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