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