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