wireless_status_work);
1915
1916 device_lock(iface->dev.parent);
1917 if (iface->sysfs_files_created)
1918 usb_update_wireless_status_attr(iface);
1919 device_unlock(iface->dev.parent);
1920 usb_put_intf(iface); /* Undo _get_ in usb_set_wireless_status() */
1921}
1922
1923/**
1924 * usb_set_wireless_status - sets the wireless_status struct member
1925 * @iface: the interface to modify
1926 * @status: the new wireless status
1927 *
1928 * Set the wireless_status struct member to the new value, and emit
1929 * sysfs changes as necessary.
1930 *
1931 * Returns: 0 on success, -EALREADY if already set.
1932 */
1933int usb_set_wireless_status(struct usb_interface *iface,
1934 enum usb_wireless_status status)
1935{
1936 if (iface->wireless_status == status)
1937 return -EALREADY;
1938
1939 usb_get_intf(iface);
1940 iface->wireless_status = status;
1941 schedule_work(&iface->wireless_status_work);
1942
1943 return 0;
1944}
1945EXPORT_SYMBOL_GPL(usb_set_wireless_status);
1946
1947/*
1948 * usb_set_configuration - Makes a particular device setting be current
1949 * @dev: the device whose configuration is being updated
1950 * @configuration: the configuration being chosen.
1951 *
1952 * Context: task context, might sleep. Caller holds device lock.
1953 *
1954 * This is used to enable non-default device modes. Not all devices
1955 * use this kind of configurability; many devices only have one
1956 * configuration.
1957 *
1958 * @configuration is the value of the configuration to be installed.
1959 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1960 * must be non-zero; a value of zero indicates that the device in
1961 * unconfigured. However some devices erroneously use 0 as one of their
1962 * configuration values. To help manage such devices, this routine will
1963 * accept @configuration = -1 as indicating the device should be put in
1964 * an unconfigured state.
1965 *
1966 * USB device configurations may affect Linux interoperability,
1967 * power consumption and the functionality available. For example,
1968 * the default configuration is limited to using 100mA of bus power,
1969 * so that when certain device functionality requires more power,
1970 * and the device is bus powered, that functionality should be in some
1971 * non-default device configuration. Other device modes may also be
1972 * reflected as configuration options, such as whether two ISDN
1973 * channels are available independently; and choosing between open
1974 * standard device protocols (like CDC) or proprietary ones.
1975 *
1976 * Note that a non-authorized device (dev->authorized == 0) will only
1977 * be put in unconfigured mode.
1978 *
1979 * Note that USB has an additional level of device configurability,
1980 * associated with interfaces. That configurability is accessed using
1981 * usb_set_interface().
1982 *
1983 * This call is synchronous. The calling context must be able to sleep,
1984 * must own the device lock, and must not hold the driver model's USB
1985 * bus mutex; usb interface driver probe() methods cannot use this routine.
1986 *
1987 * Returns zero on success, or else the status code returned by the
1988 * underlying call that failed. On successful completion, each interface
1989 * in the original device configuration has been destroyed, and each one
1990 * in the new configuration has been probed by all relevant usb device
1991 * drivers currently known to the kernel.
1992 */
1993int usb_set_configuration(struct usb_device *dev, int configuration)
1994{
1995 int i, ret;
1996 struct usb_host_config *cp = NULL;
1997 struct usb_interface **new_interfaces = NULL;
1998 struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1999 int n, nintf;
2000
2001 if (dev->authorized == 0 || configuration == -1)
2002 configuration = 0;
2003 else {
2004 for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
2005 if (dev->config[i].desc.bConfigurationValue ==
2006 configuration) {
2007 cp = &dev->config[i];
2008 break;
2009 }
2010 }
2011 }
2012 if ((!cp && configuration != 0))
2013 return -EINVAL;
2014
2015 /* The USB spec says configuration 0 means unconfigured.
2016 * But if a device includes a configuration numbered 0,
2017 * we will accept it as a correctly configured state.
2018 * Use -1 if you really want to unconfigure the device.
2019 */
2020 if (cp && configuration == 0)
2021 dev_warn(&dev->dev, "config 0 descriptor??\n");
2022
2023 /* Allocate memory for new interfaces before doing anything else,
2024 * so that if we run out then nothing will have changed. */
2025 n = nintf = 0;
2026 if (cp) {
2027 nintf = cp->desc.bNumInterfaces;
2028 new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
2029 GFP_NOIO);
2030 if (!new_interfaces)
2031 return -ENOMEM;
2032
2033 for (; n < nintf; ++n) {
2034 new_interfaces[n] = kzalloc(
2035 sizeof(struct usb_interface),
2036 GFP_NOIO);
2037 if (!new_interfaces[n]) {
2038 ret = -ENOMEM;
2039free_interfaces:
2040 while (--n >= 0)
2041 kfree(new_interfaces[n]);
2042 kfree(new_interfaces);
2043 return ret;
2044 }
2045 }
2046
2047 i = dev->bus_mA - usb_get_max_power(dev, cp);
2048 if (i < 0)
2049 dev_warn(&dev->dev, "new config #%d exceeds power "
2050 "limit by %dmA\n",
2051 configuration, -i);
2052 }
2053
2054 /* Wake up the device so we can send it the Set-Config request */
2055 ret = usb_autoresume_device(dev);
2056 if (ret)
2057 goto free_interfaces;
2058
2059 /* if it's already configured, clear out old state first.
2060 * getting rid of old interfaces means unbinding their drivers.
2061 */
2062 if (dev->state != USB_STATE_ADDRESS)
2063 usb_disable_device(dev, 1); /* Skip ep0 */
2064
2065 /* Get rid of pending async Set-Config requests for this device */
2066 cancel_async_set_config(dev);
2067
2068 /* Make sure we have bandwidth (and available HCD resources) for this
2069 * configuration. Remove endpoints from the schedule if we're dropping
2070 * this configuration to set configuration 0. After this point, the
2071 * host controller will not allow submissions to dropped endpoints. If
2072 * this call fails, the device state is unchanged.
2073 */
2074 mutex_lock(hcd->bandwidth_mutex);
2075 /* Disable LPM, and re-enable it once the new configuration is
2076 * installed, so that the xHCI driver can recalculate the U1/U2
2077 * timeouts.
2078 */
2079 if (dev->actconfig && usb_disable_lpm(dev)) {
2080 dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2081 mutex_unlock(hcd->bandwidth_mutex);
2082 ret = -ENOMEM;
2083 goto free_interfaces;
2084 }
2085 ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
2086 if (ret < 0) {
2087 if (dev->actconfig)
2088 usb_enable_lpm(dev);
2089 mutex_unlock(hcd->bandwidth_mutex);
2090 usb_autosuspend_device(dev);
2091 goto free_interfaces;
2092 }
2093
2094 /*
2095 * Initialize the new interface structures and the
2096 * hc/hcd/usbcore interface/endpoint state.
2097 */
2098 for (i = 0; i < nintf; ++i) {
2099 struct usb_interface_cache *intfc;
2100 struct usb_interface *intf;
2101 struct usb_host_interface *alt;
2102 u8 ifnum;
2103
2104 cp->interface[i] = intf = new_interfaces[i];
2105 intfc = cp->intf_cache[i];
2106 intf->altsetting = intfc->altsetting;
2107 intf->num_altsetting = intfc->num_altsetting;
2108 intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2109 kref_get(&intfc->ref);
2110
2111 alt = usb_altnum_to_altsetting(intf, 0);
2112
2113 /* No altsetting 0? We'll assume the first altsetting.
2114 * We could use a GetInterface call, but if a device is
2115 * so non-compliant that it doesn't have altsetting 0
2116 * then I wouldn't trust its reply anyway.
2117 */
2118 if (!alt)
2119 alt = &intf->altsetting[0];
2120
2121 ifnum = alt->desc.bInterfaceNumber;
2122 intf->intf_assoc = find_iad(dev, cp, ifnum);
2123 intf->cur_altsetting = alt;
2124 usb_enable_interface(dev, intf, true);
2125 intf->dev.parent = &dev->dev;
2126 if (usb_of_has_combined_node(dev)) {
2127 device_set_of_node_from_dev(&intf->dev, &dev->dev);
2128 } else {
2129 intf->dev.of_node = usb_of_get_interface_node(dev,
2130 configuration, ifnum);
2131 }
2132 ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2133 intf->dev.driver = NULL;
2134 intf->dev.bus = &usb_bus_type;
2135 intf->dev.type = &usb_if_device_type;
2136 intf->dev.groups = usb_interface_groups;
2137 INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2138 INIT_WORK(&intf->wireless_status_work, __usb_wireless_status_intf);
2139 intf->minor = -1;
2140 device_initialize(&intf->dev);
2141 pm_runtime_no_callbacks(&intf->dev);
2142 dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
2143 dev->devpath, configuration, ifnum);
2144 usb_get_dev(dev);
2145 }
2146 kfree(new_interfaces);
2147
2148 ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2149 configuration, 0, NULL, 0,
2150 USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2151 if (ret && cp) {
2152 /*
2153 * All the old state is gone, so what else can we do?
2154 * The device is probably useless now anyway.
2155 */
2156 usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
2157 for (i = 0; i < nintf; ++i) {
2158 usb_disable_interface(dev, cp->interface[i], true);
2159 put_device(&cp->interface[i]->dev);
2160 cp->interface[i] = NULL;
2161 }
2162 cp = NULL;
2163 }
2164
2165 dev->actconfig = cp;
2166 mutex_unlock(hcd->bandwidth_mutex);
2167
2168 if (!cp) {
2169 usb_set_device_state(dev, USB_STATE_ADDRESS);
2170
2171 /* Leave LPM disabled while the device is unconfigured. */
2172 usb_autosuspend_device(dev);
2173 return ret;
2174 }
2175 usb_set_device_state(dev, USB_STATE_CONFIGURED);
2176
2177 if (cp->string == NULL &&
2178 !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2179 cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2180
2181 /* Now that the interfaces are installed, re-enable LPM. */
2182 usb_unlocked_enable_lpm(dev);
2183 /* Enable LTM if it was turned off by usb_disable_device. */
2184 usb_enable_ltm(dev);
2185
2186 /* Now that all the interfaces are set up, register them
2187 * to trigger binding of drivers to interfaces. probe()
2188 * routines may install different altsettings and may
2189 * claim() any interfaces not yet bound. Many class drivers
2190 * need that: CDC, audio, video, etc.
2191 */
2192 for (i = 0; i < nintf; ++i) {
2193 struct usb_interface *intf = cp->interface[i];
2194
2195 if (intf->dev.of_node &&
2196 !of_device_is_available(intf->dev.of_node)) {
2197 dev_info(&dev->dev, "skipping disabled interface %d\n",
2198 intf->cur_altsetting->desc.bInterfaceNumber);
2199 continue;
2200 }
2201
2202 dev_dbg(&dev->dev,
2203 "adding %s (config #%d, interface %d)\n",
2204 dev_name(&intf->dev), configuration,
2205 intf->cur_altsetting->desc.bInterfaceNumber);
2206 device_enable_async_suspend(&intf->dev);
2207 ret = device_add(&intf->dev);
2208 if (ret != 0) {
2209 dev_err(&dev->dev, "device_add(%s) --> %d\n",
2210 dev_name(&intf->dev), ret);
2211 continue;
2212 }
2213 create_intf_ep_devs(intf);
2214 }
2215
2216 usb_autosuspend_device(dev);
2217 return 0;
2218}
2219EXPORT_SYMBOL_GPL(usb_set_configuration);
2220
2221static LIST_HEAD(set_config_list);
2222static DEFINE_SPINLOCK(set_config_lock);
2223
2224struct set_config_request {
2225 struct usb_device *udev;
2226 int config;
2227 struct work_struct work;
2228 struct list_head node;
2229};
2230
2231/* Worker routine for usb_driver_set_configuration() */
2232static void driver_set_config_work(struct work_struct *work)
2233{
2234 struct set_config_request *req =
2235 container_of(work, struct set_config_request, work);
2236 struct usb_device *udev = req->udev;
2237
2238 usb_lock_device(udev);
2239 spin_lock(&set_config_lock);
2240 list_del(&req->node);
2241 spin_unlock(&set_config_lock);
2242
2243 if (req->config >= -1) /* Is req still valid? */
2244 usb_set_configuration(udev, req->config);
2245 usb_unlock_device(udev);
2246 usb_put_dev(udev);
2247 kfree(req);
2248}
2249
2250/* Cancel pending Set-Config requests for a device whose configuration
2251 * was just changed
2252 */
2253static void cancel_async_set_config(struct usb_device *udev)
2254{
2255 struct set_config_request *req;
2256
2257 spin_lock(&set_config_lock);
2258 list_for_each_entry(req, &set_config_list, node) {
2259 if (req->udev == udev)
2260 req->config = -999; /* Mark as cancelled */
2261 }
2262 spin_unlock(&set_config_lock);
2263}
2264
2265/**
2266 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2267 * @udev: the device whose configuration is being updated
2268 * @config: the configuration being chosen.
2269 * Context: In process context, must be able to sleep
2270 *
2271 * Device interface drivers are not allowed to change device configurations.
2272 * This is because changing configurations will destroy the interface the
2273 * driver is bound to and create new ones; it would be like a floppy-disk
2274 * driver telling the computer to replace the floppy-disk drive with a
2275 * tape drive!
2276 *
2277 * Still, in certain specialized circumstances the need may arise. This
2278 * routine gets around the normal restrictions by using a work thread to
2279 * submit the change-config request.
2280 *
2281 * Return: 0 if the request was successfully queued, error code otherwise.
2282 * The caller has no way to know whether the queued request will eventually
2283 * succeed.
2284 */
2285int usb_driver_set_configuration(struct usb_device *udev, int config)
2286{
2287 struct set_config_request *req;
2288
2289 req = kmalloc(sizeof(*req), GFP_KERNEL);
2290 if (!req)
2291 return -ENOMEM;
2292 req->udev = udev;
2293 req->config = config;
2294 INIT_WORK(&req->work, driver_set_config_work);
2295
2296 spin_lock(&set_config_lock);
2297 list_add(&req->node, &set_config_list);
2298 spin_unlock(&set_config_lock);
2299
2300 usb_get_dev(udev);
2301 schedule_work(&req->work);
2302 return 0;
2303}
2304EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2305
2306/**
2307 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2308 * @hdr: the place to put the results of the parsing
2309 * @intf: the interface for which parsing is requested
2310 * @buffer: pointer to the extra headers to be parsed
2311 * @buflen: length of the extra headers
2312 *
2313 * This evaluates the extra headers present in CDC devices which
2314 * bind the interfaces for data and control and provide details
2315 * about the capabilities of the device.
2316 *
2317 * Return: number of descriptors parsed or -EINVAL
2318 * if the header is contradictory beyond salvage
2319 */
2320
2321int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2322 struct usb_interface *intf,
2323 u8 *buffer,
2324 int buflen)
2325{
2326 /* duplicates are ignored */
2327 struct usb_cdc_union_desc *union_header = NULL;
2328
2329 /* duplicates are not tolerated */
2330 struct usb_cdc_header_desc *header = NULL;
2331 struct usb_cdc_ether_desc *ether = NULL;
2332 struct usb_cdc_mdlm_detail_desc *detail = NULL;
2333 struct usb_cdc_mdlm_desc *desc = NULL;
2334
2335 unsigned int elength;
2336 int cnt = 0;
2337
2338 memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2339 hdr->phonet_magic_present = false;
2340 while (buflen > 0) {
2341 elength = buffer[0];
2342 if (!elength) {
2343 dev_err(&intf->dev, "skipping garbage byte\n");
2344 elength = 1;
2345 goto next_desc;
2346 }
2347 if ((buflen < elength) || (elength < 3)) {
2348 dev_err(&intf->dev, "invalid descriptor buffer length\n");
2349 break;
2350 }
2351 if (buffer[1] != USB_DT_CS_INTERFACE) {
2352 dev_err(&intf->dev, "skipping garbage\n");
2353 goto next_desc;
2354 }
2355
2356 switch (buffer[2]) {
2357 case USB_CDC_UNION_TYPE: /* we've found it */
2358 if (elength < sizeof(struct usb_cdc_union_desc))
2359 goto next_desc;
2360 if (union_header) {
2361 dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2362 goto next_desc;
2363 }
2364 union_header = (struct usb_cdc_union_desc *)buffer;
2365 break;
2366 case USB_CDC_COUNTRY_TYPE:
2367 if (elength < sizeof(struct usb_cdc_country_functional_desc))
2368 goto next_desc;
2369 hdr->usb_cdc_country_functional_desc =
2370 (struct usb_cdc_country_functional_desc *)buffer;
2371 break;
2372 case USB_CDC_HEADER_TYPE:
2373 if (elength != sizeof(struct usb_cdc_header_desc))
2374 goto next_desc;
2375 if (header)
2376 return -EINVAL;
2377 header = (struct usb_cdc_header_desc *)buffer;
2378 break;
2379 case USB_CDC_ACM_TYPE:
2380 if (elength < sizeof(struct usb_cdc_acm_descriptor))
2381 goto next_desc;
2382 hdr->usb_cdc_acm_descriptor =
2383 (struct usb_cdc_acm_descriptor *)buffer;
2384 break;
2385 case USB_CDC_ETHERNET_TYPE:
2386 if (elength != sizeof(struct usb_cdc_ether_desc))
2387 goto next_desc;
2388 if (ether)
2389 return -EINVAL;
2390 ether = (struct usb_cdc_ether_desc *)buffer;
2391 break;
2392 case USB_CDC_CALL_MANAGEMENT_TYPE:
2393 if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2394 goto next_desc;
2395 hdr->usb_cdc_call_mgmt_descriptor =
2396 (struct usb_cdc_call_mgmt_descriptor *)buffer;
2397 break;
2398 case USB_CDC_DMM_TYPE:
2399 if (elength < sizeof(struct usb_cdc_dmm_desc))
2400 goto next_desc;
2401 hdr->usb_cdc_dmm_desc =
2402 (struct usb_cdc_dmm_desc *)buffer;
2403 break;
2404 case USB_CDC_MDLM_TYPE:
2405 if (elength < sizeof(struct usb_cdc_mdlm_desc))
2406 goto next_desc;
2407 if (desc)
2408 return -EINVAL;
2409 desc = (struct usb_cdc_mdlm_desc *)buffer;
2410 break;
2411 case USB_CDC_MDLM_DETAIL_TYPE:
2412 if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2413 goto next_desc;
2414 if (detail)
2415 return -EINVAL;
2416 detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2417 break;
2418 case USB_CDC_NCM_TYPE:
2419 if (elength < sizeof(struct usb_cdc_ncm_desc))
2420 goto next_desc;
2421 hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2422 break;
2423 case USB_CDC_MBIM_TYPE:
2424 if (elength < sizeof(struct usb_cdc_mbim_desc))
2425 goto next_desc;
2426
2427 hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2428 break;
2429 case USB_CDC_MBIM_EXTENDED_TYPE:
2430 if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2431 break;
2432 hdr->usb_cdc_mbim_extended_desc =
2433 (struct usb_cdc_mbim_extended_desc *)buffer;
2434 break;
2435 case CDC_PHONET_MAGIC_NUMBER:
2436 hdr->phonet_magic_present = true;
2437 break;
2438 default:
2439 /*
2440 * there are LOTS more CDC descriptors that
2441 * could legitimately be found here.
2442 */
2443 dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2444 buffer[2], elength);
2445 goto next_desc;
2446 }
2447 cnt++;
2448next_desc:
2449 buflen -= elength;
2450 buffer += elength;
2451 }
2452 hdr->usb_cdc_union_desc = union_header;
2453 hdr->usb_cdc_header_desc = header;
2454 hdr->usb_cdc_mdlm_detail_desc = detail;
2455 hdr->usb_cdc_mdlm_desc = desc;
2456 hdr->usb_cdc_ether_desc = ether;
2457 return cnt;
2458}
2459
2460EXPORT_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);