linux/drivers/usb/core/message.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * message.c - synchronous message handling
   4 *
   5 * Released under the GPLv2 only.
   6 */
   7
   8#include <linux/acpi.h>
   9#include <linux/pci.h>  /* for scatterlist macros */
  10#include <linux/usb.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
  13#include <linux/mm.h>
  14#include <linux/timer.h>
  15#include <linux/ctype.h>
  16#include <linux/nls.h>
  17#include <linux/device.h>
  18#include <linux/scatterlist.h>
  19#include <linux/usb/cdc.h>
  20#include <linux/usb/quirks.h>
  21#include <linux/usb/hcd.h>      /* for usbcore internals */
  22#include <linux/usb/of.h>
  23#include <asm/byteorder.h>
  24
  25#include "usb.h"
  26
  27static void cancel_async_set_config(struct usb_device *udev);
  28
  29struct api_context {
  30        struct completion       done;
  31        int                     status;
  32};
  33
  34static void usb_api_blocking_completion(struct urb *urb)
  35{
  36        struct api_context *ctx = urb->context;
  37
  38        ctx->status = urb->status;
  39        complete(&ctx->done);
  40}
  41
  42
  43/*
  44 * Starts urb and waits for completion or timeout. Note that this call
  45 * is NOT interruptible. Many device driver i/o requests should be
  46 * interruptible and therefore these drivers should implement their
  47 * own interruptible routines.
  48 */
  49static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
  50{
  51        struct api_context ctx;
  52        unsigned long expire;
  53        int retval;
  54
  55        init_completion(&ctx.done);
  56        urb->context = &ctx;
  57        urb->actual_length = 0;
  58        retval = usb_submit_urb(urb, GFP_NOIO);
  59        if (unlikely(retval))
  60                goto out;
  61
  62        expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
  63        if (!wait_for_completion_timeout(&ctx.done, expire)) {
  64                usb_kill_urb(urb);
  65                retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
  66
  67                dev_dbg(&urb->dev->dev,
  68                        "%s timed out on ep%d%s len=%u/%u\n",
  69                        current->comm,
  70                        usb_endpoint_num(&urb->ep->desc),
  71                        usb_urb_dir_in(urb) ? "in" : "out",
  72                        urb->actual_length,
  73                        urb->transfer_buffer_length);
  74        } else
  75                retval = ctx.status;
  76out:
  77        if (actual_length)
  78                *actual_length = urb->actual_length;
  79
  80        usb_free_urb(urb);
  81        return retval;
  82}
  83
  84/*-------------------------------------------------------------------*/
  85/* returns status (negative) or length (positive) */
  86static int usb_internal_control_msg(struct usb_device *usb_dev,
  87                                    unsigned int pipe,
  88                                    struct usb_ctrlrequest *cmd,
  89                                    void *data, int len, int timeout)
  90{
  91        struct urb *urb;
  92        int retv;
  93        int length;
  94
  95        urb = usb_alloc_urb(0, GFP_NOIO);
  96        if (!urb)
  97                return -ENOMEM;
  98
  99        usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
 100                             len, usb_api_blocking_completion, NULL);
 101
 102        retv = usb_start_wait_urb(urb, timeout, &length);
 103        if (retv < 0)
 104                return retv;
 105        else
 106                return length;
 107}
 108
 109/**
 110 * usb_control_msg - Builds a control urb, sends it off and waits for completion
 111 * @dev: pointer to the usb device to send the message to
 112 * @pipe: endpoint "pipe" to send the message to
 113 * @request: USB message request value
 114 * @requesttype: USB message request type value
 115 * @value: USB message value
 116 * @index: USB message index value
 117 * @data: pointer to the data to send
 118 * @size: length in bytes of the data to send
 119 * @timeout: time in msecs to wait for the message to complete before timing
 120 *      out (if 0 the wait is forever)
 121 *
 122 * Context: task context, might sleep.
 123 *
 124 * This function sends a simple control message to a specified endpoint and
 125 * waits for the message to complete, or timeout.
 126 *
 127 * Don't use this function from within an interrupt context. If you need
 128 * an asynchronous message, or need to send a message from within interrupt
 129 * context, use usb_submit_urb(). If a thread in your driver uses this call,
 130 * make sure your disconnect() method can wait for it to complete. Since you
 131 * don't have a handle on the URB used, you can't cancel the request.
 132 *
 133 * Return: If successful, the number of bytes transferred. Otherwise, a negative
 134 * error number.
 135 */
 136int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
 137                    __u8 requesttype, __u16 value, __u16 index, void *data,
 138                    __u16 size, int timeout)
 139{
 140        struct usb_ctrlrequest *dr;
 141        int ret;
 142
 143        dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 144        if (!dr)
 145                return -ENOMEM;
 146
 147        dr->bRequestType = requesttype;
 148        dr->bRequest = request;
 149        dr->wValue = cpu_to_le16(value);
 150        dr->wIndex = cpu_to_le16(index);
 151        dr->wLength = cpu_to_le16(size);
 152
 153        ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
 154
 155        /* Linger a bit, prior to the next control message. */
 156        if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
 157                msleep(200);
 158
 159        kfree(dr);
 160
 161        return ret;
 162}
 163EXPORT_SYMBOL_GPL(usb_control_msg);
 164
 165/**
 166 * usb_control_msg_send - Builds a control "send" message, sends it off and waits for completion
 167 * @dev: pointer to the usb device to send the message to
 168 * @endpoint: endpoint to send the message to
 169 * @request: USB message request value
 170 * @requesttype: USB message request type value
 171 * @value: USB message value
 172 * @index: USB message index value
 173 * @driver_data: pointer to the data to send
 174 * @size: length in bytes of the data to send
 175 * @timeout: time in msecs to wait for the message to complete before timing
 176 *      out (if 0 the wait is forever)
 177 * @memflags: the flags for memory allocation for buffers
 178 *
 179 * Context: !in_interrupt ()
 180 *
 181 * This function sends a control message to a specified endpoint that is not
 182 * expected to fill in a response (i.e. a "send message") and waits for the
 183 * message to complete, or timeout.
 184 *
 185 * Do not use this function from within an interrupt context. If you need
 186 * an asynchronous message, or need to send a message from within interrupt
 187 * context, use usb_submit_urb(). If a thread in your driver uses this call,
 188 * make sure your disconnect() method can wait for it to complete. Since you
 189 * don't have a handle on the URB used, you can't cancel the request.
 190 *
 191 * The data pointer can be made to a reference on the stack, or anywhere else,
 192 * as it will not be modified at all.  This does not have the restriction that
 193 * usb_control_msg() has where the data pointer must be to dynamically allocated
 194 * memory (i.e. memory that can be successfully DMAed to a device).
 195 *
 196 * Return: If successful, 0 is returned, Otherwise, a negative error number.
 197 */
 198int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request,
 199                         __u8 requesttype, __u16 value, __u16 index,
 200                         const void *driver_data, __u16 size, int timeout,
 201                         gfp_t memflags)
 202{
 203        unsigned int pipe = usb_sndctrlpipe(dev, endpoint);
 204        int ret;
 205        u8 *data = NULL;
 206
 207        if (size) {
 208                data = kmemdup(driver_data, size, memflags);
 209                if (!data)
 210                        return -ENOMEM;
 211        }
 212
 213        ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
 214                              data, size, timeout);
 215        kfree(data);
 216
 217        if (ret < 0)
 218                return ret;
 219
 220        return 0;
 221}
 222EXPORT_SYMBOL_GPL(usb_control_msg_send);
 223
 224/**
 225 * usb_control_msg_recv - Builds a control "receive" message, sends it off and waits for completion
 226 * @dev: pointer to the usb device to send the message to
 227 * @endpoint: endpoint to send the message to
 228 * @request: USB message request value
 229 * @requesttype: USB message request type value
 230 * @value: USB message value
 231 * @index: USB message index value
 232 * @driver_data: pointer to the data to be filled in by the message
 233 * @size: length in bytes of the data to be received
 234 * @timeout: time in msecs to wait for the message to complete before timing
 235 *      out (if 0 the wait is forever)
 236 * @memflags: the flags for memory allocation for buffers
 237 *
 238 * Context: !in_interrupt ()
 239 *
 240 * This function sends a control message to a specified endpoint that is
 241 * expected to fill in a response (i.e. a "receive message") and waits for the
 242 * message to complete, or timeout.
 243 *
 244 * Do not use this function from within an interrupt context. If you need
 245 * an asynchronous message, or need to send a message from within interrupt
 246 * context, use usb_submit_urb(). If a thread in your driver uses this call,
 247 * make sure your disconnect() method can wait for it to complete. Since you
 248 * don't have a handle on the URB used, you can't cancel the request.
 249 *
 250 * The data pointer can be made to a reference on the stack, or anywhere else
 251 * that can be successfully written to.  This function does not have the
 252 * restriction that usb_control_msg() has where the data pointer must be to
 253 * dynamically allocated memory (i.e. memory that can be successfully DMAed to a
 254 * device).
 255 *
 256 * The "whole" message must be properly received from the device in order for
 257 * this function to be successful.  If a device returns less than the expected
 258 * amount of data, then the function will fail.  Do not use this for messages
 259 * where a variable amount of data might be returned.
 260 *
 261 * Return: If successful, 0 is returned, Otherwise, a negative error number.
 262 */
 263int usb_control_msg_recv(struct usb_device *dev, __u8 endpoint, __u8 request,
 264                         __u8 requesttype, __u16 value, __u16 index,
 265                         void *driver_data, __u16 size, int timeout,
 266                         gfp_t memflags)
 267{
 268        unsigned int pipe = usb_rcvctrlpipe(dev, endpoint);
 269        int ret;
 270        u8 *data;
 271
 272        if (!size || !driver_data)
 273                return -EINVAL;
 274
 275        data = kmalloc(size, memflags);
 276        if (!data)
 277                return -ENOMEM;
 278
 279        ret = usb_control_msg(dev, pipe, request, requesttype, value, index,
 280                              data, size, timeout);
 281
 282        if (ret < 0)
 283                goto exit;
 284
 285        if (ret == size) {
 286                memcpy(driver_data, data, size);
 287                ret = 0;
 288        } else {
 289                ret = -EREMOTEIO;
 290        }
 291
 292exit:
 293        kfree(data);
 294        return ret;
 295}
 296EXPORT_SYMBOL_GPL(usb_control_msg_recv);
 297
 298/**
 299 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
 300 * @usb_dev: pointer to the usb device to send the message to
 301 * @pipe: endpoint "pipe" to send the message to
 302 * @data: pointer to the data to send
 303 * @len: length in bytes of the data to send
 304 * @actual_length: pointer to a location to put the actual length transferred
 305 *      in bytes
 306 * @timeout: time in msecs to wait for the message to complete before
 307 *      timing out (if 0 the wait is forever)
 308 *
 309 * Context: task context, might sleep.
 310 *
 311 * This function sends a simple interrupt message to a specified endpoint and
 312 * waits for the message to complete, or timeout.
 313 *
 314 * Don't use this function from within an interrupt context. If you need
 315 * an asynchronous message, or need to send a message from within interrupt
 316 * context, use usb_submit_urb() If a thread in your driver uses this call,
 317 * make sure your disconnect() method can wait for it to complete. Since you
 318 * don't have a handle on the URB used, you can't cancel the request.
 319 *
 320 * Return:
 321 * If successful, 0. Otherwise a negative error number. The number of actual
 322 * bytes transferred will be stored in the @actual_length parameter.
 323 */
 324int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
 325                      void *data, int len, int *actual_length, int timeout)
 326{
 327        return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
 328}
 329EXPORT_SYMBOL_GPL(usb_interrupt_msg);
 330
 331/**
 332 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
 333 * @usb_dev: pointer to the usb device to send the message to
 334 * @pipe: endpoint "pipe" to send the message to
 335 * @data: pointer to the data to send
 336 * @len: length in bytes of the data to send
 337 * @actual_length: pointer to a location to put the actual length transferred
 338 *      in bytes
 339 * @timeout: time in msecs to wait for the message to complete before
 340 *      timing out (if 0 the wait is forever)
 341 *
 342 * Context: task context, might sleep.
 343 *
 344 * This function sends a simple bulk message to a specified endpoint
 345 * and waits for the message to complete, or timeout.
 346 *
 347 * Don't use this function from within an interrupt context. If you need
 348 * an asynchronous message, or need to send a message from within interrupt
 349 * context, use usb_submit_urb() If a thread in your driver uses this call,
 350 * make sure your disconnect() method can wait for it to complete. Since you
 351 * don't have a handle on the URB used, you can't cancel the request.
 352 *
 353 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
 354 * users are forced to abuse this routine by using it to submit URBs for
 355 * interrupt endpoints.  We will take the liberty of creating an interrupt URB
 356 * (with the default interval) if the target is an interrupt endpoint.
 357 *
 358 * Return:
 359 * If successful, 0. Otherwise a negative error number. The number of actual
 360 * bytes transferred will be stored in the @actual_length parameter.
 361 *
 362 */
 363int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
 364                 void *data, int len, int *actual_length, int timeout)
 365{
 366        struct urb *urb;
 367        struct usb_host_endpoint *ep;
 368
 369        ep = usb_pipe_endpoint(usb_dev, pipe);
 370        if (!ep || len < 0)
 371                return -EINVAL;
 372
 373        urb = usb_alloc_urb(0, GFP_KERNEL);
 374        if (!urb)
 375                return -ENOMEM;
 376
 377        if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 378                        USB_ENDPOINT_XFER_INT) {
 379                pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
 380                usb_fill_int_urb(urb, usb_dev, pipe, data, len,
 381                                usb_api_blocking_completion, NULL,
 382                                ep->desc.bInterval);
 383        } else
 384                usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
 385                                usb_api_blocking_completion, NULL);
 386
 387        return usb_start_wait_urb(urb, timeout, actual_length);
 388}
 389EXPORT_SYMBOL_GPL(usb_bulk_msg);
 390
 391/*-------------------------------------------------------------------*/
 392
 393static void sg_clean(struct usb_sg_request *io)
 394{
 395        if (io->urbs) {
 396                while (io->entries--)
 397                        usb_free_urb(io->urbs[io->entries]);
 398                kfree(io->urbs);
 399                io->urbs = NULL;
 400        }
 401        io->dev = NULL;
 402}
 403
 404static void sg_complete(struct urb *urb)
 405{
 406        unsigned long flags;
 407        struct usb_sg_request *io = urb->context;
 408        int status = urb->status;
 409
 410        spin_lock_irqsave(&io->lock, flags);
 411
 412        /* In 2.5 we require hcds' endpoint queues not to progress after fault
 413         * reports, until the completion callback (this!) returns.  That lets
 414         * device driver code (like this routine) unlink queued urbs first,
 415         * if it needs to, since the HC won't work on them at all.  So it's
 416         * not possible for page N+1 to overwrite page N, and so on.
 417         *
 418         * That's only for "hard" faults; "soft" faults (unlinks) sometimes
 419         * complete before the HCD can get requests away from hardware,
 420         * though never during cleanup after a hard fault.
 421         */
 422        if (io->status
 423                        && (io->status != -ECONNRESET
 424                                || status != -ECONNRESET)
 425                        && urb->actual_length) {
 426                dev_err(io->dev->bus->controller,
 427                        "dev %s ep%d%s scatterlist error %d/%d\n",
 428                        io->dev->devpath,
 429                        usb_endpoint_num(&urb->ep->desc),
 430                        usb_urb_dir_in(urb) ? "in" : "out",
 431                        status, io->status);
 432                /* BUG (); */
 433        }
 434
 435        if (io->status == 0 && status && status != -ECONNRESET) {
 436                int i, found, retval;
 437
 438                io->status = status;
 439
 440                /* the previous urbs, and this one, completed already.
 441                 * unlink pending urbs so they won't rx/tx bad data.
 442                 * careful: unlink can sometimes be synchronous...
 443                 */
 444                spin_unlock_irqrestore(&io->lock, flags);
 445                for (i = 0, found = 0; i < io->entries; i++) {
 446                        if (!io->urbs[i])
 447                                continue;
 448                        if (found) {
 449                                usb_block_urb(io->urbs[i]);
 450                                retval = usb_unlink_urb(io->urbs[i]);
 451                                if (retval != -EINPROGRESS &&
 452                                    retval != -ENODEV &&
 453                                    retval != -EBUSY &&
 454                                    retval != -EIDRM)
 455                                        dev_err(&io->dev->dev,
 456                                                "%s, unlink --> %d\n",
 457                                                __func__, retval);
 458                        } else if (urb == io->urbs[i])
 459                                found = 1;
 460                }
 461                spin_lock_irqsave(&io->lock, flags);
 462        }
 463
 464        /* on the last completion, signal usb_sg_wait() */
 465        io->bytes += urb->actual_length;
 466        io->count--;
 467        if (!io->count)
 468                complete(&io->complete);
 469
 470        spin_unlock_irqrestore(&io->lock, flags);
 471}
 472
 473
 474/**
 475 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
 476 * @io: request block being initialized.  until usb_sg_wait() returns,
 477 *      treat this as a pointer to an opaque block of memory,
 478 * @dev: the usb device that will send or receive the data
 479 * @pipe: endpoint "pipe" used to transfer the data
 480 * @period: polling rate for interrupt endpoints, in frames or
 481 *      (for high speed endpoints) microframes; ignored for bulk
 482 * @sg: scatterlist entries
 483 * @nents: how many entries in the scatterlist
 484 * @length: how many bytes to send from the scatterlist, or zero to
 485 *      send every byte identified in the list.
 486 * @mem_flags: SLAB_* flags affecting memory allocations in this call
 487 *
 488 * This initializes a scatter/gather request, allocating resources such as
 489 * I/O mappings and urb memory (except maybe memory used by USB controller
 490 * drivers).
 491 *
 492 * The request must be issued using usb_sg_wait(), which waits for the I/O to
 493 * complete (or to be canceled) and then cleans up all resources allocated by
 494 * usb_sg_init().
 495 *
 496 * The request may be canceled with usb_sg_cancel(), either before or after
 497 * usb_sg_wait() is called.
 498 *
 499 * Return: Zero for success, else a negative errno value.
 500 */
 501int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
 502                unsigned pipe, unsigned period, struct scatterlist *sg,
 503                int nents, size_t length, gfp_t mem_flags)
 504{
 505        int i;
 506        int urb_flags;
 507        int use_sg;
 508
 509        if (!io || !dev || !sg
 510                        || usb_pipecontrol(pipe)
 511                        || usb_pipeisoc(pipe)
 512                        || nents <= 0)
 513                return -EINVAL;
 514
 515        spin_lock_init(&io->lock);
 516        io->dev = dev;
 517        io->pipe = pipe;
 518
 519        if (dev->bus->sg_tablesize > 0) {
 520                use_sg = true;
 521                io->entries = 1;
 522        } else {
 523                use_sg = false;
 524                io->entries = nents;
 525        }
 526
 527        /* initialize all the urbs we'll use */
 528        io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
 529        if (!io->urbs)
 530                goto nomem;
 531
 532        urb_flags = URB_NO_INTERRUPT;
 533        if (usb_pipein(pipe))
 534                urb_flags |= URB_SHORT_NOT_OK;
 535
 536        for_each_sg(sg, sg, io->entries, i) {
 537                struct urb *urb;
 538                unsigned len;
 539
 540                urb = usb_alloc_urb(0, mem_flags);
 541                if (!urb) {
 542                        io->entries = i;
 543                        goto nomem;
 544                }
 545                io->urbs[i] = urb;
 546
 547                urb->dev = NULL;
 548                urb->pipe = pipe;
 549                urb->interval = period;
 550                urb->transfer_flags = urb_flags;
 551                urb->complete = sg_complete;
 552                urb->context = io;
 553                urb->sg = sg;
 554
 555                if (use_sg) {
 556                        /* There is no single transfer buffer */
 557                        urb->transfer_buffer = NULL;
 558                        urb->num_sgs = nents;
 559
 560                        /* A length of zero means transfer the whole sg list */
 561                        len = length;
 562                        if (len == 0) {
 563                                struct scatterlist      *sg2;
 564                                int                     j;
 565
 566                                for_each_sg(sg, sg2, nents, j)
 567                                        len += sg2->length;
 568                        }
 569                } else {
 570                        /*
 571                         * Some systems can't use DMA; they use PIO instead.
 572                         * For their sakes, transfer_buffer is set whenever
 573                         * possible.
 574                         */
 575                        if (!PageHighMem(sg_page(sg)))
 576                                urb->transfer_buffer = sg_virt(sg);
 577                        else
 578                                urb->transfer_buffer = NULL;
 579
 580                        len = sg->length;
 581                        if (length) {
 582                                len = min_t(size_t, len, length);
 583                                length -= len;
 584                                if (length == 0)
 585                                        io->entries = i + 1;
 586                        }
 587                }
 588                urb->transfer_buffer_length = len;
 589        }
 590        io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
 591
 592        /* transaction state */
 593        io->count = io->entries;
 594        io->status = 0;
 595        io->bytes = 0;
 596        init_completion(&io->complete);
 597        return 0;
 598
 599nomem:
 600        sg_clean(io);
 601        return -ENOMEM;
 602}
 603EXPORT_SYMBOL_GPL(usb_sg_init);
 604
 605/**
 606 * usb_sg_wait - synchronously execute scatter/gather request
 607 * @io: request block handle, as initialized with usb_sg_init().
 608 *      some fields become accessible when this call returns.
 609 *
 610 * Context: task context, might sleep.
 611 *
 612 * This function blocks until the specified I/O operation completes.  It
 613 * leverages the grouping of the related I/O requests to get good transfer
 614 * rates, by queueing the requests.  At higher speeds, such queuing can
 615 * significantly improve USB throughput.
 616 *
 617 * There are three kinds of completion for this function.
 618 *
 619 * (1) success, where io->status is zero.  The number of io->bytes
 620 *     transferred is as requested.
 621 * (2) error, where io->status is a negative errno value.  The number
 622 *     of io->bytes transferred before the error is usually less
 623 *     than requested, and can be nonzero.
 624 * (3) cancellation, a type of error with status -ECONNRESET that
 625 *     is initiated by usb_sg_cancel().
 626 *
 627 * When this function returns, all memory allocated through usb_sg_init() or
 628 * this call will have been freed.  The request block parameter may still be
 629 * passed to usb_sg_cancel(), or it may be freed.  It could also be
 630 * reinitialized and then reused.
 631 *
 632 * Data Transfer Rates:
 633 *
 634 * Bulk transfers are valid for full or high speed endpoints.
 635 * The best full speed data rate is 19 packets of 64 bytes each
 636 * per frame, or 1216 bytes per millisecond.
 637 * The best high speed data rate is 13 packets of 512 bytes each
 638 * per microframe, or 52 KBytes per millisecond.
 639 *
 640 * The reason to use interrupt transfers through this API would most likely
 641 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
 642 * could be transferred.  That capability is less useful for low or full
 643 * speed interrupt endpoints, which allow at most one packet per millisecond,
 644 * of at most 8 or 64 bytes (respectively).
 645 *
 646 * It is not necessary to call this function to reserve bandwidth for devices
 647 * under an xHCI host controller, as the bandwidth is reserved when the
 648 * configuration or interface alt setting is selected.
 649 */
 650void usb_sg_wait(struct usb_sg_request *io)
 651{
 652        int i;
 653        int entries = io->entries;
 654
 655        /* queue the urbs.  */
 656        spin_lock_irq(&io->lock);
 657        i = 0;
 658        while (i < entries && !io->status) {
 659                int retval;
 660
 661                io->urbs[i]->dev = io->dev;
 662                spin_unlock_irq(&io->lock);
 663
 664                retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
 665
 666                switch (retval) {
 667                        /* maybe we retrying will recover */
 668                case -ENXIO:    /* hc didn't queue this one */
 669                case -EAGAIN:
 670                case -ENOMEM:
 671                        retval = 0;
 672                        yield();
 673                        break;
 674
 675                        /* no error? continue immediately.
 676                         *
 677                         * NOTE: to work better with UHCI (4K I/O buffer may
 678                         * need 3K of TDs) it may be good to limit how many
 679                         * URBs are queued at once; N milliseconds?
 680                         */
 681                case 0:
 682                        ++i;
 683                        cpu_relax();
 684                        break;
 685
 686                        /* fail any uncompleted urbs */
 687                default:
 688                        io->urbs[i]->status = retval;
 689                        dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
 690                                __func__, retval);
 691                        usb_sg_cancel(io);
 692                }
 693                spin_lock_irq(&io->lock);
 694                if (retval && (io->status == 0 || io->status == -ECONNRESET))
 695                        io->status = retval;
 696        }
 697        io->count -= entries - i;
 698        if (io->count == 0)
 699                complete(&io->complete);
 700        spin_unlock_irq(&io->lock);
 701
 702        /* OK, yes, this could be packaged as non-blocking.
 703         * So could the submit loop above ... but it's easier to
 704         * solve neither problem than to solve both!
 705         */
 706        wait_for_completion(&io->complete);
 707
 708        sg_clean(io);
 709}
 710EXPORT_SYMBOL_GPL(usb_sg_wait);
 711
 712/**
 713 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
 714 * @io: request block, initialized with usb_sg_init()
 715 *
 716 * This stops a request after it has been started by usb_sg_wait().
 717 * It can also prevents one initialized by usb_sg_init() from starting,
 718 * so that call just frees resources allocated to the request.
 719 */
 720void usb_sg_cancel(struct usb_sg_request *io)
 721{
 722        unsigned long flags;
 723        int i, retval;
 724
 725        spin_lock_irqsave(&io->lock, flags);
 726        if (io->status || io->count == 0) {
 727                spin_unlock_irqrestore(&io->lock, flags);
 728                return;
 729        }
 730        /* shut everything down */
 731        io->status = -ECONNRESET;
 732        io->count++;            /* Keep the request alive until we're done */
 733        spin_unlock_irqrestore(&io->lock, flags);
 734
 735        for (i = io->entries - 1; i >= 0; --i) {
 736                usb_block_urb(io->urbs[i]);
 737
 738                retval = usb_unlink_urb(io->urbs[i]);
 739                if (retval != -EINPROGRESS
 740                    && retval != -ENODEV
 741                    && retval != -EBUSY
 742                    && retval != -EIDRM)
 743                        dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
 744                                 __func__, retval);
 745        }
 746
 747        spin_lock_irqsave(&io->lock, flags);
 748        io->count--;
 749        if (!io->count)
 750                complete(&io->complete);
 751        spin_unlock_irqrestore(&io->lock, flags);
 752}
 753EXPORT_SYMBOL_GPL(usb_sg_cancel);
 754
 755/*-------------------------------------------------------------------*/
 756
 757/**
 758 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
 759 * @dev: the device whose descriptor is being retrieved
 760 * @type: the descriptor type (USB_DT_*)
 761 * @index: the number of the descriptor
 762 * @buf: where to put the descriptor
 763 * @size: how big is "buf"?
 764 *
 765 * Context: task context, might sleep.
 766 *
 767 * Gets a USB descriptor.  Convenience functions exist to simplify
 768 * getting some types of descriptors.  Use
 769 * usb_get_string() or usb_string() for USB_DT_STRING.
 770 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
 771 * are part of the device structure.
 772 * In addition to a number of USB-standard descriptors, some
 773 * devices also use class-specific or vendor-specific descriptors.
 774 *
 775 * This call is synchronous, and may not be used in an interrupt context.
 776 *
 777 * Return: The number of bytes received on success, or else the status code
 778 * returned by the underlying usb_control_msg() call.
 779 */
 780int usb_get_descriptor(struct usb_device *dev, unsigned char type,
 781                       unsigned char index, void *buf, int size)
 782{
 783        int i;
 784        int result;
 785
 786        if (size <= 0)          /* No point in asking for no data */
 787                return -EINVAL;
 788
 789        memset(buf, 0, size);   /* Make sure we parse really received data */
 790
 791        for (i = 0; i < 3; ++i) {
 792                /* retry on length 0 or error; some devices are flakey */
 793                result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 794                                USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 795                                (type << 8) + index, 0, buf, size,
 796                                USB_CTRL_GET_TIMEOUT);
 797                if (result <= 0 && result != -ETIMEDOUT)
 798                        continue;
 799                if (result > 1 && ((u8 *)buf)[1] != type) {
 800                        result = -ENODATA;
 801                        continue;
 802                }
 803                break;
 804        }
 805        return result;
 806}
 807EXPORT_SYMBOL_GPL(usb_get_descriptor);
 808
 809/**
 810 * usb_get_string - gets a string descriptor
 811 * @dev: the device whose string descriptor is being retrieved
 812 * @langid: code for language chosen (from string descriptor zero)
 813 * @index: the number of the descriptor
 814 * @buf: where to put the string
 815 * @size: how big is "buf"?
 816 *
 817 * Context: task context, might sleep.
 818 *
 819 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
 820 * in little-endian byte order).
 821 * The usb_string() function will often be a convenient way to turn
 822 * these strings into kernel-printable form.
 823 *
 824 * Strings may be referenced in device, configuration, interface, or other
 825 * descriptors, and could also be used in vendor-specific ways.
 826 *
 827 * This call is synchronous, and may not be used in an interrupt context.
 828 *
 829 * Return: The number of bytes received on success, or else the status code
 830 * returned by the underlying usb_control_msg() call.
 831 */
 832static int usb_get_string(struct usb_device *dev, unsigned short langid,
 833                          unsigned char index, void *buf, int size)
 834{
 835        int i;
 836        int result;
 837
 838        if (size <= 0)          /* No point in asking for no data */
 839                return -EINVAL;
 840
 841        for (i = 0; i < 3; ++i) {
 842                /* retry on length 0 or stall; some devices are flakey */
 843                result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 844                        USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 845                        (USB_DT_STRING << 8) + index, langid, buf, size,
 846                        USB_CTRL_GET_TIMEOUT);
 847                if (result == 0 || result == -EPIPE)
 848                        continue;
 849                if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
 850                        result = -ENODATA;
 851                        continue;
 852                }
 853                break;
 854        }
 855        return result;
 856}
 857
 858static void usb_try_string_workarounds(unsigned char *buf, int *length)
 859{
 860        int newlength, oldlength = *length;
 861
 862        for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
 863                if (!isprint(buf[newlength]) || buf[newlength + 1])
 864                        break;
 865
 866        if (newlength > 2) {
 867                buf[0] = newlength;
 868                *length = newlength;
 869        }
 870}
 871
 872static int usb_string_sub(struct usb_device *dev, unsigned int langid,
 873                          unsigned int index, unsigned char *buf)
 874{
 875        int rc;
 876
 877        /* Try to read the string descriptor by asking for the maximum
 878         * possible number of bytes */
 879        if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
 880                rc = -EIO;
 881        else
 882                rc = usb_get_string(dev, langid, index, buf, 255);
 883
 884        /* If that failed try to read the descriptor length, then
 885         * ask for just that many bytes */
 886        if (rc < 2) {
 887                rc = usb_get_string(dev, langid, index, buf, 2);
 888                if (rc == 2)
 889                        rc = usb_get_string(dev, langid, index, buf, buf[0]);
 890        }
 891
 892        if (rc >= 2) {
 893                if (!buf[0] && !buf[1])
 894                        usb_try_string_workarounds(buf, &rc);
 895
 896                /* There might be extra junk at the end of the descriptor */
 897                if (buf[0] < rc)
 898                        rc = buf[0];
 899
 900                rc = rc - (rc & 1); /* force a multiple of two */
 901        }
 902
 903        if (rc < 2)
 904                rc = (rc < 0 ? rc : -EINVAL);
 905
 906        return rc;
 907}
 908
 909static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
 910{
 911        int err;
 912
 913        if (dev->have_langid)
 914                return 0;
 915
 916        if (dev->string_langid < 0)
 917                return -EPIPE;
 918
 919        err = usb_string_sub(dev, 0, 0, tbuf);
 920
 921        /* If the string was reported but is malformed, default to english
 922         * (0x0409) */
 923        if (err == -ENODATA || (err > 0 && err < 4)) {
 924                dev->string_langid = 0x0409;
 925                dev->have_langid = 1;
 926                dev_err(&dev->dev,
 927                        "language id specifier not provided by device, defaulting to English\n");
 928                return 0;
 929        }
 930
 931        /* In case of all other errors, we assume the device is not able to
 932         * deal with strings at all. Set string_langid to -1 in order to
 933         * prevent any string to be retrieved from the device */
 934        if (err < 0) {
 935                dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
 936                                        err);
 937                dev->string_langid = -1;
 938                return -EPIPE;
 939        }
 940
 941        /* always use the first langid listed */
 942        dev->string_langid = tbuf[2] | (tbuf[3] << 8);
 943        dev->have_langid = 1;
 944        dev_dbg(&dev->dev, "default language 0x%04x\n",
 945                                dev->string_langid);
 946        return 0;
 947}
 948
 949/**
 950 * usb_string - returns UTF-8 version of a string descriptor
 951 * @dev: the device whose string descriptor is being retrieved
 952 * @index: the number of the descriptor
 953 * @buf: where to put the string
 954 * @size: how big is "buf"?
 955 *
 956 * Context: task context, might sleep.
 957 *
 958 * This converts the UTF-16LE encoded strings returned by devices, from
 959 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
 960 * that are more usable in most kernel contexts.  Note that this function
 961 * chooses strings in the first language supported by the device.
 962 *
 963 * This call is synchronous, and may not be used in an interrupt context.
 964 *
 965 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
 966 */
 967int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
 968{
 969        unsigned char *tbuf;
 970        int err;
 971
 972        if (dev->state == USB_STATE_SUSPENDED)
 973                return -EHOSTUNREACH;
 974        if (size <= 0 || !buf)
 975                return -EINVAL;
 976        buf[0] = 0;
 977        if (index <= 0 || index >= 256)
 978                return -EINVAL;
 979        tbuf = kmalloc(256, GFP_NOIO);
 980        if (!tbuf)
 981                return -ENOMEM;
 982
 983        err = usb_get_langid(dev, tbuf);
 984        if (err < 0)
 985                goto errout;
 986
 987        err = usb_string_sub(dev, dev->string_langid, index, tbuf);
 988        if (err < 0)
 989                goto errout;
 990
 991        size--;         /* leave room for trailing NULL char in output buffer */
 992        err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
 993                        UTF16_LITTLE_ENDIAN, buf, size);
 994        buf[err] = 0;
 995
 996        if (tbuf[1] != USB_DT_STRING)
 997                dev_dbg(&dev->dev,
 998                        "wrong descriptor type %02x for string %d (\"%s\")\n",
 999                        tbuf[1], index, buf);
1000
1001 errout:
1002        kfree(tbuf);
1003        return err;
1004}
1005EXPORT_SYMBOL_GPL(usb_string);
1006
1007/* one UTF-8-encoded 16-bit character has at most three bytes */
1008#define MAX_USB_STRING_SIZE (127 * 3 + 1)
1009
1010/**
1011 * usb_cache_string - read a string descriptor and cache it for later use
1012 * @udev: the device whose string descriptor is being read
1013 * @index: the descriptor index
1014 *
1015 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
1016 * or %NULL if the index is 0 or the string could not be read.
1017 */
1018char *usb_cache_string(struct usb_device *udev, int index)
1019{
1020        char *buf;
1021        char *smallbuf = NULL;
1022        int len;
1023
1024        if (index <= 0)
1025                return NULL;
1026
1027        buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
1028        if (buf) {
1029                len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
1030                if (len > 0) {
1031                        smallbuf = kmalloc(++len, GFP_NOIO);
1032                        if (!smallbuf)
1033                                return buf;
1034                        memcpy(smallbuf, buf, len);
1035                }
1036                kfree(buf);
1037        }
1038        return smallbuf;
1039}
1040
1041/*
1042 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
1043 * @dev: the device whose device descriptor is being updated
1044 * @size: how much of the descriptor to read
1045 *
1046 * Context: task context, might sleep.
1047 *
1048 * Updates the copy of the device descriptor stored in the device structure,
1049 * which dedicates space for this purpose.
1050 *
1051 * Not exported, only for use by the core.  If drivers really want to read
1052 * the device descriptor directly, they can call usb_get_descriptor() with
1053 * type = USB_DT_DEVICE and index = 0.
1054 *
1055 * This call is synchronous, and may not be used in an interrupt context.
1056 *
1057 * Return: The number of bytes received on success, or else the status code
1058 * returned by the underlying usb_control_msg() call.
1059 */
1060int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
1061{
1062        struct usb_device_descriptor *desc;
1063        int ret;
1064
1065        if (size > sizeof(*desc))
1066                return -EINVAL;
1067        desc = kmalloc(sizeof(*desc), GFP_NOIO);
1068        if (!desc)
1069                return -ENOMEM;
1070
1071        ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
1072        if (ret >= 0)
1073                memcpy(&dev->descriptor, desc, size);
1074        kfree(desc);
1075        return ret;
1076}
1077
1078/*
1079 * usb_set_isoch_delay - informs the device of the packet transmit delay
1080 * @dev: the device whose delay is to be informed
1081 * Context: task context, might sleep
1082 *
1083 * Since this is an optional request, we don't bother if it fails.
1084 */
1085int usb_set_isoch_delay(struct usb_device *dev)
1086{
1087        /* skip hub devices */
1088        if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
1089                return 0;
1090
1091        /* skip non-SS/non-SSP devices */
1092        if (dev->speed < USB_SPEED_SUPER)
1093                return 0;
1094
1095        return usb_control_msg_send(dev, 0,
1096                        USB_REQ_SET_ISOCH_DELAY,
1097                        USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
1098                        dev->hub_delay, 0, NULL, 0,
1099                        USB_CTRL_SET_TIMEOUT,
1100                        GFP_NOIO);
1101}
1102
1103/**
1104 * usb_get_status - issues a GET_STATUS call
1105 * @dev: the device whose status is being checked
1106 * @recip: USB_RECIP_*; for device, interface, or endpoint
1107 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
1108 * @target: zero (for device), else interface or endpoint number
1109 * @data: pointer to two bytes of bitmap data
1110 *
1111 * Context: task context, might sleep.
1112 *
1113 * Returns device, interface, or endpoint status.  Normally only of
1114 * interest to see if the device is self powered, or has enabled the
1115 * remote wakeup facility; or whether a bulk or interrupt endpoint
1116 * is halted ("stalled").
1117 *
1118 * Bits in these status bitmaps are set using the SET_FEATURE request,
1119 * and cleared using the CLEAR_FEATURE request.  The usb_clear_halt()
1120 * function should be used to clear halt ("stall") status.
1121 *
1122 * This call is synchronous, and may not be used in an interrupt context.
1123 *
1124 * Returns 0 and the status value in *@data (in host byte order) on success,
1125 * or else the status code from the underlying usb_control_msg() call.
1126 */
1127int usb_get_status(struct usb_device *dev, int recip, int type, int target,
1128                void *data)
1129{
1130        int ret;
1131        void *status;
1132        int length;
1133
1134        switch (type) {
1135        case USB_STATUS_TYPE_STANDARD:
1136                length = 2;
1137                break;
1138        case USB_STATUS_TYPE_PTM:
1139                if (recip != USB_RECIP_DEVICE)
1140                        return -EINVAL;
1141
1142                length = 4;
1143                break;
1144        default:
1145                return -EINVAL;
1146        }
1147
1148        status =  kmalloc(length, GFP_KERNEL);
1149        if (!status)
1150                return -ENOMEM;
1151
1152        ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1153                USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1154                target, status, length, USB_CTRL_GET_TIMEOUT);
1155
1156        switch (ret) {
1157        case 4:
1158                if (type != USB_STATUS_TYPE_PTM) {
1159                        ret = -EIO;
1160                        break;
1161                }
1162
1163                *(u32 *) data = le32_to_cpu(*(__le32 *) status);
1164                ret = 0;
1165                break;
1166        case 2:
1167                if (type != USB_STATUS_TYPE_STANDARD) {
1168                        ret = -EIO;
1169                        break;
1170                }
1171
1172                *(u16 *) data = le16_to_cpu(*(__le16 *) status);
1173                ret = 0;
1174                break;
1175        default:
1176                ret = -EIO;
1177        }
1178
1179        kfree(status);
1180        return ret;
1181}
1182EXPORT_SYMBOL_GPL(usb_get_status);
1183
1184/**
1185 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1186 * @dev: device whose endpoint is halted
1187 * @pipe: endpoint "pipe" being cleared
1188 *
1189 * Context: task context, might sleep.
1190 *
1191 * This is used to clear halt conditions for bulk and interrupt endpoints,
1192 * as reported by URB completion status.  Endpoints that are halted are
1193 * sometimes referred to as being "stalled".  Such endpoints are unable
1194 * to transmit or receive data until the halt status is cleared.  Any URBs
1195 * queued for such an endpoint should normally be unlinked by the driver
1196 * before clearing the halt condition, as described in sections 5.7.5
1197 * and 5.8.5 of the USB 2.0 spec.
1198 *
1199 * Note that control and isochronous endpoints don't halt, although control
1200 * endpoints report "protocol stall" (for unsupported requests) using the
1201 * same status code used to report a true stall.
1202 *
1203 * This call is synchronous, and may not be used in an interrupt context.
1204 *
1205 * Return: Zero on success, or else the status code returned by the
1206 * underlying usb_control_msg() call.
1207 */
1208int usb_clear_halt(struct usb_device *dev, int pipe)
1209{
1210        int result;
1211        int endp = usb_pipeendpoint(pipe);
1212
1213        if (usb_pipein(pipe))
1214                endp |= USB_DIR_IN;
1215
1216        /* we don't care if it wasn't halted first. in fact some devices
1217         * (like some ibmcam model 1 units) seem to expect hosts to make
1218         * this request for iso endpoints, which can't halt!
1219         */
1220        result = usb_control_msg_send(dev, 0,
1221                                      USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1222                                      USB_ENDPOINT_HALT, endp, NULL, 0,
1223                                      USB_CTRL_SET_TIMEOUT, GFP_NOIO);
1224
1225        /* don't un-halt or force to DATA0 except on success */
1226        if (result)
1227                return result;
1228
1229        /* NOTE:  seems like Microsoft and Apple don't bother verifying
1230         * the clear "took", so some devices could lock up if you check...
1231         * such as the Hagiwara FlashGate DUAL.  So we won't bother.
1232         *
1233         * NOTE:  make sure the logic here doesn't diverge much from
1234         * the copy in usb-storage, for as long as we need two copies.
1235         */
1236
1237        usb_reset_endpoint(dev, endp);
1238
1239        return 0;
1240}
1241EXPORT_SYMBOL_GPL(usb_clear_halt);
1242
1243static int create_intf_ep_devs(struct usb_interface *intf)
1244{
1245        struct usb_device *udev = interface_to_usbdev(intf);
1246        struct usb_host_interface *alt = intf->cur_altsetting;
1247        int i;
1248
1249        if (intf->ep_devs_created || intf->unregistering)
1250                return 0;
1251
1252        for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1253                (void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1254        intf->ep_devs_created = 1;
1255        return 0;
1256}
1257
1258static void remove_intf_ep_devs(struct usb_interface *intf)
1259{
1260        struct usb_host_interface *alt = intf->cur_altsetting;
1261        int i;
1262
1263        if (!intf->ep_devs_created)
1264                return;
1265
1266        for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1267                usb_remove_ep_devs(&alt->endpoint[i]);
1268        intf->ep_devs_created = 0;
1269}
1270
1271/**
1272 * usb_disable_endpoint -- Disable an endpoint by address
1273 * @dev: the device whose endpoint is being disabled
1274 * @epaddr: the endpoint's address.  Endpoint number for output,
1275 *      endpoint number + USB_DIR_IN for input
1276 * @reset_hardware: flag to erase any endpoint state stored in the
1277 *      controller hardware
1278 *
1279 * Disables the endpoint for URB submission and nukes all pending URBs.
1280 * If @reset_hardware is set then also deallocates hcd/hardware state
1281 * for the endpoint.
1282 */
1283void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1284                bool reset_hardware)
1285{
1286        unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1287        struct usb_host_endpoint *ep;
1288
1289        if (!dev)
1290                return;
1291
1292        if (usb_endpoint_out(epaddr)) {
1293                ep = dev->ep_out[epnum];
1294                if (reset_hardware && epnum != 0)
1295                        dev->ep_out[epnum] = NULL;
1296        } else {
1297                ep = dev->ep_in[epnum];
1298                if (reset_hardware && epnum != 0)
1299                        dev->ep_in[epnum] = NULL;
1300        }
1301        if (ep) {
1302                ep->enabled = 0;
1303                usb_hcd_flush_endpoint(dev, ep);
1304                if (reset_hardware)
1305                        usb_hcd_disable_endpoint(dev, ep);
1306        }
1307}
1308
1309/**
1310 * usb_reset_endpoint - Reset an endpoint's state.
1311 * @dev: the device whose endpoint is to be reset
1312 * @epaddr: the endpoint's address.  Endpoint number for output,
1313 *      endpoint number + USB_DIR_IN for input
1314 *
1315 * Resets any host-side endpoint state such as the toggle bit,
1316 * sequence number or current window.
1317 */
1318void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1319{
1320        unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1321        struct usb_host_endpoint *ep;
1322
1323        if (usb_endpoint_out(epaddr))
1324                ep = dev->ep_out[epnum];
1325        else
1326                ep = dev->ep_in[epnum];
1327        if (ep)
1328                usb_hcd_reset_endpoint(dev, ep);
1329}
1330EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1331
1332
1333/**
1334 * usb_disable_interface -- Disable all endpoints for an interface
1335 * @dev: the device whose interface is being disabled
1336 * @intf: pointer to the interface descriptor
1337 * @reset_hardware: flag to erase any endpoint state stored in the
1338 *      controller hardware
1339 *
1340 * Disables all the endpoints for the interface's current altsetting.
1341 */
1342void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1343                bool reset_hardware)
1344{
1345        struct usb_host_interface *alt = intf->cur_altsetting;
1346        int i;
1347
1348        for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1349                usb_disable_endpoint(dev,
1350                                alt->endpoint[i].desc.bEndpointAddress,
1351                                reset_hardware);
1352        }
1353}
1354
1355/*
1356 * usb_disable_device_endpoints -- Disable all endpoints for a device
1357 * @dev: the device whose endpoints are being disabled
1358 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1359 */
1360static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1361{
1362        struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1363        int i;
1364
1365        if (hcd->driver->check_bandwidth) {
1366                /* First pass: Cancel URBs, leave endpoint pointers intact. */
1367                for (i = skip_ep0; i < 16; ++i) {
1368                        usb_disable_endpoint(dev, i, false);
1369                        usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1370                }
1371                /* Remove endpoints from the host controller internal state */
1372                mutex_lock(hcd->bandwidth_mutex);
1373                usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1374                mutex_unlock(hcd->bandwidth_mutex);
1375        }
1376        /* Second pass: remove endpoint pointers */
1377        for (i = skip_ep0; i < 16; ++i) {
1378                usb_disable_endpoint(dev, i, true);
1379                usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1380        }
1381}
1382
1383/**
1384 * usb_disable_device - Disable all the endpoints for a USB device
1385 * @dev: the device whose endpoints are being disabled
1386 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1387 *
1388 * Disables all the device's endpoints, potentially including endpoint 0.
1389 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1390 * pending urbs) and usbcore state for the interfaces, so that usbcore
1391 * must usb_set_configuration() before any interfaces could be used.
1392 */
1393void usb_disable_device(struct usb_device *dev, int skip_ep0)
1394{
1395        int i;
1396
1397        /* getting rid of interfaces will disconnect
1398         * any drivers bound to them (a key side effect)
1399         */
1400        if (dev->actconfig) {
1401                /*
1402                 * FIXME: In order to avoid self-deadlock involving the
1403                 * bandwidth_mutex, we have to mark all the interfaces
1404                 * before unregistering any of them.
1405                 */
1406                for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1407                        dev->actconfig->interface[i]->unregistering = 1;
1408
1409                for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1410                        struct usb_interface    *interface;
1411
1412                        /* remove this interface if it has been registered */
1413                        interface = dev->actconfig->interface[i];
1414                        if (!device_is_registered(&interface->dev))
1415                                continue;
1416                        dev_dbg(&dev->dev, "unregistering interface %s\n",
1417                                dev_name(&interface->dev));
1418                        remove_intf_ep_devs(interface);
1419                        device_del(&interface->dev);
1420                }
1421
1422                /* Now that the interfaces are unbound, nobody should
1423                 * try to access them.
1424                 */
1425                for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1426                        put_device(&dev->actconfig->interface[i]->dev);
1427                        dev->actconfig->interface[i] = NULL;
1428                }
1429
1430                usb_disable_usb2_hardware_lpm(dev);
1431                usb_unlocked_disable_lpm(dev);
1432                usb_disable_ltm(dev);
1433
1434                dev->actconfig = NULL;
1435                if (dev->state == USB_STATE_CONFIGURED)
1436                        usb_set_device_state(dev, USB_STATE_ADDRESS);
1437        }
1438
1439        dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1440                skip_ep0 ? "non-ep0" : "all");
1441
1442        usb_disable_device_endpoints(dev, skip_ep0);
1443}
1444
1445/**
1446 * usb_enable_endpoint - Enable an endpoint for USB communications
1447 * @dev: the device whose interface is being enabled
1448 * @ep: the endpoint
1449 * @reset_ep: flag to reset the endpoint state
1450 *
1451 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1452 * For control endpoints, both the input and output sides are handled.
1453 */
1454void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1455                bool reset_ep)
1456{
1457        int epnum = usb_endpoint_num(&ep->desc);
1458        int is_out = usb_endpoint_dir_out(&ep->desc);
1459        int is_control = usb_endpoint_xfer_control(&ep->desc);
1460
1461        if (reset_ep)
1462                usb_hcd_reset_endpoint(dev, ep);
1463        if (is_out || is_control)
1464                dev->ep_out[epnum] = ep;
1465        if (!is_out || is_control)
1466                dev->ep_in[epnum] = ep;
1467        ep->enabled = 1;
1468}
1469
1470/**
1471 * usb_enable_interface - Enable all the endpoints for an interface
1472 * @dev: the device whose interface is being enabled
1473 * @intf: pointer to the interface descriptor
1474 * @reset_eps: flag to reset the endpoints' state
1475 *
1476 * Enables all the endpoints for the interface's current altsetting.
1477 */
1478void usb_enable_interface(struct usb_device *dev,
1479                struct usb_interface *intf, bool reset_eps)
1480{
1481        struct usb_host_interface *alt = intf->cur_altsetting;
1482        int i;
1483
1484        for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1485                usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1486}
1487
1488/**
1489 * usb_set_interface - Makes a particular alternate setting be current
1490 * @dev: the device whose interface is being updated
1491 * @interface: the interface being updated
1492 * @alternate: the setting being chosen.
1493 *
1494 * Context: task context, might sleep.
1495 *
1496 * This is used to enable data transfers on interfaces that may not
1497 * be enabled by default.  Not all devices support such configurability.
1498 * Only the driver bound to an interface may change its setting.
1499 *
1500 * Within any given configuration, each interface may have several
1501 * alternative settings.  These are often used to control levels of
1502 * bandwidth consumption.  For example, the default setting for a high
1503 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1504 * while interrupt transfers of up to 3KBytes per microframe are legal.
1505 * Also, isochronous endpoints may never be part of an
1506 * interface's default setting.  To access such bandwidth, alternate
1507 * interface settings must be made current.
1508 *
1509 * Note that in the Linux USB subsystem, bandwidth associated with
1510 * an endpoint in a given alternate setting is not reserved until an URB
1511 * is submitted that needs that bandwidth.  Some other operating systems
1512 * allocate bandwidth early, when a configuration is chosen.
1513 *
1514 * xHCI reserves bandwidth and configures the alternate setting in
1515 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1516 * may be disabled. Drivers cannot rely on any particular alternate
1517 * setting being in effect after a failure.
1518 *
1519 * This call is synchronous, and may not be used in an interrupt context.
1520 * Also, drivers must not change altsettings while urbs are scheduled for
1521 * endpoints in that interface; all such urbs must first be completed
1522 * (perhaps forced by unlinking).
1523 *
1524 * Return: Zero on success, or else the status code returned by the
1525 * underlying usb_control_msg() call.
1526 */
1527int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1528{
1529        struct usb_interface *iface;
1530        struct usb_host_interface *alt;
1531        struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1532        int i, ret, manual = 0;
1533        unsigned int epaddr;
1534        unsigned int pipe;
1535
1536        if (dev->state == USB_STATE_SUSPENDED)
1537                return -EHOSTUNREACH;
1538
1539        iface = usb_ifnum_to_if(dev, interface);
1540        if (!iface) {
1541                dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1542                        interface);
1543                return -EINVAL;
1544        }
1545        if (iface->unregistering)
1546                return -ENODEV;
1547
1548        alt = usb_altnum_to_altsetting(iface, alternate);
1549        if (!alt) {
1550                dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1551                         alternate);
1552                return -EINVAL;
1553        }
1554        /*
1555         * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1556         * including freeing dropped endpoint ring buffers.
1557         * Make sure the interface endpoints are flushed before that
1558         */
1559        usb_disable_interface(dev, iface, false);
1560
1561        /* Make sure we have enough bandwidth for this alternate interface.
1562         * Remove the current alt setting and add the new alt setting.
1563         */
1564        mutex_lock(hcd->bandwidth_mutex);
1565        /* Disable LPM, and re-enable it once the new alt setting is installed,
1566         * so that the xHCI driver can recalculate the U1/U2 timeouts.
1567         */
1568        if (usb_disable_lpm(dev)) {
1569                dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1570                mutex_unlock(hcd->bandwidth_mutex);
1571                return -ENOMEM;
1572        }
1573        /* Changing alt-setting also frees any allocated streams */
1574        for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1575                iface->cur_altsetting->endpoint[i].streams = 0;
1576
1577        ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1578        if (ret < 0) {
1579                dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1580                                alternate);
1581                usb_enable_lpm(dev);
1582                mutex_unlock(hcd->bandwidth_mutex);
1583                return ret;
1584        }
1585
1586        if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1587                ret = -EPIPE;
1588        else
1589                ret = usb_control_msg_send(dev, 0,
1590                                           USB_REQ_SET_INTERFACE,
1591                                           USB_RECIP_INTERFACE, alternate,
1592                                           interface, NULL, 0, 5000,
1593                                           GFP_NOIO);
1594
1595        /* 9.4.10 says devices don't need this and are free to STALL the
1596         * request if the interface only has one alternate setting.
1597         */
1598        if (ret == -EPIPE && iface->num_altsetting == 1) {
1599                dev_dbg(&dev->dev,
1600                        "manual set_interface for iface %d, alt %d\n",
1601                        interface, alternate);
1602                manual = 1;
1603        } else if (ret) {
1604                /* Re-instate the old alt setting */
1605                usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1606                usb_enable_lpm(dev);
1607                mutex_unlock(hcd->bandwidth_mutex);
1608                return ret;
1609        }
1610        mutex_unlock(hcd->bandwidth_mutex);
1611
1612        /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1613         * when they implement async or easily-killable versions of this or
1614         * other "should-be-internal" functions (like clear_halt).
1615         * should hcd+usbcore postprocess control requests?
1616         */
1617
1618        /* prevent submissions using previous endpoint settings */
1619        if (iface->cur_altsetting != alt) {
1620                remove_intf_ep_devs(iface);
1621                usb_remove_sysfs_intf_files(iface);
1622        }
1623        usb_disable_interface(dev, iface, true);
1624
1625        iface->cur_altsetting = alt;
1626
1627        /* Now that the interface is installed, re-enable LPM. */
1628        usb_unlocked_enable_lpm(dev);
1629
1630        /* If the interface only has one altsetting and the device didn't
1631         * accept the request, we attempt to carry out the equivalent action
1632         * by manually clearing the HALT feature for each endpoint in the
1633         * new altsetting.
1634         */
1635        if (manual) {
1636                for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1637                        epaddr = alt->endpoint[i].desc.bEndpointAddress;
1638                        pipe = __create_pipe(dev,
1639                                        USB_ENDPOINT_NUMBER_MASK & epaddr) |
1640                                        (usb_endpoint_out(epaddr) ?
1641                                        USB_DIR_OUT : USB_DIR_IN);
1642
1643                        usb_clear_halt(dev, pipe);
1644                }
1645        }
1646
1647        /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1648         *
1649         * Note:
1650         * Despite EP0 is always present in all interfaces/AS, the list of
1651         * endpoints from the descriptor does not contain EP0. Due to its
1652         * omnipresence one might expect EP0 being considered "affected" by
1653         * any SetInterface request and hence assume toggles need to be reset.
1654         * However, EP0 toggles are re-synced for every individual transfer
1655         * during the SETUP stage - hence EP0 toggles are "don't care" here.
1656         * (Likewise, EP0 never "halts" on well designed devices.)
1657         */
1658        usb_enable_interface(dev, iface, true);
1659        if (device_is_registered(&iface->dev)) {
1660                usb_create_sysfs_intf_files(iface);
1661                create_intf_ep_devs(iface);
1662        }
1663        return 0;
1664}
1665EXPORT_SYMBOL_GPL(usb_set_interface);
1666
1667/**
1668 * usb_reset_configuration - lightweight device reset
1669 * @dev: the device whose configuration is being reset
1670 *
1671 * This issues a standard SET_CONFIGURATION request to the device using
1672 * the current configuration.  The effect is to reset most USB-related
1673 * state in the device, including interface altsettings (reset to zero),
1674 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1675 * endpoints).  Other usbcore state is unchanged, including bindings of
1676 * usb device drivers to interfaces.
1677 *
1678 * Because this affects multiple interfaces, avoid using this with composite
1679 * (multi-interface) devices.  Instead, the driver for each interface may
1680 * use usb_set_interface() on the interfaces it claims.  Be careful though;
1681 * some devices don't support the SET_INTERFACE request, and others won't
1682 * reset all the interface state (notably endpoint state).  Resetting the whole
1683 * configuration would affect other drivers' interfaces.
1684 *
1685 * The caller must own the device lock.
1686 *
1687 * Return: Zero on success, else a negative error code.
1688 *
1689 * If this routine fails the device will probably be in an unusable state
1690 * with endpoints disabled, and interfaces only partially enabled.
1691 */
1692int usb_reset_configuration(struct usb_device *dev)
1693{
1694        int                     i, retval;
1695        struct usb_host_config  *config;
1696        struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1697
1698        if (dev->state == USB_STATE_SUSPENDED)
1699                return -EHOSTUNREACH;
1700
1701        /* caller must have locked the device and must own
1702         * the usb bus readlock (so driver bindings are stable);
1703         * calls during probe() are fine
1704         */
1705
1706        usb_disable_device_endpoints(dev, 1); /* skip ep0*/
1707
1708        config = dev->actconfig;
1709        retval = 0;
1710        mutex_lock(hcd->bandwidth_mutex);
1711        /* Disable LPM, and re-enable it once the configuration is reset, so
1712         * that the xHCI driver can recalculate the U1/U2 timeouts.
1713         */
1714        if (usb_disable_lpm(dev)) {
1715                dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1716                mutex_unlock(hcd->bandwidth_mutex);
1717                return -ENOMEM;
1718        }
1719
1720        /* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1721        retval = usb_hcd_alloc_bandwidth(dev, config, NULL, NULL);
1722        if (retval < 0) {
1723                usb_enable_lpm(dev);
1724                mutex_unlock(hcd->bandwidth_mutex);
1725                return retval;
1726        }
1727        retval = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
1728                                      config->desc.bConfigurationValue, 0,
1729                                      NULL, 0, USB_CTRL_SET_TIMEOUT,
1730                                      GFP_NOIO);
1731        if (retval) {
1732                usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1733                usb_enable_lpm(dev);
1734                mutex_unlock(hcd->bandwidth_mutex);
1735                return retval;
1736        }
1737        mutex_unlock(hcd->bandwidth_mutex);
1738
1739        /* re-init hc/hcd interface/endpoint state */
1740        for (i = 0; i < config->desc.bNumInterfaces; i++) {
1741                struct usb_interface *intf = config->interface[i];
1742                struct usb_host_interface *alt;
1743
1744                alt = usb_altnum_to_altsetting(intf, 0);
1745
1746                /* No altsetting 0?  We'll assume the first altsetting.
1747                 * We could use a GetInterface call, but if a device is
1748                 * so non-compliant that it doesn't have altsetting 0
1749                 * then I wouldn't trust its reply anyway.
1750                 */
1751                if (!alt)
1752                        alt = &intf->altsetting[0];
1753
1754                if (alt != intf->cur_altsetting) {
1755                        remove_intf_ep_devs(intf);
1756                        usb_remove_sysfs_intf_files(intf);
1757                }
1758                intf->cur_altsetting = alt;
1759                usb_enable_interface(dev, intf, true);
1760                if (device_is_registered(&intf->dev)) {
1761                        usb_create_sysfs_intf_files(intf);
1762                        create_intf_ep_devs(intf);
1763                }
1764        }
1765        /* Now that the interfaces are installed, re-enable LPM. */
1766        usb_unlocked_enable_lpm(dev);
1767        return 0;
1768}
1769EXPORT_SYMBOL_GPL(usb_reset_configuration);
1770
1771static void usb_release_interface(struct device *dev)
1772{
1773        struct usb_interface *intf = to_usb_interface(dev);
1774        struct usb_interface_cache *intfc =
1775                        altsetting_to_usb_interface_cache(intf->altsetting);
1776
1777        kref_put(&intfc->ref, usb_release_interface_cache);
1778        usb_put_dev(interface_to_usbdev(intf));
1779        of_node_put(dev->of_node);
1780        kfree(intf);
1781}
1782
1783/*
1784 * usb_deauthorize_interface - deauthorize an USB interface
1785 *
1786 * @intf: USB interface structure
1787 */
1788void usb_deauthorize_interface(struct usb_interface *intf)
1789{
1790        struct device *dev = &intf->dev;
1791
1792        device_lock(dev->parent);
1793
1794        if (intf->authorized) {
1795                device_lock(dev);
1796                intf->authorized = 0;
1797                device_unlock(dev);
1798
1799                usb_forced_unbind_intf(intf);
1800        }
1801
1802        device_unlock(dev->parent);
1803}
1804
1805/*
1806 * usb_authorize_interface - authorize an USB interface
1807 *
1808 * @intf: USB interface structure
1809 */
1810void usb_authorize_interface(struct usb_interface *intf)
1811{
1812        struct device *dev = &intf->dev;
1813
1814        if (!intf->authorized) {
1815                device_lock(dev);
1816                intf->authorized = 1; /* authorize interface */
1817                device_unlock(dev);
1818        }
1819}
1820
1821static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1822{
1823        struct usb_device *usb_dev;
1824        struct usb_interface *intf;
1825        struct usb_host_interface *alt;
1826
1827        intf = to_usb_interface(dev);
1828        usb_dev = interface_to_usbdev(intf);
1829        alt = intf->cur_altsetting;
1830
1831        if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1832                   alt->desc.bInterfaceClass,
1833                   alt->desc.bInterfaceSubClass,
1834                   alt->desc.bInterfaceProtocol))
1835                return -ENOMEM;
1836
1837        if (add_uevent_var(env,
1838                   "MODALIAS=usb:"
1839                   "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1840                   le16_to_cpu(usb_dev->descriptor.idVendor),
1841                   le16_to_cpu(usb_dev->descriptor.idProduct),
1842                   le16_to_cpu(usb_dev->descriptor.bcdDevice),
1843                   usb_dev->descriptor.bDeviceClass,
1844                   usb_dev->descriptor.bDeviceSubClass,
1845                   usb_dev->descriptor.bDeviceProtocol,
1846                   alt->desc.bInterfaceClass,
1847                   alt->desc.bInterfaceSubClass,
1848                   alt->desc.bInterfaceProtocol,
1849                   alt->desc.bInterfaceNumber))
1850                return -ENOMEM;
1851
1852        return 0;
1853}
1854
1855struct device_type usb_if_device_type = {
1856        .name =         "usb_interface",
1857        .release =      usb_release_interface,
1858        .uevent =       usb_if_uevent,
1859};
1860
1861static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1862                                                struct usb_host_config *config,
1863                                                u8 inum)
1864{
1865        struct usb_interface_assoc_descriptor *retval = NULL;
1866        struct usb_interface_assoc_descriptor *intf_assoc;
1867        int first_intf;
1868        int last_intf;
1869        int i;
1870
1871        for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1872                intf_assoc = config->intf_assoc[i];
1873                if (intf_assoc->bInterfaceCount == 0)
1874                        continue;
1875
1876                first_intf = intf_assoc->bFirstInterface;
1877                last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1878                if (inum >= first_intf && inum <= last_intf) {
1879                        if (!retval)
1880                                retval = intf_assoc;
1881                        else
1882                                dev_err(&dev->dev, "Interface #%d referenced"
1883                                        " by multiple IADs\n", inum);
1884                }
1885        }
1886
1887        return retval;
1888}
1889
1890
1891/*
1892 * Internal function to queue a device reset
1893 * See usb_queue_reset_device() for more details
1894 */
1895static void __usb_queue_reset_device(struct work_struct *ws)
1896{
1897        int rc;
1898        struct usb_interface *iface =
1899                container_of(ws, struct usb_interface, reset_ws);
1900        struct usb_device *udev = interface_to_usbdev(iface);
1901
1902        rc = usb_lock_device_for_reset(udev, iface);
1903        if (rc >= 0) {
1904                usb_reset_device(udev);
1905                usb_unlock_device(udev);
1906        }
1907        usb_put_intf(iface);    /* Undo _get_ in usb_queue_reset_device() */
1908}
1909
1910
1911/*
1912 * usb_set_configuration - Makes a particular device setting be current
1913 * @dev: the device whose configuration is being updated
1914 * @configuration: the configuration being chosen.
1915 *
1916 * Context: task context, might sleep. Caller holds device lock.
1917 *
1918 * This is used to enable non-default device modes.  Not all devices
1919 * use this kind of configurability; many devices only have one
1920 * configuration.
1921 *
1922 * @configuration is the value of the configuration to be installed.
1923 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1924 * must be non-zero; a value of zero indicates that the device in
1925 * unconfigured.  However some devices erroneously use 0 as one of their
1926 * configuration values.  To help manage such devices, this routine will
1927 * accept @configuration = -1 as indicating the device should be put in
1928 * an unconfigured state.
1929 *
1930 * USB device configurations may affect Linux interoperability,
1931 * power consumption and the functionality available.  For example,
1932 * the default configuration is limited to using 100mA of bus power,
1933 * so that when certain device functionality requires more power,
1934 * and the device is bus powered, that functionality should be in some
1935 * non-default device configuration.  Other device modes may also be
1936 * reflected as configuration options, such as whether two ISDN
1937 * channels are available independently; and choosing between open
1938 * standard device protocols (like CDC) or proprietary ones.
1939 *
1940 * Note that a non-authorized device (dev->authorized == 0) will only
1941 * be put in unconfigured mode.
1942 *
1943 * Note that USB has an additional level of device configurability,
1944 * associated with interfaces.  That configurability is accessed using
1945 * usb_set_interface().
1946 *
1947 * This call is synchronous. The calling context must be able to sleep,
1948 * must own the device lock, and must not hold the driver model's USB
1949 * bus mutex; usb interface driver probe() methods cannot use this routine.
1950 *
1951 * Returns zero on success, or else the status code returned by the
1952 * underlying call that failed.  On successful completion, each interface
1953 * in the original device configuration has been destroyed, and each one
1954 * in the new configuration has been probed by all relevant usb device
1955 * drivers currently known to the kernel.
1956 */
1957int usb_set_configuration(struct usb_device *dev, int configuration)
1958{
1959        int i, ret;
1960        struct usb_host_config *cp = NULL;
1961        struct usb_interface **new_interfaces = NULL;
1962        struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1963        int n, nintf;
1964
1965        if (dev->authorized == 0 || configuration == -1)
1966                configuration = 0;
1967        else {
1968                for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1969                        if (dev->config[i].desc.bConfigurationValue ==
1970                                        configuration) {
1971                                cp = &dev->config[i];
1972                                break;
1973                        }
1974                }
1975        }
1976        if ((!cp && configuration != 0))
1977                return -EINVAL;
1978
1979        /* The USB spec says configuration 0 means unconfigured.
1980         * But if a device includes a configuration numbered 0,
1981         * we will accept it as a correctly configured state.
1982         * Use -1 if you really want to unconfigure the device.
1983         */
1984        if (cp && configuration == 0)
1985                dev_warn(&dev->dev, "config 0 descriptor??\n");
1986
1987        /* Allocate memory for new interfaces before doing anything else,
1988         * so that if we run out then nothing will have changed. */
1989        n = nintf = 0;
1990        if (cp) {
1991                nintf = cp->desc.bNumInterfaces;
1992                new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
1993                                               GFP_NOIO);
1994                if (!new_interfaces)
1995                        return -ENOMEM;
1996
1997                for (; n < nintf; ++n) {
1998                        new_interfaces[n] = kzalloc(
1999                                        sizeof(struct usb_interface),
2000                                        GFP_NOIO);
2001                        if (!new_interfaces[n]) {
2002                                ret = -ENOMEM;
2003free_interfaces:
2004                                while (--n >= 0)
2005                                        kfree(new_interfaces[n]);
2006                                kfree(new_interfaces);
2007                                return ret;
2008                        }
2009                }
2010
2011                i = dev->bus_mA - usb_get_max_power(dev, cp);
2012                if (i < 0)
2013                        dev_warn(&dev->dev, "new config #%d exceeds power "
2014                                        "limit by %dmA\n",
2015                                        configuration, -i);
2016        }
2017
2018        /* Wake up the device so we can send it the Set-Config request */
2019        ret = usb_autoresume_device(dev);
2020        if (ret)
2021                goto free_interfaces;
2022
2023        /* if it's already configured, clear out old state first.
2024         * getting rid of old interfaces means unbinding their drivers.
2025         */
2026        if (dev->state != USB_STATE_ADDRESS)
2027                usb_disable_device(dev, 1);     /* Skip ep0 */
2028
2029        /* Get rid of pending async Set-Config requests for this device */
2030        cancel_async_set_config(dev);
2031
2032        /* Make sure we have bandwidth (and available HCD resources) for this
2033         * configuration.  Remove endpoints from the schedule if we're dropping
2034         * this configuration to set configuration 0.  After this point, the
2035         * host controller will not allow submissions to dropped endpoints.  If
2036         * this call fails, the device state is unchanged.
2037         */
2038        mutex_lock(hcd->bandwidth_mutex);
2039        /* Disable LPM, and re-enable it once the new configuration is
2040         * installed, so that the xHCI driver can recalculate the U1/U2
2041         * timeouts.
2042         */
2043        if (dev->actconfig && usb_disable_lpm(dev)) {
2044                dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
2045                mutex_unlock(hcd->bandwidth_mutex);
2046                ret = -ENOMEM;
2047                goto free_interfaces;
2048        }
2049        ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
2050        if (ret < 0) {
2051                if (dev->actconfig)
2052                        usb_enable_lpm(dev);
2053                mutex_unlock(hcd->bandwidth_mutex);
2054                usb_autosuspend_device(dev);
2055                goto free_interfaces;
2056        }
2057
2058        /*
2059         * Initialize the new interface structures and the
2060         * hc/hcd/usbcore interface/endpoint state.
2061         */
2062        for (i = 0; i < nintf; ++i) {
2063                struct usb_interface_cache *intfc;
2064                struct usb_interface *intf;
2065                struct usb_host_interface *alt;
2066                u8 ifnum;
2067
2068                cp->interface[i] = intf = new_interfaces[i];
2069                intfc = cp->intf_cache[i];
2070                intf->altsetting = intfc->altsetting;
2071                intf->num_altsetting = intfc->num_altsetting;
2072                intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
2073                kref_get(&intfc->ref);
2074
2075                alt = usb_altnum_to_altsetting(intf, 0);
2076
2077                /* No altsetting 0?  We'll assume the first altsetting.
2078                 * We could use a GetInterface call, but if a device is
2079                 * so non-compliant that it doesn't have altsetting 0
2080                 * then I wouldn't trust its reply anyway.
2081                 */
2082                if (!alt)
2083                        alt = &intf->altsetting[0];
2084
2085                ifnum = alt->desc.bInterfaceNumber;
2086                intf->intf_assoc = find_iad(dev, cp, ifnum);
2087                intf->cur_altsetting = alt;
2088                usb_enable_interface(dev, intf, true);
2089                intf->dev.parent = &dev->dev;
2090                if (usb_of_has_combined_node(dev)) {
2091                        device_set_of_node_from_dev(&intf->dev, &dev->dev);
2092                } else {
2093                        intf->dev.of_node = usb_of_get_interface_node(dev,
2094                                        configuration, ifnum);
2095                }
2096                ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
2097                intf->dev.driver = NULL;
2098                intf->dev.bus = &usb_bus_type;
2099                intf->dev.type = &usb_if_device_type;
2100                intf->dev.groups = usb_interface_groups;
2101                INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
2102                intf->minor = -1;
2103                device_initialize(&intf->dev);
2104                pm_runtime_no_callbacks(&intf->dev);
2105                dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
2106                                dev->devpath, configuration, ifnum);
2107                usb_get_dev(dev);
2108        }
2109        kfree(new_interfaces);
2110
2111        ret = usb_control_msg_send(dev, 0, USB_REQ_SET_CONFIGURATION, 0,
2112                                   configuration, 0, NULL, 0,
2113                                   USB_CTRL_SET_TIMEOUT, GFP_NOIO);
2114        if (ret && cp) {
2115                /*
2116                 * All the old state is gone, so what else can we do?
2117                 * The device is probably useless now anyway.
2118                 */
2119                usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
2120                for (i = 0; i < nintf; ++i) {
2121                        usb_disable_interface(dev, cp->interface[i], true);
2122                        put_device(&cp->interface[i]->dev);
2123                        cp->interface[i] = NULL;
2124                }
2125                cp = NULL;
2126        }
2127
2128        dev->actconfig = cp;
2129        mutex_unlock(hcd->bandwidth_mutex);
2130
2131        if (!cp) {
2132                usb_set_device_state(dev, USB_STATE_ADDRESS);
2133
2134                /* Leave LPM disabled while the device is unconfigured. */
2135                usb_autosuspend_device(dev);
2136                return ret;
2137        }
2138        usb_set_device_state(dev, USB_STATE_CONFIGURED);
2139
2140        if (cp->string == NULL &&
2141                        !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
2142                cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
2143
2144        /* Now that the interfaces are installed, re-enable LPM. */
2145        usb_unlocked_enable_lpm(dev);
2146        /* Enable LTM if it was turned off by usb_disable_device. */
2147        usb_enable_ltm(dev);
2148
2149        /* Now that all the interfaces are set up, register them
2150         * to trigger binding of drivers to interfaces.  probe()
2151         * routines may install different altsettings and may
2152         * claim() any interfaces not yet bound.  Many class drivers
2153         * need that: CDC, audio, video, etc.
2154         */
2155        for (i = 0; i < nintf; ++i) {
2156                struct usb_interface *intf = cp->interface[i];
2157
2158                if (intf->dev.of_node &&
2159                    !of_device_is_available(intf->dev.of_node)) {
2160                        dev_info(&dev->dev, "skipping disabled interface %d\n",
2161                                 intf->cur_altsetting->desc.bInterfaceNumber);
2162                        continue;
2163                }
2164
2165                dev_dbg(&dev->dev,
2166                        "adding %s (config #%d, interface %d)\n",
2167                        dev_name(&intf->dev), configuration,
2168                        intf->cur_altsetting->desc.bInterfaceNumber);
2169                device_enable_async_suspend(&intf->dev);
2170                ret = device_add(&intf->dev);
2171                if (ret != 0) {
2172                        dev_err(&dev->dev, "device_add(%s) --> %d\n",
2173                                dev_name(&intf->dev), ret);
2174                        continue;
2175                }
2176                create_intf_ep_devs(intf);
2177        }
2178
2179        usb_autosuspend_device(dev);
2180        return 0;
2181}
2182EXPORT_SYMBOL_GPL(usb_set_configuration);
2183
2184static LIST_HEAD(set_config_list);
2185static DEFINE_SPINLOCK(set_config_lock);
2186
2187struct set_config_request {
2188        struct usb_device       *udev;
2189        int                     config;
2190        struct work_struct      work;
2191        struct list_head        node;
2192};
2193
2194/* Worker routine for usb_driver_set_configuration() */
2195static void driver_set_config_work(struct work_struct *work)
2196{
2197        struct set_config_request *req =
2198                container_of(work, struct set_config_request, work);
2199        struct usb_device *udev = req->udev;
2200
2201        usb_lock_device(udev);
2202        spin_lock(&set_config_lock);
2203        list_del(&req->node);
2204        spin_unlock(&set_config_lock);
2205
2206        if (req->config >= -1)          /* Is req still valid? */
2207                usb_set_configuration(udev, req->config);
2208        usb_unlock_device(udev);
2209        usb_put_dev(udev);
2210        kfree(req);
2211}
2212
2213/* Cancel pending Set-Config requests for a device whose configuration
2214 * was just changed
2215 */
2216static void cancel_async_set_config(struct usb_device *udev)
2217{
2218        struct set_config_request *req;
2219
2220        spin_lock(&set_config_lock);
2221        list_for_each_entry(req, &set_config_list, node) {
2222                if (req->udev == udev)
2223                        req->config = -999;     /* Mark as cancelled */
2224        }
2225        spin_unlock(&set_config_lock);
2226}
2227
2228/**
2229 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2230 * @udev: the device whose configuration is being updated
2231 * @config: the configuration being chosen.
2232 * Context: In process context, must be able to sleep
2233 *
2234 * Device interface drivers are not allowed to change device configurations.
2235 * This is because changing configurations will destroy the interface the
2236 * driver is bound to and create new ones; it would be like a floppy-disk
2237 * driver telling the computer to replace the floppy-disk drive with a
2238 * tape drive!
2239 *
2240 * Still, in certain specialized circumstances the need may arise.  This
2241 * routine gets around the normal restrictions by using a work thread to
2242 * submit the change-config request.
2243 *
2244 * Return: 0 if the request was successfully queued, error code otherwise.
2245 * The caller has no way to know whether the queued request will eventually
2246 * succeed.
2247 */
2248int usb_driver_set_configuration(struct usb_device *udev, int config)
2249{
2250        struct set_config_request *req;
2251
2252        req = kmalloc(sizeof(*req), GFP_KERNEL);
2253        if (!req)
2254                return -ENOMEM;
2255        req->udev = udev;
2256        req->config = config;
2257        INIT_WORK(&req->work, driver_set_config_work);
2258
2259        spin_lock(&set_config_lock);
2260        list_add(&req->node, &set_config_list);
2261        spin_unlock(&set_config_lock);
2262
2263        usb_get_dev(udev);
2264        schedule_work(&req->work);
2265        return 0;
2266}
2267EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2268
2269/**
2270 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2271 * @hdr: the place to put the results of the parsing
2272 * @intf: the interface for which parsing is requested
2273 * @buffer: pointer to the extra headers to be parsed
2274 * @buflen: length of the extra headers
2275 *
2276 * This evaluates the extra headers present in CDC devices which
2277 * bind the interfaces for data and control and provide details
2278 * about the capabilities of the device.
2279 *
2280 * Return: number of descriptors parsed or -EINVAL
2281 * if the header is contradictory beyond salvage
2282 */
2283
2284int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2285                                struct usb_interface *intf,
2286                                u8 *buffer,
2287                                int buflen)
2288{
2289        /* duplicates are ignored */
2290        struct usb_cdc_union_desc *union_header = NULL;
2291
2292        /* duplicates are not tolerated */
2293        struct usb_cdc_header_desc *header = NULL;
2294        struct usb_cdc_ether_desc *ether = NULL;
2295        struct usb_cdc_mdlm_detail_desc *detail = NULL;
2296        struct usb_cdc_mdlm_desc *desc = NULL;
2297
2298        unsigned int elength;
2299        int cnt = 0;
2300
2301        memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2302        hdr->phonet_magic_present = false;
2303        while (buflen > 0) {
2304                elength = buffer[0];
2305                if (!elength) {
2306                        dev_err(&intf->dev, "skipping garbage byte\n");
2307                        elength = 1;
2308                        goto next_desc;
2309                }
2310                if ((buflen < elength) || (elength < 3)) {
2311                        dev_err(&intf->dev, "invalid descriptor buffer length\n");
2312                        break;
2313                }
2314                if (buffer[1] != USB_DT_CS_INTERFACE) {
2315                        dev_err(&intf->dev, "skipping garbage\n");
2316                        goto next_desc;
2317                }
2318
2319                switch (buffer[2]) {
2320                case USB_CDC_UNION_TYPE: /* we've found it */
2321                        if (elength < sizeof(struct usb_cdc_union_desc))
2322                                goto next_desc;
2323                        if (union_header) {
2324                                dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2325                                goto next_desc;
2326                        }
2327                        union_header = (struct usb_cdc_union_desc *)buffer;
2328                        break;
2329                case USB_CDC_COUNTRY_TYPE:
2330                        if (elength < sizeof(struct usb_cdc_country_functional_desc))
2331                                goto next_desc;
2332                        hdr->usb_cdc_country_functional_desc =
2333                                (struct usb_cdc_country_functional_desc *)buffer;
2334                        break;
2335                case USB_CDC_HEADER_TYPE:
2336                        if (elength != sizeof(struct usb_cdc_header_desc))
2337                                goto next_desc;
2338                        if (header)
2339                                return -EINVAL;
2340                        header = (struct usb_cdc_header_desc *)buffer;
2341                        break;
2342                case USB_CDC_ACM_TYPE:
2343                        if (elength < sizeof(struct usb_cdc_acm_descriptor))
2344                                goto next_desc;
2345                        hdr->usb_cdc_acm_descriptor =
2346                                (struct usb_cdc_acm_descriptor *)buffer;
2347                        break;
2348                case USB_CDC_ETHERNET_TYPE:
2349                        if (elength != sizeof(struct usb_cdc_ether_desc))
2350                                goto next_desc;
2351                        if (ether)
2352                                return -EINVAL;
2353                        ether = (struct usb_cdc_ether_desc *)buffer;
2354                        break;
2355                case USB_CDC_CALL_MANAGEMENT_TYPE:
2356                        if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2357                                goto next_desc;
2358                        hdr->usb_cdc_call_mgmt_descriptor =
2359                                (struct usb_cdc_call_mgmt_descriptor *)buffer;
2360                        break;
2361                case USB_CDC_DMM_TYPE:
2362                        if (elength < sizeof(struct usb_cdc_dmm_desc))
2363                                goto next_desc;
2364                        hdr->usb_cdc_dmm_desc =
2365                                (struct usb_cdc_dmm_desc *)buffer;
2366                        break;
2367                case USB_CDC_MDLM_TYPE:
2368                        if (elength < sizeof(struct usb_cdc_mdlm_desc))
2369                                goto next_desc;
2370                        if (desc)
2371                                return -EINVAL;
2372                        desc = (struct usb_cdc_mdlm_desc *)buffer;
2373                        break;
2374                case USB_CDC_MDLM_DETAIL_TYPE:
2375                        if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2376                                goto next_desc;
2377                        if (detail)
2378                                return -EINVAL;
2379                        detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2380                        break;
2381                case USB_CDC_NCM_TYPE:
2382                        if (elength < sizeof(struct usb_cdc_ncm_desc))
2383                                goto next_desc;
2384                        hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2385                        break;
2386                case USB_CDC_MBIM_TYPE:
2387                        if (elength < sizeof(struct usb_cdc_mbim_desc))
2388                                goto next_desc;
2389
2390                        hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2391                        break;
2392                case USB_CDC_MBIM_EXTENDED_TYPE:
2393                        if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2394                                break;
2395                        hdr->usb_cdc_mbim_extended_desc =
2396                                (struct usb_cdc_mbim_extended_desc *)buffer;
2397                        break;
2398                case CDC_PHONET_MAGIC_NUMBER:
2399                        hdr->phonet_magic_present = true;
2400                        break;
2401                default:
2402                        /*
2403                         * there are LOTS more CDC descriptors that
2404                         * could legitimately be found here.
2405                         */
2406                        dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2407                                        buffer[2], elength);
2408                        goto next_desc;
2409                }
2410                cnt++;
2411next_desc:
2412                buflen -= elength;
2413                buffer += elength;
2414        }
2415        hdr->usb_cdc_union_desc = union_header;
2416        hdr->usb_cdc_header_desc = header;
2417        hdr->usb_cdc_mdlm_detail_desc = detail;
2418        hdr->usb_cdc_mdlm_desc = desc;
2419        hdr->usb_cdc_ether_desc = ether;
2420        return cnt;
2421}
2422
2423EXPORT_SYMBOL(cdc_parse_cdc_header);
2424
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