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