drivers/usb/gadget/composite.c

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