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  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /* #define VERBOSE_DEBUG */
  22
  23 #include <linux/kallsyms.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/device.h>
  27
  28 #include <linux/usb/composite.h>
  29
  30
  31 /*
  32  * The code in this file is utility code, used to build a gadget driver
  33  * from one or more "function" drivers, one or more "configuration"
  34  * objects, and a "usb_composite_driver" by gluing them together along
  35  * with the relevant device-wide data.
  36  */
  37
  38 /* big enough to hold our biggest descriptor */
  39 #define USB_BUFSIZ      1024
  40
  41 static struct usb_composite_driver *composite;
  42
  43 /* Some systems will need runtime overrides for the  product identifers
  44  * published in the device descriptor, either numbers or strings or both.
  45  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  46  */
  47
  48 static ushort idVendor;
  49 module_param(idVendor, ushort, 0);
  50 MODULE_PARM_DESC(idVendor, "USB Vendor ID");
  51
  52 static ushort idProduct;
  53 module_param(idProduct, ushort, 0);
  54 MODULE_PARM_DESC(idProduct, "USB Product ID");
  55
  56 static ushort bcdDevice;
  57 module_param(bcdDevice, ushort, 0);
  58 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
  59
  60 static char *iManufacturer;
  61 module_param(iManufacturer, charp, 0);
  62 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
  63
  64 static char *iProduct;
  65 module_param(iProduct, charp, 0);
  66 MODULE_PARM_DESC(iProduct, "USB Product string");
  67
  68 static char *iSerialNumber;
  69 module_param(iSerialNumber, charp, 0);
  70 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
  71
  72 /*-------------------------------------------------------------------------*/
  73
  74 static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
  75                 char *buf)
  76 {
  77         struct usb_function *f = dev_get_drvdata(dev);
  78         return sprintf(buf, "%d\n", !f->disabled);
  79 }
  80
  81 static ssize_t enable_store(
  82                 struct device *dev, struct device_attribute *attr,
  83                 const char *buf, size_t size)
  84 {
  85         struct usb_function *f = dev_get_drvdata(dev);
  86         struct usb_composite_driver     *driver = f->config->cdev->driver;
  87         int value;
  88
  89         sscanf(buf, "%d", &value);
  90         if (driver->enable_function)
  91                 driver->enable_function(f, value);
  92         else
  93                 usb_function_set_enabled(f, value);
  94
  95         return size;
  96 }
  97
  98 static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, enable_show, enable_store);
  99
 100 void usb_function_set_enabled(struct usb_function *f, int enabled)
 101 {
 102         f->disabled = !enabled;
 103         kobject_uevent(&f->dev->kobj, KOBJ_CHANGE);
 104 }
 105
 106
 107 void usb_composite_force_reset(struct usb_composite_dev *cdev)
 108 {
 109         unsigned long                   flags;
 110
 111         spin_lock_irqsave(&cdev->lock, flags);
 112         /* force reenumeration */
 113         if (cdev && cdev->gadget && cdev->gadget->speed != USB_SPEED_UNKNOWN) {
 114                 spin_unlock_irqrestore(&cdev->lock, flags);
 115
 116                 usb_gadget_disconnect(cdev->gadget);
 117                 msleep(10);
 118                 usb_gadget_connect(cdev->gadget);
 119         } else {
 120                 spin_unlock_irqrestore(&cdev->lock, flags);
 121         }
 122 }
 123
 124 /**
 125  * usb_add_function() - add a function to a configuration
 126  * @config: the configuration
 127  * @function: the function being added
 128  * Context: single threaded during gadget setup
 129  *
 130  * After initialization, each configuration must have one or more
 131  * functions added to it.  Adding a function involves calling its @bind()
 132  * method to allocate resources such as interface and string identifiers
 133  * and endpoints.
 134  *
 135  * This function returns the value of the function's bind(), which is
 136  * zero for success else a negative errno value.
 137  */
 138 int usb_add_function(struct usb_configuration *config,
 139                 struct usb_function *function)
 140 {
 141         struct usb_composite_dev        *cdev = config->cdev;
 142         int     value = -EINVAL;
 143         int index;
 144
 145         DBG(cdev, "adding '%s'/%p to config '%s'/%p\n",
 146                         function->name, function,
 147                         config->label, config);
 148
 149         if (!function->set_alt || !function->disable)
 150                 goto done;
 151
 152         index = atomic_inc_return(&cdev->driver->function_count);
 153         function->dev = device_create(cdev->driver->class, NULL,
 154                 MKDEV(0, index), NULL, function->name);
 155         if (IS_ERR(function->dev))
 156                 return PTR_ERR(function->dev);
 157
 158         value = device_create_file(function->dev, &dev_attr_enable);
 159         if (value < 0) {
 160                 device_destroy(cdev->driver->class, MKDEV(0, index));
 161                 return value;
 162         }
 163         dev_set_drvdata(function->dev, function);
 164
 165         function->config = config;
 166         list_add_tail(&function->list, &config->functions);
 167
 168         /* REVISIT *require* function->bind? */
 169         if (function->bind) {
 170                 value = function->bind(config, function);
 171                 if (value < 0) {
 172                         list_del(&function->list);
 173                         function->config = NULL;
 174                 }
 175         } else
 176                 value = 0;
 177
 178         /* We allow configurations that don't work at both speeds.
 179          * If we run into a lowspeed Linux system, treat it the same
 180          * as full speed ... it's the function drivers that will need
 181          * to avoid bulk and ISO transfers.
 182          */
 183         if (!config->fullspeed && function->descriptors)
 184                 config->fullspeed = true;
 185         if (!config->highspeed && function->hs_descriptors)
 186                 config->highspeed = true;
 187
 188 done:
 189         if (value)
 190                 DBG(cdev, "adding '%s'/%p --> %d\n",
 191                                 function->name, function, value);
 192         return value;
 193 }
 194
 195 /**
 196  * usb_function_deactivate - prevent function and gadget enumeration
 197  * @function: the function that isn't yet ready to respond
 198  *
 199  * Blocks response of the gadget driver to host enumeration by
 200  * preventing the data line pullup from being activated.  This is
 201  * normally called during @bind() processing to change from the
 202  * initial "ready to respond" state, or when a required resource
 203  * becomes available.
 204  *
 205  * For example, drivers that serve as a passthrough to a userspace
 206  * daemon can block enumeration unless that daemon (such as an OBEX,
 207  * MTP, or print server) is ready to handle host requests.
 208  *
 209  * Not all systems support software control of their USB peripheral
 210  * data pullups.
 211  *
 212  * Returns zero on success, else negative errno.
 213  */
 214 int usb_function_deactivate(struct usb_function *function)
 215 {
 216         struct usb_composite_dev        *cdev = function->config->cdev;
 217         unsigned long                   flags;
 218         int                             status = 0;
 219
 220         spin_lock_irqsave(&cdev->lock, flags);
 221
 222         if (cdev->deactivations == 0)
 223                 status = usb_gadget_disconnect(cdev->gadget);
 224         if (status == 0)
 225                 cdev->deactivations++;
 226
 227         spin_unlock_irqrestore(&cdev->lock, flags);
 228         return status;
 229 }
 230
 231 /**
 232  * usb_function_activate - allow function and gadget enumeration
 233  * @function: function on which usb_function_activate() was called
 234  *
 235  * Reverses effect of usb_function_deactivate().  If no more functions
 236  * are delaying their activation, the gadget driver will respond to
 237  * host enumeration procedures.
 238  *
 239  * Returns zero on success, else negative errno.
 240  */
 241 int usb_function_activate(struct usb_function *function)
 242 {
 243         struct usb_composite_dev        *cdev = function->config->cdev;
 244         int                             status = 0;
 245
 246         spin_lock(&cdev->lock);
 247
 248         if (WARN_ON(cdev->deactivations == 0))
 249                 status = -EINVAL;
 250         else {
 251                 cdev->deactivations--;
 252                 if (cdev->deactivations == 0)
 253                         status = usb_gadget_connect(cdev->gadget);
 254         }
 255
 256         spin_unlock(&cdev->lock);
 257         return status;
 258 }
 259
 260 /**
 261  * usb_interface_id() - allocate an unused interface ID
 262  * @config: configuration associated with the interface
 263  * @function: function handling the interface
 264  * Context: single threaded during gadget setup
 265  *
 266  * usb_interface_id() is called from usb_function.bind() callbacks to
 267  * allocate new interface IDs.  The function driver will then store that
 268  * ID in interface, association, CDC union, and other descriptors.  It
 269  * will also handle any control requests targetted at that interface,
 270  * particularly changing its altsetting via set_alt().  There may
 271  * also be class-specific or vendor-specific requests to handle.
 272  *
 273  * All interface identifier should be allocated using this routine, to
 274  * ensure that for example different functions don't wrongly assign
 275  * different meanings to the same identifier.  Note that since interface
 276  * identifers are configuration-specific, functions used in more than
 277  * one configuration (or more than once in a given configuration) need
 278  * multiple versions of the relevant descriptors.
 279  *
 280  * Returns the interface ID which was allocated; or -ENODEV if no
 281  * more interface IDs can be allocated.
 282  */
 283 int usb_interface_id(struct usb_configuration *config,
 284                 struct usb_function *function)
 285 {
 286         unsigned id = config->next_interface_id;
 287
 288         if (id < MAX_CONFIG_INTERFACES) {
 289                 config->interface[id] = function;
 290                 config->next_interface_id = id + 1;
 291                 return id;
 292         }
 293         return -ENODEV;
 294 }
 295
 296 static int config_buf(struct usb_configuration *config,
 297                 enum usb_device_speed speed, void *buf, u8 type)
 298 {
 299         struct usb_config_descriptor    *c = buf;
 300         struct usb_interface_descriptor *intf;
 301         struct usb_interface_assoc_descriptor *iad = NULL;
 302         void                            *next = buf + USB_DT_CONFIG_SIZE;
 303         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 304         struct usb_function             *f;
 305         int                             status;
 306         int                             interfaceCount = 0;
 307         u8 *dest;
 308
 309         /* write the config descriptor */
 310         c = buf;
 311         c->bLength = USB_DT_CONFIG_SIZE;
 312         c->bDescriptorType = type;
 313         /* wTotalLength and bNumInterfaces are written later */
 314         c->bConfigurationValue = config->bConfigurationValue;
 315         c->iConfiguration = config->iConfiguration;
 316         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 317         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 318
 319         /* There may be e.g. OTG descriptors */
 320         if (config->descriptors) {
 321                 status = usb_descriptor_fillbuf(next, len,
 322                                 config->descriptors);
 323                 if (status < 0)
 324                         return status;
 325                 len -= status;
 326                 next += status;
 327         }
 328
 329         /* add each function's descriptors */
 330         list_for_each_entry(f, &config->functions, list) {
 331                 struct usb_descriptor_header **descriptors;
 332                 struct usb_descriptor_header *descriptor;
 333
 334                 if (speed == USB_SPEED_HIGH)
 335                         descriptors = f->hs_descriptors;
 336                 else
 337                         descriptors = f->descriptors;
 338                 if (f->disabled || !descriptors || descriptors[0] == NULL)
 339                         continue;
 340                 status = usb_descriptor_fillbuf(next, len,
 341                         (const struct usb_descriptor_header **) descriptors);
 342                 if (status < 0)
 343                         return status;
 344
 345                 /* set interface numbers dynamically */
 346                 dest = next;
 347                 while ((descriptor = *descriptors++) != NULL) {
 348                         intf = (struct usb_interface_descriptor *)dest;
 349                         if (intf->bDescriptorType == USB_DT_INTERFACE) {
 350                                 /* don't increment bInterfaceNumber for alternate settings */
 351                                 if (intf->bAlternateSetting == 0)
 352                                         intf->bInterfaceNumber = interfaceCount++;
 353                                 else
 354                                         intf->bInterfaceNumber = interfaceCount - 1;
 355                                 if (iad) {
 356                                         iad->bFirstInterface =
 357                                                         intf->bInterfaceNumber;
 358                                         iad = NULL;
 359                                 }
 360                         } else if (intf->bDescriptorType ==
 361                                         USB_DT_INTERFACE_ASSOCIATION) {
 362                                 /* This will be first if it exists. Save
 363                                  * a pointer to it so we can properly set
 364                                  * bFirstInterface when we process the first
 365                                  * interface.
 366                                  */
 367                                 iad = (struct usb_interface_assoc_descriptor *)
 368                                                 dest;
 369                         }
 370                         dest += intf->bLength;
 371                 }
 372
 373                 len -= status;
 374                 next += status;
 375         }
 376
 377         len = next - buf;
 378         c->wTotalLength = cpu_to_le16(len);
 379         c->bNumInterfaces = interfaceCount;
 380         return len;
 381 }
 382
 383 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 384 {
 385         struct usb_gadget               *gadget = cdev->gadget;
 386         struct usb_configuration        *c;
 387         u8                              type = w_value >> 8;
 388         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 389
 390         if (gadget_is_dualspeed(gadget)) {
 391                 int                     hs = 0;
 392
 393                 if (gadget->speed == USB_SPEED_HIGH)
 394                         hs = 1;
 395                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 396                         hs = !hs;
 397                 if (hs)
 398                         speed = USB_SPEED_HIGH;
 399
 400         }
 401
 402         /* This is a lookup by config *INDEX* */
 403         w_value &= 0xff;
 404         list_for_each_entry(c, &cdev->configs, list) {
 405                 /* ignore configs that won't work at this speed */
 406                 if (speed == USB_SPEED_HIGH) {
 407                         if (!c->highspeed)
 408                                 continue;
 409                 } else {
 410                         if (!c->fullspeed)
 411                                 continue;
 412                 }
 413                 if (w_value == 0)
 414                         return config_buf(c, speed, cdev->req->buf, type);
 415                 w_value--;
 416         }
 417         return -EINVAL;
 418 }
 419
 420 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 421 {
 422         struct usb_gadget               *gadget = cdev->gadget;
 423         struct usb_configuration        *c;
 424         unsigned                        count = 0;
 425         int                             hs = 0;
 426
 427         if (gadget_is_dualspeed(gadget)) {
 428                 if (gadget->speed == USB_SPEED_HIGH)
 429                         hs = 1;
 430                 if (type == USB_DT_DEVICE_QUALIFIER)
 431                         hs = !hs;
 432         }
 433         list_for_each_entry(c, &cdev->configs, list) {
 434                 /* ignore configs that won't work at this speed */
 435                 if (hs) {
 436                         if (!c->highspeed)
 437                                 continue;
 438                 } else {
 439                         if (!c->fullspeed)
 440                                 continue;
 441                 }
 442                 count++;
 443         }
 444         return count;
 445 }
 446
 447 static void device_qual(struct usb_composite_dev *cdev)
 448 {
 449         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 450
 451         qual->bLength = sizeof(*qual);
 452         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 453         /* POLICY: same bcdUSB and device type info at both speeds */
 454         qual->bcdUSB = cdev->desc.bcdUSB;
 455         qual->bDeviceClass = cdev->desc.bDeviceClass;
 456         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 457         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 458         /* ASSUME same EP0 fifo size at both speeds */
 459         qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
 460         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 461         qual->bRESERVED = 0;
 462 }
 463
 464 /*-------------------------------------------------------------------------*/
 465
 466 static void reset_config(struct usb_composite_dev *cdev)
 467 {
 468         struct usb_function             *f;
 469
 470         DBG(cdev, "reset config\n");
 471
 472         list_for_each_entry(f, &cdev->config->functions, list) {
 473                 if (f->disable)
 474                         f->disable(f);
 475
 476                 bitmap_zero(f->endpoints, 32);
 477         }
 478         cdev->config = NULL;
 479 }
 480
 481 static int set_config(struct usb_composite_dev *cdev,
 482                 const struct usb_ctrlrequest *ctrl, unsigned number)
 483 {
 484         struct usb_gadget       *gadget = cdev->gadget;
 485         struct usb_configuration *c = NULL;
 486         int                     result = -EINVAL;
 487         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 488         int                     tmp;
 489
 490         if (cdev->config)
 491                 reset_config(cdev);
 492
 493         if (number) {
 494                 list_for_each_entry(c, &cdev->configs, list) {
 495                         if (c->bConfigurationValue == number) {
 496                                 result = 0;
 497                                 break;
 498                         }
 499                 }
 500                 if (result < 0)
 501                         goto done;
 502         } else
 503                 result = 0;
 504
 505         INFO(cdev, "%s speed config #%d: %s\n",
 506                 ({ char *speed;
 507                 switch (gadget->speed) {
 508                 case USB_SPEED_LOW:     speed = "low"; break;
 509                 case USB_SPEED_FULL:    speed = "full"; break;
 510                 case USB_SPEED_HIGH:    speed = "high"; break;
 511                 default:                speed = "?"; break;
 512                 } ; speed; }), number, c ? c->label : "unconfigured");
 513
 514         if (!c)
 515                 goto done;
 516
 517         cdev->config = c;
 518
 519         /* Initialize all interfaces by setting them to altsetting zero. */
 520         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 521                 struct usb_function     *f = c->interface[tmp];
 522                 struct usb_descriptor_header **descriptors;
 523
 524                 if (!f)
 525                         break;
 526                 if (f->disabled)
 527                         continue;
 528
 529                 /*
 530                  * Record which endpoints are used by the function. This is used
 531                  * to dispatch control requests targeted at that endpoint to the
 532                  * function's setup callback instead of the current
 533                  * configuration's setup callback.
 534                  */
 535                 if (gadget->speed == USB_SPEED_HIGH)
 536                         descriptors = f->hs_descriptors;
 537                 else
 538                         descriptors = f->descriptors;
 539
 540                 for (; *descriptors; ++descriptors) {
 541                         struct usb_endpoint_descriptor *ep;
 542                         int addr;
 543
 544                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 545                                 continue;
 546
 547                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 548                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 549                              |  (ep->bEndpointAddress & 0x0f);
 550                         set_bit(addr, f->endpoints);
 551                 }
 552
 553                 result = f->set_alt(f, tmp, 0);
 554                 if (result < 0) {
 555                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 556                                         tmp, f->name, f, result);
 557
 558                         reset_config(cdev);
 559                         goto done;
 560                 }
 561         }
 562
 563         /* when we return, be sure our power usage is valid */
 564         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 565 done:
 566         usb_gadget_vbus_draw(gadget, power);
 567
 568         schedule_work(&cdev->switch_work);
 569         return result;
 570 }
 571
 572 /**
 573  * usb_add_config() - add a configuration to a device.
 574  * @cdev: wraps the USB gadget
 575  * @config: the configuration, with bConfigurationValue assigned
 576  * Context: single threaded during gadget setup
 577  *
 578  * One of the main tasks of a composite driver's bind() routine is to
 579  * add each of the configurations it supports, using this routine.
 580  *
 581  * This function returns the value of the configuration's bind(), which
 582  * is zero for success else a negative errno value.  Binding configurations
 583  * assigns global resources including string IDs, and per-configuration
 584  * resources such as interface IDs and endpoints.
 585  */
 586 int usb_add_config(struct usb_composite_dev *cdev,
 587                 struct usb_configuration *config)
 588 {
 589         int                             status = -EINVAL;
 590         struct usb_configuration        *c;
 591
 592         DBG(cdev, "adding config #%u '%s'/%p\n",
 593                         config->bConfigurationValue,
 594                         config->label, config);
 595
 596         if (!config->bConfigurationValue || !config->bind)
 597                 goto done;
 598
 599         /* Prevent duplicate configuration identifiers */
 600         list_for_each_entry(c, &cdev->configs, list) {
 601                 if (c->bConfigurationValue == config->bConfigurationValue) {
 602                         status = -EBUSY;
 603                         goto done;
 604                 }
 605         }
 606
 607         config->cdev = cdev;
 608         list_add_tail(&config->list, &cdev->configs);
 609
 610         INIT_LIST_HEAD(&config->functions);
 611         config->next_interface_id = 0;
 612
 613         status = config->bind(config);
 614         if (status < 0) {
 615                 list_del(&config->list);
 616                 config->cdev = NULL;
 617         } else {
 618                 unsigned        i;
 619
 620                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
 621                         config->bConfigurationValue, config,
 622                         config->highspeed ? " high" : "",
 623                         config->fullspeed
 624                                 ? (gadget_is_dualspeed(cdev->gadget)
 625                                         ? " full"
 626                                         : " full/low")
 627                                 : "");
 628
 629                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 630                         struct usb_function     *f = config->interface[i];
 631
 632                         if (!f)
 633                                 continue;
 634                         DBG(cdev, "  interface %d = %s/%p\n",
 635                                 i, f->name, f);
 636                 }
 637         }
 638
 639         /* set_alt(), or next config->bind(), sets up
 640          * ep->driver_data as needed.
 641          */
 642         usb_ep_autoconfig_reset(cdev->gadget);
 643
 644 done:
 645         if (status)
 646                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 647                                 config->bConfigurationValue, status);
 648         return status;
 649 }
 650
 651 /*-------------------------------------------------------------------------*/
 652
 653 /* We support strings in multiple languages ... string descriptor zero
 654  * says which languages are supported.  The typical case will be that
 655  * only one language (probably English) is used, with I18N handled on
 656  * the host side.
 657  */
 658
 659 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 660 {
 661         const struct usb_gadget_strings *s;
 662         u16                             language;
 663         __le16                          *tmp;
 664
 665         while (*sp) {
 666                 s = *sp;
 667                 language = cpu_to_le16(s->language);
 668                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 669                         if (*tmp == language)
 670                                 goto repeat;
 671                 }
 672                 *tmp++ = language;
 673 repeat:
 674                 sp++;
 675         }
 676 }
 677
 678 static int lookup_string(
 679         struct usb_gadget_strings       **sp,
 680         void                            *buf,
 681         u16                             language,
 682         int                             id
 683 )
 684 {
 685         struct usb_gadget_strings       *s;
 686         int                             value;
 687
 688         while (*sp) {
 689                 s = *sp++;
 690                 if (s->language != language)
 691                         continue;
 692                 value = usb_gadget_get_string(s, id, buf);
 693                 if (value > 0)
 694                         return value;
 695         }
 696         return -EINVAL;
 697 }
 698
 699 static int get_string(struct usb_composite_dev *cdev,
 700                 void *buf, u16 language, int id)
 701 {
 702         struct usb_configuration        *c;
 703         struct usb_function             *f;
 704         int                             len;
 705
 706         /* Yes, not only is USB's I18N support probably more than most
 707          * folk will ever care about ... also, it's all supported here.
 708          * (Except for UTF8 support for Unicode's "Astral Planes".)
 709          */
 710
 711         /* 0 == report all available language codes */
 712         if (id == 0) {
 713                 struct usb_string_descriptor    *s = buf;
 714                 struct usb_gadget_strings       **sp;
 715
 716                 memset(s, 0, 256);
 717                 s->bDescriptorType = USB_DT_STRING;
 718
 719                 sp = composite->strings;
 720                 if (sp)
 721                         collect_langs(sp, s->wData);
 722
 723                 list_for_each_entry(c, &cdev->configs, list) {
 724                         sp = c->strings;
 725                         if (sp)
 726                                 collect_langs(sp, s->wData);
 727
 728                         list_for_each_entry(f, &c->functions, list) {
 729                                 sp = f->strings;
 730                                 if (sp)
 731                                         collect_langs(sp, s->wData);
 732                         }
 733                 }
 734
 735                 for (len = 0; len <= 126 && s->wData[len]; len++)
 736                         continue;
 737                 if (!len)
 738                         return -EINVAL;
 739
 740                 s->bLength = 2 * (len + 1);
 741                 return s->bLength;
 742         }
 743
 744         /* Otherwise, look up and return a specified string.  String IDs
 745          * are device-scoped, so we look up each string table we're told
 746          * about.  These lookups are infrequent; simpler-is-better here.
 747          */
 748         if (composite->strings) {
 749                 len = lookup_string(composite->strings, buf, language, id);
 750                 if (len > 0)
 751                         return len;
 752         }
 753         list_for_each_entry(c, &cdev->configs, list) {
 754                 if (c->strings) {
 755                         len = lookup_string(c->strings, buf, language, id);
 756                         if (len > 0)
 757                                 return len;
 758                 }
 759                 list_for_each_entry(f, &c->functions, list) {
 760                         if (!f->strings)
 761                                 continue;
 762                         len = lookup_string(f->strings, buf, language, id);
 763                         if (len > 0)
 764                                 return len;
 765                 }
 766         }
 767         return -EINVAL;
 768 }
 769
 770 /**
 771  * usb_string_id() - allocate an unused string ID
 772  * @cdev: the device whose string descriptor IDs are being allocated
 773  * Context: single threaded during gadget setup
 774  *
 775  * @usb_string_id() is called from bind() callbacks to allocate
 776  * string IDs.  Drivers for functions, configurations, or gadgets will
 777  * then store that ID in the appropriate descriptors and string table.
 778  *
 779  * All string identifier should be allocated using this,
 780  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 781  * that for example different functions don't wrongly assign different
 782  * meanings to the same identifier.
 783  */
 784 int usb_string_id(struct usb_composite_dev *cdev)
 785 {
 786         if (cdev->next_string_id < 254) {
 787                 /* string id 0 is reserved by USB spec for list of
 788                  * supported languages */
 789                 /* 255 reserved as well? -- mina86 */
 790                 cdev->next_string_id++;
 791                 return cdev->next_string_id;
 792         }
 793         return -ENODEV;
 794 }
 795
 796 /**
 797  * usb_string_ids() - allocate unused string IDs in batch
 798  * @cdev: the device whose string descriptor IDs are being allocated
 799  * @str: an array of usb_string objects to assign numbers to
 800  * Context: single threaded during gadget setup
 801  *
 802  * @usb_string_ids() is called from bind() callbacks to allocate
 803  * string IDs.  Drivers for functions, configurations, or gadgets will
 804  * then copy IDs from the string table to the appropriate descriptors
 805  * and string table for other languages.
 806  *
 807  * All string identifier should be allocated using this,
 808  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 809  * example different functions don't wrongly assign different meanings
 810  * to the same identifier.
 811  */
 812 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 813 {
 814         int next = cdev->next_string_id;
 815
 816         for (; str->s; ++str) {
 817                 if (unlikely(next >= 254))
 818                         return -ENODEV;
 819                 str->id = ++next;
 820         }
 821
 822         cdev->next_string_id = next;
 823
 824         return 0;
 825 }
 826
 827 /**
 828  * usb_string_ids_n() - allocate unused string IDs in batch
 829  * @c: the device whose string descriptor IDs are being allocated
 830  * @n: number of string IDs to allocate
 831  * Context: single threaded during gadget setup
 832  *
 833  * Returns the first requested ID.  This ID and next @n-1 IDs are now
 834  * valid IDs.  At least provided that @n is non-zero because if it
 835  * is, returns last requested ID which is now very useful information.
 836  *
 837  * @usb_string_ids_n() is called from bind() callbacks to allocate
 838  * string IDs.  Drivers for functions, configurations, or gadgets will
 839  * then store that ID in the appropriate descriptors and string table.
 840  *
 841  * All string identifier should be allocated using this,
 842  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 843  * example different functions don't wrongly assign different meanings
 844  * to the same identifier.
 845  */
 846 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
 847 {
 848         unsigned next = c->next_string_id;
 849         if (unlikely(n > 254 || (unsigned)next + n > 254))
 850                 return -ENODEV;
 851         c->next_string_id += n;
 852         return next + 1;
 853 }
 854
 855
 856 /*-------------------------------------------------------------------------*/
 857
 858 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 859 {
 860         if (req->status || req->actual != req->length)
 861                 DBG((struct usb_composite_dev *) ep->driver_data,
 862                                 "setup complete --> %d, %d/%d\n",
 863                                 req->status, req->actual, req->length);
 864 }
 865
 866 /*
 867  * The setup() callback implements all the ep0 functionality that's
 868  * not handled lower down, in hardware or the hardware driver(like
 869  * device and endpoint feature flags, and their status).  It's all
 870  * housekeeping for the gadget function we're implementing.  Most of
 871  * the work is in config and function specific setup.
 872  */
 873 static int
 874 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 875 {
 876         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 877         struct usb_request              *req = cdev->req;
 878         int                             value = -EOPNOTSUPP;
 879         u16                             w_index = le16_to_cpu(ctrl->wIndex);
 880         u8                              intf = w_index & 0xFF;
 881         u16                             w_value = le16_to_cpu(ctrl->wValue);
 882         u16                             w_length = le16_to_cpu(ctrl->wLength);
 883         struct usb_function             *f = NULL;
 884         u8                              endp;
 885         unsigned long                   flags;
 886
 887         spin_lock_irqsave(&cdev->lock, flags);
 888         if (!cdev->connected) {
 889                 cdev->connected = 1;
 890                 schedule_work(&cdev->switch_work);
 891         }
 892         spin_unlock_irqrestore(&cdev->lock, flags);
 893
 894         /* partial re-init of the response message; the function or the
 895          * gadget might need to intercept e.g. a control-OUT completion
 896          * when we delegate to it.
 897          */
 898         req->zero = 0;
 899         req->complete = composite_setup_complete;
 900         req->length = USB_BUFSIZ;
 901         gadget->ep0->driver_data = cdev;
 902
 903         switch (ctrl->bRequest) {
 904
 905         /* we handle all standard USB descriptors */
 906         case USB_REQ_GET_DESCRIPTOR:
 907                 if (ctrl->bRequestType != USB_DIR_IN)
 908                         goto unknown;
 909                 switch (w_value >> 8) {
 910
 911                 case USB_DT_DEVICE:
 912                         cdev->desc.bNumConfigurations =
 913                                 count_configs(cdev, USB_DT_DEVICE);
 914                         value = min(w_length, (u16) sizeof cdev->desc);
 915                         memcpy(req->buf, &cdev->desc, value);
 916                         break;
 917                 case USB_DT_DEVICE_QUALIFIER:
 918                         if (!gadget_is_dualspeed(gadget))
 919                                 break;
 920                         device_qual(cdev);
 921                         value = min_t(int, w_length,
 922                                 sizeof(struct usb_qualifier_descriptor));
 923                         break;
 924                 case USB_DT_OTHER_SPEED_CONFIG:
 925                         if (!gadget_is_dualspeed(gadget))
 926                                 break;
 927                         /* FALLTHROUGH */
 928                 case USB_DT_CONFIG:
 929                         value = config_desc(cdev, w_value);
 930                         if (value >= 0)
 931                                 value = min(w_length, (u16) value);
 932                         break;
 933                 case USB_DT_STRING:
 934                         value = get_string(cdev, req->buf,
 935                                         w_index, w_value & 0xff);
 936
 937                         /* Allow functions to handle USB_DT_STRING.
 938                          * This is required for MTP.
 939                          */
 940                         if (value < 0) {
 941                                 struct usb_configuration        *cfg;
 942                                 list_for_each_entry(cfg, &cdev->configs, list) {
 943                                         if (cfg && cfg->setup) {
 944                                                 value = cfg->setup(cfg, ctrl);
 945                                                 if (value >= 0)
 946                                                         break;
 947                                         }
 948                                 }
 949                         }
 950
 951                         if (value >= 0)
 952                                 value = min(w_length, (u16) value);
 953                         break;
 954                 }
 955                 break;
 956
 957         /* any number of configs can work */
 958         case USB_REQ_SET_CONFIGURATION:
 959                 if (ctrl->bRequestType != 0)
 960                         goto unknown;
 961                 if (gadget_is_otg(gadget)) {
 962                         if (gadget->a_hnp_support)
 963                                 DBG(cdev, "HNP available\n");
 964                         else if (gadget->a_alt_hnp_support)
 965                                 DBG(cdev, "HNP on another port\n");
 966                         else
 967                                 VDBG(cdev, "HNP inactive\n");
 968                 }
 969                 spin_lock(&cdev->lock);
 970                 value = set_config(cdev, ctrl, w_value);
 971                 spin_unlock(&cdev->lock);
 972                 break;
 973         case USB_REQ_GET_CONFIGURATION:
 974                 if (ctrl->bRequestType != USB_DIR_IN)
 975                         goto unknown;
 976                 if (cdev->config) {
 977                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
 978                         value = min(w_length, (u16) 1);
 979                 } else
 980                         *(u8 *)req->buf = 0;
 981                 break;
 982
 983         /* function drivers must handle get/set altsetting; if there's
 984          * no get() method, we know only altsetting zero works.
 985          */
 986         case USB_REQ_SET_INTERFACE:
 987                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
 988                         goto unknown;
 989                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
 990                         break;
 991                 f = cdev->config->interface[intf];
 992                 if (!f)
 993                         break;
 994                 if (w_value && !f->set_alt)
 995                         break;
 996                 value = f->set_alt(f, w_index, w_value);
 997                 break;
 998         case USB_REQ_GET_INTERFACE:
 999                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1000                         goto unknown;
1001                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
1002                         break;
1003                 f = cdev->config->interface[intf];
1004                 if (!f)
1005                         break;
1006                 /* lots of interfaces only need altsetting zero... */
1007                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1008                 if (value < 0)
1009                         break;
1010                 *((u8 *)req->buf) = value;
1011                 value = min(w_length, (u16) 1);
1012                 break;
1013         default:
1014 unknown:
1015                 VDBG(cdev,
1016                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
1017                         ctrl->bRequestType, ctrl->bRequest,
1018                         w_value, w_index, w_length);
1019
1020                 /* functions always handle their interfaces and endpoints...
1021                  * punt other recipients (other, WUSB, ...) to the current
1022                  * configuration code.
1023                  *
1024                  * REVISIT it could make sense to let the composite device
1025                  * take such requests too, if that's ever needed:  to work
1026                  * in config 0, etc.
1027                  */
1028                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
1029                 case USB_RECIP_INTERFACE:
1030                         if (cdev->config)
1031                                 f = cdev->config->interface[intf];
1032                         break;
1033
1034                 case USB_RECIP_ENDPOINT:
1035                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1036                         list_for_each_entry(f, &cdev->config->functions, list) {
1037                                 if (test_bit(endp, f->endpoints))
1038                                         break;
1039                         }
1040                         if (&f->list == &cdev->config->functions)
1041                                 f = NULL;
1042                         break;
1043                 }
1044
1045                 if (f && f->setup)
1046                         value = f->setup(f, ctrl);
1047                 else {
1048                         struct usb_configuration        *c;
1049
1050                         c = cdev->config;
1051                         if (c && c->setup)
1052                                 value = c->setup(c, ctrl);
1053                 }
1054
1055                 /* If the vendor request is not processed (value < 0),
1056                  * call all device registered configure setup callbacks
1057                  * to process it.
1058                  * This is used to handle the following cases:
1059                  * - vendor request is for the device and arrives before
1060                  * setconfiguration.
1061                  * - Some devices are required to handle vendor request before
1062                  * setconfiguration such as MTP, USBNET.
1063                  */
1064
1065                 if (value < 0) {
1066                         struct usb_configuration        *cfg;
1067
1068                         list_for_each_entry(cfg, &cdev->configs, list) {
1069                         if (cfg && cfg->setup)
1070                                 value = cfg->setup(cfg, ctrl);
1071                         }
1072                 }
1073
1074                 goto done;
1075         }
1076
1077         /* respond with data transfer before status phase? */
1078         if (value >= 0) {
1079                 req->length = value;
1080                 req->zero = value < w_length;
1081                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
1082                 if (value < 0) {
1083                         DBG(cdev, "ep_queue --> %d\n", value);
1084                         req->status = 0;
1085                         composite_setup_complete(gadget->ep0, req);
1086                 }
1087         }
1088
1089 done:
1090         /* device either stalls (value < 0) or reports success */
1091         return value;
1092 }
1093
1094 static void composite_disconnect(struct usb_gadget *gadget)
1095 {
1096         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1097         unsigned long                   flags;
1098
1099         /* REVISIT:  should we have config and device level
1100          * disconnect callbacks?
1101          */
1102         spin_lock_irqsave(&cdev->lock, flags);
1103         if (cdev->config)
1104                 reset_config(cdev);
1105
1106         if (composite->disconnect)
1107                 composite->disconnect(cdev);
1108
1109         cdev->connected = 0;
1110         schedule_work(&cdev->switch_work);
1111         spin_unlock_irqrestore(&cdev->lock, flags);
1112 }
1113
1114 /*-------------------------------------------------------------------------*/
1115
1116 static ssize_t composite_show_suspended(struct device *dev,
1117                                         struct device_attribute *attr,
1118                                         char *buf)
1119 {
1120         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1121         struct usb_composite_dev *cdev = get_gadget_data(gadget);
1122
1123         return sprintf(buf, "%d\n", cdev->suspended);
1124 }
1125
1126 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1127
1128 static void
1129 composite_unbind(struct usb_gadget *gadget)
1130 {
1131         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1132
1133         /* composite_disconnect() must already have been called
1134          * by the underlying peripheral controller driver!
1135          * so there's no i/o concurrency that could affect the
1136          * state protected by cdev->lock.
1137          */
1138         WARN_ON(cdev->config);
1139
1140         while (!list_empty(&cdev->configs)) {
1141                 struct usb_configuration        *c;
1142
1143                 c = list_first_entry(&cdev->configs,
1144                                 struct usb_configuration, list);
1145                 while (!list_empty(&c->functions)) {
1146                         struct usb_function             *f;
1147
1148                         f = list_first_entry(&c->functions,
1149                                         struct usb_function, list);
1150                         list_del(&f->list);
1151                         if (f->unbind) {
1152                                 DBG(cdev, "unbind function '%s'/%p\n",
1153                                                 f->name, f);
1154                                 f->unbind(c, f);
1155                                 /* may free memory for "f" */
1156                         }
1157                 }
1158                 list_del(&c->list);
1159                 if (c->unbind) {
1160                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
1161                         c->unbind(c);
1162                         /* may free memory for "c" */
1163                 }
1164         }
1165         if (composite->unbind)
1166                 composite->unbind(cdev);
1167
1168         if (cdev->req) {
1169                 kfree(cdev->req->buf);
1170                 usb_ep_free_request(gadget->ep0, cdev->req);
1171         }
1172
1173         switch_dev_unregister(&cdev->sw_connected);
1174         switch_dev_unregister(&cdev->sw_config);
1175         kfree(cdev);
1176         set_gadget_data(gadget, NULL);
1177         device_remove_file(&gadget->dev, &dev_attr_suspended);
1178         composite = NULL;
1179 }
1180
1181 static void
1182 string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
1183 {
1184         struct usb_string               *str = tab->strings;
1185
1186         for (str = tab->strings; str->s; str++) {
1187                 if (str->id == id) {
1188                         str->s = s;
1189                         return;
1190                 }
1191         }
1192 }
1193
1194 static void
1195 string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
1196 {
1197         while (*tab) {
1198                 string_override_one(*tab, id, s);
1199                 tab++;
1200         }
1201 }
1202
1203 static void
1204 composite_switch_work(struct work_struct *data)
1205 {
1206         struct usb_composite_dev        *cdev =
1207                 container_of(data, struct usb_composite_dev, switch_work);
1208         struct usb_configuration *config = cdev->config;
1209         int connected;
1210         unsigned long flags;
1211
1212         spin_lock_irqsave(&cdev->lock, flags);
1213         if (cdev->connected != cdev->sw_connected.state) {
1214                 connected = cdev->connected;
1215                 spin_unlock_irqrestore(&cdev->lock, flags);
1216                 switch_set_state(&cdev->sw_connected, connected);
1217         } else {
1218                 spin_unlock_irqrestore(&cdev->lock, flags);
1219         }
1220
1221         if (config)
1222                 switch_set_state(&cdev->sw_config, config->bConfigurationValue);
1223         else
1224                 switch_set_state(&cdev->sw_config, 0);
1225 }
1226
1227 static int composite_bind(struct usb_gadget *gadget)
1228 {
1229         struct usb_composite_dev        *cdev;
1230         int                             status = -ENOMEM;
1231
1232         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1233         if (!cdev)
1234                 return status;
1235
1236         spin_lock_init(&cdev->lock);
1237         cdev->gadget = gadget;
1238         set_gadget_data(gadget, cdev);
1239         INIT_LIST_HEAD(&cdev->configs);
1240
1241         /* preallocate control response and buffer */
1242         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1243         if (!cdev->req)
1244                 goto fail;
1245         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
1246         if (!cdev->req->buf)
1247                 goto fail;
1248         cdev->req->complete = composite_setup_complete;
1249         gadget->ep0->driver_data = cdev;
1250
1251         cdev->bufsiz = USB_BUFSIZ;
1252         cdev->driver = composite;
1253
1254         usb_gadget_set_selfpowered(gadget);
1255
1256         /* interface and string IDs start at zero via kzalloc.
1257          * we force endpoints to start unassigned; few controller
1258          * drivers will zero ep->driver_data.
1259          */
1260         usb_ep_autoconfig_reset(cdev->gadget);
1261
1262         /* composite gadget needs to assign strings for whole device (like
1263          * serial number), register function drivers, potentially update
1264          * power state and consumption, etc
1265          */
1266         status = composite->bind(cdev);
1267         if (status < 0)
1268                 goto fail;
1269
1270         cdev->sw_connected.name = "usb_connected";
1271         status = switch_dev_register(&cdev->sw_connected);
1272         if (status < 0)
1273                 goto fail;
1274         cdev->sw_config.name = "usb_configuration";
1275         status = switch_dev_register(&cdev->sw_config);
1276         if (status < 0)
1277                 goto fail;
1278         INIT_WORK(&cdev->switch_work, composite_switch_work);
1279
1280         cdev->desc = *composite->dev;
1281         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
1282
1283         /* standardized runtime overrides for device ID data */
1284         if (idVendor)
1285                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1286         if (idProduct)
1287                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1288         if (bcdDevice)
1289                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1290
1291         /* strings can't be assigned before bind() allocates the
1292          * releavnt identifiers
1293          */
1294         if (cdev->desc.iManufacturer && iManufacturer)
1295                 string_override(composite->strings,
1296                         cdev->desc.iManufacturer, iManufacturer);
1297         if (cdev->desc.iProduct && iProduct)
1298                 string_override(composite->strings,
1299                         cdev->desc.iProduct, iProduct);
1300         if (cdev->desc.iSerialNumber && iSerialNumber)
1301                 string_override(composite->strings,
1302                         cdev->desc.iSerialNumber, iSerialNumber);
1303
1304         status = device_create_file(&gadget->dev, &dev_attr_suspended);
1305         if (status)
1306                 goto fail;
1307
1308         INFO(cdev, "%s ready\n", composite->name);
1309         return 0;
1310
1311 fail:
1312         composite_unbind(gadget);
1313         return status;
1314 }
1315
1316 /*-------------------------------------------------------------------------*/
1317
1318 static void
1319 composite_suspend(struct usb_gadget *gadget)
1320 {
1321         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1322         struct usb_function             *f;
1323
1324         /* REVISIT:  should we have config level
1325          * suspend/resume callbacks?
1326          */
1327         DBG(cdev, "suspend\n");
1328         if (cdev->config) {
1329                 list_for_each_entry(f, &cdev->config->functions, list) {
1330                         if (f->suspend)
1331                                 f->suspend(f);
1332                 }
1333         }
1334         if (composite->suspend)
1335                 composite->suspend(cdev);
1336
1337         cdev->suspended = 1;
1338 }
1339
1340 static void
1341 composite_resume(struct usb_gadget *gadget)
1342 {
1343         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1344         struct usb_function             *f;
1345
1346         /* REVISIT:  should we have config level
1347          * suspend/resume callbacks?
1348          */
1349         DBG(cdev, "resume\n");
1350         if (composite->resume)
1351                 composite->resume(cdev);
1352         if (cdev->config) {
1353                 list_for_each_entry(f, &cdev->config->functions, list) {
1354                         if (f->resume)
1355                                 f->resume(f);
1356                 }
1357         }
1358
1359         cdev->suspended = 0;
1360 }
1361
1362 static int
1363 composite_uevent(struct device *dev, struct kobj_uevent_env *env)
1364 {
1365         struct usb_function *f = dev_get_drvdata(dev);
1366
1367         if (!f) {
1368                 /* this happens when the device is first created */
1369                 return 0;
1370         }
1371
1372         if (add_uevent_var(env, "FUNCTION=%s", f->name))
1373                 return -ENOMEM;
1374         if (add_uevent_var(env, "ENABLED=%d", !f->disabled))
1375                 return -ENOMEM;
1376         return 0;
1377 }
1378
1379 /*-------------------------------------------------------------------------*/
1380
1381 static struct usb_gadget_driver composite_driver = {
1382         .speed          = USB_SPEED_HIGH,
1383
1384         .bind           = composite_bind,
1385         .unbind         = composite_unbind,
1386
1387         .setup          = composite_setup,
1388         .disconnect     = composite_disconnect,
1389
1390         .suspend        = composite_suspend,
1391         .resume         = composite_resume,
1392
1393         .driver = {
1394                 .owner          = THIS_MODULE,
1395         },
1396 };
1397
1398 /**
1399  * usb_composite_register() - register a composite driver
1400  * @driver: the driver to register
1401  * Context: single threaded during gadget setup
1402  *
1403  * This function is used to register drivers using the composite driver
1404  * framework.  The return value is zero, or a negative errno value.
1405  * Those values normally come from the driver's @bind method, which does
1406  * all the work of setting up the driver to match the hardware.
1407  *
1408  * On successful return, the gadget is ready to respond to requests from
1409  * the host, unless one of its components invokes usb_gadget_disconnect()
1410  * while it was binding.  That would usually be done in order to wait for
1411  * some userspace participation.
1412  */
1413 int usb_composite_register(struct usb_composite_driver *driver)
1414 {
1415         if (!driver || !driver->dev || !driver->bind || composite)
1416                 return -EINVAL;
1417
1418         if (!driver->name)
1419                 driver->name = "composite";
1420         composite_driver.function =  (char *) driver->name;
1421         composite_driver.driver.name = driver->name;
1422         composite = driver;
1423
1424         driver->class = class_create(THIS_MODULE, "usb_composite");
1425         if (IS_ERR(driver->class))
1426                 return PTR_ERR(driver->class);
1427         driver->class->dev_uevent = composite_uevent;
1428
1429         return usb_gadget_register_driver(&composite_driver);
1430 }
1431
1432 /**
1433  * usb_composite_unregister() - unregister a composite driver
1434  * @driver: the driver to unregister
1435  *
1436  * This function is used to unregister drivers using the composite
1437  * driver framework.
1438  */
1439 void usb_composite_unregister(struct usb_composite_driver *driver)
1440 {
1441         if (composite != driver)
1442                 return;
1443         usb_gadget_unregister_driver(&composite_driver);
1444 }