drivers/usb/gadget/composite.c

   1 /*
   2  * composite.c - infrastructure for Composite USB Gadgets
   3  *
   4  * Copyright (C) 2006-2008 David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 /* #define VERBOSE_DEBUG */
  13
  14 #include <linux/kallsyms.h>
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/device.h>
  19 #include <linux/utsname.h>
  20
  21 #include <linux/usb/composite.h>
  22 #include <asm/unaligned.h>
  23
  24 /*
  25  * The code in this file is utility code, used to build a gadget driver
  26  * from one or more "function" drivers, one or more "configuration"
  27  * objects, and a "usb_composite_driver" by gluing them together along
  28  * with the relevant device-wide data.
  29  */
  30
  31 /* big enough to hold our biggest descriptor */
  32 #define USB_BUFSIZ      1024
  33
  34 static struct usb_composite_driver *composite;
  35 static int (*composite_gadget_bind)(struct usb_composite_dev *cdev);
  36
  37 /* Some systems will need runtime overrides for the  product identifiers
  38  * published in the device descriptor, either numbers or strings or both.
  39  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  40  */
  41
  42 static ushort idVendor;
  43 module_param(idVendor, ushort, 0644);
  44 MODULE_PARM_DESC(idVendor, "USB Vendor ID");
  45
  46 static ushort idProduct;
  47 module_param(idProduct, ushort, 0644);
  48 MODULE_PARM_DESC(idProduct, "USB Product ID");
  49
  50 static ushort bcdDevice;
  51 module_param(bcdDevice, ushort, 0644);
  52 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
  53
  54 static char *iManufacturer;
  55 module_param(iManufacturer, charp, 0644);
  56 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
  57
  58 static char *iProduct;
  59 module_param(iProduct, charp, 0644);
  60 MODULE_PARM_DESC(iProduct, "USB Product string");
  61
  62 static char *iSerialNumber;
  63 module_param(iSerialNumber, charp, 0644);
  64 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
  65
  66 static char composite_manufacturer[50];
  67
  68 /*-------------------------------------------------------------------------*/
  69 /**
  70  * next_ep_desc() - advance to the next EP descriptor
  71  * @t: currect pointer within descriptor array
  72  *
  73  * Return: next EP descriptor or NULL
  74  *
  75  * Iterate over @t until either EP descriptor found or
  76  * NULL (that indicates end of list) encountered
  77  */
  78 static struct usb_descriptor_header**
  79 next_ep_desc(struct usb_descriptor_header **t)
  80 {
  81         for (; *t; t++) {
  82                 if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
  83                         return t;
  84         }
  85         return NULL;
  86 }
  87
  88 /*
  89  * for_each_ep_desc()- iterate over endpoint descriptors in the
  90  *              descriptors list
  91  * @start:      pointer within descriptor array.
  92  * @ep_desc:    endpoint descriptor to use as the loop cursor
  93  */
  94 #define for_each_ep_desc(start, ep_desc) \
  95         for (ep_desc = next_ep_desc(start); \
  96               ep_desc; ep_desc = next_ep_desc(ep_desc+1))
  97
  98 /**
  99  * config_ep_by_speed() - configures the given endpoint
 100  * according to gadget speed.
 101  * @g: pointer to the gadget
 102  * @f: usb function
 103  * @_ep: the endpoint to configure
 104  *
 105  * Return: error code, 0 on success
 106  *
 107  * This function chooses the right descriptors for a given
 108  * endpoint according to gadget speed and saves it in the
 109  * endpoint desc field. If the endpoint already has a descriptor
 110  * assigned to it - overwrites it with currently corresponding
 111  * descriptor. The endpoint maxpacket field is updated according
 112  * to the chosen descriptor.
 113  * Note: the supplied function should hold all the descriptors
 114  * for supported speeds
 115  */
 116 int config_ep_by_speed(struct usb_gadget *g,
 117                         struct usb_function *f,
 118                         struct usb_ep *_ep)
 119 {
 120         struct usb_endpoint_descriptor *chosen_desc = NULL;
 121         struct usb_descriptor_header **speed_desc = NULL;
 122
 123         struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
 124         int want_comp_desc = 0;
 125
 126         struct usb_descriptor_header **d_spd; /* cursor for speed desc */
 127
 128         if (!g || !f || !_ep)
 129                 return -EIO;
 130
 131         /* select desired speed */
 132         switch (g->speed) {
 133         case USB_SPEED_SUPER:
 134                 if (gadget_is_superspeed(g)) {
 135                         speed_desc = f->ss_descriptors;
 136                         want_comp_desc = 1;
 137                         break;
 138                 }
 139                 /* else: Fall trough */
 140         case USB_SPEED_HIGH:
 141                 if (gadget_is_dualspeed(g)) {
 142                         speed_desc = f->hs_descriptors;
 143                         break;
 144                 }
 145                 /* else: fall through */
 146         default:
 147                 speed_desc = f->descriptors;
 148         }
 149         /* find descriptors */
 150         for_each_ep_desc(speed_desc, d_spd) {
 151                 chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 152                 if (chosen_desc->bEndpointAddress == _ep->address)
 153                         goto ep_found;
 154         }
 155         return -EIO;
 156
 157 ep_found:
 158         /* commit results */
 159         _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 160         _ep->desc = chosen_desc;
 161         _ep->comp_desc = NULL;
 162         _ep->maxburst = 0;
 163         _ep->mult = 0;
 164         if (!want_comp_desc)
 165                 return 0;
 166
 167         /*
 168          * Companion descriptor should follow EP descriptor
 169          * USB 3.0 spec, #9.6.7
 170          */
 171         comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 172         if (!comp_desc ||
 173             (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 174                 return -EIO;
 175         _ep->comp_desc = comp_desc;
 176         if (g->speed == USB_SPEED_SUPER) {
 177                 switch (usb_endpoint_type(_ep->desc)) {
 178                 case USB_ENDPOINT_XFER_ISOC:
 179                         /* mult: bits 1:0 of bmAttributes */
 180                         _ep->mult = comp_desc->bmAttributes & 0x3;
 181                 case USB_ENDPOINT_XFER_BULK:
 182                 case USB_ENDPOINT_XFER_INT:
 183                         _ep->maxburst = comp_desc->bMaxBurst;
 184                         break;
 185                 default:
 186                         /* Do nothing for control endpoints */
 187                         break;
 188                 }
 189         }
 190         return 0;
 191 }
 192
 193 /**
 194  * usb_add_function() - add a function to a configuration
 195  * @config: the configuration
 196  * @function: the function being added
 197  * Context: single threaded during gadget setup
 198  *
 199  * After initialization, each configuration must have one or more
 200  * functions added to it.  Adding a function involves calling its @bind()
 201  * method to allocate resources such as interface and string identifiers
 202  * and endpoints.
 203  *
 204  * This function returns the value of the function's bind(), which is
 205  * zero for success else a negative errno value.
 206  */
 207 int usb_add_function(struct usb_configuration *config,
 208                 struct usb_function *function)
 209 {
 210         int     value = -EINVAL;
 211
 212         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 213                         function->name, function,
 214                         config->label, config);
 215
 216         if (!function->set_alt || !function->disable)
 217                 goto done;
 218
 219         function->config = config;
 220         list_add_tail(&function->list, &config->functions);
 221
 222         /* REVISIT *require* function->bind? */
 223         if (function->bind) {
 224                 value = function->bind(config, function);
 225                 if (value < 0) {
 226                         list_del(&function->list);
 227                         function->config = NULL;
 228                 }
 229         } else
 230                 value = 0;
 231
 232         /* We allow configurations that don't work at both speeds.
 233          * If we run into a lowspeed Linux system, treat it the same
 234          * as full speed ... it's the function drivers that will need
 235          * to avoid bulk and ISO transfers.
 236          */
 237         if (!config->fullspeed && function->descriptors)
 238                 config->fullspeed = true;
 239         if (!config->highspeed && function->hs_descriptors)
 240                 config->highspeed = true;
 241         if (!config->superspeed && function->ss_descriptors)
 242                 config->superspeed = true;
 243
 244 done:
 245         if (value)
 246                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 247                                 function->name, function, value);
 248         return value;
 249 }
 250
 251 /**
 252  * usb_function_deactivate - prevent function and gadget enumeration
 253  * @function: the function that isn't yet ready to respond
 254  *
 255  * Blocks response of the gadget driver to host enumeration by
 256  * preventing the data line pullup from being activated.  This is
 257  * normally called during @bind() processing to change from the
 258  * initial "ready to respond" state, or when a required resource
 259  * becomes available.
 260  *
 261  * For example, drivers that serve as a passthrough to a userspace
 262  * daemon can block enumeration unless that daemon (such as an OBEX,
 263  * MTP, or print server) is ready to handle host requests.
 264  *
 265  * Not all systems support software control of their USB peripheral
 266  * data pullups.
 267  *
 268  * Returns zero on success, else negative errno.
 269  */
 270 int usb_function_deactivate(struct usb_function *function)
 271 {
 272         struct usb_composite_dev        *cdev = function->config->cdev;
 273         unsigned long                   flags;
 274         int                             status = 0;
 275
 276         spin_lock_irqsave(&cdev->lock, flags);
 277
 278         if (cdev->deactivations == 0)
 279                 status = usb_gadget_disconnect(cdev->gadget);
 280         if (status == 0)
 281                 cdev->deactivations++;
 282
 283         spin_unlock_irqrestore(&cdev->lock, flags);
 284         return status;
 285 }
 286
 287 /**
 288  * usb_function_activate - allow function and gadget enumeration
 289  * @function: function on which usb_function_activate() was called
 290  *
 291  * Reverses effect of usb_function_deactivate().  If no more functions
 292  * are delaying their activation, the gadget driver will respond to
 293  * host enumeration procedures.
 294  *
 295  * Returns zero on success, else negative errno.
 296  */
 297 int usb_function_activate(struct usb_function *function)
 298 {
 299         struct usb_composite_dev        *cdev = function->config->cdev;
 300         int                             status = 0;
 301
 302         spin_lock(&cdev->lock);
 303
 304         if (WARN_ON(cdev->deactivations == 0))
 305                 status = -EINVAL;
 306         else {
 307                 cdev->deactivations--;
 308                 if (cdev->deactivations == 0)
 309                         status = usb_gadget_connect(cdev->gadget);
 310         }
 311
 312         spin_unlock(&cdev->lock);
 313         return status;
 314 }
 315
 316 /**
 317  * usb_interface_id() - allocate an unused interface ID
 318  * @config: configuration associated with the interface
 319  * @function: function handling the interface
 320  * Context: single threaded during gadget setup
 321  *
 322  * usb_interface_id() is called from usb_function.bind() callbacks to
 323  * allocate new interface IDs.  The function driver will then store that
 324  * ID in interface, association, CDC union, and other descriptors.  It
 325  * will also handle any control requests targeted at that interface,
 326  * particularly changing its altsetting via set_alt().  There may
 327  * also be class-specific or vendor-specific requests to handle.
 328  *
 329  * All interface identifier should be allocated using this routine, to
 330  * ensure that for example different functions don't wrongly assign
 331  * different meanings to the same identifier.  Note that since interface
 332  * identifiers are configuration-specific, functions used in more than
 333  * one configuration (or more than once in a given configuration) need
 334  * multiple versions of the relevant descriptors.
 335  *
 336  * Returns the interface ID which was allocated; or -ENODEV if no
 337  * more interface IDs can be allocated.
 338  */
 339 int usb_interface_id(struct usb_configuration *config,
 340                 struct usb_function *function)
 341 {
 342         unsigned id = config->next_interface_id;
 343
 344         if (id < MAX_CONFIG_INTERFACES) {
 345                 config->interface[id] = function;
 346                 config->next_interface_id = id + 1;
 347                 return id;
 348         }
 349         return -ENODEV;
 350 }
 351
 352 static int config_buf(struct usb_configuration *config,
 353                 enum usb_device_speed speed, void *buf, u8 type)
 354 {
 355         struct usb_config_descriptor    *c = buf;
 356         void                            *next = buf + USB_DT_CONFIG_SIZE;
 357         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 358         struct usb_function             *f;
 359         int                             status;
 360
 361         /* write the config descriptor */
 362         c = buf;
 363         c->bLength = USB_DT_CONFIG_SIZE;
 364         c->bDescriptorType = type;
 365         /* wTotalLength is written later */
 366         c->bNumInterfaces = config->next_interface_id;
 367         c->bConfigurationValue = config->bConfigurationValue;
 368         c->iConfiguration = config->iConfiguration;
 369         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 370         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 371
 372         /* There may be e.g. OTG descriptors */
 373         if (config->descriptors) {
 374                 status = usb_descriptor_fillbuf(next, len,
 375                                 config->descriptors);
 376                 if (status < 0)
 377                         return status;
 378                 len -= status;
 379                 next += status;
 380         }
 381
 382         /* add each function's descriptors */
 383         list_for_each_entry(f, &config->functions, list) {
 384                 struct usb_descriptor_header **descriptors;
 385
 386                 switch (speed) {
 387                 case USB_SPEED_SUPER:
 388                         descriptors = f->ss_descriptors;
 389                         break;
 390                 case USB_SPEED_HIGH:
 391                         descriptors = f->hs_descriptors;
 392                         break;
 393                 default:
 394                         descriptors = f->descriptors;
 395                 }
 396
 397                 if (!descriptors)
 398                         continue;
 399                 status = usb_descriptor_fillbuf(next, len,
 400                         (const struct usb_descriptor_header **) descriptors);
 401                 if (status < 0)
 402                         return status;
 403                 len -= status;
 404                 next += status;
 405         }
 406
 407         len = next - buf;
 408         c->wTotalLength = cpu_to_le16(len);
 409         return len;
 410 }
 411
 412 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 413 {
 414         struct usb_gadget               *gadget = cdev->gadget;
 415         struct usb_configuration        *c;
 416         u8                              type = w_value >> 8;
 417         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 418
 419         if (gadget->speed == USB_SPEED_SUPER)
 420                 speed = gadget->speed;
 421         else if (gadget_is_dualspeed(gadget)) {
 422                 int     hs = 0;
 423                 if (gadget->speed == USB_SPEED_HIGH)
 424                         hs = 1;
 425                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 426                         hs = !hs;
 427                 if (hs)
 428                         speed = USB_SPEED_HIGH;
 429
 430         }
 431
 432         /* This is a lookup by config *INDEX* */
 433         w_value &= 0xff;
 434         list_for_each_entry(c, &cdev->configs, list) {
 435                 /* ignore configs that won't work at this speed */
 436                 switch (speed) {
 437                 case USB_SPEED_SUPER:
 438                         if (!c->superspeed)
 439                                 continue;
 440                         break;
 441                 case USB_SPEED_HIGH:
 442                         if (!c->highspeed)
 443                                 continue;
 444                         break;
 445                 default:
 446                         if (!c->fullspeed)
 447                                 continue;
 448                 }
 449
 450                 if (w_value == 0)
 451                         return config_buf(c, speed, cdev->req->buf, type);
 452                 w_value--;
 453         }
 454         return -EINVAL;
 455 }
 456
 457 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 458 {
 459         struct usb_gadget               *gadget = cdev->gadget;
 460         struct usb_configuration        *c;
 461         unsigned                        count = 0;
 462         int                             hs = 0;
 463         int                             ss = 0;
 464
 465         if (gadget_is_dualspeed(gadget)) {
 466                 if (gadget->speed == USB_SPEED_HIGH)
 467                         hs = 1;
 468                 if (gadget->speed == USB_SPEED_SUPER)
 469                         ss = 1;
 470                 if (type == USB_DT_DEVICE_QUALIFIER)
 471                         hs = !hs;
 472         }
 473         list_for_each_entry(c, &cdev->configs, list) {
 474                 /* ignore configs that won't work at this speed */
 475                 if (ss) {
 476                         if (!c->superspeed)
 477                                 continue;
 478                 } else if (hs) {
 479                         if (!c->highspeed)
 480                                 continue;
 481                 } else {
 482                         if (!c->fullspeed)
 483                                 continue;
 484                 }
 485                 count++;
 486         }
 487         return count;
 488 }
 489
 490 /**
 491  * bos_desc() - prepares the BOS descriptor.
 492  * @cdev: pointer to usb_composite device to generate the bos
 493  *      descriptor for
 494  *
 495  * This function generates the BOS (Binary Device Object)
 496  * descriptor and its device capabilities descriptors. The BOS
 497  * descriptor should be supported by a SuperSpeed device.
 498  */
 499 static int bos_desc(struct usb_composite_dev *cdev)
 500 {
 501         struct usb_ext_cap_descriptor   *usb_ext;
 502         struct usb_ss_cap_descriptor    *ss_cap;
 503         struct usb_dcd_config_params    dcd_config_params;
 504         struct usb_bos_descriptor       *bos = cdev->req->buf;
 505
 506         bos->bLength = USB_DT_BOS_SIZE;
 507         bos->bDescriptorType = USB_DT_BOS;
 508
 509         bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 510         bos->bNumDeviceCaps = 0;
 511
 512         /*
 513          * A SuperSpeed device shall include the USB2.0 extension descriptor
 514          * and shall support LPM when operating in USB2.0 HS mode.
 515          */
 516         usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 517         bos->bNumDeviceCaps++;
 518         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 519         usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 520         usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 521         usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 522         usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT);
 523
 524         /*
 525          * The Superspeed USB Capability descriptor shall be implemented by all
 526          * SuperSpeed devices.
 527          */
 528         ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 529         bos->bNumDeviceCaps++;
 530         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 531         ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 532         ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 533         ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 534         ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 535         ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 536                                 USB_FULL_SPEED_OPERATION |
 537                                 USB_HIGH_SPEED_OPERATION |
 538                                 USB_5GBPS_OPERATION);
 539         ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 540
 541         /* Get Controller configuration */
 542         if (cdev->gadget->ops->get_config_params)
 543                 cdev->gadget->ops->get_config_params(&dcd_config_params);
 544         else {
 545                 dcd_config_params.bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT;
 546                 dcd_config_params.bU2DevExitLat =
 547                         cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
 548         }
 549         ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 550         ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 551
 552         return le16_to_cpu(bos->wTotalLength);
 553 }
 554
 555 static void device_qual(struct usb_composite_dev *cdev)
 556 {
 557         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 558
 559         qual->bLength = sizeof(*qual);
 560         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 561         /* POLICY: same bcdUSB and device type info at both speeds */
 562         qual->bcdUSB = cdev->desc.bcdUSB;
 563         qual->bDeviceClass = cdev->desc.bDeviceClass;
 564         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 565         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 566         /* ASSUME same EP0 fifo size at both speeds */
 567         qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 568         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 569         qual->bRESERVED = 0;
 570 }
 571
 572 /*-------------------------------------------------------------------------*/
 573
 574 static void reset_config(struct usb_composite_dev *cdev)
 575 {
 576         struct usb_function             *f;
 577
 578         DBG(cdev, "reset config\n");
 579
 580         list_for_each_entry(f, &cdev->config->functions, list) {
 581                 if (f->disable)
 582                         f->disable(f);
 583
 584                 bitmap_zero(f->endpoints, 32);
 585         }
 586         cdev->config = NULL;
 587 }
 588
 589 static int set_config(struct usb_composite_dev *cdev,
 590                 const struct usb_ctrlrequest *ctrl, unsigned number)
 591 {
 592         struct usb_gadget       *gadget = cdev->gadget;
 593         struct usb_configuration *c = NULL;
 594         int                     result = -EINVAL;
 595         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 596         int                     tmp;
 597
 598         if (number) {
 599                 list_for_each_entry(c, &cdev->configs, list) {
 600                         if (c->bConfigurationValue == number) {
 601                                 /*
 602                                  * We disable the FDs of the previous
 603                                  * configuration only if the new configuration
 604                                  * is a valid one
 605                                  */
 606                                 if (cdev->config)
 607                                         reset_config(cdev);
 608                                 result = 0;
 609                                 break;
 610                         }
 611                 }
 612                 if (result < 0)
 613                         goto done;
 614         } else { /* Zero configuration value - need to reset the config */
 615                 if (cdev->config)
 616                         reset_config(cdev);
 617                 result = 0;
 618         }
 619
 620         INFO(cdev, "%s config #%d: %s\n",
 621              usb_speed_string(gadget->speed),
 622              number, c ? c->label : "unconfigured");
 623
 624         if (!c)
 625                 goto done;
 626
 627         cdev->config = c;
 628
 629         /* Initialize all interfaces by setting them to altsetting zero. */
 630         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 631                 struct usb_function     *f = c->interface[tmp];
 632                 struct usb_descriptor_header **descriptors;
 633
 634                 if (!f)
 635                         break;
 636
 637                 /*
 638                  * Record which endpoints are used by the function. This is used
 639                  * to dispatch control requests targeted at that endpoint to the
 640                  * function's setup callback instead of the current
 641                  * configuration's setup callback.
 642                  */
 643                 switch (gadget->speed) {
 644                 case USB_SPEED_SUPER:
 645                         descriptors = f->ss_descriptors;
 646                         break;
 647                 case USB_SPEED_HIGH:
 648                         descriptors = f->hs_descriptors;
 649                         break;
 650                 default:
 651                         descriptors = f->descriptors;
 652                 }
 653
 654                 for (; *descriptors; ++descriptors) {
 655                         struct usb_endpoint_descriptor *ep;
 656                         int addr;
 657
 658                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 659                                 continue;
 660
 661                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 662                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 663                              |  (ep->bEndpointAddress & 0x0f);
 664                         set_bit(addr, f->endpoints);
 665                 }
 666
 667                 result = f->set_alt(f, tmp, 0);
 668                 if (result < 0) {
 669                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 670                                         tmp, f->name, f, result);
 671
 672                         reset_config(cdev);
 673                         goto done;
 674                 }
 675
 676                 if (result == USB_GADGET_DELAYED_STATUS) {
 677                         DBG(cdev,
 678                          "%s: interface %d (%s) requested delayed status\n",
 679                                         __func__, tmp, f->name);
 680                         cdev->delayed_status++;
 681                         DBG(cdev, "delayed_status count %d\n",
 682                                         cdev->delayed_status);
 683                 }
 684         }
 685
 686         /* when we return, be sure our power usage is valid */
 687         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 688 done:
 689         usb_gadget_vbus_draw(gadget, power);
 690         if (result >= 0 && cdev->delayed_status)
 691                 result = USB_GADGET_DELAYED_STATUS;
 692         return result;
 693 }
 694
 695 /**
 696  * usb_add_config() - add a configuration to a device.
 697  * @cdev: wraps the USB gadget
 698  * @config: the configuration, with bConfigurationValue assigned
 699  * @bind: the configuration's bind function
 700  * Context: single threaded during gadget setup
 701  *
 702  * One of the main tasks of a composite @bind() routine is to
 703  * add each of the configurations it supports, using this routine.
 704  *
 705  * This function returns the value of the configuration's @bind(), which
 706  * is zero for success else a negative errno value.  Binding configurations
 707  * assigns global resources including string IDs, and per-configuration
 708  * resources such as interface IDs and endpoints.
 709  */
 710 int usb_add_config(struct usb_composite_dev *cdev,
 711                 struct usb_configuration *config,
 712                 int (*bind)(struct usb_configuration *))
 713 {
 714         int                             status = -EINVAL;
 715         struct usb_configuration        *c;
 716
 717         DBG(cdev, "adding config #%u '%s'/%p\n",
 718                         config->bConfigurationValue,
 719                         config->label, config);
 720
 721         if (!config->bConfigurationValue || !bind)
 722                 goto done;
 723
 724         /* Prevent duplicate configuration identifiers */
 725         list_for_each_entry(c, &cdev->configs, list) {
 726                 if (c->bConfigurationValue == config->bConfigurationValue) {
 727                         status = -EBUSY;
 728                         goto done;
 729                 }
 730         }
 731
 732         config->cdev = cdev;
 733         list_add_tail(&config->list, &cdev->configs);
 734
 735         INIT_LIST_HEAD(&config->functions);
 736         config->next_interface_id = 0;
 737         memset(config->interface, 0, sizeof(config->interface));
 738
 739         status = bind(config);
 740         if (status < 0) {
 741                 while (!list_empty(&config->functions)) {
 742                         struct usb_function             *f;
 743
 744                         f = list_first_entry(&config->functions,
 745                                         struct usb_function, list);
 746                         list_del(&f->list);
 747                         if (f->unbind) {
 748                                 DBG(cdev, "unbind function '%s'/%p\n",
 749                                         f->name, f);
 750                                 f->unbind(config, f);
 751                                 /* may free memory for "f" */
 752                         }
 753                 }
 754                 list_del(&config->list);
 755                 config->cdev = NULL;
 756         } else {
 757                 unsigned        i;
 758
 759                 DBG(cdev, "cfg %d/%p speeds:%s%s%s\n",
 760                         config->bConfigurationValue, config,
 761                         config->superspeed ? " super" : "",
 762                         config->highspeed ? " high" : "",
 763                         config->fullspeed
 764                                 ? (gadget_is_dualspeed(cdev->gadget)
 765                                         ? " full"
 766                                         : " full/low")
 767                                 : "");
 768
 769                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 770                         struct usb_function     *f = config->interface[i];
 771
 772                         if (!f)
 773                                 continue;
 774                         DBG(cdev, "  interface %d = %s/%p\n",
 775                                 i, f->name, f);
 776                 }
 777         }
 778
 779         /* set_alt(), or next bind(), sets up
 780          * ep->driver_data as needed.
 781          */
 782         usb_ep_autoconfig_reset(cdev->gadget);
 783
 784 done:
 785         if (status)
 786                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 787                                 config->bConfigurationValue, status);
 788         return status;
 789 }
 790
 791 static void remove_config(struct usb_composite_dev *cdev,
 792                               struct usb_configuration *config)
 793 {
 794         while (!list_empty(&config->functions)) {
 795                 struct usb_function             *f;
 796
 797                 f = list_first_entry(&config->functions,
 798                                 struct usb_function, list);
 799                 list_del(&f->list);
 800                 if (f->unbind) {
 801                         DBG(cdev, "unbind function '%s'/%p\n", f->name, f);
 802                         f->unbind(config, f);
 803                         /* may free memory for "f" */
 804                 }
 805         }
 806         list_del(&config->list);
 807         if (config->unbind) {
 808                 DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
 809                 config->unbind(config);
 810                         /* may free memory for "c" */
 811         }
 812 }
 813
 814 /**
 815  * usb_remove_config() - remove a configuration from a device.
 816  * @cdev: wraps the USB gadget
 817  * @config: the configuration
 818  *
 819  * Drivers must call usb_gadget_disconnect before calling this function
 820  * to disconnect the device from the host and make sure the host will not
 821  * try to enumerate the device while we are changing the config list.
 822  */
 823 void usb_remove_config(struct usb_composite_dev *cdev,
 824                       struct usb_configuration *config)
 825 {
 826         unsigned long flags;
 827
 828         spin_lock_irqsave(&cdev->lock, flags);
 829
 830         if (cdev->config == config)
 831                 reset_config(cdev);
 832
 833         spin_unlock_irqrestore(&cdev->lock, flags);
 834
 835         remove_config(cdev, config);
 836 }
 837
 838 /*-------------------------------------------------------------------------*/
 839
 840 /* We support strings in multiple languages ... string descriptor zero
 841  * says which languages are supported.  The typical case will be that
 842  * only one language (probably English) is used, with I18N handled on
 843  * the host side.
 844  */
 845
 846 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 847 {
 848         const struct usb_gadget_strings *s;
 849         __le16                          language;
 850         __le16                          *tmp;
 851
 852         while (*sp) {
 853                 s = *sp;
 854                 language = cpu_to_le16(s->language);
 855                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 856                         if (*tmp == language)
 857                                 goto repeat;
 858                 }
 859                 *tmp++ = language;
 860 repeat:
 861                 sp++;
 862         }
 863 }
 864
 865 static int lookup_string(
 866         struct usb_gadget_strings       **sp,
 867         void                            *buf,
 868         u16                             language,
 869         int                             id
 870 )
 871 {
 872         struct usb_gadget_strings       *s;
 873         int                             value;
 874
 875         while (*sp) {
 876                 s = *sp++;
 877                 if (s->language != language)
 878                         continue;
 879                 value = usb_gadget_get_string(s, id, buf);
 880                 if (value > 0)
 881                         return value;
 882         }
 883         return -EINVAL;
 884 }
 885
 886 static int get_string(struct usb_composite_dev *cdev,
 887                 void *buf, u16 language, int id)
 888 {
 889         struct usb_configuration        *c;
 890         struct usb_function             *f;
 891         int                             len;
 892         const char                      *str;
 893
 894         /* Yes, not only is USB's I18N support probably more than most
 895          * folk will ever care about ... also, it's all supported here.
 896          * (Except for UTF8 support for Unicode's "Astral Planes".)
 897          */
 898
 899         /* 0 == report all available language codes */
 900         if (id == 0) {
 901                 struct usb_string_descriptor    *s = buf;
 902                 struct usb_gadget_strings       **sp;
 903
 904                 memset(s, 0, 256);
 905                 s->bDescriptorType = USB_DT_STRING;
 906
 907                 sp = composite->strings;
 908                 if (sp)
 909                         collect_langs(sp, s->wData);
 910
 911                 list_for_each_entry(c, &cdev->configs, list) {
 912                         sp = c->strings;
 913                         if (sp)
 914                                 collect_langs(sp, s->wData);
 915
 916                         list_for_each_entry(f, &c->functions, list) {
 917                                 sp = f->strings;
 918                                 if (sp)
 919                                         collect_langs(sp, s->wData);
 920                         }
 921                 }
 922
 923                 for (len = 0; len <= 126 && s->wData[len]; len++)
 924                         continue;
 925                 if (!len)
 926                         return -EINVAL;
 927
 928                 s->bLength = 2 * (len + 1);
 929                 return s->bLength;
 930         }
 931
 932         /* Otherwise, look up and return a specified string.  First
 933          * check if the string has not been overridden.
 934          */
 935         if (cdev->manufacturer_override == id)
 936                 str = iManufacturer ?: composite->iManufacturer ?:
 937                         composite_manufacturer;
 938         else if (cdev->product_override == id)
 939                 str = iProduct ?: composite->iProduct;
 940         else if (cdev->serial_override == id)
 941                 str = iSerialNumber ?: composite->iSerialNumber;
 942         else
 943                 str = NULL;
 944         if (str) {
 945                 struct usb_gadget_strings strings = {
 946                         .language = language,
 947                         .strings  = &(struct usb_string) { 0xff, str }
 948                 };
 949                 return usb_gadget_get_string(&strings, 0xff, buf);
 950         }
 951
 952         /* String IDs are device-scoped, so we look up each string
 953          * table we're told about.  These lookups are infrequent;
 954          * simpler-is-better here.
 955          */
 956         if (composite->strings) {
 957                 len = lookup_string(composite->strings, buf, language, id);
 958                 if (len > 0)
 959                         return len;
 960         }
 961         list_for_each_entry(c, &cdev->configs, list) {
 962                 if (c->strings) {
 963                         len = lookup_string(c->strings, buf, language, id);
 964                         if (len > 0)
 965                                 return len;
 966                 }
 967                 list_for_each_entry(f, &c->functions, list) {
 968                         if (!f->strings)
 969                                 continue;
 970                         len = lookup_string(f->strings, buf, language, id);
 971                         if (len > 0)
 972                                 return len;
 973                 }
 974         }
 975         return -EINVAL;
 976 }
 977
 978 /**
 979  * usb_string_id() - allocate an unused string ID
 980  * @cdev: the device whose string descriptor IDs are being allocated
 981  * Context: single threaded during gadget setup
 982  *
 983  * @usb_string_id() is called from bind() callbacks to allocate
 984  * string IDs.  Drivers for functions, configurations, or gadgets will
 985  * then store that ID in the appropriate descriptors and string table.
 986  *
 987  * All string identifier should be allocated using this,
 988  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 989  * that for example different functions don't wrongly assign different
 990  * meanings to the same identifier.
 991  */
 992 int usb_string_id(struct usb_composite_dev *cdev)
 993 {
 994         if (cdev->next_string_id < 254) {
 995                 /* string id 0 is reserved by USB spec for list of
 996                  * supported languages */
 997                 /* 255 reserved as well? -- mina86 */
 998                 cdev->next_string_id++;
 999                 return cdev->next_string_id;
1000         }
1001         return -ENODEV;
1002 }
1003
1004 /**
1005  * usb_string_ids() - allocate unused string IDs in batch
1006  * @cdev: the device whose string descriptor IDs are being allocated
1007  * @str: an array of usb_string objects to assign numbers to
1008  * Context: single threaded during gadget setup
1009  *
1010  * @usb_string_ids() is called from bind() callbacks to allocate
1011  * string IDs.  Drivers for functions, configurations, or gadgets will
1012  * then copy IDs from the string table to the appropriate descriptors
1013  * and string table for other languages.
1014  *
1015  * All string identifier should be allocated using this,
1016  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1017  * example different functions don't wrongly assign different meanings
1018  * to the same identifier.
1019  */
1020 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
1021 {
1022         int next = cdev->next_string_id;
1023
1024         for (; str->s; ++str) {
1025                 if (unlikely(next >= 254))
1026                         return -ENODEV;
1027                 str->id = ++next;
1028         }
1029
1030         cdev->next_string_id = next;
1031
1032         return 0;
1033 }
1034
1035 /**
1036  * usb_string_ids_n() - allocate unused string IDs in batch
1037  * @c: the device whose string descriptor IDs are being allocated
1038  * @n: number of string IDs to allocate
1039  * Context: single threaded during gadget setup
1040  *
1041  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1042  * valid IDs.  At least provided that @n is non-zero because if it
1043  * is, returns last requested ID which is now very useful information.
1044  *
1045  * @usb_string_ids_n() is called from bind() callbacks to allocate
1046  * string IDs.  Drivers for functions, configurations, or gadgets will
1047  * then store that ID in the appropriate descriptors and string table.
1048  *
1049  * All string identifier should be allocated using this,
1050  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1051  * example different functions don't wrongly assign different meanings
1052  * to the same identifier.
1053  */
1054 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1055 {
1056         unsigned next = c->next_string_id;
1057         if (unlikely(n > 254 || (unsigned)next + n > 254))
1058                 return -ENODEV;
1059         c->next_string_id += n;
1060         return next + 1;
1061 }
1062
1063
1064 /*-------------------------------------------------------------------------*/
1065
1066 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1067 {
1068         if (req->status || req->actual != req->length)
1069                 DBG((struct usb_composite_dev *) ep->driver_data,
1070                                 "setup complete --> %d, %d/%d\n",
1071                                 req->status, req->actual, req->length);
1072 }
1073
1074 /*
1075  * The setup() callback implements all the ep0 functionality that's
1076  * not handled lower down, in hardware or the hardware driver(like
1077  * device and endpoint feature flags, and their status).  It's all
1078  * housekeeping for the gadget function we're implementing.  Most of
1079  * the work is in config and function specific setup.
1080  */
1081 static int
1082 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1083 {
1084         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1085         struct usb_request              *req = cdev->req;
1086         int                             value = -EOPNOTSUPP;
1087         int                             status = 0;
1088         u16                             w_index = le16_to_cpu(ctrl->wIndex);
1089         u8                              intf = w_index & 0xFF;
1090         u16                             w_value = le16_to_cpu(ctrl->wValue);
1091         u16                             w_length = le16_to_cpu(ctrl->wLength);
1092         struct usb_function             *f = NULL;
1093         u8                              endp;
1094
1095         /* partial re-init of the response message; the function or the
1096          * gadget might need to intercept e.g. a control-OUT completion
1097          * when we delegate to it.
1098          */
1099         req->zero = 0;
1100         req->complete = composite_setup_complete;
1101         req->length = 0;
1102         gadget->ep0->driver_data = cdev;
1103
1104         switch (ctrl->bRequest) {
1105
1106         /* we handle all standard USB descriptors */
1107         case USB_REQ_GET_DESCRIPTOR:
1108                 if (ctrl->bRequestType != USB_DIR_IN)
1109                         goto unknown;
1110                 switch (w_value >> 8) {
1111
1112                 case USB_DT_DEVICE:
1113                         cdev->desc.bNumConfigurations =
1114                                 count_configs(cdev, USB_DT_DEVICE);
1115                         cdev->desc.bMaxPacketSize0 =
1116                                 cdev->gadget->ep0->maxpacket;
1117                         if (gadget_is_superspeed(gadget)) {
1118                                 if (gadget->speed >= USB_SPEED_SUPER) {
1119                                         cdev->desc.bcdUSB = cpu_to_le16(0x0300);
1120                                         cdev->desc.bMaxPacketSize0 = 9;
1121                                 } else {
1122                                         cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1123                                 }
1124                         }
1125
1126                         value = min(w_length, (u16) sizeof cdev->desc);
1127                         memcpy(req->buf, &cdev->desc, value);
1128                         break;
1129                 case USB_DT_DEVICE_QUALIFIER:
1130                         if (!gadget_is_dualspeed(gadget) ||
1131                             gadget->speed >= USB_SPEED_SUPER)
1132                                 break;
1133                         device_qual(cdev);
1134                         value = min_t(int, w_length,
1135                                 sizeof(struct usb_qualifier_descriptor));
1136                         break;
1137                 case USB_DT_OTHER_SPEED_CONFIG:
1138                         if (!gadget_is_dualspeed(gadget) ||
1139                             gadget->speed >= USB_SPEED_SUPER)
1140                                 break;
1141                         /* FALLTHROUGH */
1142                 case USB_DT_CONFIG:
1143                         value = config_desc(cdev, w_value);
1144                         if (value >= 0)
1145                                 value = min(w_length, (u16) value);
1146                         break;
1147                 case USB_DT_STRING:
1148                         value = get_string(cdev, req->buf,
1149                                         w_index, w_value & 0xff);
1150                         if (value >= 0)
1151                                 value = min(w_length, (u16) value);
1152                         break;
1153                 case USB_DT_BOS:
1154                         if (gadget_is_superspeed(gadget)) {
1155                                 value = bos_desc(cdev);
1156                                 value = min(w_length, (u16) value);
1157                         }
1158                         break;
1159                 }
1160                 break;
1161
1162         /* any number of configs can work */
1163         case USB_REQ_SET_CONFIGURATION:
1164                 if (ctrl->bRequestType != 0)
1165                         goto unknown;
1166                 if (gadget_is_otg(gadget)) {
1167                         if (gadget->a_hnp_support)
1168                                 DBG(cdev, "HNP available\n");
1169                         else if (gadget->a_alt_hnp_support)
1170                                 DBG(cdev, "HNP on another port\n");
1171                         else
1172                                 VDBG(cdev, "HNP inactive\n");
1173                 }
1174                 spin_lock(&cdev->lock);
1175                 value = set_config(cdev, ctrl, w_value);
1176                 spin_unlock(&cdev->lock);
1177                 break;
1178         case USB_REQ_GET_CONFIGURATION:
1179                 if (ctrl->bRequestType != USB_DIR_IN)
1180                         goto unknown;
1181                 if (cdev->config)
1182                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
1183                 else
1184                         *(u8 *)req->buf = 0;
1185                 value = min(w_length, (u16) 1);
1186                 break;
1187
1188         /* function drivers must handle get/set altsetting; if there's
1189          * no get() method, we know only altsetting zero works.
1190          */
1191         case USB_REQ_SET_INTERFACE:
1192                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1193                         goto unknown;
1194                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1195                         break;
1196                 f = cdev->config->interface[intf];
1197                 if (!f)
1198                         break;
1199                 if (w_value && !f->set_alt)
1200                         break;
1201                 value = f->set_alt(f, w_index, w_value);
1202                 if (value == USB_GADGET_DELAYED_STATUS) {
1203                         DBG(cdev,
1204                          "%s: interface %d (%s) requested delayed status\n",
1205                                         __func__, intf, f->name);
1206                         cdev->delayed_status++;
1207                         DBG(cdev, "delayed_status count %d\n",
1208                                         cdev->delayed_status);
1209                 }
1210                 break;
1211         case USB_REQ_GET_INTERFACE:
1212                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1213                         goto unknown;
1214                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1215                         break;
1216                 f = cdev->config->interface[intf];
1217                 if (!f)
1218                         break;
1219                 /* lots of interfaces only need altsetting zero... */
1220                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1221                 if (value < 0)
1222                         break;
1223                 *((u8 *)req->buf) = value;
1224                 value = min(w_length, (u16) 1);
1225                 break;
1226
1227         /*
1228          * USB 3.0 additions:
1229          * Function driver should handle get_status request. If such cb
1230          * wasn't supplied we respond with default value = 0
1231          * Note: function driver should supply such cb only for the first
1232          * interface of the function
1233          */
1234         case USB_REQ_GET_STATUS:
1235                 if (!gadget_is_superspeed(gadget))
1236                         goto unknown;
1237                 if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1238                         goto unknown;
1239                 value = 2;      /* This is the length of the get_status reply */
1240                 put_unaligned_le16(0, req->buf);
1241                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1242                         break;
1243                 f = cdev->config->interface[intf];
1244                 if (!f)
1245                         break;
1246                 status = f->get_status ? f->get_status(f) : 0;
1247                 if (status < 0)
1248                         break;
1249                 put_unaligned_le16(status & 0x0000ffff, req->buf);
1250                 break;
1251         /*
1252          * Function drivers should handle SetFeature/ClearFeature
1253          * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1254          * only for the first interface of the function
1255          */
1256         case USB_REQ_CLEAR_FEATURE:
1257         case USB_REQ_SET_FEATURE:
1258                 if (!gadget_is_superspeed(gadget))
1259                         goto unknown;
1260                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1261                         goto unknown;
1262                 switch (w_value) {
1263                 case USB_INTRF_FUNC_SUSPEND:
1264                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1265                                 break;
1266                         f = cdev->config->interface[intf];
1267                         if (!f)
1268                                 break;
1269                         value = 0;
1270                         if (f->func_suspend)
1271                                 value = f->func_suspend(f, w_index >> 8);
1272                         if (value < 0) {
1273                                 ERROR(cdev,
1274                                       "func_suspend() returned error %d\n",
1275                                       value);
1276                                 value = 0;
1277                         }
1278                         break;
1279                 }
1280                 break;
1281         default:
1282 unknown:
1283                 VDBG(cdev,
1284                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
1285                         ctrl->bRequestType, ctrl->bRequest,
1286                         w_value, w_index, w_length);
1287
1288                 /* functions always handle their interfaces and endpoints...
1289                  * punt other recipients (other, WUSB, ...) to the current
1290                  * configuration code.
1291                  *
1292                  * REVISIT it could make sense to let the composite device
1293                  * take such requests too, if that's ever needed:  to work
1294                  * in config 0, etc.
1295                  */
1296                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
1297                 case USB_RECIP_INTERFACE:
1298                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1299                                 break;
1300                         f = cdev->config->interface[intf];
1301                         break;
1302
1303                 case USB_RECIP_ENDPOINT:
1304                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1305                         list_for_each_entry(f, &cdev->config->functions, list) {
1306                                 if (test_bit(endp, f->endpoints))
1307                                         break;
1308                         }
1309                         if (&f->list == &cdev->config->functions)
1310                                 f = NULL;
1311                         break;
1312                 }
1313
1314                 if (f && f->setup)
1315                         value = f->setup(f, ctrl);
1316                 else {
1317                         struct usb_configuration        *c;
1318
1319                         c = cdev->config;
1320                         if (c && c->setup)
1321                                 value = c->setup(c, ctrl);
1322                 }
1323
1324                 goto done;
1325         }
1326
1327         /* respond with data transfer before status phase? */
1328         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
1329                 req->length = value;
1330                 req->zero = value < w_length;
1331                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
1332                 if (value < 0) {
1333                         DBG(cdev, "ep_queue --> %d\n", value);
1334                         req->status = 0;
1335                         composite_setup_complete(gadget->ep0, req);
1336                 }
1337         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
1338                 WARN(cdev,
1339                         "%s: Delayed status not supported for w_length != 0",
1340                         __func__);
1341         }
1342
1343 done:
1344         /* device either stalls (value < 0) or reports success */
1345         return value;
1346 }
1347
1348 static void composite_disconnect(struct usb_gadget *gadget)
1349 {
1350         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1351         unsigned long                   flags;
1352
1353         /* REVISIT:  should we have config and device level
1354          * disconnect callbacks?
1355          */
1356         spin_lock_irqsave(&cdev->lock, flags);
1357         if (cdev->config)
1358                 reset_config(cdev);
1359         if (composite->disconnect)
1360                 composite->disconnect(cdev);
1361         spin_unlock_irqrestore(&cdev->lock, flags);
1362 }
1363
1364 /*-------------------------------------------------------------------------*/
1365
1366 static ssize_t composite_show_suspended(struct device *dev,
1367                                         struct device_attribute *attr,
1368                                         char *buf)
1369 {
1370         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1371         struct usb_composite_dev *cdev = get_gadget_data(gadget);
1372
1373         return sprintf(buf, "%d\n", cdev->suspended);
1374 }
1375
1376 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1377
1378 static void
1379 composite_unbind(struct usb_gadget *gadget)
1380 {
1381         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1382
1383         /* composite_disconnect() must already have been called
1384          * by the underlying peripheral controller driver!
1385          * so there's no i/o concurrency that could affect the
1386          * state protected by cdev->lock.
1387          */
1388         WARN_ON(cdev->config);
1389
1390         while (!list_empty(&cdev->configs)) {
1391                 struct usb_configuration        *c;
1392                 c = list_first_entry(&cdev->configs,
1393                                 struct usb_configuration, list);
1394                 remove_config(cdev, c);
1395         }
1396         if (composite->unbind)
1397                 composite->unbind(cdev);
1398
1399         if (cdev->req) {
1400                 kfree(cdev->req->buf);
1401                 usb_ep_free_request(gadget->ep0, cdev->req);
1402         }
1403         device_remove_file(&gadget->dev, &dev_attr_suspended);
1404         kfree(cdev);
1405         set_gadget_data(gadget, NULL);
1406         composite = NULL;
1407 }
1408
1409 static u8 override_id(struct usb_composite_dev *cdev, u8 *desc)
1410 {
1411         if (!*desc) {
1412                 int ret = usb_string_id(cdev);
1413                 if (unlikely(ret < 0))
1414                         WARNING(cdev, "failed to override string ID\n");
1415                 else
1416                         *desc = ret;
1417         }
1418
1419         return *desc;
1420 }
1421
1422 static int composite_bind(struct usb_gadget *gadget)
1423 {
1424         struct usb_composite_dev        *cdev;
1425         int                             status = -ENOMEM;
1426
1427         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1428         if (!cdev)
1429                 return status;
1430
1431         spin_lock_init(&cdev->lock);
1432         cdev->gadget = gadget;
1433         set_gadget_data(gadget, cdev);
1434         INIT_LIST_HEAD(&cdev->configs);
1435
1436         /* preallocate control response and buffer */
1437         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1438         if (!cdev->req)
1439                 goto fail;
1440         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
1441         if (!cdev->req->buf)
1442                 goto fail;
1443         cdev->req->complete = composite_setup_complete;
1444         gadget->ep0->driver_data = cdev;
1445
1446         cdev->bufsiz = USB_BUFSIZ;
1447         cdev->driver = composite;
1448
1449         /*
1450          * As per USB compliance update, a device that is actively drawing
1451          * more than 100mA from USB must report itself as bus-powered in
1452          * the GetStatus(DEVICE) call.
1453          */
1454         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
1455                 usb_gadget_set_selfpowered(gadget);
1456
1457         /* interface and string IDs start at zero via kzalloc.
1458          * we force endpoints to start unassigned; few controller
1459          * drivers will zero ep->driver_data.
1460          */
1461         usb_ep_autoconfig_reset(cdev->gadget);
1462
1463         /* composite gadget needs to assign strings for whole device (like
1464          * serial number), register function drivers, potentially update
1465          * power state and consumption, etc
1466          */
1467         status = composite_gadget_bind(cdev);
1468         if (status < 0)
1469                 goto fail;
1470
1471         cdev->desc = *composite->dev;
1472
1473         /* standardized runtime overrides for device ID data */
1474         if (idVendor)
1475                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1476         else
1477                 idVendor = le16_to_cpu(cdev->desc.idVendor);
1478         if (idProduct)
1479                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1480         else
1481                 idProduct = le16_to_cpu(cdev->desc.idProduct);
1482         if (bcdDevice)
1483                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1484         else
1485                 bcdDevice = le16_to_cpu(cdev->desc.bcdDevice);
1486
1487         /* string overrides */
1488         if (iManufacturer || !cdev->desc.iManufacturer) {
1489                 if (!iManufacturer && !composite->iManufacturer &&
1490                     !*composite_manufacturer)
1491                         snprintf(composite_manufacturer,
1492                                  sizeof composite_manufacturer,
1493                                  "%s %s with %s",
1494                                  init_utsname()->sysname,
1495                                  init_utsname()->release,
1496                                  gadget->name);
1497
1498                 cdev->manufacturer_override =
1499                         override_id(cdev, &cdev->desc.iManufacturer);
1500         }
1501
1502         if (iProduct || (!cdev->desc.iProduct && composite->iProduct))
1503                 cdev->product_override =
1504                         override_id(cdev, &cdev->desc.iProduct);
1505
1506         if (iSerialNumber ||
1507             (!cdev->desc.iSerialNumber && composite->iSerialNumber))
1508                 cdev->serial_override =
1509                         override_id(cdev, &cdev->desc.iSerialNumber);
1510
1511         /* has userspace failed to provide a serial number? */
1512         if (composite->needs_serial && !cdev->desc.iSerialNumber)
1513                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
1514
1515         /* finish up */
1516         status = device_create_file(&gadget->dev, &dev_attr_suspended);
1517         if (status)
1518                 goto fail;
1519
1520         INFO(cdev, "%s ready\n", composite->name);
1521         return 0;
1522
1523 fail:
1524         composite_unbind(gadget);
1525         return status;
1526 }
1527
1528 /*-------------------------------------------------------------------------*/
1529
1530 static void
1531 composite_suspend(struct usb_gadget *gadget)
1532 {
1533         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1534         struct usb_function             *f;
1535
1536         /* REVISIT:  should we have config level
1537          * suspend/resume callbacks?
1538          */
1539         DBG(cdev, "suspend\n");
1540         if (cdev->config) {
1541                 list_for_each_entry(f, &cdev->config->functions, list) {
1542                         if (f->suspend)
1543                                 f->suspend(f);
1544                 }
1545         }
1546         if (composite->suspend)
1547                 composite->suspend(cdev);
1548
1549         cdev->suspended = 1;
1550
1551         usb_gadget_vbus_draw(gadget, 2);
1552 }
1553
1554 static void
1555 composite_resume(struct usb_gadget *gadget)
1556 {
1557         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1558         struct usb_function             *f;
1559         u8                              maxpower;
1560
1561         /* REVISIT:  should we have config level
1562          * suspend/resume callbacks?
1563          */
1564         DBG(cdev, "resume\n");
1565         if (composite->resume)
1566                 composite->resume(cdev);
1567         if (cdev->config) {
1568                 list_for_each_entry(f, &cdev->config->functions, list) {
1569                         if (f->resume)
1570                                 f->resume(f);
1571                 }
1572
1573                 maxpower = cdev->config->bMaxPower;
1574
1575                 usb_gadget_vbus_draw(gadget, maxpower ?
1576                         (2 * maxpower) : CONFIG_USB_GADGET_VBUS_DRAW);
1577         }
1578
1579         cdev->suspended = 0;
1580 }
1581
1582 /*-------------------------------------------------------------------------*/
1583
1584 static struct usb_gadget_driver composite_driver = {
1585 #ifdef CONFIG_USB_GADGET_SUPERSPEED
1586         .max_speed      = USB_SPEED_SUPER,
1587 #else
1588         .max_speed      = USB_SPEED_HIGH,
1589 #endif
1590
1591         .unbind         = composite_unbind,
1592
1593         .setup          = composite_setup,
1594         .disconnect     = composite_disconnect,
1595
1596         .suspend        = composite_suspend,
1597         .resume         = composite_resume,
1598
1599         .driver = {
1600                 .owner          = THIS_MODULE,
1601         },
1602 };
1603
1604 /**
1605  * usb_composite_probe() - register a composite driver
1606  * @driver: the driver to register
1607  * @bind: the callback used to allocate resources that are shared across the
1608  *      whole device, such as string IDs, and add its configurations using
1609  *      @usb_add_config().  This may fail by returning a negative errno
1610  *      value; it should return zero on successful initialization.
1611  * Context: single threaded during gadget setup
1612  *
1613  * This function is used to register drivers using the composite driver
1614  * framework.  The return value is zero, or a negative errno value.
1615  * Those values normally come from the driver's @bind method, which does
1616  * all the work of setting up the driver to match the hardware.
1617  *
1618  * On successful return, the gadget is ready to respond to requests from
1619  * the host, unless one of its components invokes usb_gadget_disconnect()
1620  * while it was binding.  That would usually be done in order to wait for
1621  * some userspace participation.
1622  */
1623 int usb_composite_probe(struct usb_composite_driver *driver,
1624                                int (*bind)(struct usb_composite_dev *cdev))
1625 {
1626         if (!driver || !driver->dev || !bind || composite)
1627                 return -EINVAL;
1628
1629         if (!driver->name)
1630                 driver->name = "composite";
1631         if (!driver->iProduct)
1632                 driver->iProduct = driver->name;
1633         composite_driver.function =  (char *) driver->name;
1634         composite_driver.driver.name = driver->name;
1635         composite_driver.max_speed =
1636                 min_t(u8, composite_driver.max_speed, driver->max_speed);
1637         composite = driver;
1638         composite_gadget_bind = bind;
1639
1640         return usb_gadget_probe_driver(&composite_driver, composite_bind);
1641 }
1642
1643 /**
1644  * usb_composite_unregister() - unregister a composite driver
1645  * @driver: the driver to unregister
1646  *
1647  * This function is used to unregister drivers using the composite
1648  * driver framework.
1649  */
1650 void usb_composite_unregister(struct usb_composite_driver *driver)
1651 {
1652         if (composite != driver)
1653                 return;
1654         usb_gadget_unregister_driver(&composite_driver);
1655 }
1656
1657 /**
1658  * usb_composite_setup_continue() - Continue with the control transfer
1659  * @cdev: the composite device who's control transfer was kept waiting
1660  *
1661  * This function must be called by the USB function driver to continue
1662  * with the control transfer's data/status stage in case it had requested to
1663  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
1664  * can request the composite framework to delay the setup request's data/status
1665  * stages by returning USB_GADGET_DELAYED_STATUS.
1666  */
1667 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
1668 {
1669         int                     value;
1670         struct usb_request      *req = cdev->req;
1671         unsigned long           flags;
1672
1673         DBG(cdev, "%s\n", __func__);
1674         spin_lock_irqsave(&cdev->lock, flags);
1675
1676         if (cdev->delayed_status == 0) {
1677                 WARN(cdev, "%s: Unexpected call\n", __func__);
1678
1679         } else if (--cdev->delayed_status == 0) {
1680                 DBG(cdev, "%s: Completing delayed status\n", __func__);
1681                 req->length = 0;
1682                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1683                 if (value < 0) {
1684                         DBG(cdev, "ep_queue --> %d\n", value);
1685                         req->status = 0;
1686                         composite_setup_complete(cdev->gadget->ep0, req);
1687                 }
1688         }
1689
1690         spin_unlock_irqrestore(&cdev->lock, flags);
1691 }
1692