drivers/usb/gadget/composite.c

   1 /*
   2  * composite.c - infrastructure for Composite USB Gadgets
   3  *
   4  * Copyright (C) 2006-2008 David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 /* #define VERBOSE_DEBUG */
  13
  14 #include <linux/kallsyms.h>
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/device.h>
  19 #include <linux/utsname.h>
  20
  21 #include <linux/usb/composite.h>
  22 #include <linux/usb/otg.h>
  23 #include <asm/unaligned.h>
  24
  25 #include "u_os_desc.h"
  26
  27 /**
  28  * struct usb_os_string - represents OS String to be reported by a gadget
  29  * @bLength: total length of the entire descritor, always 0x12
  30  * @bDescriptorType: USB_DT_STRING
  31  * @qwSignature: the OS String proper
  32  * @bMS_VendorCode: code used by the host for subsequent requests
  33  * @bPad: not used, must be zero
  34  */
  35 struct usb_os_string {
  36         __u8    bLength;
  37         __u8    bDescriptorType;
  38         __u8    qwSignature[OS_STRING_QW_SIGN_LEN];
  39         __u8    bMS_VendorCode;
  40         __u8    bPad;
  41 } __packed;
  42
  43 /*
  44  * The code in this file is utility code, used to build a gadget driver
  45  * from one or more "function" drivers, one or more "configuration"
  46  * objects, and a "usb_composite_driver" by gluing them together along
  47  * with the relevant device-wide data.
  48  */
  49
  50 static struct usb_gadget_strings **get_containers_gs(
  51                 struct usb_gadget_string_container *uc)
  52 {
  53         return (struct usb_gadget_strings **)uc->stash;
  54 }
  55
  56 /**
  57  * function_descriptors() - get function descriptors for speed
  58  * @f: the function
  59  * @speed: the speed
  60  *
  61  * Returns the descriptors or NULL if not set.
  62  */
  63 static struct usb_descriptor_header **
  64 function_descriptors(struct usb_function *f,
  65                      enum usb_device_speed speed)
  66 {
  67         struct usb_descriptor_header **descriptors;
  68
  69         /*
  70          * NOTE: we try to help gadget drivers which might not be setting
  71          * max_speed appropriately.
  72          */
  73
  74         switch (speed) {
  75         case USB_SPEED_SUPER_PLUS:
  76                 descriptors = f->ssp_descriptors;
  77                 if (descriptors)
  78                         break;
  79                 /* FALLTHROUGH */
  80         case USB_SPEED_SUPER:
  81                 descriptors = f->ss_descriptors;
  82                 if (descriptors)
  83                         break;
  84                 /* FALLTHROUGH */
  85         case USB_SPEED_HIGH:
  86                 descriptors = f->hs_descriptors;
  87                 if (descriptors)
  88                         break;
  89                 /* FALLTHROUGH */
  90         default:
  91                 descriptors = f->fs_descriptors;
  92         }
  93
  94         /*
  95          * if we can't find any descriptors at all, then this gadget deserves to
  96          * Oops with a NULL pointer dereference
  97          */
  98
  99         return descriptors;
 100 }
 101
 102 /**
 103  * next_ep_desc() - advance to the next EP descriptor
 104  * @t: currect pointer within descriptor array
 105  *
 106  * Return: next EP descriptor or NULL
 107  *
 108  * Iterate over @t until either EP descriptor found or
 109  * NULL (that indicates end of list) encountered
 110  */
 111 static struct usb_descriptor_header**
 112 next_ep_desc(struct usb_descriptor_header **t)
 113 {
 114         for (; *t; t++) {
 115                 if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
 116                         return t;
 117         }
 118         return NULL;
 119 }
 120
 121 /*
 122  * for_each_ep_desc()- iterate over endpoint descriptors in the
 123  *              descriptors list
 124  * @start:      pointer within descriptor array.
 125  * @ep_desc:    endpoint descriptor to use as the loop cursor
 126  */
 127 #define for_each_ep_desc(start, ep_desc) \
 128         for (ep_desc = next_ep_desc(start); \
 129               ep_desc; ep_desc = next_ep_desc(ep_desc+1))
 130
 131 /**
 132  * config_ep_by_speed() - configures the given endpoint
 133  * according to gadget speed.
 134  * @g: pointer to the gadget
 135  * @f: usb function
 136  * @_ep: the endpoint to configure
 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(struct usb_gadget *g,
 150                         struct usb_function *f,
 151                         struct usb_ep *_ep)
 152 {
 153         struct usb_composite_dev        *cdev = get_gadget_data(g);
 154         struct usb_endpoint_descriptor *chosen_desc = NULL;
 155         struct usb_descriptor_header **speed_desc = NULL;
 156
 157         struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
 158         int want_comp_desc = 0;
 159
 160         struct usb_descriptor_header **d_spd; /* cursor for speed desc */
 161
 162         if (!g || !f || !_ep)
 163                 return -EIO;
 164
 165         /* select desired speed */
 166         switch (g->speed) {
 167         case USB_SPEED_SUPER_PLUS:
 168                 if (gadget_is_superspeed_plus(g)) {
 169                         speed_desc = f->ssp_descriptors;
 170                         want_comp_desc = 1;
 171                         break;
 172                 }
 173                 /* else: Fall trough */
 174         case USB_SPEED_SUPER:
 175                 if (gadget_is_superspeed(g)) {
 176                         speed_desc = f->ss_descriptors;
 177                         want_comp_desc = 1;
 178                         break;
 179                 }
 180                 /* else: Fall trough */
 181         case USB_SPEED_HIGH:
 182                 if (gadget_is_dualspeed(g)) {
 183                         speed_desc = f->hs_descriptors;
 184                         break;
 185                 }
 186                 /* else: fall through */
 187         default:
 188                 speed_desc = f->fs_descriptors;
 189         }
 190         /* find descriptors */
 191         for_each_ep_desc(speed_desc, d_spd) {
 192                 chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 193                 if (chosen_desc->bEndpointAddress == _ep->address)
 194                         goto ep_found;
 195         }
 196         return -EIO;
 197
 198 ep_found:
 199         /* commit results */
 200         _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 201         _ep->desc = chosen_desc;
 202         _ep->comp_desc = NULL;
 203         _ep->maxburst = 0;
 204         _ep->mult = 0;
 205         if (!want_comp_desc)
 206                 return 0;
 207
 208         /*
 209          * Companion descriptor should follow EP descriptor
 210          * USB 3.0 spec, #9.6.7
 211          */
 212         comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 213         if (!comp_desc ||
 214             (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 215                 return -EIO;
 216         _ep->comp_desc = comp_desc;
 217         if (g->speed >= USB_SPEED_SUPER) {
 218                 switch (usb_endpoint_type(_ep->desc)) {
 219                 case USB_ENDPOINT_XFER_ISOC:
 220                         /* mult: bits 1:0 of bmAttributes */
 221                         _ep->mult = comp_desc->bmAttributes & 0x3;
 222                 case USB_ENDPOINT_XFER_BULK:
 223                 case USB_ENDPOINT_XFER_INT:
 224                         _ep->maxburst = comp_desc->bMaxBurst + 1;
 225                         break;
 226                 default:
 227                         if (comp_desc->bMaxBurst != 0)
 228                                 ERROR(cdev, "ep0 bMaxBurst must be 0\n");
 229                         _ep->maxburst = 1;
 230                         break;
 231                 }
 232         }
 233         return 0;
 234 }
 235 EXPORT_SYMBOL_GPL(config_ep_by_speed);
 236
 237 /**
 238  * usb_add_function() - add a function to a configuration
 239  * @config: the configuration
 240  * @function: the function being added
 241  * Context: single threaded during gadget setup
 242  *
 243  * After initialization, each configuration must have one or more
 244  * functions added to it.  Adding a function involves calling its @bind()
 245  * method to allocate resources such as interface and string identifiers
 246  * and endpoints.
 247  *
 248  * This function returns the value of the function's bind(), which is
 249  * zero for success else a negative errno value.
 250  */
 251 int usb_add_function(struct usb_configuration *config,
 252                 struct usb_function *function)
 253 {
 254         int     value = -EINVAL;
 255
 256         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 257                         function->name, function,
 258                         config->label, config);
 259
 260         if (!function->set_alt || !function->disable)
 261                 goto done;
 262
 263         function->config = config;
 264         list_add_tail(&function->list, &config->functions);
 265
 266         if (function->bind_deactivated) {
 267                 value = usb_function_deactivate(function);
 268                 if (value)
 269                         goto done;
 270         }
 271
 272         /* REVISIT *require* function->bind? */
 273         if (function->bind) {
 274                 value = function->bind(config, function);
 275                 if (value < 0) {
 276                         list_del(&function->list);
 277                         function->config = NULL;
 278                 }
 279         } else
 280                 value = 0;
 281
 282         /* We allow configurations that don't work at both speeds.
 283          * If we run into a lowspeed Linux system, treat it the same
 284          * as full speed ... it's the function drivers that will need
 285          * to avoid bulk and ISO transfers.
 286          */
 287         if (!config->fullspeed && function->fs_descriptors)
 288                 config->fullspeed = true;
 289         if (!config->highspeed && function->hs_descriptors)
 290                 config->highspeed = true;
 291         if (!config->superspeed && function->ss_descriptors)
 292                 config->superspeed = true;
 293         if (!config->superspeed_plus && function->ssp_descriptors)
 294                 config->superspeed_plus = true;
 295
 296 done:
 297         if (value)
 298                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 299                                 function->name, function, value);
 300         return value;
 301 }
 302 EXPORT_SYMBOL_GPL(usb_add_function);
 303
 304 void usb_remove_function(struct usb_configuration *c, struct usb_function *f)
 305 {
 306         if (f->disable)
 307                 f->disable(f);
 308
 309         bitmap_zero(f->endpoints, 32);
 310         list_del(&f->list);
 311         if (f->unbind)
 312                 f->unbind(c, f);
 313 }
 314 EXPORT_SYMBOL_GPL(usb_remove_function);
 315
 316 /**
 317  * usb_function_deactivate - prevent function and gadget enumeration
 318  * @function: the function that isn't yet ready to respond
 319  *
 320  * Blocks response of the gadget driver to host enumeration by
 321  * preventing the data line pullup from being activated.  This is
 322  * normally called during @bind() processing to change from the
 323  * initial "ready to respond" state, or when a required resource
 324  * becomes available.
 325  *
 326  * For example, drivers that serve as a passthrough to a userspace
 327  * daemon can block enumeration unless that daemon (such as an OBEX,
 328  * MTP, or print server) is ready to handle host requests.
 329  *
 330  * Not all systems support software control of their USB peripheral
 331  * data pullups.
 332  *
 333  * Returns zero on success, else negative errno.
 334  */
 335 int usb_function_deactivate(struct usb_function *function)
 336 {
 337         struct usb_composite_dev        *cdev = function->config->cdev;
 338         unsigned long                   flags;
 339         int                             status = 0;
 340
 341         spin_lock_irqsave(&cdev->lock, flags);
 342
 343         if (cdev->deactivations == 0)
 344                 status = usb_gadget_deactivate(cdev->gadget);
 345         if (status == 0)
 346                 cdev->deactivations++;
 347
 348         spin_unlock_irqrestore(&cdev->lock, flags);
 349         return status;
 350 }
 351 EXPORT_SYMBOL_GPL(usb_function_deactivate);
 352
 353 /**
 354  * usb_function_activate - allow function and gadget enumeration
 355  * @function: function on which usb_function_activate() was called
 356  *
 357  * Reverses effect of usb_function_deactivate().  If no more functions
 358  * are delaying their activation, the gadget driver will respond to
 359  * host enumeration procedures.
 360  *
 361  * Returns zero on success, else negative errno.
 362  */
 363 int usb_function_activate(struct usb_function *function)
 364 {
 365         struct usb_composite_dev        *cdev = function->config->cdev;
 366         unsigned long                   flags;
 367         int                             status = 0;
 368
 369         spin_lock_irqsave(&cdev->lock, flags);
 370
 371         if (WARN_ON(cdev->deactivations == 0))
 372                 status = -EINVAL;
 373         else {
 374                 cdev->deactivations--;
 375                 if (cdev->deactivations == 0)
 376                         status = usb_gadget_activate(cdev->gadget);
 377         }
 378
 379         spin_unlock_irqrestore(&cdev->lock, flags);
 380         return status;
 381 }
 382 EXPORT_SYMBOL_GPL(usb_function_activate);
 383
 384 /**
 385  * usb_interface_id() - allocate an unused interface ID
 386  * @config: configuration associated with the interface
 387  * @function: function handling the interface
 388  * Context: single threaded during gadget setup
 389  *
 390  * usb_interface_id() is called from usb_function.bind() callbacks to
 391  * allocate new interface IDs.  The function driver will then store that
 392  * ID in interface, association, CDC union, and other descriptors.  It
 393  * will also handle any control requests targeted at that interface,
 394  * particularly changing its altsetting via set_alt().  There may
 395  * also be class-specific or vendor-specific requests to handle.
 396  *
 397  * All interface identifier should be allocated using this routine, to
 398  * ensure that for example different functions don't wrongly assign
 399  * different meanings to the same identifier.  Note that since interface
 400  * identifiers are configuration-specific, functions used in more than
 401  * one configuration (or more than once in a given configuration) need
 402  * multiple versions of the relevant descriptors.
 403  *
 404  * Returns the interface ID which was allocated; or -ENODEV if no
 405  * more interface IDs can be allocated.
 406  */
 407 int usb_interface_id(struct usb_configuration *config,
 408                 struct usb_function *function)
 409 {
 410         unsigned id = config->next_interface_id;
 411
 412         if (id < MAX_CONFIG_INTERFACES) {
 413                 config->interface[id] = function;
 414                 config->next_interface_id = id + 1;
 415                 return id;
 416         }
 417         return -ENODEV;
 418 }
 419 EXPORT_SYMBOL_GPL(usb_interface_id);
 420
 421 static u8 encode_bMaxPower(enum usb_device_speed speed,
 422                 struct usb_configuration *c)
 423 {
 424         unsigned val;
 425
 426         if (c->MaxPower)
 427                 val = c->MaxPower;
 428         else
 429                 val = CONFIG_USB_GADGET_VBUS_DRAW;
 430         if (!val)
 431                 return 0;
 432         switch (speed) {
 433         case USB_SPEED_SUPER:
 434                 return DIV_ROUND_UP(val, 8);
 435         default:
 436                 return DIV_ROUND_UP(val, 2);
 437         }
 438 }
 439
 440 static int config_buf(struct usb_configuration *config,
 441                 enum usb_device_speed speed, void *buf, u8 type)
 442 {
 443         struct usb_config_descriptor    *c = buf;
 444         void                            *next = buf + USB_DT_CONFIG_SIZE;
 445         int                             len;
 446         struct usb_function             *f;
 447         int                             status;
 448
 449         len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
 450         /* write the config descriptor */
 451         c = buf;
 452         c->bLength = USB_DT_CONFIG_SIZE;
 453         c->bDescriptorType = type;
 454         /* wTotalLength is written later */
 455         c->bNumInterfaces = config->next_interface_id;
 456         c->bConfigurationValue = config->bConfigurationValue;
 457         c->iConfiguration = config->iConfiguration;
 458         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 459         c->bMaxPower = encode_bMaxPower(speed, config);
 460
 461         /* There may be e.g. OTG descriptors */
 462         if (config->descriptors) {
 463                 status = usb_descriptor_fillbuf(next, len,
 464                                 config->descriptors);
 465                 if (status < 0)
 466                         return status;
 467                 len -= status;
 468                 next += status;
 469         }
 470
 471         /* add each function's descriptors */
 472         list_for_each_entry(f, &config->functions, list) {
 473                 struct usb_descriptor_header **descriptors;
 474
 475                 descriptors = function_descriptors(f, speed);
 476                 if (!descriptors)
 477                         continue;
 478                 status = usb_descriptor_fillbuf(next, len,
 479                         (const struct usb_descriptor_header **) descriptors);
 480                 if (status < 0)
 481                         return status;
 482                 len -= status;
 483                 next += status;
 484         }
 485
 486         len = next - buf;
 487         c->wTotalLength = cpu_to_le16(len);
 488         return len;
 489 }
 490
 491 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 492 {
 493         struct usb_gadget               *gadget = cdev->gadget;
 494         struct usb_configuration        *c;
 495         struct list_head                *pos;
 496         u8                              type = w_value >> 8;
 497         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 498
 499         if (gadget->speed >= USB_SPEED_SUPER)
 500                 speed = gadget->speed;
 501         else if (gadget_is_dualspeed(gadget)) {
 502                 int     hs = 0;
 503                 if (gadget->speed == USB_SPEED_HIGH)
 504                         hs = 1;
 505                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 506                         hs = !hs;
 507                 if (hs)
 508                         speed = USB_SPEED_HIGH;
 509
 510         }
 511
 512         /* This is a lookup by config *INDEX* */
 513         w_value &= 0xff;
 514
 515         pos = &cdev->configs;
 516         c = cdev->os_desc_config;
 517         if (c)
 518                 goto check_config;
 519
 520         while ((pos = pos->next) !=  &cdev->configs) {
 521                 c = list_entry(pos, typeof(*c), list);
 522
 523                 /* skip OS Descriptors config which is handled separately */
 524                 if (c == cdev->os_desc_config)
 525                         continue;
 526
 527 check_config:
 528                 /* ignore configs that won't work at this speed */
 529                 switch (speed) {
 530                 case USB_SPEED_SUPER_PLUS:
 531                         if (!c->superspeed_plus)
 532                                 continue;
 533                         break;
 534                 case USB_SPEED_SUPER:
 535                         if (!c->superspeed)
 536                                 continue;
 537                         break;
 538                 case USB_SPEED_HIGH:
 539                         if (!c->highspeed)
 540                                 continue;
 541                         break;
 542                 default:
 543                         if (!c->fullspeed)
 544                                 continue;
 545                 }
 546
 547                 if (w_value == 0)
 548                         return config_buf(c, speed, cdev->req->buf, type);
 549                 w_value--;
 550         }
 551         return -EINVAL;
 552 }
 553
 554 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 555 {
 556         struct usb_gadget               *gadget = cdev->gadget;
 557         struct usb_configuration        *c;
 558         unsigned                        count = 0;
 559         int                             hs = 0;
 560         int                             ss = 0;
 561         int                             ssp = 0;
 562
 563         if (gadget_is_dualspeed(gadget)) {
 564                 if (gadget->speed == USB_SPEED_HIGH)
 565                         hs = 1;
 566                 if (gadget->speed == USB_SPEED_SUPER)
 567                         ss = 1;
 568                 if (gadget->speed == USB_SPEED_SUPER_PLUS)
 569                         ssp = 1;
 570                 if (type == USB_DT_DEVICE_QUALIFIER)
 571                         hs = !hs;
 572         }
 573         list_for_each_entry(c, &cdev->configs, list) {
 574                 /* ignore configs that won't work at this speed */
 575                 if (ssp) {
 576                         if (!c->superspeed_plus)
 577                                 continue;
 578                 } else if (ss) {
 579                         if (!c->superspeed)
 580                                 continue;
 581                 } else if (hs) {
 582                         if (!c->highspeed)
 583                                 continue;
 584                 } else {
 585                         if (!c->fullspeed)
 586                                 continue;
 587                 }
 588                 count++;
 589         }
 590         return count;
 591 }
 592
 593 /**
 594  * bos_desc() - prepares the BOS descriptor.
 595  * @cdev: pointer to usb_composite device to generate the bos
 596  *      descriptor for
 597  *
 598  * This function generates the BOS (Binary Device Object)
 599  * descriptor and its device capabilities descriptors. The BOS
 600  * descriptor should be supported by a SuperSpeed device.
 601  */
 602 static int bos_desc(struct usb_composite_dev *cdev)
 603 {
 604         struct usb_ext_cap_descriptor   *usb_ext;
 605         struct usb_ss_cap_descriptor    *ss_cap;
 606         struct usb_dcd_config_params    dcd_config_params;
 607         struct usb_bos_descriptor       *bos = cdev->req->buf;
 608
 609         bos->bLength = USB_DT_BOS_SIZE;
 610         bos->bDescriptorType = USB_DT_BOS;
 611
 612         bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 613         bos->bNumDeviceCaps = 0;
 614
 615         /*
 616          * A SuperSpeed device shall include the USB2.0 extension descriptor
 617          * and shall support LPM when operating in USB2.0 HS mode.
 618          */
 619         usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 620         bos->bNumDeviceCaps++;
 621         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 622         usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 623         usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 624         usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 625         usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT | USB_BESL_SUPPORT);
 626
 627         /*
 628          * The Superspeed USB Capability descriptor shall be implemented by all
 629          * SuperSpeed devices.
 630          */
 631         ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 632         bos->bNumDeviceCaps++;
 633         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 634         ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 635         ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 636         ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 637         ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 638         ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 639                                 USB_FULL_SPEED_OPERATION |
 640                                 USB_HIGH_SPEED_OPERATION |
 641                                 USB_5GBPS_OPERATION);
 642         ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 643
 644         /* Get Controller configuration */
 645         if (cdev->gadget->ops->get_config_params)
 646                 cdev->gadget->ops->get_config_params(&dcd_config_params);
 647         else {
 648                 dcd_config_params.bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT;
 649                 dcd_config_params.bU2DevExitLat =
 650                         cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
 651         }
 652         ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 653         ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 654
 655         /* The SuperSpeedPlus USB Device Capability descriptor */
 656         if (gadget_is_superspeed_plus(cdev->gadget)) {
 657                 struct usb_ssp_cap_descriptor *ssp_cap;
 658
 659                 ssp_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 660                 bos->bNumDeviceCaps++;
 661
 662                 /*
 663                  * Report typical values.
 664                  */
 665
 666                 le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SSP_CAP_SIZE(1));
 667                 ssp_cap->bLength = USB_DT_USB_SSP_CAP_SIZE(1);
 668                 ssp_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 669                 ssp_cap->bDevCapabilityType = USB_SSP_CAP_TYPE;
 670                 ssp_cap->bReserved = 0;
 671                 ssp_cap->wReserved = 0;
 672
 673                 /* SSAC = 1 (2 attributes) */
 674                 ssp_cap->bmAttributes = cpu_to_le32(1);
 675
 676                 /* Min RX/TX Lane Count = 1 */
 677                 ssp_cap->wFunctionalitySupport =
 678                         cpu_to_le16((1 << 8) | (1 << 12));
 679
 680                 /*
 681                  * bmSublinkSpeedAttr[0]:
 682                  *   ST  = Symmetric, RX
 683                  *   LSE =  3 (Gbps)
 684                  *   LP  =  1 (SuperSpeedPlus)
 685                  *   LSM = 10 (10 Gbps)
 686                  */
 687                 ssp_cap->bmSublinkSpeedAttr[0] =
 688                         cpu_to_le32((3 << 4) | (1 << 14) | (0xa << 16));
 689                 /*
 690                  * bmSublinkSpeedAttr[1] =
 691                  *   ST  = Symmetric, TX
 692                  *   LSE =  3 (Gbps)
 693                  *   LP  =  1 (SuperSpeedPlus)
 694                  *   LSM = 10 (10 Gbps)
 695                  */
 696                 ssp_cap->bmSublinkSpeedAttr[1] =
 697                         cpu_to_le32((3 << 4) | (1 << 14) |
 698                                     (0xa << 16) | (1 << 7));
 699         }
 700
 701         return le16_to_cpu(bos->wTotalLength);
 702 }
 703
 704 static void device_qual(struct usb_composite_dev *cdev)
 705 {
 706         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 707
 708         qual->bLength = sizeof(*qual);
 709         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 710         /* POLICY: same bcdUSB and device type info at both speeds */
 711         qual->bcdUSB = cdev->desc.bcdUSB;
 712         qual->bDeviceClass = cdev->desc.bDeviceClass;
 713         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 714         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 715         /* ASSUME same EP0 fifo size at both speeds */
 716         qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 717         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 718         qual->bRESERVED = 0;
 719 }
 720
 721 /*-------------------------------------------------------------------------*/
 722
 723 static void reset_config(struct usb_composite_dev *cdev)
 724 {
 725         struct usb_function             *f;
 726
 727         DBG(cdev, "reset config\n");
 728
 729         list_for_each_entry(f, &cdev->config->functions, list) {
 730                 if (f->disable)
 731                         f->disable(f);
 732
 733                 bitmap_zero(f->endpoints, 32);
 734         }
 735         cdev->config = NULL;
 736         cdev->delayed_status = 0;
 737 }
 738
 739 static int set_config(struct usb_composite_dev *cdev,
 740                 const struct usb_ctrlrequest *ctrl, unsigned number)
 741 {
 742         struct usb_gadget       *gadget = cdev->gadget;
 743         struct usb_configuration *c = NULL;
 744         int                     result = -EINVAL;
 745         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 746         int                     tmp;
 747
 748         if (number) {
 749                 list_for_each_entry(c, &cdev->configs, list) {
 750                         if (c->bConfigurationValue == number) {
 751                                 /*
 752                                  * We disable the FDs of the previous
 753                                  * configuration only if the new configuration
 754                                  * is a valid one
 755                                  */
 756                                 if (cdev->config)
 757                                         reset_config(cdev);
 758                                 result = 0;
 759                                 break;
 760                         }
 761                 }
 762                 if (result < 0)
 763                         goto done;
 764         } else { /* Zero configuration value - need to reset the config */
 765                 if (cdev->config)
 766                         reset_config(cdev);
 767                 result = 0;
 768         }
 769
 770         INFO(cdev, "%s config #%d: %s\n",
 771              usb_speed_string(gadget->speed),
 772              number, c ? c->label : "unconfigured");
 773
 774         if (!c)
 775                 goto done;
 776
 777         usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
 778         cdev->config = c;
 779
 780         /* Initialize all interfaces by setting them to altsetting zero. */
 781         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 782                 struct usb_function     *f = c->interface[tmp];
 783                 struct usb_descriptor_header **descriptors;
 784
 785                 if (!f)
 786                         break;
 787
 788                 /*
 789                  * Record which endpoints are used by the function. This is used
 790                  * to dispatch control requests targeted at that endpoint to the
 791                  * function's setup callback instead of the current
 792                  * configuration's setup callback.
 793                  */
 794                 descriptors = function_descriptors(f, gadget->speed);
 795
 796                 for (; *descriptors; ++descriptors) {
 797                         struct usb_endpoint_descriptor *ep;
 798                         int addr;
 799
 800                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 801                                 continue;
 802
 803                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 804                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 805                              |  (ep->bEndpointAddress & 0x0f);
 806                         set_bit(addr, f->endpoints);
 807                 }
 808
 809                 result = f->set_alt(f, tmp, 0);
 810                 if (result < 0) {
 811                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 812                                         tmp, f->name, f, result);
 813
 814                         reset_config(cdev);
 815                         goto done;
 816                 }
 817
 818                 if (result == USB_GADGET_DELAYED_STATUS) {
 819                         DBG(cdev,
 820                          "%s: interface %d (%s) requested delayed status\n",
 821                                         __func__, tmp, f->name);
 822                         cdev->delayed_status++;
 823                         DBG(cdev, "delayed_status count %d\n",
 824                                         cdev->delayed_status);
 825                 }
 826         }
 827
 828         /* when we return, be sure our power usage is valid */
 829         power = c->MaxPower ? c->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
 830 done:
 831         usb_gadget_vbus_draw(gadget, power);
 832         if (result >= 0 && cdev->delayed_status)
 833                 result = USB_GADGET_DELAYED_STATUS;
 834         return result;
 835 }
 836
 837 int usb_add_config_only(struct usb_composite_dev *cdev,
 838                 struct usb_configuration *config)
 839 {
 840         struct usb_configuration *c;
 841
 842         if (!config->bConfigurationValue)
 843                 return -EINVAL;
 844
 845         /* Prevent duplicate configuration identifiers */
 846         list_for_each_entry(c, &cdev->configs, list) {
 847                 if (c->bConfigurationValue == config->bConfigurationValue)
 848                         return -EBUSY;
 849         }
 850
 851         config->cdev = cdev;
 852         list_add_tail(&config->list, &cdev->configs);
 853
 854         INIT_LIST_HEAD(&config->functions);
 855         config->next_interface_id = 0;
 856         memset(config->interface, 0, sizeof(config->interface));
 857
 858         return 0;
 859 }
 860 EXPORT_SYMBOL_GPL(usb_add_config_only);
 861
 862 /**
 863  * usb_add_config() - add a configuration to a device.
 864  * @cdev: wraps the USB gadget
 865  * @config: the configuration, with bConfigurationValue assigned
 866  * @bind: the configuration's bind function
 867  * Context: single threaded during gadget setup
 868  *
 869  * One of the main tasks of a composite @bind() routine is to
 870  * add each of the configurations it supports, using this routine.
 871  *
 872  * This function returns the value of the configuration's @bind(), which
 873  * is zero for success else a negative errno value.  Binding configurations
 874  * assigns global resources including string IDs, and per-configuration
 875  * resources such as interface IDs and endpoints.
 876  */
 877 int usb_add_config(struct usb_composite_dev *cdev,
 878                 struct usb_configuration *config,
 879                 int (*bind)(struct usb_configuration *))
 880 {
 881         int                             status = -EINVAL;
 882
 883         if (!bind)
 884                 goto done;
 885
 886         DBG(cdev, "adding config #%u '%s'/%p\n",
 887                         config->bConfigurationValue,
 888                         config->label, config);
 889
 890         status = usb_add_config_only(cdev, config);
 891         if (status)
 892                 goto done;
 893
 894         status = bind(config);
 895         if (status < 0) {
 896                 while (!list_empty(&config->functions)) {
 897                         struct usb_function             *f;
 898
 899                         f = list_first_entry(&config->functions,
 900                                         struct usb_function, list);
 901                         list_del(&f->list);
 902                         if (f->unbind) {
 903                                 DBG(cdev, "unbind function '%s'/%p\n",
 904                                         f->name, f);
 905                                 f->unbind(config, f);
 906                                 /* may free memory for "f" */
 907                         }
 908                 }
 909                 list_del(&config->list);
 910                 config->cdev = NULL;
 911         } else {
 912                 unsigned        i;
 913
 914                 DBG(cdev, "cfg %d/%p speeds:%s%s%s%s\n",
 915                         config->bConfigurationValue, config,
 916                         config->superspeed_plus ? " superplus" : "",
 917                         config->superspeed ? " super" : "",
 918                         config->highspeed ? " high" : "",
 919                         config->fullspeed
 920                                 ? (gadget_is_dualspeed(cdev->gadget)
 921                                         ? " full"
 922                                         : " full/low")
 923                                 : "");
 924
 925                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 926                         struct usb_function     *f = config->interface[i];
 927
 928                         if (!f)
 929                                 continue;
 930                         DBG(cdev, "  interface %d = %s/%p\n",
 931                                 i, f->name, f);
 932                 }
 933         }
 934
 935         /* set_alt(), or next bind(), sets up ep->claimed as needed */
 936         usb_ep_autoconfig_reset(cdev->gadget);
 937
 938 done:
 939         if (status)
 940                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 941                                 config->bConfigurationValue, status);
 942         return status;
 943 }
 944 EXPORT_SYMBOL_GPL(usb_add_config);
 945
 946 static void remove_config(struct usb_composite_dev *cdev,
 947                               struct usb_configuration *config)
 948 {
 949         while (!list_empty(&config->functions)) {
 950                 struct usb_function             *f;
 951
 952                 f = list_first_entry(&config->functions,
 953                                 struct usb_function, list);
 954                 list_del(&f->list);
 955                 if (f->unbind) {
 956                         DBG(cdev, "unbind function '%s'/%p\n", f->name, f);
 957                         f->unbind(config, f);
 958                         /* may free memory for "f" */
 959                 }
 960         }
 961         list_del(&config->list);
 962         if (config->unbind) {
 963                 DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
 964                 config->unbind(config);
 965                         /* may free memory for "c" */
 966         }
 967 }
 968
 969 /**
 970  * usb_remove_config() - remove a configuration from a device.
 971  * @cdev: wraps the USB gadget
 972  * @config: the configuration
 973  *
 974  * Drivers must call usb_gadget_disconnect before calling this function
 975  * to disconnect the device from the host and make sure the host will not
 976  * try to enumerate the device while we are changing the config list.
 977  */
 978 void usb_remove_config(struct usb_composite_dev *cdev,
 979                       struct usb_configuration *config)
 980 {
 981         unsigned long flags;
 982
 983         spin_lock_irqsave(&cdev->lock, flags);
 984
 985         if (cdev->config == config)
 986                 reset_config(cdev);
 987
 988         spin_unlock_irqrestore(&cdev->lock, flags);
 989
 990         remove_config(cdev, config);
 991 }
 992
 993 /*-------------------------------------------------------------------------*/
 994
 995 /* We support strings in multiple languages ... string descriptor zero
 996  * says which languages are supported.  The typical case will be that
 997  * only one language (probably English) is used, with i18n handled on
 998  * the host side.
 999  */
1000
1001 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
1002 {
1003         const struct usb_gadget_strings *s;
1004         __le16                          language;
1005         __le16                          *tmp;
1006
1007         while (*sp) {
1008                 s = *sp;
1009                 language = cpu_to_le16(s->language);
1010                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
1011                         if (*tmp == language)
1012                                 goto repeat;
1013                 }
1014                 *tmp++ = language;
1015 repeat:
1016                 sp++;
1017         }
1018 }
1019
1020 static int lookup_string(
1021         struct usb_gadget_strings       **sp,
1022         void                            *buf,
1023         u16                             language,
1024         int                             id
1025 )
1026 {
1027         struct usb_gadget_strings       *s;
1028         int                             value;
1029
1030         while (*sp) {
1031                 s = *sp++;
1032                 if (s->language != language)
1033                         continue;
1034                 value = usb_gadget_get_string(s, id, buf);
1035                 if (value > 0)
1036                         return value;
1037         }
1038         return -EINVAL;
1039 }
1040
1041 static int get_string(struct usb_composite_dev *cdev,
1042                 void *buf, u16 language, int id)
1043 {
1044         struct usb_composite_driver     *composite = cdev->driver;
1045         struct usb_gadget_string_container *uc;
1046         struct usb_configuration        *c;
1047         struct usb_function             *f;
1048         int                             len;
1049
1050         /* Yes, not only is USB's i18n support probably more than most
1051          * folk will ever care about ... also, it's all supported here.
1052          * (Except for UTF8 support for Unicode's "Astral Planes".)
1053          */
1054
1055         /* 0 == report all available language codes */
1056         if (id == 0) {
1057                 struct usb_string_descriptor    *s = buf;
1058                 struct usb_gadget_strings       **sp;
1059
1060                 memset(s, 0, 256);
1061                 s->bDescriptorType = USB_DT_STRING;
1062
1063                 sp = composite->strings;
1064                 if (sp)
1065                         collect_langs(sp, s->wData);
1066
1067                 list_for_each_entry(c, &cdev->configs, list) {
1068                         sp = c->strings;
1069                         if (sp)
1070                                 collect_langs(sp, s->wData);
1071
1072                         list_for_each_entry(f, &c->functions, list) {
1073                                 sp = f->strings;
1074                                 if (sp)
1075                                         collect_langs(sp, s->wData);
1076                         }
1077                 }
1078                 list_for_each_entry(uc, &cdev->gstrings, list) {
1079                         struct usb_gadget_strings **sp;
1080
1081                         sp = get_containers_gs(uc);
1082                         collect_langs(sp, s->wData);
1083                 }
1084
1085                 for (len = 0; len <= 126 && s->wData[len]; len++)
1086                         continue;
1087                 if (!len)
1088                         return -EINVAL;
1089
1090                 s->bLength = 2 * (len + 1);
1091                 return s->bLength;
1092         }
1093
1094         if (cdev->use_os_string && language == 0 && id == OS_STRING_IDX) {
1095                 struct usb_os_string *b = buf;
1096                 b->bLength = sizeof(*b);
1097                 b->bDescriptorType = USB_DT_STRING;
1098                 compiletime_assert(
1099                         sizeof(b->qwSignature) == sizeof(cdev->qw_sign),
1100                         "qwSignature size must be equal to qw_sign");
1101                 memcpy(&b->qwSignature, cdev->qw_sign, sizeof(b->qwSignature));
1102                 b->bMS_VendorCode = cdev->b_vendor_code;
1103                 b->bPad = 0;
1104                 return sizeof(*b);
1105         }
1106
1107         list_for_each_entry(uc, &cdev->gstrings, list) {
1108                 struct usb_gadget_strings **sp;
1109
1110                 sp = get_containers_gs(uc);
1111                 len = lookup_string(sp, buf, language, id);
1112                 if (len > 0)
1113                         return len;
1114         }
1115
1116         /* String IDs are device-scoped, so we look up each string
1117          * table we're told about.  These lookups are infrequent;
1118          * simpler-is-better here.
1119          */
1120         if (composite->strings) {
1121                 len = lookup_string(composite->strings, buf, language, id);
1122                 if (len > 0)
1123                         return len;
1124         }
1125         list_for_each_entry(c, &cdev->configs, list) {
1126                 if (c->strings) {
1127                         len = lookup_string(c->strings, buf, language, id);
1128                         if (len > 0)
1129                                 return len;
1130                 }
1131                 list_for_each_entry(f, &c->functions, list) {
1132                         if (!f->strings)
1133                                 continue;
1134                         len = lookup_string(f->strings, buf, language, id);
1135                         if (len > 0)
1136                                 return len;
1137                 }
1138         }
1139         return -EINVAL;
1140 }
1141
1142 /**
1143  * usb_string_id() - allocate an unused string ID
1144  * @cdev: the device whose string descriptor IDs are being allocated
1145  * Context: single threaded during gadget setup
1146  *
1147  * @usb_string_id() is called from bind() callbacks to allocate
1148  * string IDs.  Drivers for functions, configurations, or gadgets will
1149  * then store that ID in the appropriate descriptors and string table.
1150  *
1151  * All string identifier should be allocated using this,
1152  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
1153  * that for example different functions don't wrongly assign different
1154  * meanings to the same identifier.
1155  */
1156 int usb_string_id(struct usb_composite_dev *cdev)
1157 {
1158         if (cdev->next_string_id < 254) {
1159                 /* string id 0 is reserved by USB spec for list of
1160                  * supported languages */
1161                 /* 255 reserved as well? -- mina86 */
1162                 cdev->next_string_id++;
1163                 return cdev->next_string_id;
1164         }
1165         return -ENODEV;
1166 }
1167 EXPORT_SYMBOL_GPL(usb_string_id);
1168
1169 /**
1170  * usb_string_ids() - allocate unused string IDs in batch
1171  * @cdev: the device whose string descriptor IDs are being allocated
1172  * @str: an array of usb_string objects to assign numbers to
1173  * Context: single threaded during gadget setup
1174  *
1175  * @usb_string_ids() is called from bind() callbacks to allocate
1176  * string IDs.  Drivers for functions, configurations, or gadgets will
1177  * then copy IDs from the string table to the appropriate descriptors
1178  * and string table for other languages.
1179  *
1180  * All string identifier should be allocated using this,
1181  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1182  * example different functions don't wrongly assign different meanings
1183  * to the same identifier.
1184  */
1185 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
1186 {
1187         int next = cdev->next_string_id;
1188
1189         for (; str->s; ++str) {
1190                 if (unlikely(next >= 254))
1191                         return -ENODEV;
1192                 str->id = ++next;
1193         }
1194
1195         cdev->next_string_id = next;
1196
1197         return 0;
1198 }
1199 EXPORT_SYMBOL_GPL(usb_string_ids_tab);
1200
1201 static struct usb_gadget_string_container *copy_gadget_strings(
1202                 struct usb_gadget_strings **sp, unsigned n_gstrings,
1203                 unsigned n_strings)
1204 {
1205         struct usb_gadget_string_container *uc;
1206         struct usb_gadget_strings **gs_array;
1207         struct usb_gadget_strings *gs;
1208         struct usb_string *s;
1209         unsigned mem;
1210         unsigned n_gs;
1211         unsigned n_s;
1212         void *stash;
1213
1214         mem = sizeof(*uc);
1215         mem += sizeof(void *) * (n_gstrings + 1);
1216         mem += sizeof(struct usb_gadget_strings) * n_gstrings;
1217         mem += sizeof(struct usb_string) * (n_strings + 1) * (n_gstrings);
1218         uc = kmalloc(mem, GFP_KERNEL);
1219         if (!uc)
1220                 return ERR_PTR(-ENOMEM);
1221         gs_array = get_containers_gs(uc);
1222         stash = uc->stash;
1223         stash += sizeof(void *) * (n_gstrings + 1);
1224         for (n_gs = 0; n_gs < n_gstrings; n_gs++) {
1225                 struct usb_string *org_s;
1226
1227                 gs_array[n_gs] = stash;
1228                 gs = gs_array[n_gs];
1229                 stash += sizeof(struct usb_gadget_strings);
1230                 gs->language = sp[n_gs]->language;
1231                 gs->strings = stash;
1232                 org_s = sp[n_gs]->strings;
1233
1234                 for (n_s = 0; n_s < n_strings; n_s++) {
1235                         s = stash;
1236                         stash += sizeof(struct usb_string);
1237                         if (org_s->s)
1238                                 s->s = org_s->s;
1239                         else
1240                                 s->s = "";
1241                         org_s++;
1242                 }
1243                 s = stash;
1244                 s->s = NULL;
1245                 stash += sizeof(struct usb_string);
1246
1247         }
1248         gs_array[n_gs] = NULL;
1249         return uc;
1250 }
1251
1252 /**
1253  * usb_gstrings_attach() - attach gadget strings to a cdev and assign ids
1254  * @cdev: the device whose string descriptor IDs are being allocated
1255  * and attached.
1256  * @sp: an array of usb_gadget_strings to attach.
1257  * @n_strings: number of entries in each usb_strings array (sp[]->strings)
1258  *
1259  * This function will create a deep copy of usb_gadget_strings and usb_string
1260  * and attach it to the cdev. The actual string (usb_string.s) will not be
1261  * copied but only a referenced will be made. The struct usb_gadget_strings
1262  * array may contain multiple languages and should be NULL terminated.
1263  * The ->language pointer of each struct usb_gadget_strings has to contain the
1264  * same amount of entries.
1265  * For instance: sp[0] is en-US, sp[1] is es-ES. It is expected that the first
1266  * usb_string entry of es-ES contains the translation of the first usb_string
1267  * entry of en-US. Therefore both entries become the same id assign.
1268  */
1269 struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
1270                 struct usb_gadget_strings **sp, unsigned n_strings)
1271 {
1272         struct usb_gadget_string_container *uc;
1273         struct usb_gadget_strings **n_gs;
1274         unsigned n_gstrings = 0;
1275         unsigned i;
1276         int ret;
1277
1278         for (i = 0; sp[i]; i++)
1279                 n_gstrings++;
1280
1281         if (!n_gstrings)
1282                 return ERR_PTR(-EINVAL);
1283
1284         uc = copy_gadget_strings(sp, n_gstrings, n_strings);
1285         if (IS_ERR(uc))
1286                 return ERR_CAST(uc);
1287
1288         n_gs = get_containers_gs(uc);
1289         ret = usb_string_ids_tab(cdev, n_gs[0]->strings);
1290         if (ret)
1291                 goto err;
1292
1293         for (i = 1; i < n_gstrings; i++) {
1294                 struct usb_string *m_s;
1295                 struct usb_string *s;
1296                 unsigned n;
1297
1298                 m_s = n_gs[0]->strings;
1299                 s = n_gs[i]->strings;
1300                 for (n = 0; n < n_strings; n++) {
1301                         s->id = m_s->id;
1302                         s++;
1303                         m_s++;
1304                 }
1305         }
1306         list_add_tail(&uc->list, &cdev->gstrings);
1307         return n_gs[0]->strings;
1308 err:
1309         kfree(uc);
1310         return ERR_PTR(ret);
1311 }
1312 EXPORT_SYMBOL_GPL(usb_gstrings_attach);
1313
1314 /**
1315  * usb_string_ids_n() - allocate unused string IDs in batch
1316  * @c: the device whose string descriptor IDs are being allocated
1317  * @n: number of string IDs to allocate
1318  * Context: single threaded during gadget setup
1319  *
1320  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1321  * valid IDs.  At least provided that @n is non-zero because if it
1322  * is, returns last requested ID which is now very useful information.
1323  *
1324  * @usb_string_ids_n() is called from bind() callbacks to allocate
1325  * string IDs.  Drivers for functions, configurations, or gadgets will
1326  * then store that ID in the appropriate descriptors and string table.
1327  *
1328  * All string identifier should be allocated using this,
1329  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1330  * example different functions don't wrongly assign different meanings
1331  * to the same identifier.
1332  */
1333 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1334 {
1335         unsigned next = c->next_string_id;
1336         if (unlikely(n > 254 || (unsigned)next + n > 254))
1337                 return -ENODEV;
1338         c->next_string_id += n;
1339         return next + 1;
1340 }
1341 EXPORT_SYMBOL_GPL(usb_string_ids_n);
1342
1343 /*-------------------------------------------------------------------------*/
1344
1345 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1346 {
1347         struct usb_composite_dev *cdev;
1348
1349         if (req->status || req->actual != req->length)
1350                 DBG((struct usb_composite_dev *) ep->driver_data,
1351                                 "setup complete --> %d, %d/%d\n",
1352                                 req->status, req->actual, req->length);
1353
1354         /*
1355          * REVIST The same ep0 requests are shared with function drivers
1356          * so they don't have to maintain the same ->complete() stubs.
1357          *
1358          * Because of that, we need to check for the validity of ->context
1359          * here, even though we know we've set it to something useful.
1360          */
1361         if (!req->context)
1362                 return;
1363
1364         cdev = req->context;
1365
1366         if (cdev->req == req)
1367                 cdev->setup_pending = false;
1368         else if (cdev->os_desc_req == req)
1369                 cdev->os_desc_pending = false;
1370         else
1371                 WARN(1, "unknown request %p\n", req);
1372 }
1373
1374 static int composite_ep0_queue(struct usb_composite_dev *cdev,
1375                 struct usb_request *req, gfp_t gfp_flags)
1376 {
1377         int ret;
1378
1379         ret = usb_ep_queue(cdev->gadget->ep0, req, gfp_flags);
1380         if (ret == 0) {
1381                 if (cdev->req == req)
1382                         cdev->setup_pending = true;
1383                 else if (cdev->os_desc_req == req)
1384                         cdev->os_desc_pending = true;
1385                 else
1386                         WARN(1, "unknown request %p\n", req);
1387         }
1388
1389         return ret;
1390 }
1391
1392 static int count_ext_compat(struct usb_configuration *c)
1393 {
1394         int i, res;
1395
1396         res = 0;
1397         for (i = 0; i < c->next_interface_id; ++i) {
1398                 struct usb_function *f;
1399                 int j;
1400
1401                 f = c->interface[i];
1402                 for (j = 0; j < f->os_desc_n; ++j) {
1403                         struct usb_os_desc *d;
1404
1405                         if (i != f->os_desc_table[j].if_id)
1406                                 continue;
1407                         d = f->os_desc_table[j].os_desc;
1408                         if (d && d->ext_compat_id)
1409                                 ++res;
1410                 }
1411         }
1412         BUG_ON(res > 255);
1413         return res;
1414 }
1415
1416 static void fill_ext_compat(struct usb_configuration *c, u8 *buf)
1417 {
1418         int i, count;
1419
1420         count = 16;
1421         for (i = 0; i < c->next_interface_id; ++i) {
1422                 struct usb_function *f;
1423                 int j;
1424
1425                 f = c->interface[i];
1426                 for (j = 0; j < f->os_desc_n; ++j) {
1427                         struct usb_os_desc *d;
1428
1429                         if (i != f->os_desc_table[j].if_id)
1430                                 continue;
1431                         d = f->os_desc_table[j].os_desc;
1432                         if (d && d->ext_compat_id) {
1433                                 *buf++ = i;
1434                                 *buf++ = 0x01;
1435                                 memcpy(buf, d->ext_compat_id, 16);
1436                                 buf += 22;
1437                         } else {
1438                                 ++buf;
1439                                 *buf = 0x01;
1440                                 buf += 23;
1441                         }
1442                         count += 24;
1443                         if (count >= 4096)
1444                                 return;
1445                 }
1446         }
1447 }
1448
1449 static int count_ext_prop(struct usb_configuration *c, int interface)
1450 {
1451         struct usb_function *f;
1452         int j;
1453
1454         f = c->interface[interface];
1455         for (j = 0; j < f->os_desc_n; ++j) {
1456                 struct usb_os_desc *d;
1457
1458                 if (interface != f->os_desc_table[j].if_id)
1459                         continue;
1460                 d = f->os_desc_table[j].os_desc;
1461                 if (d && d->ext_compat_id)
1462                         return d->ext_prop_count;
1463         }
1464         return 0;
1465 }
1466
1467 static int len_ext_prop(struct usb_configuration *c, int interface)
1468 {
1469         struct usb_function *f;
1470         struct usb_os_desc *d;
1471         int j, res;
1472
1473         res = 10; /* header length */
1474         f = c->interface[interface];
1475         for (j = 0; j < f->os_desc_n; ++j) {
1476                 if (interface != f->os_desc_table[j].if_id)
1477                         continue;
1478                 d = f->os_desc_table[j].os_desc;
1479                 if (d)
1480                         return min(res + d->ext_prop_len, 4096);
1481         }
1482         return res;
1483 }
1484
1485 static int fill_ext_prop(struct usb_configuration *c, int interface, u8 *buf)
1486 {
1487         struct usb_function *f;
1488         struct usb_os_desc *d;
1489         struct usb_os_desc_ext_prop *ext_prop;
1490         int j, count, n, ret;
1491         u8 *start = buf;
1492
1493         f = c->interface[interface];
1494         for (j = 0; j < f->os_desc_n; ++j) {
1495                 if (interface != f->os_desc_table[j].if_id)
1496                         continue;
1497                 d = f->os_desc_table[j].os_desc;
1498                 if (d)
1499                         list_for_each_entry(ext_prop, &d->ext_prop, entry) {
1500                                 /* 4kB minus header length */
1501                                 n = buf - start;
1502                                 if (n >= 4086)
1503                                         return 0;
1504
1505                                 count = ext_prop->data_len +
1506                                         ext_prop->name_len + 14;
1507                                 if (count > 4086 - n)
1508                                         return -EINVAL;
1509                                 usb_ext_prop_put_size(buf, count);
1510                                 usb_ext_prop_put_type(buf, ext_prop->type);
1511                                 ret = usb_ext_prop_put_name(buf, ext_prop->name,
1512                                                             ext_prop->name_len);
1513                                 if (ret < 0)
1514                                         return ret;
1515                                 switch (ext_prop->type) {
1516                                 case USB_EXT_PROP_UNICODE:
1517                                 case USB_EXT_PROP_UNICODE_ENV:
1518                                 case USB_EXT_PROP_UNICODE_LINK:
1519                                         usb_ext_prop_put_unicode(buf, ret,
1520                                                          ext_prop->data,
1521                                                          ext_prop->data_len);
1522                                         break;
1523                                 case USB_EXT_PROP_BINARY:
1524                                         usb_ext_prop_put_binary(buf, ret,
1525                                                         ext_prop->data,
1526                                                         ext_prop->data_len);
1527                                         break;
1528                                 case USB_EXT_PROP_LE32:
1529                                         /* not implemented */
1530                                 case USB_EXT_PROP_BE32:
1531                                         /* not implemented */
1532                                 default:
1533                                         return -EINVAL;
1534                                 }
1535                                 buf += count;
1536                         }
1537         }
1538
1539         return 0;
1540 }
1541
1542 /*
1543  * The setup() callback implements all the ep0 functionality that's
1544  * not handled lower down, in hardware or the hardware driver(like
1545  * device and endpoint feature flags, and their status).  It's all
1546  * housekeeping for the gadget function we're implementing.  Most of
1547  * the work is in config and function specific setup.
1548  */
1549 int
1550 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1551 {
1552         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1553         struct usb_request              *req = cdev->req;
1554         int                             value = -EOPNOTSUPP;
1555         int                             status = 0;
1556         u16                             w_index = le16_to_cpu(ctrl->wIndex);
1557         u8                              intf = w_index & 0xFF;
1558         u16                             w_value = le16_to_cpu(ctrl->wValue);
1559         u16                             w_length = le16_to_cpu(ctrl->wLength);
1560         struct usb_function             *f = NULL;
1561         u8                              endp;
1562
1563         /* partial re-init of the response message; the function or the
1564          * gadget might need to intercept e.g. a control-OUT completion
1565          * when we delegate to it.
1566          */
1567         req->zero = 0;
1568         req->context = cdev;
1569         req->complete = composite_setup_complete;
1570         req->length = 0;
1571         gadget->ep0->driver_data = cdev;
1572
1573         /*
1574          * Don't let non-standard requests match any of the cases below
1575          * by accident.
1576          */
1577         if ((ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
1578                 goto unknown;
1579
1580         switch (ctrl->bRequest) {
1581
1582         /* we handle all standard USB descriptors */
1583         case USB_REQ_GET_DESCRIPTOR:
1584                 if (ctrl->bRequestType != USB_DIR_IN)
1585                         goto unknown;
1586                 switch (w_value >> 8) {
1587
1588                 case USB_DT_DEVICE:
1589                         cdev->desc.bNumConfigurations =
1590                                 count_configs(cdev, USB_DT_DEVICE);
1591                         cdev->desc.bMaxPacketSize0 =
1592                                 cdev->gadget->ep0->maxpacket;
1593                         if (gadget_is_superspeed(gadget)) {
1594                                 if (gadget->speed >= USB_SPEED_SUPER) {
1595                                         cdev->desc.bcdUSB = cpu_to_le16(0x0310);
1596                                         cdev->desc.bMaxPacketSize0 = 9;
1597                                 } else {
1598                                         cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1599                                 }
1600                         } else {
1601                                 cdev->desc.bcdUSB = cpu_to_le16(0x0200);
1602                         }
1603
1604                         value = min(w_length, (u16) sizeof cdev->desc);
1605                         memcpy(req->buf, &cdev->desc, value);
1606                         break;
1607                 case USB_DT_DEVICE_QUALIFIER:
1608                         if (!gadget_is_dualspeed(gadget) ||
1609                             gadget->speed >= USB_SPEED_SUPER)
1610                                 break;
1611                         device_qual(cdev);
1612                         value = min_t(int, w_length,
1613                                 sizeof(struct usb_qualifier_descriptor));
1614                         break;
1615                 case USB_DT_OTHER_SPEED_CONFIG:
1616                         if (!gadget_is_dualspeed(gadget) ||
1617                             gadget->speed >= USB_SPEED_SUPER)
1618                                 break;
1619                         /* FALLTHROUGH */
1620                 case USB_DT_CONFIG:
1621                         value = config_desc(cdev, w_value);
1622                         if (value >= 0)
1623                                 value = min(w_length, (u16) value);
1624                         break;
1625                 case USB_DT_STRING:
1626                         value = get_string(cdev, req->buf,
1627                                         w_index, w_value & 0xff);
1628                         if (value >= 0)
1629                                 value = min(w_length, (u16) value);
1630                         break;
1631                 case USB_DT_BOS:
1632                         if (gadget_is_superspeed(gadget)) {
1633                                 value = bos_desc(cdev);
1634                                 value = min(w_length, (u16) value);
1635                         }
1636                         break;
1637                 case USB_DT_OTG:
1638                         if (gadget_is_otg(gadget)) {
1639                                 struct usb_configuration *config;
1640                                 int otg_desc_len = 0;
1641
1642                                 if (cdev->config)
1643                                         config = cdev->config;
1644                                 else
1645                                         config = list_first_entry(
1646                                                         &cdev->configs,
1647                                                 struct usb_configuration, list);
1648                                 if (!config)
1649                                         goto done;
1650
1651                                 if (gadget->otg_caps &&
1652                                         (gadget->otg_caps->otg_rev >= 0x0200))
1653                                         otg_desc_len += sizeof(
1654                                                 struct usb_otg20_descriptor);
1655                                 else
1656                                         otg_desc_len += sizeof(
1657                                                 struct usb_otg_descriptor);
1658
1659                                 value = min_t(int, w_length, otg_desc_len);
1660                                 memcpy(req->buf, config->descriptors[0], value);
1661                         }
1662                         break;
1663                 }
1664                 break;
1665
1666         /* any number of configs can work */
1667         case USB_REQ_SET_CONFIGURATION:
1668                 if (ctrl->bRequestType != 0)
1669                         goto unknown;
1670                 if (gadget_is_otg(gadget)) {
1671                         if (gadget->a_hnp_support)
1672                                 DBG(cdev, "HNP available\n");
1673                         else if (gadget->a_alt_hnp_support)
1674                                 DBG(cdev, "HNP on another port\n");
1675                         else
1676                                 VDBG(cdev, "HNP inactive\n");
1677                 }
1678                 spin_lock(&cdev->lock);
1679                 value = set_config(cdev, ctrl, w_value);
1680                 spin_unlock(&cdev->lock);
1681                 break;
1682         case USB_REQ_GET_CONFIGURATION:
1683                 if (ctrl->bRequestType != USB_DIR_IN)
1684                         goto unknown;
1685                 if (cdev->config)
1686                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
1687                 else
1688                         *(u8 *)req->buf = 0;
1689                 value = min(w_length, (u16) 1);
1690                 break;
1691
1692         /* function drivers must handle get/set altsetting; if there's
1693          * no get() method, we know only altsetting zero works.
1694          */
1695         case USB_REQ_SET_INTERFACE:
1696                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1697                         goto unknown;
1698                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1699                         break;
1700                 f = cdev->config->interface[intf];
1701                 if (!f)
1702                         break;
1703                 if (w_value && !f->set_alt)
1704                         break;
1705                 value = f->set_alt(f, w_index, w_value);
1706                 if (value == USB_GADGET_DELAYED_STATUS) {
1707                         DBG(cdev,
1708                          "%s: interface %d (%s) requested delayed status\n",
1709                                         __func__, intf, f->name);
1710                         cdev->delayed_status++;
1711                         DBG(cdev, "delayed_status count %d\n",
1712                                         cdev->delayed_status);
1713                 }
1714                 break;
1715         case USB_REQ_GET_INTERFACE:
1716                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1717                         goto unknown;
1718                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1719                         break;
1720                 f = cdev->config->interface[intf];
1721                 if (!f)
1722                         break;
1723                 /* lots of interfaces only need altsetting zero... */
1724                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1725                 if (value < 0)
1726                         break;
1727                 *((u8 *)req->buf) = value;
1728                 value = min(w_length, (u16) 1);
1729                 break;
1730         case USB_REQ_GET_STATUS:
1731                 if (gadget_is_otg(gadget) && gadget->hnp_polling_support &&
1732                                                 (w_index == OTG_STS_SELECTOR)) {
1733                         if (ctrl->bRequestType != (USB_DIR_IN |
1734                                                         USB_RECIP_DEVICE))
1735                                 goto unknown;
1736                         *((u8 *)req->buf) = gadget->host_request_flag;
1737                         value = 1;
1738                         break;
1739                 }
1740
1741                 /*
1742                  * USB 3.0 additions:
1743                  * Function driver should handle get_status request. If such cb
1744                  * wasn't supplied we respond with default value = 0
1745                  * Note: function driver should supply such cb only for the
1746                  * first interface of the function
1747                  */
1748                 if (!gadget_is_superspeed(gadget))
1749                         goto unknown;
1750                 if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1751                         goto unknown;
1752                 value = 2;      /* This is the length of the get_status reply */
1753                 put_unaligned_le16(0, req->buf);
1754                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1755                         break;
1756                 f = cdev->config->interface[intf];
1757                 if (!f)
1758                         break;
1759                 status = f->get_status ? f->get_status(f) : 0;
1760                 if (status < 0)
1761                         break;
1762                 put_unaligned_le16(status & 0x0000ffff, req->buf);
1763                 break;
1764         /*
1765          * Function drivers should handle SetFeature/ClearFeature
1766          * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1767          * only for the first interface of the function
1768          */
1769         case USB_REQ_CLEAR_FEATURE:
1770         case USB_REQ_SET_FEATURE:
1771                 if (!gadget_is_superspeed(gadget))
1772                         goto unknown;
1773                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1774                         goto unknown;
1775                 switch (w_value) {
1776                 case USB_INTRF_FUNC_SUSPEND:
1777                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1778                                 break;
1779                         f = cdev->config->interface[intf];
1780                         if (!f)
1781                                 break;
1782                         value = 0;
1783                         if (f->func_suspend)
1784                                 value = f->func_suspend(f, w_index >> 8);
1785                         if (value < 0) {
1786                                 ERROR(cdev,
1787                                       "func_suspend() returned error %d\n",
1788                                       value);
1789                                 value = 0;
1790                         }
1791                         break;
1792                 }
1793                 break;
1794         default:
1795 unknown:
1796                 /*
1797                  * OS descriptors handling
1798                  */
1799                 if (cdev->use_os_string && cdev->os_desc_config &&
1800                     (ctrl->bRequestType & USB_TYPE_VENDOR) &&
1801                     ctrl->bRequest == cdev->b_vendor_code) {
1802                         struct usb_request              *req;
1803                         struct usb_configuration        *os_desc_cfg;
1804                         u8                              *buf;
1805                         int                             interface;
1806                         int                             count = 0;
1807
1808                         req = cdev->os_desc_req;
1809                         req->context = cdev;
1810                         req->complete = composite_setup_complete;
1811                         buf = req->buf;
1812                         os_desc_cfg = cdev->os_desc_config;
1813                         memset(buf, 0, w_length);
1814                         buf[5] = 0x01;
1815                         switch (ctrl->bRequestType & USB_RECIP_MASK) {
1816                         case USB_RECIP_DEVICE:
1817                                 if (w_index != 0x4 || (w_value >> 8))
1818                                         break;
1819                                 buf[6] = w_index;
1820                                 if (w_length == 0x10) {
1821                                         /* Number of ext compat interfaces */
1822                                         count = count_ext_compat(os_desc_cfg);
1823                                         buf[8] = count;
1824                                         count *= 24; /* 24 B/ext compat desc */
1825                                         count += 16; /* header */
1826                                         put_unaligned_le32(count, buf);
1827                                         value = w_length;
1828                                 } else {
1829                                         /* "extended compatibility ID"s */
1830                                         count = count_ext_compat(os_desc_cfg);
1831                                         buf[8] = count;
1832                                         count *= 24; /* 24 B/ext compat desc */
1833                                         count += 16; /* header */
1834                                         put_unaligned_le32(count, buf);
1835                                         buf += 16;
1836                                         fill_ext_compat(os_desc_cfg, buf);
1837                                         value = w_length;
1838                                 }
1839                                 break;
1840                         case USB_RECIP_INTERFACE:
1841                                 if (w_index != 0x5 || (w_value >> 8))
1842                                         break;
1843                                 interface = w_value & 0xFF;
1844                                 buf[6] = w_index;
1845                                 if (w_length == 0x0A) {
1846                                         count = count_ext_prop(os_desc_cfg,
1847                                                 interface);
1848                                         put_unaligned_le16(count, buf + 8);
1849                                         count = len_ext_prop(os_desc_cfg,
1850                                                 interface);
1851                                         put_unaligned_le32(count, buf);
1852
1853                                         value = w_length;
1854                                 } else {
1855                                         count = count_ext_prop(os_desc_cfg,
1856                                                 interface);
1857                                         put_unaligned_le16(count, buf + 8);
1858                                         count = len_ext_prop(os_desc_cfg,
1859                                                 interface);
1860                                         put_unaligned_le32(count, buf);
1861                                         buf += 10;
1862                                         value = fill_ext_prop(os_desc_cfg,
1863                                                               interface, buf);
1864                                         if (value < 0)
1865                                                 return value;
1866
1867                                         value = w_length;
1868                                 }
1869                                 break;
1870                         }
1871
1872                         if (value >= 0) {
1873                                 req->length = value;
1874                                 req->context = cdev;
1875                                 req->zero = value < w_length;
1876                                 value = composite_ep0_queue(cdev, req,
1877                                                             GFP_ATOMIC);
1878                                 if (value < 0) {
1879                                         DBG(cdev, "ep_queue --> %d\n", value);
1880                                         req->status = 0;
1881                                         composite_setup_complete(gadget->ep0,
1882                                                                  req);
1883                                 }
1884                         }
1885                         return value;
1886                 }
1887
1888                 VDBG(cdev,
1889                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
1890                         ctrl->bRequestType, ctrl->bRequest,
1891                         w_value, w_index, w_length);
1892
1893                 /* functions always handle their interfaces and endpoints...
1894                  * punt other recipients (other, WUSB, ...) to the current
1895                  * configuration code.
1896                  *
1897                  * REVISIT it could make sense to let the composite device
1898                  * take such requests too, if that's ever needed:  to work
1899                  * in config 0, etc.
1900                  */
1901                 if (cdev->config) {
1902                         list_for_each_entry(f, &cdev->config->functions, list)
1903                                 if (f->req_match && f->req_match(f, ctrl))
1904                                         goto try_fun_setup;
1905                         f = NULL;
1906                 }
1907
1908                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
1909                 case USB_RECIP_INTERFACE:
1910                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1911                                 break;
1912                         f = cdev->config->interface[intf];
1913                         break;
1914
1915                 case USB_RECIP_ENDPOINT:
1916                         if (!cdev->config)
1917                                 break;
1918                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1919                         list_for_each_entry(f, &cdev->config->functions, list) {
1920                                 if (test_bit(endp, f->endpoints))
1921                                         break;
1922                         }
1923                         if (&f->list == &cdev->config->functions)
1924                                 f = NULL;
1925                         break;
1926                 }
1927 try_fun_setup:
1928                 if (f && f->setup)
1929                         value = f->setup(f, ctrl);
1930                 else {
1931                         struct usb_configuration        *c;
1932
1933                         c = cdev->config;
1934                         if (!c)
1935                                 goto done;
1936
1937                         /* try current config's setup */
1938                         if (c->setup) {
1939                                 value = c->setup(c, ctrl);
1940                                 goto done;
1941                         }
1942
1943                         /* try the only function in the current config */
1944                         if (!list_is_singular(&c->functions))
1945                                 goto done;
1946                         f = list_first_entry(&c->functions, struct usb_function,
1947                                              list);
1948                         if (f->setup)
1949                                 value = f->setup(f, ctrl);
1950                 }
1951
1952                 goto done;
1953         }
1954
1955         /* respond with data transfer before status phase? */
1956         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
1957                 req->length = value;
1958                 req->context = cdev;
1959                 req->zero = value < w_length;
1960                 value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
1961                 if (value < 0) {
1962                         DBG(cdev, "ep_queue --> %d\n", value);
1963                         req->status = 0;
1964                         composite_setup_complete(gadget->ep0, req);
1965                 }
1966         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
1967                 WARN(cdev,
1968                         "%s: Delayed status not supported for w_length != 0",
1969                         __func__);
1970         }
1971
1972 done:
1973         /* device either stalls (value < 0) or reports success */
1974         return value;
1975 }
1976
1977 void composite_disconnect(struct usb_gadget *gadget)
1978 {
1979         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1980         unsigned long                   flags;
1981
1982         /* REVISIT:  should we have config and device level
1983          * disconnect callbacks?
1984          */
1985         spin_lock_irqsave(&cdev->lock, flags);
1986         if (cdev->config)
1987                 reset_config(cdev);
1988         if (cdev->driver->disconnect)
1989                 cdev->driver->disconnect(cdev);
1990         spin_unlock_irqrestore(&cdev->lock, flags);
1991 }
1992
1993 /*-------------------------------------------------------------------------*/
1994
1995 static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
1996                               char *buf)
1997 {
1998         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1999         struct usb_composite_dev *cdev = get_gadget_data(gadget);
2000
2001         return sprintf(buf, "%d\n", cdev->suspended);
2002 }
2003 static DEVICE_ATTR_RO(suspended);
2004
2005 static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
2006 {
2007         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2008
2009         /* composite_disconnect() must already have been called
2010          * by the underlying peripheral controller driver!
2011          * so there's no i/o concurrency that could affect the
2012          * state protected by cdev->lock.
2013          */
2014         WARN_ON(cdev->config);
2015
2016         while (!list_empty(&cdev->configs)) {
2017                 struct usb_configuration        *c;
2018                 c = list_first_entry(&cdev->configs,
2019                                 struct usb_configuration, list);
2020                 remove_config(cdev, c);
2021         }
2022         if (cdev->driver->unbind && unbind_driver)
2023                 cdev->driver->unbind(cdev);
2024
2025         composite_dev_cleanup(cdev);
2026
2027         kfree(cdev->def_manufacturer);
2028         kfree(cdev);
2029         set_gadget_data(gadget, NULL);
2030 }
2031
2032 static void composite_unbind(struct usb_gadget *gadget)
2033 {
2034         __composite_unbind(gadget, true);
2035 }
2036
2037 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
2038                 const struct usb_device_descriptor *old)
2039 {
2040         __le16 idVendor;
2041         __le16 idProduct;
2042         __le16 bcdDevice;
2043         u8 iSerialNumber;
2044         u8 iManufacturer;
2045         u8 iProduct;
2046
2047         /*
2048          * these variables may have been set in
2049          * usb_composite_overwrite_options()
2050          */
2051         idVendor = new->idVendor;
2052         idProduct = new->idProduct;
2053         bcdDevice = new->bcdDevice;
2054         iSerialNumber = new->iSerialNumber;
2055         iManufacturer = new->iManufacturer;
2056         iProduct = new->iProduct;
2057
2058         *new = *old;
2059         if (idVendor)
2060                 new->idVendor = idVendor;
2061         if (idProduct)
2062                 new->idProduct = idProduct;
2063         if (bcdDevice)
2064                 new->bcdDevice = bcdDevice;
2065         else
2066                 new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
2067         if (iSerialNumber)
2068                 new->iSerialNumber = iSerialNumber;
2069         if (iManufacturer)
2070                 new->iManufacturer = iManufacturer;
2071         if (iProduct)
2072                 new->iProduct = iProduct;
2073 }
2074
2075 int composite_dev_prepare(struct usb_composite_driver *composite,
2076                 struct usb_composite_dev *cdev)
2077 {
2078         struct usb_gadget *gadget = cdev->gadget;
2079         int ret = -ENOMEM;
2080
2081         /* preallocate control response and buffer */
2082         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
2083         if (!cdev->req)
2084                 return -ENOMEM;
2085
2086         cdev->req->buf = kmalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
2087         if (!cdev->req->buf)
2088                 goto fail;
2089
2090         ret = device_create_file(&gadget->dev, &dev_attr_suspended);
2091         if (ret)
2092                 goto fail_dev;
2093
2094         cdev->req->complete = composite_setup_complete;
2095         cdev->req->context = cdev;
2096         gadget->ep0->driver_data = cdev;
2097
2098         cdev->driver = composite;
2099
2100         /*
2101          * As per USB compliance update, a device that is actively drawing
2102          * more than 100mA from USB must report itself as bus-powered in
2103          * the GetStatus(DEVICE) call.
2104          */
2105         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
2106                 usb_gadget_set_selfpowered(gadget);
2107
2108         /* interface and string IDs start at zero via kzalloc.
2109          * we force endpoints to start unassigned; few controller
2110          * drivers will zero ep->driver_data.
2111          */
2112         usb_ep_autoconfig_reset(gadget);
2113         return 0;
2114 fail_dev:
2115         kfree(cdev->req->buf);
2116 fail:
2117         usb_ep_free_request(gadget->ep0, cdev->req);
2118         cdev->req = NULL;
2119         return ret;
2120 }
2121
2122 int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
2123                                   struct usb_ep *ep0)
2124 {
2125         int ret = 0;
2126
2127         cdev->os_desc_req = usb_ep_alloc_request(ep0, GFP_KERNEL);
2128         if (!cdev->os_desc_req) {
2129                 ret = -ENOMEM;
2130                 goto end;
2131         }
2132
2133         /* OS feature descriptor length <= 4kB */
2134         cdev->os_desc_req->buf = kmalloc(4096, GFP_KERNEL);
2135         if (!cdev->os_desc_req->buf) {
2136                 ret = -ENOMEM;
2137                 kfree(cdev->os_desc_req);
2138                 goto end;
2139         }
2140         cdev->os_desc_req->context = cdev;
2141         cdev->os_desc_req->complete = composite_setup_complete;
2142 end:
2143         return ret;
2144 }
2145
2146 void composite_dev_cleanup(struct usb_composite_dev *cdev)
2147 {
2148         struct usb_gadget_string_container *uc, *tmp;
2149
2150         list_for_each_entry_safe(uc, tmp, &cdev->gstrings, list) {
2151                 list_del(&uc->list);
2152                 kfree(uc);
2153         }
2154         if (cdev->os_desc_req) {
2155                 if (cdev->os_desc_pending)
2156                         usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req);
2157
2158                 kfree(cdev->os_desc_req->buf);
2159                 usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req);
2160         }
2161         if (cdev->req) {
2162                 if (cdev->setup_pending)
2163                         usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
2164
2165                 kfree(cdev->req->buf);
2166                 usb_ep_free_request(cdev->gadget->ep0, cdev->req);
2167         }
2168         cdev->next_string_id = 0;
2169         device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
2170 }
2171
2172 static int composite_bind(struct usb_gadget *gadget,
2173                 struct usb_gadget_driver *gdriver)
2174 {
2175         struct usb_composite_dev        *cdev;
2176         struct usb_composite_driver     *composite = to_cdriver(gdriver);
2177         int                             status = -ENOMEM;
2178
2179         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
2180         if (!cdev)
2181                 return status;
2182
2183         spin_lock_init(&cdev->lock);
2184         cdev->gadget = gadget;
2185         set_gadget_data(gadget, cdev);
2186         INIT_LIST_HEAD(&cdev->configs);
2187         INIT_LIST_HEAD(&cdev->gstrings);
2188
2189         status = composite_dev_prepare(composite, cdev);
2190         if (status)
2191                 goto fail;
2192
2193         /* composite gadget needs to assign strings for whole device (like
2194          * serial number), register function drivers, potentially update
2195          * power state and consumption, etc
2196          */
2197         status = composite->bind(cdev);
2198         if (status < 0)
2199                 goto fail;
2200
2201         if (cdev->use_os_string) {
2202                 status = composite_os_desc_req_prepare(cdev, gadget->ep0);
2203                 if (status)
2204                         goto fail;
2205         }
2206
2207         update_unchanged_dev_desc(&cdev->desc, composite->dev);
2208
2209         /* has userspace failed to provide a serial number? */
2210         if (composite->needs_serial && !cdev->desc.iSerialNumber)
2211                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
2212
2213         INFO(cdev, "%s ready\n", composite->name);
2214         return 0;
2215
2216 fail:
2217         __composite_unbind(gadget, false);
2218         return status;
2219 }
2220
2221 /*-------------------------------------------------------------------------*/
2222
2223 void composite_suspend(struct usb_gadget *gadget)
2224 {
2225         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2226         struct usb_function             *f;
2227
2228         /* REVISIT:  should we have config level
2229          * suspend/resume callbacks?
2230          */
2231         DBG(cdev, "suspend\n");
2232         if (cdev->config) {
2233                 list_for_each_entry(f, &cdev->config->functions, list) {
2234                         if (f->suspend)
2235                                 f->suspend(f);
2236                 }
2237         }
2238         if (cdev->driver->suspend)
2239                 cdev->driver->suspend(cdev);
2240
2241         cdev->suspended = 1;
2242
2243         usb_gadget_vbus_draw(gadget, 2);
2244 }
2245
2246 void composite_resume(struct usb_gadget *gadget)
2247 {
2248         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
2249         struct usb_function             *f;
2250         u16                             maxpower;
2251
2252         /* REVISIT:  should we have config level
2253          * suspend/resume callbacks?
2254          */
2255         DBG(cdev, "resume\n");
2256         if (cdev->driver->resume)
2257                 cdev->driver->resume(cdev);
2258         if (cdev->config) {
2259                 list_for_each_entry(f, &cdev->config->functions, list) {
2260                         if (f->resume)
2261                                 f->resume(f);
2262                 }
2263
2264                 maxpower = cdev->config->MaxPower;
2265
2266                 usb_gadget_vbus_draw(gadget, maxpower ?
2267                         maxpower : CONFIG_USB_GADGET_VBUS_DRAW);
2268         }
2269
2270         cdev->suspended = 0;
2271 }
2272
2273 /*-------------------------------------------------------------------------*/
2274
2275 static const struct usb_gadget_driver composite_driver_template = {
2276         .bind           = composite_bind,
2277         .unbind         = composite_unbind,
2278
2279         .setup          = composite_setup,
2280         .reset          = composite_disconnect,
2281         .disconnect     = composite_disconnect,
2282
2283         .suspend        = composite_suspend,
2284         .resume         = composite_resume,
2285
2286         .driver = {
2287                 .owner          = THIS_MODULE,
2288         },
2289 };
2290
2291 /**
2292  * usb_composite_probe() - register a composite driver
2293  * @driver: the driver to register
2294  *
2295  * Context: single threaded during gadget setup
2296  *
2297  * This function is used to register drivers using the composite driver
2298  * framework.  The return value is zero, or a negative errno value.
2299  * Those values normally come from the driver's @bind method, which does
2300  * all the work of setting up the driver to match the hardware.
2301  *
2302  * On successful return, the gadget is ready to respond to requests from
2303  * the host, unless one of its components invokes usb_gadget_disconnect()
2304  * while it was binding.  That would usually be done in order to wait for
2305  * some userspace participation.
2306  */
2307 int usb_composite_probe(struct usb_composite_driver *driver)
2308 {
2309         struct usb_gadget_driver *gadget_driver;
2310
2311         if (!driver || !driver->dev || !driver->bind)
2312                 return -EINVAL;
2313
2314         if (!driver->name)
2315                 driver->name = "composite";
2316
2317         driver->gadget_driver = composite_driver_template;
2318         gadget_driver = &driver->gadget_driver;
2319
2320         gadget_driver->function =  (char *) driver->name;
2321         gadget_driver->driver.name = driver->name;
2322         gadget_driver->max_speed = driver->max_speed;
2323
2324         return usb_gadget_probe_driver(gadget_driver);
2325 }
2326 EXPORT_SYMBOL_GPL(usb_composite_probe);
2327
2328 /**
2329  * usb_composite_unregister() - unregister a composite driver
2330  * @driver: the driver to unregister
2331  *
2332  * This function is used to unregister drivers using the composite
2333  * driver framework.
2334  */
2335 void usb_composite_unregister(struct usb_composite_driver *driver)
2336 {
2337         usb_gadget_unregister_driver(&driver->gadget_driver);
2338 }
2339 EXPORT_SYMBOL_GPL(usb_composite_unregister);
2340
2341 /**
2342  * usb_composite_setup_continue() - Continue with the control transfer
2343  * @cdev: the composite device who's control transfer was kept waiting
2344  *
2345  * This function must be called by the USB function driver to continue
2346  * with the control transfer's data/status stage in case it had requested to
2347  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
2348  * can request the composite framework to delay the setup request's data/status
2349  * stages by returning USB_GADGET_DELAYED_STATUS.
2350  */
2351 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
2352 {
2353         int                     value;
2354         struct usb_request      *req = cdev->req;
2355         unsigned long           flags;
2356
2357         DBG(cdev, "%s\n", __func__);
2358         spin_lock_irqsave(&cdev->lock, flags);
2359
2360         if (cdev->delayed_status == 0) {
2361                 WARN(cdev, "%s: Unexpected call\n", __func__);
2362
2363         } else if (--cdev->delayed_status == 0) {
2364                 DBG(cdev, "%s: Completing delayed status\n", __func__);
2365                 req->length = 0;
2366                 req->context = cdev;
2367                 value = composite_ep0_queue(cdev, req, GFP_ATOMIC);
2368                 if (value < 0) {
2369                         DBG(cdev, "ep_queue --> %d\n", value);
2370                         req->status = 0;
2371                         composite_setup_complete(cdev->gadget->ep0, req);
2372                 }
2373         }
2374
2375         spin_unlock_irqrestore(&cdev->lock, flags);
2376 }
2377 EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
2378
2379 static char *composite_default_mfr(struct usb_gadget *gadget)
2380 {
2381         char *mfr;
2382         int len;
2383
2384         len = snprintf(NULL, 0, "%s %s with %s", init_utsname()->sysname,
2385                         init_utsname()->release, gadget->name);
2386         len++;
2387         mfr = kmalloc(len, GFP_KERNEL);
2388         if (!mfr)
2389                 return NULL;
2390         snprintf(mfr, len, "%s %s with %s", init_utsname()->sysname,
2391                         init_utsname()->release, gadget->name);
2392         return mfr;
2393 }
2394
2395 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
2396                 struct usb_composite_overwrite *covr)
2397 {
2398         struct usb_device_descriptor    *desc = &cdev->desc;
2399         struct usb_gadget_strings       *gstr = cdev->driver->strings[0];
2400         struct usb_string               *dev_str = gstr->strings;
2401
2402         if (covr->idVendor)
2403                 desc->idVendor = cpu_to_le16(covr->idVendor);
2404
2405         if (covr->idProduct)
2406                 desc->idProduct = cpu_to_le16(covr->idProduct);
2407
2408         if (covr->bcdDevice)
2409                 desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
2410
2411         if (covr->serial_number) {
2412                 desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
2413                 dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
2414         }
2415         if (covr->manufacturer) {
2416                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2417                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
2418
2419         } else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
2420                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
2421                 cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
2422                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
2423         }
2424
2425         if (covr->product) {
2426                 desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
2427                 dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
2428         }
2429 }
2430 EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
2431
2432 MODULE_LICENSE("GPL");
2433 MODULE_AUTHOR("David Brownell");