drivers/usb/gadget/composite.c

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