drivers/usb/gadget/composite.c

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

DEFINITIONS
