drivers/usb/gadget/composite.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * composite.c - infrastructure for Composite USB Gadgets
   4  *
   5  * Copyright (C) 2006-2008 David Brownell
   6  */
   7
   8 /* #define VERBOSE_DEBUG */
   9
  10 #include <linux/kallsyms.h>
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/device.h>
  15 #include <linux/utsname.h>
  16 #include <linux/bitfield.h>
  17
  18 #include <linux/usb/composite.h>
  19 #include <linux/usb/otg.h>
  20 #include <asm/unaligned.h>
  21
  22 #include "u_os_desc.h"
  23
  24 /**
  25  * struct usb_os_string - represents OS String to be reported by a gadget
  26  * @bLength: total length of the entire descritor, always 0x12
  27  * @bDescriptorType: USB_DT_STRING
  28  * @qwSignature: the OS String proper
  29  * @bMS_VendorCode: code used by the host for subsequent requests
  30  * @bPad: not used, must be zero
  31  */
  32 struct usb_os_string {
  33         __u8    bLength;
  34         __u8    bDescriptorType;
  35         __u8    qwSignature[OS_STRING_QW_SIGN_LEN];
  36         __u8    bMS_VendorCode;
  37         __u8    bPad;
  38 } __packed;
  39
  40 /*
  41  * The code in this file is utility code, used to build a gadget driver
  42  * from one or more "function" drivers, one or more "configuration"
  43  * objects, and a "usb_composite_driver" by gluing them together along
  44  * with the relevant device-wide data.
  45  */
  46
  47 static struct usb_gadget_strings **get_containers_gs(
  48                 struct usb_gadget_string_container *uc)
  49 {
  50         return (struct usb_gadget_strings **)uc->stash;
  51 }
  52
  53 /**
  54  * function_descriptors() - get function descriptors for speed
  55  * @f: the function
  56  * @speed: the speed
  57  *
  58  * Returns the descriptors or NULL if not set.
  59  */
  60 static struct usb_descriptor_header **
  61 function_descriptors(struct usb_function *f,
  62                      enum usb_device_speed speed)
  63 {
  64         struct usb_descriptor_header **descriptors;
  65
  66         /*
  67          * NOTE: we try to help gadget drivers which might not be setting
  68          * max_speed appropriately.
  69          */
  70
  71         switch (speed) {
  72         case USB_SPEED_SUPER_PLUS:
  73                 descriptors = f->ssp_descriptors;
  74                 if (descriptors)
  75                         break;
  76                 fallthrough;
  77         case USB_SPEED_SUPER:
  78                 descriptors = f->ss_descriptors;
  79                 if (descriptors)
  80                         break;
  81                 fallthrough;
  82         case USB_SPEED_HIGH:
  83                 descriptors = f->hs_descriptors;
  84                 if (descriptors)
  85                         break;
  86                 fallthrough;
  87         default:
  88                 descriptors = f->fs_descriptors;
  89         }
  90
  91         /*
  92          * if we can't find any descriptors at all, then this gadget deserves to
  93          * Oops with a NULL pointer dereference
  94          */
  95
  96         return descriptors;
  97 }
  98
  99 /**
 100  * next_desc() - advance to the next desc_type descriptor
 101  * @t: currect pointer within descriptor array
 102  * @desc_type: descriptor type
 103  *
 104  * Return: next desc_type descriptor or NULL
 105  *
 106  * Iterate over @t until either desc_type descriptor found or
 107  * NULL (that indicates end of list) encountered
 108  */
 109 static struct usb_descriptor_header**
 110 next_desc(struct usb_descriptor_header **t, u8 desc_type)
 111 {
 112         for (; *t; t++) {
 113                 if ((*t)->bDescriptorType == desc_type)
 114                         return t;
 115         }
 116         return NULL;
 117 }
 118
 119 /*
 120  * for_each_desc() - iterate over desc_type descriptors in the
 121  * descriptors list
 122  * @start: pointer within descriptor array.
 123  * @iter_desc: desc_type descriptor to use as the loop cursor
 124  * @desc_type: wanted descriptr type
 125  */
 126 #define for_each_desc(start, iter_desc, desc_type) \
 127         for (iter_desc = next_desc(start, desc_type); \
 128              iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
 129
 130 /**
 131  * config_ep_by_speed_and_alt() - configures the given endpoint
 132  * according to gadget speed.
 133  * @g: pointer to the gadget
 134  * @f: usb function
 135  * @_ep: the endpoint to configure
 136  * @alt: alternate setting number
 137  *
 138  * Return: error code, 0 on success
 139  *
 140  * This function chooses the right descriptors for a given
 141  * endpoint according to gadget speed and saves it in the
 142  * endpoint desc field. If the endpoint already has a descriptor
 143  * assigned to it - overwrites it with currently corresponding
 144  * descriptor. The endpoint maxpacket field is updated according
 145  * to the chosen descriptor.
 146  * Note: the supplied function should hold all the descriptors
 147  * for supported speeds
 148  */
 149 int config_ep_by_speed_and_alt(struct usb_gadget *g,
 150                                 struct usb_function *f,
 151                                 struct usb_ep *_ep,
 152                                 u8 alt)
 153 {
 154         struct usb_endpoint_descriptor *chosen_desc = NULL;
 155         struct usb_interface_descriptor *int_desc = NULL;
 156         struct usb_descriptor_header **speed_desc = NULL;
 157
 158         struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
 159         int want_comp_desc = 0;
 160
 161         struct usb_descriptor_header **d_spd; /* cursor for speed desc */
 162
 163         if (!g || !f || !_ep)
 164                 return -EIO;
 165
 166         /* select desired speed */
 167         switch (g->speed) {
 168         case USB_SPEED_SUPER_PLUS:
 169                 if (gadget_is_superspeed_plus(g)) {
 170                         speed_desc = f->ssp_descriptors;
 171                         want_comp_desc = 1;
 172                         break;
 173                 }
 174                 fallthrough;
 175         case USB_SPEED_SUPER:
 176                 if (gadget_is_superspeed(g)) {
 177                         speed_desc = f->ss_descriptors;
 178                         want_comp_desc = 1;
 179                         break;
 180                 }
 181                 fallthrough;
 182         case USB_SPEED_HIGH:
 183                 if (gadget_is_dualspeed(g)) {
 184                         speed_desc = f->hs_descriptors;
 185                         break;
 186                 }
 187                 fallthrough;
 188         default:
 189                 speed_desc = f->fs_descriptors;
 190         }
 191
 192         /* find correct alternate setting descriptor */
 193         for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
 194                 int_desc = (struct usb_interface_descriptor *)*d_spd;
 195
 196                 if (int_desc->bAlternateSetting == alt) {
 197                         speed_desc = d_spd;
 198                         goto intf_found;
 199                 }
 200         }
 201         return -EIO;
 202
 203 intf_found:
 204         /* find descriptors */
 205         for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
 206                 chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 207                 if (chosen_desc->bEndpointAddress == _ep->address)
 208                         goto ep_found;
 209         }
 210         return -EIO;
 211
 212 ep_found:
 213         /* commit results */
 214         _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 215         _ep->desc = chosen_desc;
 216         _ep->comp_desc = NULL;
 217         _ep->maxburst = 0;
 218         _ep->mult = 1;
 219
 220         if (g->speed == USB_SPEED_HIGH && (usb_endpoint_xfer_isoc(_ep->desc) ||
 221                                 usb_endpoint_xfer_int(_ep->desc)))
 222                 _ep->mult = usb_endpoint_maxp_mult(_ep->desc);
 223
 224         if (!want_comp_desc)
 225                 return 0;
 226
 227         /*
 228          * Companion descriptor should follow EP descriptor
 229          * USB 3.0 spec, #9.6.7
 230          */
 231         comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 232         if (!comp_desc ||
 233             (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 234                 return -EIO;
 235         _ep->comp_desc = comp_desc;
 236         if (g->speed >= USB_SPEED_SUPER) {
 237                 switch (usb_endpoint_type(_ep->desc)) {
 238                 case USB_ENDPOINT_XFER_ISOC:
 239                         /* mult: bits 1:0 of bmAttributes */
 240                         _ep->mult = (comp_desc->bmAttributes & 0x3) + 1;
 241                         fallthrough;
 242                 case USB_ENDPOINT_XFER_BULK:
 243                 case USB_ENDPOINT_XFER_INT:
 244                         _ep->maxburst = comp_desc->bMaxBurst + 1;
 245                         break;
 246                 default:
 247                         if (comp_desc->bMaxBurst != 0) {
 248                                 struct usb_composite_dev *cdev;
 249
 250                                 cdev = get_gadget_data(g);
 251                                 ERROR(cdev, "ep0 bMaxBurst must be 0\n");
 252                         }
 253                         _ep->maxburst = 1;
 254                         break;
 255                 }
 256         }
 257         return 0;
 258 }
 259 EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
 260
 261 /**
 262  * config_ep_by_speed() - configures the given endpoint
 263  * according to gadget speed.
 264  * @g: pointer to the gadget
 265  * @f: usb function
 266  * @_ep: the endpoint to configure
 267  *
 268  * Return: error code, 0 on success
 269  *
 270  * This function chooses the right descriptors for a given
 271  * endpoint according to gadget speed and saves it in the
 272  * endpoint desc field. If the endpoint already has a descriptor
 273  * assigned to it - overwrites it with currently corresponding
 274  * descriptor. The endpoint maxpacket field is updated according
 275  * to the chosen descriptor.
 276  * Note: the supplied function should hold all the descriptors
 277  * for supported speeds
 278  */
 279 int config_ep_by_speed(struct usb_gadget *g,
 280                         struct usb_function *f,
 281                         struct usb_ep *_ep)
 282 {
 283         return config_ep_by_speed_and_alt(g, f, _ep, 0);
 284 }
 285 EXPORT_SYMBOL_GPL(config_ep_by_speed);
 286
 287 /**
 288  * usb_add_function() - add a function to a configuration
 289  * @config: the configuration
 290  * @function: the function being added
 291  * Context: single threaded during gadget setup
 292  *
 293  * After initialization, each configuration must have one or more
 294  * functions added to it.  Adding a function involves calling its @bind()
 295  * method to allocate resources such as interface and string identifiers
 296  * and endpoints.
 297  *
 298  * This function returns the value of the function's bind(), which is
 299  * zero for success else a negative errno value.
 300  */
 301 int usb_add_function(struct usb_configuration *config,
 302                 struct usb_function *function)
 303 {
 304         int     value = -EINVAL;
 305
 306         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 307                         function->name, function,
 308                         config->label, config);
 309
 310         if (!function->set_alt || !function->disable)
 311                 goto done;
 312
 313         function->config = config;
 314         list_add_tail(&function->list, &config->functions);
 315
 316         if (function->bind_deactivated) {
 317                 value = usb_function_deactivate(function);
 318                 if (value)
 319                         goto done;
 320         }
 321
 322         /* REVISIT *require* function->bind? */
 323         if (function->bind) {
 324                 value = function->bind(config, function);
 325                 if (value < 0) {
 326                         list_del(&function->list);
 327                         function->config = NULL;
 328                 }
 329         } else
 330                 value = 0;
 331
 332         /* We allow configurations that don't work at both speeds.
 333          * If we run into a lowspeed Linux system, treat it the same
 334          * as full speed ... it's the function drivers that will need
 335          * to avoid bulk and ISO transfers.
 336          */
 337         if (!config->fullspeed && function->fs_descriptors)
 338                 config->fullspeed = true;
 339         if (!config->highspeed && function->hs_descriptors)
 340                 config->highspeed = true;
 341         if (!config->superspeed && function->ss_descriptors)
 342                 config->superspeed = true;
 343         if (!config->superspeed_plus && function->ssp_descriptors)
 344                 config->superspeed_plus = true;
 345
 346 done:
 347         if (value)
 348                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 349                                 function->name, function, value);
 350         return value;
 351 }
 352 EXPORT_SYMBOL_GPL(usb_add_function);
 353
 354 void usb_remove_function(struct usb_configuration *c, struct usb_function *f)
 355 {
 356         if (f->disable)
 357                 f->disable(f);
 358
 359         bitmap_zero(f->endpoints, 32);
 360         list_del(&f->list);
 361         if (f->unbind)
 362                 f->unbind(c, f);
 363
 364         if (f->bind_deactivated)
 365                 usb_function_activate(f);
 366 }
 367 EXPORT_SYMBOL_GPL(usb_remove_function);
 368
 369 /**
 370  * usb_function_deactivate - prevent function and gadget enumeration
 371  * @function: the function that isn't yet ready to respond
 372  *
 373  * Blocks response of the gadget driver to host enumeration by
 374  * preventing the data line pullup from being activated.  This is
 375  * normally called during @bind() processing to change from the
 376  * initial "ready to respond" state, or when a required resource
 377  * becomes available.
 378  *
 379  * For example, drivers that serve as a passthrough to a userspace
 380  * daemon can block enumeration unless that daemon (such as an OBEX,
 381  * MTP, or print server) is ready to handle host requests.
 382  *
 383  * Not all systems support software control of their USB peripheral
 384  * data pullups.
 385  *
 386  * Returns zero on success, else negative errno.
 387  */
 388 int usb_function_deactivate(struct usb_function *function)
 389 {
 390         struct usb_composite_dev        *cdev = function->config->cdev;
 391         unsigned long                   flags;
 392         int                             status = 0;
 393
 394         spin_lock_irqsave(&cdev->lock, flags);
 395
 396         if (cdev->deactivations == 0) {
 397                 spin_unlock_irqrestore(&cdev->lock, flags);
 398                 status = usb_gadget_deactivate(cdev->gadget);
 399                 spin_lock_irqsave(&cdev->lock, flags);
 400         }
 401         if (status == 0)
 402                 cdev->deactivations++;
 403
 404         spin_unlock_irqrestore(&cdev->lock, flags);
 405         return status;
 406 }
 407 EXPORT_SYMBOL_GPL(usb_function_deactivate);
 408
 409 /**
 410  * usb_function_activate - allow function and gadget enumeration
 411  * @function: function on which usb_function_activate() was called
 412  *
 413  * Reverses effect of usb_function_deactivate().  If no more functions
 414  * are delaying their activation, the gadget driver will respond to
 415  * host enumeration procedures.
 416  *
 417  * Returns zero on success, else negative errno.
 418  */
 419 int usb_function_activate(struct usb_function *function)
 420 {
 421         struct usb_composite_dev        *cdev = function->config->cdev;
 422         unsigned long                   flags;
 423         int                             status = 0;
 424
 425         spin_lock_irqsave(&cdev->lock, flags);
 426
 427         if (WARN_ON(cdev->deactivations == 0))
 428                 status = -EINVAL;
 429         else {
 430                 cdev->deactivations--;
 431                 if (cdev->deactivations == 0) {
 432                         spin_unlock_irqrestore(&cdev->lock, flags);
 433                         status = usb_gadget_activate(cdev->gadget);
 434                         spin_lock_irqsave(&cdev->lock, flags);
 435                 }
 436         }
 437
 438         spin_unlock_irqrestore(&cdev->lock, flags);
 439         return status;
 440 }
 441 EXPORT_SYMBOL_GPL(usb_function_activate);
 442
 443 /**
 444  * usb_interface_id() - allocate an unused interface ID
 445  * @config: configuration associated with the interface
 446  * @function: function handling the interface
 447  * Context: single threaded during gadget setup
 448  *
 449  * usb_interface_id() is called from usb_function.bind() callbacks to
 450  * allocate new interface IDs.  The function driver will then store that
 451  * ID in interface, association, CDC union, and other descriptors.  It
 452  * will also handle any control requests targeted at that interface,
 453  * particularly changing its altsetting via set_alt().  There may
 454  * also be class-specific or vendor-specific requests to handle.
 455  *
 456  * All interface identifier should be allocated using this routine, to
 457  * ensure that for example different functions don't wrongly assign
 458  * different meanings to the same identifier.  Note that since interface
 459  * identifiers are configuration-specific, functions used in more than
 460  * one configuration (or more than once in a given configuration) need
 461  * multiple versions of the relevant descriptors.
 462  *
 463  * Returns the interface ID which was allocated; or -ENODEV if no
 464  * more interface IDs can be allocated.
 465  */
 466 int usb_interface_id(struct usb_configuration *config,
 467                 struct usb_function *function)
 468 {
 469         unsigned id = config->next_interface_id;
 470
 471         if (id < MAX_CONFIG_INTERFACES) {
 472                 config->interface[id] = function;
 473                 config->next_interface_id = id + 1;
 474                 return id;
 475         }
 476         return -ENODEV;
 477 }
 478 EXPORT_SYMBOL_GPL(usb_interface_id);
 479
 480 static u8 encode_bMaxPower(enum usb_device_speed speed,
 481                 struct usb_configuration *c)
 482 {
 483         unsigned val;
 484
 485         if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
 486                 val = c->MaxPower;
 487         else
 488                 val = CONFIG_USB_GADGET_VBUS_DRAW;
 489         if (!val)
 490                 return 0;
 491         if (speed < USB_SPEED_SUPER)
 492                 return min(val, 500U) / 2;
 493         else
 494                 /*
 495                  * USB 3.x supports up to 900mA, but since 900 isn't divisible
 496                  * by 8 the integral division will effectively cap to 896mA.
 497                  */
 498                 return min(val, 900U) / 8;
 499 }
 500
 501 static int config_buf(struct usb_configuration *config,
 502                 enum usb_device_speed speed, void *buf, u8 type)
 503 {
 504         struct usb_config_descriptor    *c = buf;
 505         void                            *next = buf + USB_DT_CONFIG_SIZE;
 506         int                             len;
 507         struct usb_function             *f;
 508         int                             status;
 509
 510         len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
 511         /* write the config descriptor */
 512         c = buf;
 513         c->bLength = USB_DT_CONFIG_SIZE;
 514         c->bDescriptorType = type;
 515         /* wTotalLength is written later */
 516         c->bNumInterfaces = config->next_interface_id;
 517         c->bConfigurationValue = config->bConfigurationValue;
 518         c->iConfiguration = config->iConfiguration;
 519         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 520         c->bMaxPower = encode_bMaxPower(speed, config);
 521
 522         /* There may be e.g. OTG descriptors */
 523         if (config->descriptors) {
 524                 status = usb_descriptor_fillbuf(next, len,
 525                                 config->descriptors);
 526                 if (status < 0)
 527                         return status;
 528                 len -= status;
 529                 next += status;
 530         }
 531
 532         /* add each function's descriptors */
 533         list_for_each_entry(f, &config->functions, list) {
 534                 struct usb_descriptor_header **descriptors;
 535
 536                 descriptors = function_descriptors(f, speed);
 537                 if (!descriptors)
 538                         continue;
 539                 status = usb_descriptor_fillbuf(next, len,
 540                         (const struct usb_descriptor_header **) descriptors);
 541                 if (status < 0)
 542                         return status;
 543                 len -= status;
 544                 next += status;
 545         }
 546
 547         len = next - buf;
 548         c->wTotalLength = cpu_to_le16(len);
 549         return len;
 550 }
 551
 552 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 553 {
 554         struct usb_gadget               *gadget = cdev->gadget;
 555         struct usb_configuration        *c;
 556         struct list_head                *pos;
 557         u8                              type = w_value >> 8;
 558         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 559
 560         if (gadget->speed >= USB_SPEED_SUPER)
 561                 speed = gadget->speed;
 562         else if (gadget_is_dualspeed(gadget)) {
 563                 int     hs = 0;
 564                 if (gadget->speed == USB_SPEED_HIGH)
 565                         hs = 1;
 566                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 567                         hs = !hs;
 568                 if (hs)
 569                         speed = USB_SPEED_HIGH;
 570
 571         }
 572
 573         /* This is a lookup by config *INDEX* */
 574         w_value &= 0xff;
 575
 576         pos = &cdev->configs;
 577         c = cdev->os_desc_config;
 578         if (c)
 579                 goto check_config;
 580
 581         while ((pos = pos->next) !=  &cdev->configs) {
 582                 c = list_entry(pos, typeof(*c), list);
 583
 584                 /* skip OS Descriptors config which is handled separately */
 585                 if (c == cdev->os_desc_config)
 586                         continue;
 587
 588 check_config:
 589                 /* ignore configs that won't work at this speed */
 590                 switch (speed) {
 591                 case USB_SPEED_SUPER_PLUS:
 592                         if (!c->superspeed_plus)
 593                                 continue;
 594                         break;
 595                 case USB_SPEED_SUPER:
 596                         if (!c->superspeed)
 597                                 continue;
 598                         break;
 599                 case USB_SPEED_HIGH:
 600                         if (!c->highspeed)
 601                                 continue;
 602                         break;
 603                 default:
 604                         if (!c->fullspeed)
 605                                 continue;
 606                 }
 607
 608                 if (w_value == 0)
 609                         return config_buf(c, speed, cdev->req->buf, type);
 610                 w_value--;
 611         }
 612         return -EINVAL;
 613 }
 614
 615 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 616 {
 617         struct usb_gadget               *gadget = cdev->gadget;
 618         struct usb_configuration        *c;
 619         unsigned                        count = 0;
 620         int                             hs = 0;
 621         int                             ss = 0;
 622         int                             ssp = 0;
 623
 624         if (gadget_is_dualspeed(gadget)) {
 625                 if (gadget->speed == USB_SPEED_HIGH)
 626                         hs = 1;
 627                 if (gadget->speed == USB_SPEED_SUPER)
 628                         ss = 1;
 629                 if (gadget->speed == USB_SPEED_SUPER_PLUS)
 630                         ssp = 1;
 631                 if (type == USB_DT_DEVICE_QUALIFIER)
 632                         hs = !hs;
 633         }
 634         list_for_each_entry(c, &cdev->configs, list) {
 635                 /* ignore configs that won't work at this speed */
 636                 if (ssp) {
 637                         if (!c->superspeed_plus)
 638                                 continue;
 639                 } else if (ss) {
 640                         if (!c->superspeed)
 641                                 continue;
 642                 } else if (hs) {
 643                         if (!c->highspeed)
 644                                 continue;
 645                 } else {
 646                         if (!c->fullspeed)
 647                                 continue;
 648                 }
 649                 count++;
 650         }
 651         return count;
 652 }
 653
 654 /**
 655  * bos_desc() - prepares the BOS descriptor.
 656  * @cdev: pointer to usb_composite device to generate the bos
 657  *      descriptor for
 658  *
 659  * This function generates the BOS (Binary Device Object)
 660  * descriptor and its device capabilities descriptors. The BOS
 661  * descriptor should be supported by a SuperSpeed device.
 662  */
 663 static int bos_desc(struct usb_composite_dev *cdev)
 664 {
 665         struct usb_ext_cap_descriptor   *usb_ext;
 666         struct usb_dcd_config_params    dcd_config_params;
 667         struct usb_bos_descriptor       *bos = cdev->req->buf;
 668         unsigned int                    besl = 0;
 669
 670         bos->bLength = USB_DT_BOS_SIZE;
 671         bos->bDescriptorType = USB_DT_BOS;
 672
 673         bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 674         bos->bNumDeviceCaps = 0;
 675
 676         /* Get Controller configuration */
 677         if (cdev->gadget->ops->get_config_params) {
 678                 cdev->gadget->ops->get_config_params(cdev->gadget,
 679                                                      &dcd_config_params);
 680         } else {
 681                 dcd_config_params.besl_baseline =
 682                         USB_DEFAULT_BESL_UNSPECIFIED;
 683                 dcd_config_params.besl_deep =
 684                         USB_DEFAULT_BESL_UNSPECIFIED;
 685                 dcd_config_params.bU1devExitLat =
 686                         USB_DEFAULT_U1_DEV_EXIT_LAT;
 687                 dcd_config_params.bU2DevExitLat =
 688                         cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
 689         }
 690
 691         if (dcd_config_params.besl_baseline != USB_DEFAULT_BESL_UNSPECIFIED)
 692                 besl = USB_BESL_BASELINE_VALID |
 693                         USB_SET_BESL_BASELINE(dcd_config_params.besl_baseline);
 694
 695         if (dcd_config_params.besl_deep != USB_DEFAULT_BESL_UNSPECIFIED)
 696                 besl |= USB_BESL_DEEP_VALID |
 697                         USB_SET_BESL_DEEP(dcd_config_params.besl_deep);
 698
 699         /*
 700          * A SuperSpeed device shall include the USB2.0 extension descriptor
 701          * and shall support LPM when operating in USB2.0 HS mode.
 702          */
 703         usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 704         bos->bNumDeviceCaps++;
 705         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 706         usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 707         usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 708         usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 709         usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT |
 710                                             USB_BESL_SUPPORT | besl);
 711
 712         /*
 713          * The Superspeed USB Capability descriptor shall be implemented by all
 714          * SuperSpeed devices.
 715          */
 716         if (gadget_is_superspeed(cdev->gadget)) {
 717                 struct usb_ss_cap_descriptor *ss_cap;
 718
 719                 ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 720                 bos->bNumDeviceCaps++;
 721                 le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 722                 ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 723                 ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 724                 ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 725                 ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 726                 ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 727                                                       USB_FULL_SPEED_OPERATION |
 728                                                       USB_HIGH_SPEED_OPERATION |
 729                                                       USB_5GBPS_OPERATION);
 730                 ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 731                 ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 732                 ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 733         }
 734
 735         /* The SuperSpeedPlus USB Device Capability descriptor */
 736         if (gadget_is_superspeed_plus(cdev->gadget)) {
 737                 struct usb_ssp_cap_descriptor *ssp_cap;
 738                 u8 ssac = 1;
 739                 u8 ssic;
 740                 int i;
 741
 742                 if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x2)
 743                         ssac = 3;
 744
 745                 /*
 746                  * Paired RX and TX sublink speed attributes share
 747                  * the same SSID.
 748                  */
 749                 ssic = (ssac + 1) / 2 - 1;
 750
 751                 ssp_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 752                 bos->bNumDeviceCaps++;
 753
 754                 le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SSP_CAP_SIZE(ssac));
 755                 ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(ssac);
 756                 ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 757                 ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
 758                 ssp_cap->bReserved = 0;
 759                 ssp_cap->wReserved = 0;
 760
 761                 ssp_cap->bmAttributes =
 762                         cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_ATTRIBS, ssac) |
 763                                     FIELD_PREP(USB_SSP_SUBLINK_SPEED_IDS, ssic));
 764
 765                 ssp_cap->wFunctionalitySupport =
 766                         cpu_to_le16(FIELD_PREP(USB_SSP_MIN_SUBLINK_SPEED_ATTRIBUTE_ID, 0) |
 767                                     FIELD_PREP(USB_SSP_MIN_RX_LANE_COUNT, 1) |
 768                                     FIELD_PREP(USB_SSP_MIN_TX_LANE_COUNT, 1));
 769
 770                 /*
 771                  * Use 1 SSID if the gadget supports up to gen2x1 or not
 772                  * specified:
 773                  * - SSID 0 for symmetric RX/TX sublink speed of 10 Gbps.
 774                  *
 775                  * Use 1 SSID if the gadget supports up to gen1x2:
 776                  * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
 777                  *
 778                  * Use 2 SSIDs if the gadget supports up to gen2x2:
 779                  * - SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
 780                  * - SSID 1 for symmetric RX/TX sublink speed of 10 Gbps.
 781                  */
 782                 for (i = 0; i < ssac + 1; i++) {
 783                         u8 ssid;
 784                         u8 mantissa;
 785                         u8 type;
 786
 787                         ssid = i >> 1;
 788
 789                         if (cdev->gadget->max_ssp_rate == USB_SSP_GEN_2x1 ||
 790                             cdev->gadget->max_ssp_rate == USB_SSP_GEN_UNKNOWN)
 791                                 mantissa = 10;
 792                         else
 793                                 mantissa = 5 << ssid;
 794
 795                         if (i % 2)
 796                                 type = USB_SSP_SUBLINK_SPEED_ST_SYM_TX;
 797                         else
 798                                 type = USB_SSP_SUBLINK_SPEED_ST_SYM_RX;
 799
 800                         ssp_cap->bmSublinkSpeedAttr[i] =
 801                                 cpu_to_le32(FIELD_PREP(USB_SSP_SUBLINK_SPEED_SSID, ssid) |
 802                                             FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSE,
 803                                                        USB_SSP_SUBLINK_SPEED_LSE_GBPS) |
 804                                             FIELD_PREP(USB_SSP_SUBLINK_SPEED_ST, type) |
 805                                             FIELD_PREP(USB_SSP_SUBLINK_SPEED_LP,
 806                                                        USB_SSP_SUBLINK_SPEED_LP_SSP) |
 807                                             FIELD_PREP(USB_SSP_SUBLINK_SPEED_LSM, mantissa));
 808                 }
 809         }
 810
 811         return le16_to_cpu(bos->wTotalLength);
 812 }
 813
 814 static void device_qual(struct usb_composite_dev *cdev)
 815 {
 816         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 817
 818         qual->bLength = sizeof(*qual);
 819         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 820         /* POLICY: same bcdUSB and device type info at both speeds */
 821         qual->bcdUSB = cdev->desc.bcdUSB;
 822         qual->bDeviceClass = cdev->desc.bDeviceClass;
 823         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 824         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 825         /* ASSUME same EP0 fifo size at both speeds */
 826         qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 827         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 828         qual->bRESERVED = 0;
 829 }
 830
 831 /*-------------------------------------------------------------------------*/
 832
 833 static void reset_config(struct usb_composite_dev *cdev)
 834 {
 835         struct usb_function             *f;
 836
 837         DBG(cdev, "reset config\n");
 838
 839         list_for_each_entry(f, &cdev->config->functions, list) {
 840                 if (f->disable)
 841                         f->disable(f);
 842
 843                 bitmap_zero(f->endpoints, 32);
 844         }
 845         cdev->config = NULL;
 846         cdev->delayed_status = 0;
 847 }
 848
 849 static int set_config(struct usb_composite_dev *cdev,
 850                 const struct usb_ctrlrequest *ctrl, unsigned number)
 851 {
 852         struct usb_gadget       *gadget = cdev->gadget;
 853         struct usb_configuration *c = NULL;
 854         int                     result = -EINVAL;
 855         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 856         int                     tmp;
 857
 858         if (number) {
 859                 list_for_each_entry(c, &cdev->configs, list) {
 860                         if (c->bConfigurationValue == number) {
 861                                 /*
 862                                  * We disable the FDs of the previous
 863                                  * configuration only if the new configuration
 864                                  * is a valid one
 865                                  */
 866                                 if (cdev->config)
 867                                         reset_config(cdev);
 868                                 result = 0;
 869                                 break;
 870                         }
 871                 }
 872                 if (result < 0)
 873                         goto done;
 874         } else { /* Zero configuration value - need to reset the config */
 875                 if (cdev->config)
 876                         reset_config(cdev);
 877                 result = 0;
 878         }
 879
 880         DBG(cdev, "%s config #%d: %s\n",
 881             usb_speed_string(gadget->speed),
 882             number, c ? c->label : "unconfigured");
 883
 884         if (!c)
 885                 goto done;
 886
 887         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
 888         cdev->config = c;
 889
 890         /* Initialize all interfaces by setting them to altsetting zero. */
 891         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 892                 struct usb_function     *f = c->interface[tmp];
 893                 struct usb_descriptor_header **descriptors;
 894
 895                 if (!f)
 896                         break;
 897
 898                 /*
 899                  * Record which endpoints are used by the function. This is used
 900                  * to dispatch control requests targeted at that endpoint to the
 901                  * function's setup callback instead of the current
 902                  * configuration's setup callback.
 903                  */
 904                 descriptors = function_descriptors(f, gadget->speed);
 905
 906                 for (; *descriptors; ++descriptors) {
 907                         struct usb_endpoint_descriptor *ep;
 908                         int addr;
 909
 910                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 911                                 continue;
 912
 913                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 914                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 915                              |  (ep->bEndpointAddress & 0x0f);
 916                         set_bit(addr, f->endpoints);
 917                 }
 918
 919                 result = f->set_alt(f, tmp, 0);
 920                 if (result < 0) {
 921                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 922                                         tmp, f->name, f, result);
 923
 924                         reset_config(cdev);
 925                         goto done;
 926                 }
 927
 928                 if (result == USB_GADGET_DELAYED_STATUS) {
 929                         DBG(cdev,
 930                          "%s: interface %d (%s) requested delayed status\n",
 931                                         __func__, tmp, f->name);
 932                         cdev->delayed_status++;
 933                         DBG(cdev, "delayed_status count %d\n",
 934                                         cdev->delayed_status);
 935                 }
 936         }
 937
 938         /* when we return, be sure our power usage is valid */
 939         if (c->MaxPower || (c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
 940                 power = c->MaxPower;
 941         else
 942                 power = CONFIG_USB_GADGET_VBUS_DRAW;
 943
 944         if (gadget->speed < USB_SPEED_SUPER)
 945                 power = min(power, 500U);
 946         else
 947                 power = min(power, 900U);
 948 done:
 949         if (power <= USB_SELF_POWER_VBUS_MAX_DRAW)
 950                 usb_gadget_set_selfpowered(gadget);
 951         else
 952                 usb_gadget_clear_selfpowered(gadget);
 953
 954         usb_gadget_vbus_draw(gadget, power);
 955         if (result >= 0 && cdev->delayed_status)
 956                 result = USB_GADGET_DELAYED_STATUS;
 957         return result;
 958 }
 959
 960 int usb_add_config_only(struct usb_composite_dev *cdev,
 961                 struct usb_configuration *config)
 962 {
 963         struct usb_configuration *c;
 964
 965         if (!config->bConfigurationValue)
 966                 return -EINVAL;
 967
 968         /* Prevent duplicate configuration identifiers */
 969         list_for_each_entry(c, &cdev->configs, list) {
 970                 if (c->bConfigurationValue == config->bConfigurationValue)
 971                         return -EBUSY;
 972         }
 973
 974         config->cdev = cdev;
 975         list_add_tail(&config->list, &cdev->configs);
 976
 977         INIT_LIST_HEAD(&config->functions);
 978         config->next_interface_id = 0;
 979         memset(config->interface, 0, sizeof(config->interface));
 980
 981         return 0;
 982 }
 983 EXPORT_SYMBOL_GPL(usb_add_config_only);
 984
 985 /**
 986  * usb_add_config() - add a configuration to a device.
 987  * @cdev: wraps the USB gadget
 988  * @config: the configuration, with bConfigurationValue assigned
 989  * @bind: the configuration's bind function
 990  * Context: single threaded during gadget setup
 991  *
 992  * One of the main tasks of a composite @bind() routine is to
 993  * add each of the configurations it supports, using this routine.
 994  *
 995  * This function returns the value of the configuration's @bind(), which
 996  * is zero for success else a negative errno value.  Binding configurations
 997  * assigns global resources including string IDs, and per-configuration
 998  * resources such as interface IDs and endpoints.
 999  */
1000 int usb_add_config(struct usb_composite_dev *cdev,
1001                 struct usb_configuration *config,
1002                 int (*bind)(struct usb_configuration *))
1003 {
1004         int                             status = -EINVAL;
1005
1006         if (!bind)
1007                 goto done;
1008
1009         DBG(cdev, "adding config #%u '%s'/%p\n",
1010                         config->bConfigurationValue,
1011                         config->label, config);
1012
1013         status = usb_add_config_only(cdev, config);
1014         if (status)
1015                 goto done;
1016
1017         status = bind(config);
1018         if (status < 0) {
1019                 while (!list_empty(&config->functions)) {
1020                         struct usb_function             *f;
1021
1022                         f = list_first_entry(&config->functions,
1023                                         struct usb_function, list);
1024                         list_del(&f->list);
1025                         if (f->unbind) {
1026                                 DBG(cdev, "unbind function '%s'/%p\n",
1027                                         f->name, f);
1028                                 f->unbind(config, f);
1029                                 /* may free memory for "f" */
1030                         }
1031                 }
1032                 list_del(&config->list);
1033                 config->cdev = NULL;
1034         } else {
1035                 unsigned        i;
1036
1037                 DBG(cdev, "cfg %d/%p speeds:%s%s%s%s\n",
1038                         config->bConfigurationValue, config,
1039                         config->superspeed_plus ? " superplus" : "",
1040                         config->superspeed ? " super" : "",
1041                         config->highspeed ? " high" : "",
1042                         config->fullspeed
1043                                 ? (gadget_is_dualspeed(cdev->gadget)
1044                                         ? " full"
1045                                         : " full/low")
1046                                 : "");
1047
1048                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
1049                         struct usb_function     *f = config->interface[i];
1050
1051                         if (!f)
1052                                 continue;
1053                         DBG(cdev, "  interface %d = %s/%p\n",
1054                                 i, f->name, f);
1055                 }
1056         }
1057
1058         /* set_alt(), or next bind(), sets up ep->claimed as needed */
1059         usb_ep_autoconfig_reset(cdev->gadget);
1060
1061 done:
1062         if (status)
1063                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
1064                                 config->bConfigurationValue, status);
1065         return status;
1066 }
1067 EXPORT_SYMBOL_GPL(usb_add_config);
1068
1069 static void remove_config(struct usb_composite_dev *cdev,
1070                               struct usb_configuration *config)
1071 {
1072         while (!list_empty(&config->functions)) {
1073                 struct usb_function             *f;
1074
1075                 f = list_first_entry(&config->functions,
1076                                 struct usb_function, list);
1077
1078                 usb_remove_function(config, f);
1079         }
1080         list_del(&config->list);
1081         if (config->unbind) {
1082                 DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
1083                 config->unbind(config);
1084                         /* may free memory for "c" */
1085         }
1086 }
1087
1088 /**
1089  * usb_remove_config() - remove a configuration from a device.
1090  * @cdev: wraps the USB gadget
1091  * @config: the configuration
1092  *
1093  * Drivers must call usb_gadget_disconnect before calling this function
1094  * to disconnect the device from the host and make sure the host will not
1095  * try to enumerate the device while we are changing the config list.
1096  */
1097 void usb_remove_config(struct usb_composite_dev *cdev,
1098                       struct usb_configuration *config)
1099 {
1100         unsigned long flags;
1101
1102         spin_lock_irqsave(&cdev->lock, flags);
1103
1104         if (cdev->config == config)
1105                 reset_config(cdev);
1106
1107         spin_unlock_irqrestore(&cdev->lock, flags);
1108
1109         remove_config(cdev, config);
1110 }
1111
1112 /*-------------------------------------------------------------------------*/
1113
1114 /* We support strings in multiple languages ... string descriptor zero
1115  * says which languages are supported.  The typical case will be that
1116  * only one language (probably English) is used, with i18n handled on
1117  * the host side.
1118  */
1119
1120 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
1121 {
1122         const struct usb_gadget_strings *s;
1123         __le16                          language;
1124         __le16                          *tmp;
1125
1126         while (*sp) {
1127                 s = *sp;
1128                 language = cpu_to_le16(s->language);
1129                 for (tmp = buf; *tmp && tmp < &buf[USB_MAX_STRING_LEN]; tmp++) {
1130                         if (*tmp == language)
1131                                 goto repeat;
1132                 }
1133                 *tmp++ = language;
1134 repeat:
1135                 sp++;
1136         }
1137 }
1138
1139 static int lookup_string(
1140         struct usb_gadget_strings       **sp,
1141         void                            *buf,
1142         u16                             language,
1143         int                             id
1144 )
1145 {
1146         struct usb_gadget_strings       *s;
1147         int                             value;
1148
1149         while (*sp) {
1150                 s = *sp++;
1151                 if (s->language != language)
1152                         continue;
1153                 value = usb_gadget_get_string(s, id, buf);
1154                 if (value > 0)
1155                         return value;
1156         }
1157         return -EINVAL;
1158 }
1159
1160 static int get_string(struct usb_composite_dev *cdev,
1161                 void *buf, u16 language, int id)
1162 {
1163         struct usb_composite_driver     *composite = cdev->driver;
1164         struct usb_gadget_string_container *uc;
1165         struct usb_configuration        *c;
1166         struct usb_function             *f;
1167         int                             len;
1168
1169         /* Yes, not only is USB's i18n support probably more than most
1170          * folk will ever care about ... also, it's all supported here.
1171          * (Except for UTF8 support for Unicode's "Astral Planes".)
1172          */
1173
1174         /* 0 == report all available language codes */
1175         if (id == 0) {
1176                 struct usb_string_descriptor    *s = buf;
1177                 struct usb_gadget_strings       **sp;
1178
1179                 memset(s, 0, 256);
1180                 s->bDescriptorType = USB_DT_STRING;
1181
1182                 sp = composite->strings;
1183                 if (sp)
1184                         collect_langs(sp, s->wData);
1185
1186                 list_for_each_entry(c, &cdev->configs, list) {
1187                         sp = c->strings;
1188                         if (sp)
1189                                 collect_langs(sp, s->wData);
1190
1191                         list_for_each_entry(f, &c->functions, list) {
1192                                 sp = f->strings;
1193                                 if (sp)
1194                                         collect_langs(sp, s->wData);
1195                         }
1196                 }
1197                 list_for_each_entry(uc, &cdev->gstrings, list) {
1198                         struct usb_gadget_strings **sp;
1199
1200                         sp = get_containers_gs(uc);
1201                         collect_langs(sp, s->wData);
1202                 }
1203
1204                 for (len = 0; len <= USB_MAX_STRING_LEN && s->wData[len]; len++)
1205                         continue;
1206                 if (!len)
1207                         return -EINVAL;
1208
1209                 s->bLength = 2 * (len + 1);
1210                 return s->bLength;
1211         }
1212
1213         if (cdev->use_os_string && language == 0 && id == OS_STRING_IDX) {
1214                 struct usb_os_string *b = buf;
1215                 b->bLength = sizeof(*b);
1216                 b->bDescriptorType = USB_DT_STRING;
1217                 compiletime_assert(
1218                         sizeof(b->qwSignature) == sizeof(cdev->qw_sign),
1219                         "qwSignature size must be equal to qw_sign");
1220                 memcpy(&b->qwSignature, cdev->qw_sign, sizeof(b->qwSignature));
1221                 b->bMS_VendorCode = cdev->b_vendor_code;
1222                 b->bPad = 0;
1223                 return sizeof(*b);
1224         }
1225
1226         list_for_each_entry(uc, &cdev->gstrings, list) {
1227                 struct usb_gadget_strings **sp;
1228
1229                 sp = get_containers_gs(uc);
1230                 len = lookup_string(sp, buf, language, id);
1231                 if (len > 0)
1232                         return len;
1233         }
1234
1235         /* String IDs are device-scoped, so we look up each string
1236          * table we're told about.  These lookups are infrequent;
1237          * simpler-is-better here.
1238          */
1239         if (composite->strings) {
1240                 len = lookup_string(composite->strings, buf, language, id);
1241                 if (len > 0)
1242                         return len;
1243         }
1244         list_for_each_entry(c, &cdev->configs, list) {
1245                 if (c->strings) {
1246                         len = lookup_string(c->strings, buf, language, id);
1247                         if (len > 0)
1248                                 return len;
1249                 }
1250                 list_for_each_entry(f, &c->functions, list) {
1251                         if (!f->strings)
1252                                 continue;
1253                         len = lookup_string(f->strings, buf, language, id);
1254                         if (len > 0)
1255                                 return len;
1256                 }
1257         }
1258         return -EINVAL;
1259 }
1260
1261 /**
1262  * usb_string_id() - allocate an unused string ID
1263  * @cdev: the device whose string descriptor IDs are being allocated
1264  * Context: single threaded during gadget setup
1265  *
1266  * @usb_string_id() is called from bind() callbacks to allocate
1267  * string IDs.  Drivers for functions, configurations, or gadgets will
1268  * then store that ID in the appropriate descriptors and string table.
1269  *
1270  * All string identifier should be allocated using this,
1271  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
1272  * that for example different functions don't wrongly assign different
1273  * meanings to the same identifier.
1274  */
1275 int usb_string_id(struct usb_composite_dev *cdev)
1276 {
1277         if (cdev->next_string_id < 254) {
1278                 /* string id 0 is reserved by USB spec for list of
1279                  * supported languages */
1280                 /* 255 reserved as well? -- mina86 */
1281                 cdev->next_string_id++;
1282                 return cdev->next_string_id;
1283         }
1284         return -ENODEV;
1285 }
1286 EXPORT_SYMBOL_GPL(usb_string_id);
1287
1288 /**
1289  * usb_string_ids_tab() - allocate unused string IDs in batch
1290  * @cdev: the device whose string descriptor IDs are being allocated
1291  * @str: an array of usb_string objects to assign numbers to
1292  * Context: single threaded during gadget setup
1293  *
1294  * @usb_string_ids() is called from bind() callbacks to allocate
1295  * string IDs.  Drivers for functions, configurations, or gadgets will
1296  * then copy IDs from the string table to the appropriate descriptors
1297  * and string table for other languages.
1298  *
1299  * All string identifier should be allocated using this,
1300  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1301  * example different functions don't wrongly assign different meanings
1302  * to the same identifier.
1303  */
1304 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
1305 {
1306         int next = cdev->next_string_id;
1307
1308         for (; str->s; ++str) {
1309                 if (unlikely(next >= 254))
1310                         return -ENODEV;
1311                 str->id = ++next;
1312         }
1313
1314         cdev->next_string_id = next;
1315
1316         return 0;
1317 }
1318 EXPORT_SYMBOL_GPL(usb_string_ids_tab);
1319
1320 static struct usb_gadget_string_container *copy_gadget_strings(
1321                 struct usb_gadget_strings **sp, unsigned n_gstrings,
1322                 unsigned n_strings)
1323 {
1324         struct usb_gadget_string_container *uc;
1325         struct usb_gadget_strings **gs_array;
1326         struct usb_gadget_strings *gs;
1327         struct usb_string *s;
1328         unsigned mem;
1329         unsigned n_gs;
1330         unsigned n_s;
1331         void *stash;
1332
1333         mem = sizeof(*uc);
1334         mem += sizeof(void *) * (n_gstrings + 1);
1335         mem += sizeof(struct usb_gadget_strings) * n_gstrings;
1336         mem += sizeof(struct usb_string) * (n_strings + 1) * (n_gstrings);
1337         uc = kmalloc(mem, GFP_KERNEL);
1338         if (!uc)
1339                 return ERR_PTR(-ENOMEM);
1340         gs_array = get_containers_gs(uc);
1341         stash = uc->stash;
1342         stash += sizeof(void *) * (n_gstrings + 1);
1343         for (n_gs = 0; n_gs < n_gstrings; n_gs++) {
1344                 struct usb_string *org_s;
1345
1346                 gs_array[n_gs] = stash;
1347                 gs = gs_array[n_gs];
1348                 stash += sizeof(struct usb_gadget_strings);
1349                 gs->language = sp[n_gs]->language;
1350                 gs->strings = stash;
1351                 org_s = sp[n_gs]->strings;
1352
1353                 for (n_s = 0; n_s < n_strings; n_s++) {
1354                         s = stash;
1355                         stash += sizeof(struct usb_string);
1356                         if (org_s->s)
1357                                 s->s = org_s->s;
1358                         else
1359                                 s->s = "";
1360                         org_s++;
1361                 }
1362                 s = stash;
1363                 s->s = NULL;
1364                 stash += sizeof(struct usb_string);
1365
1366         }
1367         gs_array[n_gs] = NULL;
1368         return uc;
1369 }
1370
1371 /**
1372  * usb_gstrings_attach() - attach gadget strings to a cdev and assign ids
1373  * @cdev: the device whose string descriptor IDs are being allocated
1374  * and attached.
1375  * @sp: an array of usb_gadget_strings to attach.
1376  * @n_strings: number of entries in each usb_strings array (sp[]->strings)
1377  *
1378  * This function will create a deep copy of usb_gadget_strings and usb_string
1379  * and attach it to the cdev. The actual string (usb_string.s) will not be
1380  * copied but only a referenced will be made. The struct usb_gadget_strings
1381  * array may contain multiple languages and should be NULL terminated.
1382  * The ->language pointer of each struct usb_gadget_strings has to contain the
1383  * same amount of entries.
1384  * For instance: sp[0] is en-US, sp[1] is es-ES. It is expected that the first
1385  * usb_string entry of es-ES contains the translation of the first usb_string
1386  * entry of en-US. Therefore both entries become the same id assign.
1387  */
1388 struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
1389                 struct usb_gadget_strings **sp, unsigned n_strings)
1390 {
1391         struct usb_gadget_string_container *uc;
1392         struct usb_gadget_strings **n_gs;
1393         unsigned n_gstrings = 0;
1394         unsigned i;
1395         int ret;
1396
1397         for (i = 0; sp[i]; i++)
1398                 n_gstrings++;
1399
1400         if (!n_gstrings)
1401                 return ERR_PTR(-EINVAL);
1402
1403         uc = copy_gadget_strings(sp, n_gstrings, n_strings);
1404         if (IS_ERR(uc))
1405                 return ERR_CAST(uc);
1406
1407         n_gs = get_containers_gs(uc);
1408         ret = usb_string_ids_tab(cdev, n_gs[0]->strings);
1409         if (ret)
1410                 goto err;
1411
1412         for (i = 1; i < n_gstrings; i++) {
1413                 struct usb_string *m_s;
1414                 struct usb_string *s;
1415                 unsigned n;
1416
1417                 m_s = n_gs[0]->strings;
1418                 s = n_gs[i]->strings;
1419                 for (n = 0; n < n_strings; n++) {
1420                         s->id = m_s->id;
1421                         s++;
1422                         m_s++;
1423                 }
1424         }
1425         list_add_tail(&uc->list, &cdev->gstrings);
1426         return n_gs[0]->strings;
1427 err:
1428         kfree(uc);
1429         return ERR_PTR(ret);
1430 }
1431 EXPORT_SYMBOL_GPL(usb_gstrings_attach);
1432
1433 /**
1434  * usb_string_ids_n() - allocate unused string IDs in batch
1435  * @c: the device whose string descriptor IDs are being allocated
1436  * @n: number of string IDs to allocate
1437  * Context: single threaded during gadget setup
1438  *
1439  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1440  * valid IDs.  At least provided that @n is non-zero because if it
1441  * is, returns last requested ID which is now very useful information.
1442  *
1443  * @usb_string_ids_n() is called from bind() callbacks to allocate
1444  * string IDs.  Drivers for functions, configurations, or gadgets will
1445  * then store that ID in the appropriate descriptors and string table.
1446  *
1447  * All string identifier should be allocated using this,
1448  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1449  * example different functions don't wrongly assign different meanings
1450  * to the same identifier.
1451  */
1452 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1453 {
1454         unsigned next = c->next_string_id;
1455         if (unlikely(n > 254 || (unsigned)next + n > 254))
1456                 return -ENODEV;
1457         c->next_string_id += n;
1458         return next + 1;
1459 }
1460 EXPORT_SYMBOL_GPL(usb_string_ids_n);
1461
1462 /*-------------------------------------------------------------------------*/
1463
1464 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1465 {
1466         struct usb_composite_dev *cdev;
1467
1468         if (req->status || req->actual != req->length)
1469                 DBG((struct usb_composite_dev *) ep->driver_data,
1470                                 "setup complete --> %d, %d/%d\n",
1471                                 req->status, req->actual, req->length);
1472
1473         /*
1474          * REVIST The same ep0 requests are shared with function drivers
1475          * so they don't have to maintain the same ->complete() stubs.
1476          *
1477          * Because of that, we need to check for the validity of ->context
1478          * here, even though we know we've set it to something useful.
1479          */
1480         if (!req->context)
1481                 return;
1482
1483         cdev = req->context;
1484
1485         if (cdev->req == req)
1486                 cdev->setup_pending = false;
1487         else if (cdev->os_desc_req == req)
1488                 cdev->os_desc_pending = false;
1489         else
1490                 WARN(1, "unknown request %p\n", req);
1491 }
1492
1493 static int composite_ep0_queue(struct usb_composite_dev *cdev,
1494                 struct usb_request *req, gfp_t gfp_flags)
1495 {
1496         int ret;
1497
1498         ret = usb_ep_queue(cdev->gadget->ep0, req, gfp_flags);
1499         if (ret == 0) {
1500                 if (cdev->req == req)
1501                         cdev->setup_pending = true;
1502                 else if (cdev->os_desc_req == req)
1503                         cdev->os_desc_pending = true;
1504                 else
1505                         WARN(1, "unknown request %p\n", req);
1506         }
1507
1508         return ret;
1509 }
1510
1511 static int count_ext_compat(struct usb_configuration *c)
1512 {
1513         int i, res;
1514
1515         res = 0;
1516         for (i = 0; i < c->next_interface_id; ++i) {
1517                 struct usb_function *f;
1518                 int j;
1519
1520                 f = c->interface[i];
1521                 for (j = 0; j < f->os_desc_n; ++j) {
1522                         struct usb_os_desc *d;
1523
1524                         if (i != f->os_desc_table[j].if_id)
1525                                 continue;
1526                         d = f->os_desc_table[j].os_desc;
1527                         if (d && d->ext_compat_id)
1528                                 ++res;
1529                 }
1530         }
1531         BUG_ON(res > 255);
1532         return res;
1533 }
1534
1535 static int fill_ext_compat(struct usb_configuration *c, u8 *buf)
1536 {
1537         int i, count;
1538
1539         count = 16;
1540         buf += 16;
1541         for (i = 0; i < c->next_interface_id; ++i) {
1542                 struct usb_function *f;
1543                 int j;
1544
1545                 f = c->interface[i];
1546                 for (j = 0; j < f->os_desc_n; ++j) {
1547                         struct usb_os_desc *d;
1548
1549                         if (i != f->os_desc_table[j].if_id)
1550                                 continue;
1551                         d = f->os_desc_table[j].os_desc;
1552                         if (d && d->ext_compat_id) {
1553                                 *buf++ = i;
1554                                 *buf++ = 0x01;
1555                                 memcpy(buf, d->ext_compat_id, 16);
1556                                 buf += 22;
1557                         } else {
1558                                 ++buf;
1559                                 *buf = 0x01;
1560                                 buf += 23;
1561                         }
1562                         count += 24;
1563                         if (count + 24 >= USB_COMP_EP0_OS_DESC_BUFSIZ)
1564                                 return count;
1565                 }
1566         }
1567
1568         return count;
1569 }
1570
1571 static int count_ext_prop(struct usb_configuration *c, int interface)
1572 {
1573         struct usb_function *f;
1574         int j;
1575
1576         f = c->interface[interface];
1577         for (j = 0; j < f->os_desc_n; ++j) {
1578                 struct usb_os_desc *d;
1579
1580                 if (interface != f->os_desc_table[j].if_id)
1581                         continue;
1582                 d = f->os_desc_table[j].os_desc;
1583                 if (d && d->ext_compat_id)
1584                         return d->ext_prop_count;
1585         }
1586         return 0;
1587 }
1588
1589 static int len_ext_prop(struct usb_configuration *c, int interface)
1590 {
1591         struct usb_function *f;
1592         struct usb_os_desc *d;
1593         int j, res;
1594
1595         res = 10; /* header length */
1596         f = c->interface[interface];
1597         for (j = 0; j < f->os_desc_n; ++j) {
1598                 if (interface != f->os_desc_table[j].if_id)
1599                         continue;
1600                 d = f->os_desc_table[j].os_desc;
1601                 if (d)
1602                         return min(res + d->ext_prop_len, 4096);
1603         }
1604         return res;
1605 }
1606
1607 static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
1608 {
1609         struct usb_function *f;
1610         struct usb_os_desc *d;
1611         struct usb_os_desc_ext_prop *ext_prop;
1612         int j, count, n, ret;
1613
1614         f = c->interface[interface];
1615         count = 10; /* header length */
1616         buf += 10;
1617         for (j = 0; j < f->os_desc_n; ++j) {
1618                 if (interface != f->os_desc_table[j].if_id)
1619                         continue;
1620                 d = f->os_desc_table[j].os_desc;
1621                 if (d)
1622                         list_for_each_entry(ext_prop, &d->ext_prop, entry) {
1623                                 n = ext_prop->data_len +
1624                                         ext_prop->name_len + 14;
1625                                 if (count + n >= USB_COMP_EP0_OS_DESC_BUFSIZ)
1626                                         return count;
1627                                 usb_ext_prop_put_size(buf, n);
1628                                 usb_ext_prop_put_type(buf, ext_prop->type);
1629                                 ret = usb_ext_prop_put_name(buf, ext_prop->name,
1630                                                             ext_prop->name_len);
1631                                 if (ret < 0)
1632                                         return ret;
1633                                 switch (ext_prop->type) {
1634                                 case USB_EXT_PROP_UNICODE:
1635                                 case USB_EXT_PROP_UNICODE_ENV:
1636                                 case USB_EXT_PROP_UNICODE_LINK:
1637                                         usb_ext_prop_put_unicode(buf, ret,
1638                                                          ext_prop->data,
1639                                                          ext_prop->data_len);
1640                                         break;
1641                                 case USB_EXT_PROP_BINARY:
1642                                         usb_ext_prop_put_binary(buf, ret,
1643                                                         ext_prop->data,
1644                                                         ext_prop->data_len);
1645                                         break;
1646                                 case USB_EXT_PROP_LE32:
1647                                         /* not implemented */
1648                                 case USB_EXT_PROP_BE32:
1649                                         /* not implemented */
1650                                 default:
1651                                         return -EINVAL;
1652                                 }
1653                                 buf += n;
1654                                 count += n;
1655                         }
1656         }
1657
1658         return count;
1659 }
1660
1661 /*
1662  * The setup() callback implements all the ep0 functionality that's
1663  * not handled lower down, in hardware or the hardware driver(like
1664  * device and endpoint feature flags, and their status).  It's all
1665  * housekeeping for the gadget function we're implementing.  Most of
1666  * the work is in config and function specific setup.
1667  */
1668 int
1669 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1670 {
1671         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1672         struct usb_request              *req = cdev->req;
1673         int                             value = -EOPNOTSUPP;
1674         int                             status = 0;
1675         u16                             w_index = le16_to_cpu(ctrl->wIndex);
1676         u8                              intf = w_index & 0xFF;
1677         u16                             w_value = le16_to_cpu(ctrl->wValue);
1678         u16                             w_length = le16_to_cpu(ctrl->wLength);
1679         struct usb_function             *f = NULL;
1680         u8                              endp;
1681
1682         if (w_length > USB_COMP_EP0_BUFSIZ) {
1683                 if (ctrl->bRequestType & USB_DIR_IN) {
1684                         /* Cast away the const, we are going to overwrite on purpose. */
1685                         __le16 *temp = (__le16 *)&ctrl->wLength;
1686
1687                         *temp = cpu_to_le16(USB_COMP_EP0_BUFSIZ);
1688                         w_length = USB_COMP_EP0_BUFSIZ;
1689                 } else {
1690                         goto done;
1691                 }
1692         }
1693
1694         /* partial re-init of the response message; the function or the
1695          * gadget might need to intercept e.g. a control-OUT completion
1696          * when we delegate to it.
1697          */
1698         req->zero = 0;
1699         req->context = cdev;
1700         req->complete = composite_setup_complete;
1701         req->length = 0;
1702         gadget->ep0->driver_data = cdev;
1703
1704         /*
1705          * Don't let non-standard requests match any of the cases below
1706          * by accident.
1707          */
1708         if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
1709                 goto unknown;
1710
1711         switch (ctrl->bRequest) {
1712
1713         /* we handle all standard USB descriptors */
1714         case USB_REQ_GET_DESCRIPTOR:
1715                 if (ctrl->bRequestType != USB_DIR_IN)
1716                         goto unknown;
1717                 switch (w_value >> 8) {
1718
1719                 case USB_DT_DEVICE:
1720                         cdev->desc.bNumConfigurations =
1721                                 count_configs(cdev, USB_DT_DEVICE);
1722                         cdev->desc.bMaxPacketSize0 =
1723                                 cdev->gadget->ep0->maxpacket;
1724                         if (gadget_is_superspeed(gadget)) {
1725                                 if (gadget->speed >= USB_SPEED_SUPER) {
1726                                         cdev->desc.bcdUSB = cpu_to_le16(0x0320);
1727                                         cdev->desc.bMaxPacketSize0 = 9;
1728                                 } else {
1729                                         cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1730                                 }
1731                         } else {
1732                                 if (gadget->lpm_capable)
1733                                         cdev->desc.bcdUSB = cpu_to_le16(0x0201);
1734                                 else
1735                                         cdev->desc.bcdUSB = cpu_to_le16(0x0200);
1736                         }
1737
1738                         value = min(w_length, (u16) sizeof cdev->desc);
1739                         memcpy(req->buf, &cdev->desc, value);
1740                         break;
1741                 case USB_DT_DEVICE_QUALIFIER:
1742                         if (!gadget_is_dualspeed(gadget) ||
1743                             gadget->speed >= USB_SPEED_SUPER)
1744                                 break;
1745                         device_qual(cdev);
1746                         value = min_t(int, w_length,
1747                                 sizeof(struct usb_qualifier_descriptor));
1748                         break;
1749                 case USB_DT_OTHER_SPEED_CONFIG:
1750                         if (!gadget_is_dualspeed(gadget) ||
1751                             gadget->speed >= USB_SPEED_SUPER)
1752                                 break;
1753                         fallthrough;
1754                 case USB_DT_CONFIG:
1755                         value = config_desc(cdev, w_value);
1756                         if (value >= 0)
1757                                 value = min(w_length, (u16) value);
1758                         break;
1759                 case USB_DT_STRING:
1760                         value = get_string(cdev, req->buf,
1761                                         w_index, w_value & 0xff);
1762                         if (value >= 0)
1763                                 value = min(w_length, (u16) value);
1764                         break;
1765                 case USB_DT_BOS:
1766                         if (gadget_is_superspeed(gadget) ||
1767                             gadget->lpm_capable) {
1768                                 value = bos_desc(cdev);
1769                                 value = min(w_length, (u16) value);
1770                         }
1771                         break;
1772                 case USB_DT_OTG:
1773                         if (gadget_is_otg(gadget)) {
1774                                 struct usb_configuration *config;
1775                                 int otg_desc_len = 0;
1776
1777                                 if (cdev->config)
1778                                         config = cdev->config;
1779                                 else
1780                                         config = list_first_entry(
1781                                                         &cdev->configs,
1782                                                 struct usb_configuration, list);
1783                                 if (!config)
1784                                         goto done;
1785
1786                                 if (gadget->otg_caps &&
1787                                         (gadget->otg_caps->otg_rev >= 0x0200))
1788                                         otg_desc_len += sizeof(
1789                                                 struct usb_otg20_descriptor);
1790                                 else
1791                                         otg_desc_len += sizeof(
1792                                                 struct usb_otg_descriptor);
1793
1794                                 value = min_t(int, w_length, otg_desc_len);
1795                                 memcpy(req->buf, config->descriptors[0], value);
1796                         }
1797                         break;
1798                 }
1799                 break;
1800
1801         /* any number of configs can work */
1802         case USB_REQ_SET_CONFIGURATION:
1803                 if (ctrl->bRequestType != 0)
1804                         goto unknown;
1805                 if (gadget_is_otg(gadget)) {
1806                         if (gadget->a_hnp_support)
1807                                 DBG(cdev, "HNP available\n");
1808                         else if (gadget->a_alt_hnp_support)
1809                                 DBG(cdev, "HNP on another port\n");
1810                         else
1811                                 VDBG(cdev, "HNP inactive\n");
1812                 }
1813                 spin_lock(&cdev->lock);
1814                 value = set_config(cdev, ctrl, w_value);
1815                 spin_unlock(&cdev->lock);
1816                 break;
1817         case USB_REQ_GET_CONFIGURATION:
1818                 if (ctrl->bRequestType != USB_DIR_IN)
1819                         goto unknown;
1820                 if (cdev->config)
1821                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
1822                 else
1823                         *(u8 *)req->buf = 0;
1824                 value = min(w_length, (u16) 1);
1825                 break;
1826
1827         /* function drivers must handle get/set altsetting */
1828         case USB_REQ_SET_INTERFACE:
1829                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1830                         goto unknown;
1831                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1832                         break;
1833                 f = cdev->config->interface[intf];
1834                 if (!f)
1835                         break;
1836
1837                 /*
1838                  * If there's no get_alt() method, we know only altsetting zero
1839                  * works. There is no need to check if set_alt() is not NULL
1840                  * as we check this in usb_add_function().
1841                  */
1842                 if (w_value && !f->get_alt)
1843                         break;
1844
1845                 spin_lock(&cdev->lock);
1846                 value = f->set_alt(f, w_index, w_value);
1847                 if (value == USB_GADGET_DELAYED_STATUS) {
1848                         DBG(cdev,
1849                          "%s: interface %d (%s) requested delayed status\n",
1850                                         __func__, intf, f->name);
1851                         cdev->delayed_status++;
1852                         DBG(cdev, "delayed_status count %d\n",
1853                                         cdev->delayed_status);
1854                 }
1855                 spin_unlock(&cdev->lock);
1856                 break;
1857         case USB_REQ_GET_INTERFACE:
1858                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1859                         goto unknown;
1860                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1861                         break;
1862                 f = cdev->config->interface[intf];
1863                 if (!f)
1864                         break;
1865                 /* lots of interfaces only need altsetting zero... */
1866                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1867                 if (value < 0)
1868                         break;
1869                 *((u8 *)req->buf) = value;
1870                 value = min(w_length, (u16) 1);
1871                 break;
1872         case USB_REQ_GET_STATUS:
1873                 if (gadget_is_otg(gadget) && gadget->hnp_polling_support &&
1874                                                 (w_index == OTG_STS_SELECTOR)) {
1875                         if (ctrl->bRequestType != (USB_DIR_IN |
1876                                                         USB_RECIP_DEVICE))
1877                                 goto unknown;
1878                         *((u8 *)req->buf) = gadget->host_request_flag;
1879                         value = 1;
1880                         break;
1881                 }
1882
1883                 /*
1884                  * USB 3.0 additions:
1885                  * Function driver should handle get_status request. If such cb
1886                  * wasn't supplied we respond with default value = 0
1887                  * Note: function driver should supply such cb only for the
1888                  * first interface of the function
1889                  */
1890                 if (!gadget_is_superspeed(gadget))
1891                         goto unknown;
1892                 if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1893                         goto unknown;
1894                 value = 2;      /* This is the length of the get_status reply */
1895                 put_unaligned_le16(0, req->buf);
1896                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1897                         break;
1898                 f = cdev->config->interface[intf];
1899                 if (!f)
1900                         break;
1901                 status = f->get_status ? f->get_status(f) : 0;
1902                 if (status < 0)
1903                         break;
1904                 put_unaligned_le16(status & 0x0000ffff, req->buf);
1905                 break;
1906         /*
1907          * Function drivers should handle SetFeature/ClearFeature
1908          * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1909          * only for the first interface of the function
1910          */
1911         case USB_REQ_CLEAR_FEATURE:
1912         case USB_REQ_SET_FEATURE:
1913                 if (!gadget_is_superspeed(gadget))
1914                         goto unknown;
1915                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1916                         goto unknown;
1917                 switch (w_value) {
1918                 case USB_INTRF_FUNC_SUSPEND:
1919                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1920                                 break;
1921                         f = cdev->config->interface[intf];
1922                         if (!f)
1923                                 break;
1924                         value = 0;
1925                         if (f->func_suspend)
1926                                 value = f->func_suspend(f, w_index >> 8);
1927                         if (value < 0) {
1928                                 ERROR(cdev,
1929                                       "func_suspend() returned error %d\n",
1930                                       value);
1931                                 value = 0;
1932                         }
1933                         break;
1934                 }
1935                 break;
1936         default:
1937 unknown:
1938                 /*
1939                  * OS descriptors handling
1940                  */
1941                 if (cdev->use_os_string && cdev->os_desc_config &&
1942                     (ctrl->bRequestType & USB_TYPE_VENDOR) &&
1943                     ctrl->bRequest == cdev->b_vendor_code) {
1944                         struct usb_configuration        *os_desc_cfg;
1945                         u8                              *buf;
1946                         int                             interface;
1947                         int                             count = 0;
1948
1949                         req = cdev->os_desc_req;
1950                         req->context = cdev;
1951                         req->complete = composite_setup_complete;
1952                         buf = req->buf;
1953                         os_desc_cfg = cdev->os_desc_config;
1954                         w_length = min_t(u16, w_length, USB_COMP_EP0_OS_DESC_BUFSIZ);
1955                         memset(buf, 0, w_length);
1956                         buf[5] = 0x01;
1957                         switch (ctrl->bRequestType & USB_RECIP_MASK) {
1958                         case USB_RECIP_DEVICE:
1959                                 if (w_index != 0x4 || (w_value >> 8))
1960                                         break;
1961                                 buf[6] = w_index;
1962                                 /* Number of ext compat interfaces */
1963                                 count = count_ext_compat(os_desc_cfg);
1964                                 buf[8] = count;
1965                                 count *= 24; /* 24 B/ext compat desc */
1966                                 count += 16; /* header */
1967                                 put_unaligned_le32(count, buf);
1968                                 value = w_length;
1969                                 if (w_length > 0x10) {
1970                                         value = fill_ext_compat(os_desc_cfg, buf);
1971                                         value = min_t(u16, w_length, value);
1972                                 }
1973                                 break;
1974                         case USB_RECIP_INTERFACE:
1975                                 if (w_index != 0x5 || (w_value >> 8))
1976                                         break;
1977                                 interface = w_value & 0xFF;
1978                                 if (interface >= MAX_CONFIG_INTERFACES ||
1979                                     !os_desc_cfg->interface[interface])
1980                                         break;
1981                                 buf[6] = w_index;
1982                                 count = count_ext_prop(os_desc_cfg,
1983                                         interface);
1984                                 put_unaligned_le16(count, buf + 8);
1985                                 count = len_ext_prop(os_desc_cfg,
1986                                         interface);
1987                                 put_unaligned_le32(count, buf);
1988                                 value = w_length;
1989                                 if (w_length > 0x0A) {
1990                                         value = fill_ext_prop(os_desc_cfg,
1991                                                               interface, buf);
1992                                         if (value >= 0)
1993                                                 value = min_t(u16, w_length, value);
1994                                 }
1995                                 break;
1996                         }
1997
1998                         goto check_value;
1999                 }
2000
2001                 VDBG(cdev,
2002                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
2003                         ctrl->bRequestType, ctrl->bRequest,
2004                         w_value, w_index, w_length);
2005
2006                 /* functions always handle their interfaces and endpoints...
2007                  * punt other recipients (other, WUSB, ...) to the current
2008                  * configuration code.
2009                  */
2010                 if (cdev->config) {
2011                         list_for_each_entry(f, &cdev->config->functions, list)
2012                                 if (f->req_match &&
2013                                     f->req_match(f, ctrl, false))
2014                                         goto try_fun_setup;
2015                 } else {
2016                         struct usb_configuration *c;
2017                         list_for_each_entry(c, &cdev->configs, list)
2018                                 list_for_each_entry(f, &c->functions, list)
2019                                         if (f->req_match &&
2020                                             f->req_match(f, ctrl, true))
2021                                                 goto try_fun_setup;
2022                 }
2023                 f = NULL;
2024
2025                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
2026                 case USB_RECIP_INTERFACE:
2027                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
2028                                 break;
2029                         f = cdev->config->interface[intf];
2030                         break;
2031
2032                 case USB_RECIP_ENDPOINT:
2033                         if (!cdev->config)
2034                                 break;
2035                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
2036                         list_for_each_entry(f, &cdev->config->functions, list) {
2037                                 if (test_bit(endp, f->endpoints))
2038                                         break;
2039                         }
2040                         if (&f->list == &cdev->config->functions)
2041                                 f = NULL;
2042                         break;
2043                 }
2044 try_fun_setup:
2045                 if (f && f->setup)
2046                         value = f->setup(f, ctrl);
2047                 else {
2048                         struct usb_configuration        *c;
2049
2050                         c = cdev->config;
2051                         if (!c)
2052                                 goto done;
2053
2054                         /* try current config's setup */
2055                         if (c->setup) {
2056                                 value = c->setup(c, ctrl);
2057                                 goto done;
2058                         }
2059
2060                         /* try the only function in the current config */
2061                         if (!list_is_singular(&c->functions))
2062                                 goto done;
2063                         f = list_first_entry(&c->functions, struct usb_function,
2064                                              list);
2065                         if (f->setup)
2066                                 value = f->setup(f, ctrl);
2067                 }
2068
2069                 goto done;
2070         }
2071
2072 check_value:
2073         /* respond with data transfer before status phase? */
2074         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
2075                 req->length = value;
2076                 req->context = cdev;
2077                 req->zero = value < w_length;
2078                 value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
2079                 if (value < 0) {
2080                         DBG(cdev, "ep_queue --> %d\n", value);
2081                         req->status = 0;
2082                         composite_setup_complete(gadget->ep0, req);
2083                 }
2084         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
2085                 WARN(cdev,
2086                         "%s: Delayed status not supported for w_length != 0",
2087                         __func__);
2088         }
2089
2090 done:
2091         /* device either stalls (value < 0) or reports success */
2092         return value;
2093 }
2094
2095 static void __composite_disconnect(struct usb_gadget *gadget)
2096 {
2097         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2098         unsigned long                   flags;
2099
2100         /* REVISIT:  should we have config and device level
2101          * disconnect callbacks?
2102          */
2103         spin_lock_irqsave(&cdev->lock, flags);
2104         cdev->suspended = 0;
2105         if (cdev->config)
2106                 reset_config(cdev);
2107         if (cdev->driver->disconnect)
2108                 cdev->driver->disconnect(cdev);
2109         spin_unlock_irqrestore(&cdev->lock, flags);
2110 }
2111
2112 void composite_disconnect(struct usb_gadget *gadget)
2113 {
2114         usb_gadget_vbus_draw(gadget, 0);
2115         __composite_disconnect(gadget);
2116 }
2117
2118 void composite_reset(struct usb_gadget *gadget)
2119 {
2120         /*
2121          * Section 1.4.13 Standard Downstream Port of the USB battery charging
2122          * specification v1.2 states that a device connected on a SDP shall only
2123          * draw at max 100mA while in a connected, but unconfigured state.
2124          */
2125         usb_gadget_vbus_draw(gadget, 100);
2126         __composite_disconnect(gadget);
2127 }
2128
2129 /*-------------------------------------------------------------------------*/
2130
2131 static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
2132                               char *buf)
2133 {
2134         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
2135         struct usb_composite_dev *cdev = get_gadget_data(gadget);
2136
2137         return sprintf(buf, "%d\n", cdev->suspended);
2138 }
2139 static DEVICE_ATTR_RO(suspended);
2140
2141 static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
2142 {
2143         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2144         struct usb_gadget_strings       *gstr = cdev->driver->strings[0];
2145         struct usb_string               *dev_str = gstr->strings;
2146
2147         /* composite_disconnect() must already have been called
2148          * by the underlying peripheral controller driver!
2149          * so there's no i/o concurrency that could affect the
2150          * state protected by cdev->lock.
2151          */
2152         WARN_ON(cdev->config);
2153
2154         while (!list_empty(&cdev->configs)) {
2155                 struct usb_configuration        *c;
2156                 c = list_first_entry(&cdev->configs,
2157                                 struct usb_configuration, list);
2158                 remove_config(cdev, c);
2159         }
2160         if (cdev->driver->unbind && unbind_driver)
2161                 cdev->driver->unbind(cdev);
2162
2163         composite_dev_cleanup(cdev);
2164
2165         if (dev_str[USB_GADGET_MANUFACTURER_IDX].s == cdev->def_manufacturer)
2166                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = "";
2167
2168         kfree(cdev->def_manufacturer);
2169         kfree(cdev);
2170         set_gadget_data(gadget, NULL);
2171 }
2172
2173 static void composite_unbind(struct usb_gadget *gadget)
2174 {
2175         __composite_unbind(gadget, true);
2176 }
2177
2178 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
2179                 const struct usb_device_descriptor *old)
2180 {
2181         __le16 idVendor;
2182         __le16 idProduct;
2183         __le16 bcdDevice;
2184         u8 iSerialNumber;
2185         u8 iManufacturer;
2186         u8 iProduct;
2187
2188         /*
2189          * these variables may have been set in
2190          * usb_composite_overwrite_options()
2191          */
2192         idVendor = new->idVendor;
2193         idProduct = new->idProduct;
2194         bcdDevice = new->bcdDevice;
2195         iSerialNumber = new->iSerialNumber;
2196         iManufacturer = new->iManufacturer;
2197         iProduct = new->iProduct;
2198
2199         *new = *old;
2200         if (idVendor)
2201                 new->idVendor = idVendor;
2202         if (idProduct)
2203                 new->idProduct = idProduct;
2204         if (bcdDevice)
2205                 new->bcdDevice = bcdDevice;
2206         else
2207                 new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
2208         if (iSerialNumber)
2209                 new->iSerialNumber = iSerialNumber;
2210         if (iManufacturer)
2211                 new->iManufacturer = iManufacturer;
2212         if (iProduct)
2213                 new->iProduct = iProduct;
2214 }
2215
2216 int composite_dev_prepare(struct usb_composite_driver *composite,
2217                 struct usb_composite_dev *cdev)
2218 {
2219         struct usb_gadget *gadget = cdev->gadget;
2220         int ret = -ENOMEM;
2221
2222         /* preallocate control response and buffer */
2223         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
2224         if (!cdev->req)
2225                 return -ENOMEM;
2226
2227         cdev->req->buf = kzalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
2228         if (!cdev->req->buf)
2229                 goto fail;
2230
2231         ret = device_create_file(&gadget->dev, &dev_attr_suspended);
2232         if (ret)
2233                 goto fail_dev;
2234
2235         cdev->req->complete = composite_setup_complete;
2236         cdev->req->context = cdev;
2237         gadget->ep0->driver_data = cdev;
2238
2239         cdev->driver = composite;
2240
2241         /*
2242          * As per USB compliance update, a device that is actively drawing
2243          * more than 100mA from USB must report itself as bus-powered in
2244          * the GetStatus(DEVICE) call.
2245          */
2246         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
2247                 usb_gadget_set_selfpowered(gadget);
2248
2249         /* interface and string IDs start at zero via kzalloc.
2250          * we force endpoints to start unassigned; few controller
2251          * drivers will zero ep->driver_data.
2252          */
2253         usb_ep_autoconfig_reset(gadget);
2254         return 0;
2255 fail_dev:
2256         kfree(cdev->req->buf);
2257 fail:
2258         usb_ep_free_request(gadget->ep0, cdev->req);
2259         cdev->req = NULL;
2260         return ret;
2261 }
2262
2263 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
2264                                   struct usb_ep *ep0)
2265 {
2266         int ret = 0;
2267
2268         cdev->os_desc_req = usb_ep_alloc_request(ep0, GFP_KERNEL);
2269         if (!cdev->os_desc_req) {
2270                 ret = -ENOMEM;
2271                 goto end;
2272         }
2273
2274         cdev->os_desc_req->buf = kmalloc(USB_COMP_EP0_OS_DESC_BUFSIZ,
2275                                          GFP_KERNEL);
2276         if (!cdev->os_desc_req->buf) {
2277                 ret = -ENOMEM;
2278                 usb_ep_free_request(ep0, cdev->os_desc_req);
2279                 goto end;
2280         }
2281         cdev->os_desc_req->context = cdev;
2282         cdev->os_desc_req->complete = composite_setup_complete;
2283 end:
2284         return ret;
2285 }
2286
2287 void composite_dev_cleanup(struct usb_composite_dev *cdev)
2288 {
2289         struct usb_gadget_string_container *uc, *tmp;
2290         struct usb_ep                      *ep, *tmp_ep;
2291
2292         list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
2293                 list_del(&uc->list);
2294                 kfree(uc);
2295         }
2296         if (cdev->os_desc_req) {
2297                 if (cdev->os_desc_pending)
2298                         usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req);
2299
2300                 kfree(cdev->os_desc_req->buf);
2301                 cdev->os_desc_req->buf = NULL;
2302                 usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
2303                 cdev->os_desc_req = NULL;
2304         }
2305         if (cdev->req) {
2306                 if (cdev->setup_pending)
2307                         usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
2308
2309                 kfree(cdev->req->buf);
2310                 cdev->req->buf = NULL;
2311                 usb_ep_free_request(cdev->gadget->ep0, cdev->req);
2312                 cdev->req = NULL;
2313         }
2314         cdev->next_string_id = 0;
2315         device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
2316
2317         /*
2318          * Some UDC backends have a dynamic EP allocation scheme.
2319          *
2320          * In that case, the dispose() callback is used to notify the
2321          * backend that the EPs are no longer in use.
2322          *
2323          * Note: The UDC backend can remove the EP from the ep_list as
2324          *       a result, so we need to use the _safe list iterator.
2325          */
2326         list_for_each_entry_safe(ep, tmp_ep,
2327                                  &cdev->gadget->ep_list, ep_list) {
2328                 if (ep->ops->dispose)
2329                         ep->ops->dispose(ep);
2330         }
2331 }
2332
2333 static int composite_bind(struct usb_gadget *gadget,
2334                 struct usb_gadget_driver *gdriver)
2335 {
2336         struct usb_composite_dev        *cdev;
2337         struct usb_composite_driver     *composite = to_cdriver(gdriver);
2338         int                             status = -ENOMEM;
2339
2340         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
2341         if (!cdev)
2342                 return status;
2343
2344         spin_lock_init(&cdev->lock);
2345         cdev->gadget = gadget;
2346         set_gadget_data(gadget, cdev);
2347         INIT_LIST_HEAD(&cdev->configs);
2348         INIT_LIST_HEAD(&cdev->gstrings);
2349
2350         status = composite_dev_prepare(composite, cdev);
2351         if (status)
2352                 goto fail;
2353
2354         /* composite gadget needs to assign strings for whole device (like
2355          * serial number), register function drivers, potentially update
2356          * power state and consumption, etc
2357          */
2358         status = composite->bind(cdev);
2359         if (status < 0)
2360                 goto fail;
2361
2362         if (cdev->use_os_string) {
2363                 status = composite_os_desc_req_prepare(cdev, gadget->ep0);
2364                 if (status)
2365                         goto fail;
2366         }
2367
2368         update_unchanged_dev_desc(&cdev->desc, composite->dev);
2369
2370         /* has userspace failed to provide a serial number? */
2371         if (composite->needs_serial && !cdev->desc.iSerialNumber)
2372                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
2373
2374         INFO(cdev, "%s ready\n", composite->name);
2375         return 0;
2376
2377 fail:
2378         __composite_unbind(gadget, false);
2379         return status;
2380 }
2381
2382 /*-------------------------------------------------------------------------*/
2383
2384 void composite_suspend(struct usb_gadget *gadget)
2385 {
2386         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2387         struct usb_function             *f;
2388
2389         /* REVISIT:  should we have config level
2390          * suspend/resume callbacks?
2391          */
2392         DBG(cdev, "suspend\n");
2393         if (cdev->config) {
2394                 list_for_each_entry(f, &cdev->config->functions, list) {
2395                         if (f->suspend)
2396                                 f->suspend(f);
2397                 }
2398         }
2399         if (cdev->driver->suspend)
2400                 cdev->driver->suspend(cdev);
2401
2402         cdev->suspended = 1;
2403
2404         usb_gadget_set_selfpowered(gadget);
2405         usb_gadget_vbus_draw(gadget, 2);
2406 }
2407
2408 void composite_resume(struct usb_gadget *gadget)
2409 {
2410         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2411         struct usb_function             *f;
2412         unsigned                        maxpower;
2413
2414         /* REVISIT:  should we have config level
2415          * suspend/resume callbacks?
2416          */
2417         DBG(cdev, "resume\n");
2418         if (cdev->driver->resume)
2419                 cdev->driver->resume(cdev);
2420         if (cdev->config) {
2421                 list_for_each_entry(f, &cdev->config->functions, list) {
2422                         if (f->resume)
2423                                 f->resume(f);
2424                 }
2425
2426                 maxpower = cdev->config->MaxPower ?
2427                         cdev->config->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
2428                 if (gadget->speed < USB_SPEED_SUPER)
2429                         maxpower = min(maxpower, 500U);
2430                 else
2431                         maxpower = min(maxpower, 900U);
2432
2433                 if (maxpower > USB_SELF_POWER_VBUS_MAX_DRAW)
2434                         usb_gadget_clear_selfpowered(gadget);
2435
2436                 usb_gadget_vbus_draw(gadget, maxpower);
2437         }
2438
2439         cdev->suspended = 0;
2440 }
2441
2442 /*-------------------------------------------------------------------------*/
2443
2444 static const struct usb_gadget_driver composite_driver_template = {
2445         .bind           = composite_bind,
2446         .unbind         = composite_unbind,
2447
2448         .setup          = composite_setup,
2449         .reset          = composite_reset,
2450         .disconnect     = composite_disconnect,
2451
2452         .suspend        = composite_suspend,
2453         .resume         = composite_resume,
2454
2455         .driver = {
2456                 .owner          = THIS_MODULE,
2457         },
2458 };
2459
2460 /**
2461  * usb_composite_probe() - register a composite driver
2462  * @driver: the driver to register
2463  *
2464  * Context: single threaded during gadget setup
2465  *
2466  * This function is used to register drivers using the composite driver
2467  * framework.  The return value is zero, or a negative errno value.
2468  * Those values normally come from the driver's @bind method, which does
2469  * all the work of setting up the driver to match the hardware.
2470  *
2471  * On successful return, the gadget is ready to respond to requests from
2472  * the host, unless one of its components invokes usb_gadget_disconnect()
2473  * while it was binding.  That would usually be done in order to wait for
2474  * some userspace participation.
2475  */
2476 int usb_composite_probe(struct usb_composite_driver *driver)
2477 {
2478         struct usb_gadget_driver *gadget_driver;
2479
2480         if (!driver || !driver->dev || !driver->bind)
2481                 return -EINVAL;
2482
2483         if (!driver->name)
2484                 driver->name = "composite";
2485
2486         driver->gadget_driver = composite_driver_template;
2487         gadget_driver = &driver->gadget_driver;
2488
2489         gadget_driver->function =  (char *) driver->name;
2490         gadget_driver->driver.name = driver->name;
2491         gadget_driver->max_speed = driver->max_speed;
2492
2493         return usb_gadget_probe_driver(gadget_driver);
2494 }
2495 EXPORT_SYMBOL_GPL(usb_composite_probe);
2496
2497 /**
2498  * usb_composite_unregister() - unregister a composite driver
2499  * @driver: the driver to unregister
2500  *
2501  * This function is used to unregister drivers using the composite
2502  * driver framework.
2503  */
2504 void usb_composite_unregister(struct usb_composite_driver *driver)
2505 {
2506         usb_gadget_unregister_driver(&driver->gadget_driver);
2507 }
2508 EXPORT_SYMBOL_GPL(usb_composite_unregister);
2509
2510 /**
2511  * usb_composite_setup_continue() - Continue with the control transfer
2512  * @cdev: the composite device who's control transfer was kept waiting
2513  *
2514  * This function must be called by the USB function driver to continue
2515  * with the control transfer's data/status stage in case it had requested to
2516  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
2517  * can request the composite framework to delay the setup request's data/status
2518  * stages by returning USB_GADGET_DELAYED_STATUS.
2519  */
2520 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
2521 {
2522         int                     value;
2523         struct usb_request      *req = cdev->req;
2524         unsigned long           flags;
2525
2526         DBG(cdev, "%s\n", __func__);
2527         spin_lock_irqsave(&cdev->lock, flags);
2528
2529         if (cdev->delayed_status == 0) {
2530                 WARN(cdev, "%s: Unexpected call\n", __func__);
2531
2532         } else if (--cdev->delayed_status == 0) {
2533                 DBG(cdev, "%s: Completing delayed status\n", __func__);
2534                 req->length = 0;
2535                 req->context = cdev;
2536                 value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
2537                 if (value < 0) {
2538                         DBG(cdev, "ep_queue --> %d\n", value);
2539                         req->status = 0;
2540                         composite_setup_complete(cdev->gadget->ep0, req);
2541                 }
2542         }
2543
2544         spin_unlock_irqrestore(&cdev->lock, flags);
2545 }
2546 EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
2547
2548 static char *composite_default_mfr(struct usb_gadget *gadget)
2549 {
2550         return kasprintf(GFP_KERNEL, "%s %s with %s", init_utsname()->sysname,
2551                          init_utsname()->release, gadget->name);
2552 }
2553
2554 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
2555                 struct usb_composite_overwrite *covr)
2556 {
2557         struct usb_device_descriptor    *desc = &cdev->desc;
2558         struct usb_gadget_strings       *gstr = cdev->driver->strings[0];
2559         struct usb_string               *dev_str = gstr->strings;
2560
2561         if (covr->idVendor)
2562                 desc->idVendor = cpu_to_le16(covr->idVendor);
2563
2564         if (covr->idProduct)
2565                 desc->idProduct = cpu_to_le16(covr->idProduct);
2566
2567         if (covr->bcdDevice)
2568                 desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
2569
2570         if (covr->serial_number) {
2571                 desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
2572                 dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
2573         }
2574         if (covr->manufacturer) {
2575                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2576                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
2577
2578         } else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
2579                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2580                 cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
2581                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
2582         }
2583
2584         if (covr->product) {
2585                 desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
2586                 dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
2587         }
2588 }
2589 EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
2590
2591 MODULE_LICENSE("GPL");
2592 MODULE_AUTHOR("David Brownell");