git.oblomov.eu Git - linux-2.6/blob - 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      512
  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 /**
  75  * usb_add_function() - add a function to a configuration
  76  * @config: the configuration
  77  * @function: the function being added
  78  * Context: single threaded during gadget setup
  79  *
  80  * After initialization, each configuration must have one or more
  81  * functions added to it.  Adding a function involves calling its @bind()
  82  * method to allocate resources such as interface and string identifiers
  83  * and endpoints.
  84  *
  85  * This function returns the value of the function's bind(), which is
  86  * zero for success else a negative errno value.
  87  */
  88 int __init usb_add_function(struct usb_configuration *config,
  89                 struct usb_function *function)
  90 {
  91         int     value = -EINVAL;
  92
  93         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
  94                         function->name, function,
  95                         config->label, config);
  96
  97         if (!function->set_alt || !function->disable)
  98                 goto done;
  99
 100         function->config = config;
 101         list_add_tail(&function->list, &config->functions);
 102
 103         /* REVISIT *require* function->bind? */
 104         if (function->bind) {
 105                 value = function->bind(config, function);
 106                 if (value < 0) {
 107                         list_del(&function->list);
 108                         function->config = NULL;
 109                 }
 110         } else
 111                 value = 0;
 112
 113         /* We allow configurations that don't work at both speeds.
 114          * If we run into a lowspeed Linux system, treat it the same
 115          * as full speed ... it's the function drivers that will need
 116          * to avoid bulk and ISO transfers.
 117          */
 118         if (!config->fullspeed && function->descriptors)
 119                 config->fullspeed = true;
 120         if (!config->highspeed && function->hs_descriptors)
 121                 config->highspeed = true;
 122
 123 done:
 124         if (value)
 125                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 126                                 function->name, function, value);
 127         return value;
 128 }
 129
 130 /**
 131  * usb_function_deactivate - prevent function and gadget enumeration
 132  * @function: the function that isn't yet ready to respond
 133  *
 134  * Blocks response of the gadget driver to host enumeration by
 135  * preventing the data line pullup from being activated.  This is
 136  * normally called during @bind() processing to change from the
 137  * initial "ready to respond" state, or when a required resource
 138  * becomes available.
 139  *
 140  * For example, drivers that serve as a passthrough to a userspace
 141  * daemon can block enumeration unless that daemon (such as an OBEX,
 142  * MTP, or print server) is ready to handle host requests.
 143  *
 144  * Not all systems support software control of their USB peripheral
 145  * data pullups.
 146  *
 147  * Returns zero on success, else negative errno.
 148  */
 149 int usb_function_deactivate(struct usb_function *function)
 150 {
 151         struct usb_composite_dev        *cdev = function->config->cdev;
 152         unsigned long                   flags;
 153         int                             status = 0;
 154
 155         spin_lock_irqsave(&cdev->lock, flags);
 156
 157         if (cdev->deactivations == 0)
 158                 status = usb_gadget_disconnect(cdev->gadget);
 159         if (status == 0)
 160                 cdev->deactivations++;
 161
 162         spin_unlock_irqrestore(&cdev->lock, flags);
 163         return status;
 164 }
 165
 166 /**
 167  * usb_function_activate - allow function and gadget enumeration
 168  * @function: function on which usb_function_activate() was called
 169  *
 170  * Reverses effect of usb_function_deactivate().  If no more functions
 171  * are delaying their activation, the gadget driver will respond to
 172  * host enumeration procedures.
 173  *
 174  * Returns zero on success, else negative errno.
 175  */
 176 int usb_function_activate(struct usb_function *function)
 177 {
 178         struct usb_composite_dev        *cdev = function->config->cdev;
 179         int                             status = 0;
 180
 181         spin_lock(&cdev->lock);
 182
 183         if (WARN_ON(cdev->deactivations == 0))
 184                 status = -EINVAL;
 185         else {
 186                 cdev->deactivations--;
 187                 if (cdev->deactivations == 0)
 188                         status = usb_gadget_connect(cdev->gadget);
 189         }
 190
 191         spin_unlock(&cdev->lock);
 192         return status;
 193 }
 194
 195 /**
 196  * usb_interface_id() - allocate an unused interface ID
 197  * @config: configuration associated with the interface
 198  * @function: function handling the interface
 199  * Context: single threaded during gadget setup
 200  *
 201  * usb_interface_id() is called from usb_function.bind() callbacks to
 202  * allocate new interface IDs.  The function driver will then store that
 203  * ID in interface, association, CDC union, and other descriptors.  It
 204  * will also handle any control requests targetted at that interface,
 205  * particularly changing its altsetting via set_alt().  There may
 206  * also be class-specific or vendor-specific requests to handle.
 207  *
 208  * All interface identifier should be allocated using this routine, to
 209  * ensure that for example different functions don't wrongly assign
 210  * different meanings to the same identifier.  Note that since interface
 211  * identifers are configuration-specific, functions used in more than
 212  * one configuration (or more than once in a given configuration) need
 213  * multiple versions of the relevant descriptors.
 214  *
 215  * Returns the interface ID which was allocated; or -ENODEV if no
 216  * more interface IDs can be allocated.
 217  */
 218 int __init usb_interface_id(struct usb_configuration *config,
 219                 struct usb_function *function)
 220 {
 221         unsigned id = config->next_interface_id;
 222
 223         if (id < MAX_CONFIG_INTERFACES) {
 224                 config->interface[id] = function;
 225                 config->next_interface_id = id + 1;
 226                 return id;
 227         }
 228         return -ENODEV;
 229 }
 230
 231 static int config_buf(struct usb_configuration *config,
 232                 enum usb_device_speed speed, void *buf, u8 type)
 233 {
 234         struct usb_config_descriptor    *c = buf;
 235         void                            *next = buf + USB_DT_CONFIG_SIZE;
 236         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 237         struct usb_function             *f;
 238         int                             status;
 239
 240         /* write the config descriptor */
 241         c = buf;
 242         c->bLength = USB_DT_CONFIG_SIZE;
 243         c->bDescriptorType = type;
 244         /* wTotalLength is written later */
 245         c->bNumInterfaces = config->next_interface_id;
 246         c->bConfigurationValue = config->bConfigurationValue;
 247         c->iConfiguration = config->iConfiguration;
 248         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 249         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 250
 251         /* There may be e.g. OTG descriptors */
 252         if (config->descriptors) {
 253                 status = usb_descriptor_fillbuf(next, len,
 254                                 config->descriptors);
 255                 if (status < 0)
 256                         return status;
 257                 len -= status;
 258                 next += status;
 259         }
 260
 261         /* add each function's descriptors */
 262         list_for_each_entry(f, &config->functions, list) {
 263                 struct usb_descriptor_header **descriptors;
 264
 265                 if (speed == USB_SPEED_HIGH)
 266                         descriptors = f->hs_descriptors;
 267                 else
 268                         descriptors = f->descriptors;
 269                 if (!descriptors)
 270                         continue;
 271                 status = usb_descriptor_fillbuf(next, len,
 272                         (const struct usb_descriptor_header **) descriptors);
 273                 if (status < 0)
 274                         return status;
 275                 len -= status;
 276                 next += status;
 277         }
 278
 279         len = next - buf;
 280         c->wTotalLength = cpu_to_le16(len);
 281         return len;
 282 }
 283
 284 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 285 {
 286         struct usb_gadget               *gadget = cdev->gadget;
 287         struct usb_configuration        *c;
 288         u8                              type = w_value >> 8;
 289         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 290
 291         if (gadget_is_dualspeed(gadget)) {
 292                 int                     hs = 0;
 293
 294                 if (gadget->speed == USB_SPEED_HIGH)
 295                         hs = 1;
 296                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 297                         hs = !hs;
 298                 if (hs)
 299                         speed = USB_SPEED_HIGH;
 300
 301         }
 302
 303         /* This is a lookup by config *INDEX* */
 304         w_value &= 0xff;
 305         list_for_each_entry(c, &cdev->configs, list) {
 306                 /* ignore configs that won't work at this speed */
 307                 if (speed == USB_SPEED_HIGH) {
 308                         if (!c->highspeed)
 309                                 continue;
 310                 } else {
 311                         if (!c->fullspeed)
 312                                 continue;
 313                 }
 314                 if (w_value == 0)
 315                         return config_buf(c, speed, cdev->req->buf, type);
 316                 w_value--;
 317         }
 318         return -EINVAL;
 319 }
 320
 321 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 322 {
 323         struct usb_gadget               *gadget = cdev->gadget;
 324         struct usb_configuration        *c;
 325         unsigned                        count = 0;
 326         int                             hs = 0;
 327
 328         if (gadget_is_dualspeed(gadget)) {
 329                 if (gadget->speed == USB_SPEED_HIGH)
 330                         hs = 1;
 331                 if (type == USB_DT_DEVICE_QUALIFIER)
 332                         hs = !hs;
 333         }
 334         list_for_each_entry(c, &cdev->configs, list) {
 335                 /* ignore configs that won't work at this speed */
 336                 if (hs) {
 337                         if (!c->highspeed)
 338                                 continue;
 339                 } else {
 340                         if (!c->fullspeed)
 341                                 continue;
 342                 }
 343                 count++;
 344         }
 345         return count;
 346 }
 347
 348 static void device_qual(struct usb_composite_dev *cdev)
 349 {
 350         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 351
 352         qual->bLength = sizeof(*qual);
 353         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 354         /* POLICY: same bcdUSB and device type info at both speeds */
 355         qual->bcdUSB = cdev->desc.bcdUSB;
 356         qual->bDeviceClass = cdev->desc.bDeviceClass;
 357         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 358         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 359         /* ASSUME same EP0 fifo size at both speeds */
 360         qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
 361         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 362         qual->bRESERVED = 0;
 363 }
 364
 365 /*-------------------------------------------------------------------------*/
 366
 367 static void reset_config(struct usb_composite_dev *cdev)
 368 {
 369         struct usb_function             *f;
 370
 371         DBG(cdev, "reset config\n");
 372
 373         list_for_each_entry(f, &cdev->config->functions, list) {
 374                 if (f->disable)
 375                         f->disable(f);
 376         }
 377         cdev->config = NULL;
 378 }
 379
 380 static int set_config(struct usb_composite_dev *cdev,
 381                 const struct usb_ctrlrequest *ctrl, unsigned number)
 382 {
 383         struct usb_gadget       *gadget = cdev->gadget;
 384         struct usb_configuration *c = NULL;
 385         int                     result = -EINVAL;
 386         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 387         int                     tmp;
 388
 389         if (cdev->config)
 390                 reset_config(cdev);
 391
 392         if (number) {
 393                 list_for_each_entry(c, &cdev->configs, list) {
 394                         if (c->bConfigurationValue == number) {
 395                                 result = 0;
 396                                 break;
 397                         }
 398                 }
 399                 if (result < 0)
 400                         goto done;
 401         } else
 402                 result = 0;
 403
 404         INFO(cdev, "%s speed config #%d: %s\n",
 405                 ({ char *speed;
 406                 switch (gadget->speed) {
 407                 case USB_SPEED_LOW:     speed = "low"; break;
 408                 case USB_SPEED_FULL:    speed = "full"; break;
 409                 case USB_SPEED_HIGH:    speed = "high"; break;
 410                 default:                speed = "?"; break;
 411                 } ; speed; }), number, c ? c->label : "unconfigured");
 412
 413         if (!c)
 414                 goto done;
 415
 416         cdev->config = c;
 417
 418         /* Initialize all interfaces by setting them to altsetting zero. */
 419         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 420                 struct usb_function     *f = c->interface[tmp];
 421
 422                 if (!f)
 423                         break;
 424
 425                 result = f->set_alt(f, tmp, 0);
 426                 if (result < 0) {
 427                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 428                                         tmp, f->name, f, result);
 429
 430                         reset_config(cdev);
 431                         goto done;
 432                 }
 433         }
 434
 435         /* when we return, be sure our power usage is valid */
 436         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 437 done:
 438         usb_gadget_vbus_draw(gadget, power);
 439         return result;
 440 }
 441
 442 /**
 443  * usb_add_config() - add a configuration to a device.
 444  * @cdev: wraps the USB gadget
 445  * @config: the configuration, with bConfigurationValue assigned
 446  * Context: single threaded during gadget setup
 447  *
 448  * One of the main tasks of a composite driver's bind() routine is to
 449  * add each of the configurations it supports, using this routine.
 450  *
 451  * This function returns the value of the configuration's bind(), which
 452  * is zero for success else a negative errno value.  Binding configurations
 453  * assigns global resources including string IDs, and per-configuration
 454  * resources such as interface IDs and endpoints.
 455  */
 456 int __init usb_add_config(struct usb_composite_dev *cdev,
 457                 struct usb_configuration *config)
 458 {
 459         int                             status = -EINVAL;
 460         struct usb_configuration        *c;
 461
 462         DBG(cdev, "adding config #%u '%s'/%p\n",
 463                         config->bConfigurationValue,
 464                         config->label, config);
 465
 466         if (!config->bConfigurationValue || !config->bind)
 467                 goto done;
 468
 469         /* Prevent duplicate configuration identifiers */
 470         list_for_each_entry(c, &cdev->configs, list) {
 471                 if (c->bConfigurationValue == config->bConfigurationValue) {
 472                         status = -EBUSY;
 473                         goto done;
 474                 }
 475         }
 476
 477         config->cdev = cdev;
 478         list_add_tail(&config->list, &cdev->configs);
 479
 480         INIT_LIST_HEAD(&config->functions);
 481         config->next_interface_id = 0;
 482
 483         status = config->bind(config);
 484         if (status < 0) {
 485                 list_del(&config->list);
 486                 config->cdev = NULL;
 487         } else {
 488                 unsigned        i;
 489
 490                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
 491                         config->bConfigurationValue, config,
 492                         config->highspeed ? " high" : "",
 493                         config->fullspeed
 494                                 ? (gadget_is_dualspeed(cdev->gadget)
 495                                         ? " full"
 496                                         : " full/low")
 497                                 : "");
 498
 499                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 500                         struct usb_function     *f = config->interface[i];
 501
 502                         if (!f)
 503                                 continue;
 504                         DBG(cdev, "  interface %d = %s/%p\n",
 505                                 i, f->name, f);
 506                 }
 507         }
 508
 509         /* set_alt(), or next config->bind(), sets up
 510          * ep->driver_data as needed.
 511          */
 512         usb_ep_autoconfig_reset(cdev->gadget);
 513
 514 done:
 515         if (status)
 516                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 517                                 config->bConfigurationValue, status);
 518         return status;
 519 }
 520
 521 /*-------------------------------------------------------------------------*/
 522
 523 /* We support strings in multiple languages ... string descriptor zero
 524  * says which languages are supported.  The typical case will be that
 525  * only one language (probably English) is used, with I18N handled on
 526  * the host side.
 527  */
 528
 529 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 530 {
 531         const struct usb_gadget_strings *s;
 532         u16                             language;
 533         __le16                          *tmp;
 534
 535         while (*sp) {
 536                 s = *sp;
 537                 language = cpu_to_le16(s->language);
 538                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 539                         if (*tmp == language)
 540                                 goto repeat;
 541                 }
 542                 *tmp++ = language;
 543 repeat:
 544                 sp++;
 545         }
 546 }
 547
 548 static int lookup_string(
 549         struct usb_gadget_strings       **sp,
 550         void                            *buf,
 551         u16                             language,
 552         int                             id
 553 )
 554 {
 555         struct usb_gadget_strings       *s;
 556         int                             value;
 557
 558         while (*sp) {
 559                 s = *sp++;
 560                 if (s->language != language)
 561                         continue;
 562                 value = usb_gadget_get_string(s, id, buf);
 563                 if (value > 0)
 564                         return value;
 565         }
 566         return -EINVAL;
 567 }
 568
 569 static int get_string(struct usb_composite_dev *cdev,
 570                 void *buf, u16 language, int id)
 571 {
 572         struct usb_configuration        *c;
 573         struct usb_function             *f;
 574         int                             len;
 575
 576         /* Yes, not only is USB's I18N support probably more than most
 577          * folk will ever care about ... also, it's all supported here.
 578          * (Except for UTF8 support for Unicode's "Astral Planes".)
 579          */
 580
 581         /* 0 == report all available language codes */
 582         if (id == 0) {
 583                 struct usb_string_descriptor    *s = buf;
 584                 struct usb_gadget_strings       **sp;
 585
 586                 memset(s, 0, 256);
 587                 s->bDescriptorType = USB_DT_STRING;
 588
 589                 sp = composite->strings;
 590                 if (sp)
 591                         collect_langs(sp, s->wData);
 592
 593                 list_for_each_entry(c, &cdev->configs, list) {
 594                         sp = c->strings;
 595                         if (sp)
 596                                 collect_langs(sp, s->wData);
 597
 598                         list_for_each_entry(f, &c->functions, list) {
 599                                 sp = f->strings;
 600                                 if (sp)
 601                                         collect_langs(sp, s->wData);
 602                         }
 603                 }
 604
 605                 for (len = 0; s->wData[len] && len <= 126; len++)
 606                         continue;
 607                 if (!len)
 608                         return -EINVAL;
 609
 610                 s->bLength = 2 * (len + 1);
 611                 return s->bLength;
 612         }
 613
 614         /* Otherwise, look up and return a specified string.  String IDs
 615          * are device-scoped, so we look up each string table we're told
 616          * about.  These lookups are infrequent; simpler-is-better here.
 617          */
 618         if (composite->strings) {
 619                 len = lookup_string(composite->strings, buf, language, id);
 620                 if (len > 0)
 621                         return len;
 622         }
 623         list_for_each_entry(c, &cdev->configs, list) {
 624                 if (c->strings) {
 625                         len = lookup_string(c->strings, buf, language, id);
 626                         if (len > 0)
 627                                 return len;
 628                 }
 629                 list_for_each_entry(f, &c->functions, list) {
 630                         if (!f->strings)
 631                                 continue;
 632                         len = lookup_string(f->strings, buf, language, id);
 633                         if (len > 0)
 634                                 return len;
 635                 }
 636         }
 637         return -EINVAL;
 638 }
 639
 640 /**
 641  * usb_string_id() - allocate an unused string ID
 642  * @cdev: the device whose string descriptor IDs are being allocated
 643  * Context: single threaded during gadget setup
 644  *
 645  * @usb_string_id() is called from bind() callbacks to allocate
 646  * string IDs.  Drivers for functions, configurations, or gadgets will
 647  * then store that ID in the appropriate descriptors and string table.
 648  *
 649  * All string identifier should be allocated using this routine, to
 650  * ensure that for example different functions don't wrongly assign
 651  * different meanings to the same identifier.
 652  */
 653 int __init usb_string_id(struct usb_composite_dev *cdev)
 654 {
 655         if (cdev->next_string_id < 254) {
 656                 /* string id 0 is reserved */
 657                 cdev->next_string_id++;
 658                 return cdev->next_string_id;
 659         }
 660         return -ENODEV;
 661 }
 662
 663 /*-------------------------------------------------------------------------*/
 664
 665 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 666 {
 667         if (req->status || req->actual != req->length)
 668                 DBG((struct usb_composite_dev *) ep->driver_data,
 669                                 "setup complete --> %d, %d/%d\n",
 670                                 req->status, req->actual, req->length);
 671 }
 672
 673 /*
 674  * The setup() callback implements all the ep0 functionality that's
 675  * not handled lower down, in hardware or the hardware driver(like
 676  * device and endpoint feature flags, and their status).  It's all
 677  * housekeeping for the gadget function we're implementing.  Most of
 678  * the work is in config and function specific setup.
 679  */
 680 static int
 681 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 682 {
 683         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 684         struct usb_request              *req = cdev->req;
 685         int                             value = -EOPNOTSUPP;
 686         u16                             w_index = le16_to_cpu(ctrl->wIndex);
 687         u8                              intf = w_index & 0xFF;
 688         u16                             w_value = le16_to_cpu(ctrl->wValue);
 689         u16                             w_length = le16_to_cpu(ctrl->wLength);
 690         struct usb_function             *f = NULL;
 691
 692         /* partial re-init of the response message; the function or the
 693          * gadget might need to intercept e.g. a control-OUT completion
 694          * when we delegate to it.
 695          */
 696         req->zero = 0;
 697         req->complete = composite_setup_complete;
 698         req->length = USB_BUFSIZ;
 699         gadget->ep0->driver_data = cdev;
 700
 701         switch (ctrl->bRequest) {
 702
 703         /* we handle all standard USB descriptors */
 704         case USB_REQ_GET_DESCRIPTOR:
 705                 if (ctrl->bRequestType != USB_DIR_IN)
 706                         goto unknown;
 707                 switch (w_value >> 8) {
 708
 709                 case USB_DT_DEVICE:
 710                         cdev->desc.bNumConfigurations =
 711                                 count_configs(cdev, USB_DT_DEVICE);
 712                         value = min(w_length, (u16) sizeof cdev->desc);
 713                         memcpy(req->buf, &cdev->desc, value);
 714                         break;
 715                 case USB_DT_DEVICE_QUALIFIER:
 716                         if (!gadget_is_dualspeed(gadget))
 717                                 break;
 718                         device_qual(cdev);
 719                         value = min_t(int, w_length,
 720                                 sizeof(struct usb_qualifier_descriptor));
 721                         break;
 722                 case USB_DT_OTHER_SPEED_CONFIG:
 723                         if (!gadget_is_dualspeed(gadget))
 724                                 break;
 725                         /* FALLTHROUGH */
 726                 case USB_DT_CONFIG:
 727                         value = config_desc(cdev, w_value);
 728                         if (value >= 0)
 729                                 value = min(w_length, (u16) value);
 730                         break;
 731                 case USB_DT_STRING:
 732                         value = get_string(cdev, req->buf,
 733                                         w_index, w_value & 0xff);
 734                         if (value >= 0)
 735                                 value = min(w_length, (u16) value);
 736                         break;
 737                 }
 738                 break;
 739
 740         /* any number of configs can work */
 741         case USB_REQ_SET_CONFIGURATION:
 742                 if (ctrl->bRequestType != 0)
 743                         goto unknown;
 744                 if (gadget_is_otg(gadget)) {
 745                         if (gadget->a_hnp_support)
 746                                 DBG(cdev, "HNP available\n");
 747                         else if (gadget->a_alt_hnp_support)
 748                                 DBG(cdev, "HNP on another port\n");
 749                         else
 750                                 VDBG(cdev, "HNP inactive\n");
 751                 }
 752                 spin_lock(&cdev->lock);
 753                 value = set_config(cdev, ctrl, w_value);
 754                 spin_unlock(&cdev->lock);
 755                 break;
 756         case USB_REQ_GET_CONFIGURATION:
 757                 if (ctrl->bRequestType != USB_DIR_IN)
 758                         goto unknown;
 759                 if (cdev->config)
 760                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
 761                 else
 762                         *(u8 *)req->buf = 0;
 763                 value = min(w_length, (u16) 1);
 764                 break;
 765
 766         /* function drivers must handle get/set altsetting; if there's
 767          * no get() method, we know only altsetting zero works.
 768          */
 769         case USB_REQ_SET_INTERFACE:
 770                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
 771                         goto unknown;
 772                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
 773                         break;
 774                 f = cdev->config->interface[intf];
 775                 if (!f)
 776                         break;
 777                 if (w_value && !f->set_alt)
 778                         break;
 779                 value = f->set_alt(f, w_index, w_value);
 780                 break;
 781         case USB_REQ_GET_INTERFACE:
 782                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
 783                         goto unknown;
 784                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
 785                         break;
 786                 f = cdev->config->interface[intf];
 787                 if (!f)
 788                         break;
 789                 /* lots of interfaces only need altsetting zero... */
 790                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
 791                 if (value < 0)
 792                         break;
 793                 *((u8 *)req->buf) = value;
 794                 value = min(w_length, (u16) 1);
 795                 break;
 796         default:
 797 unknown:
 798                 VDBG(cdev,
 799                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
 800                         ctrl->bRequestType, ctrl->bRequest,
 801                         w_value, w_index, w_length);
 802
 803                 /* functions always handle their interfaces ... punt other
 804                  * recipients (endpoint, other, WUSB, ...) to the current
 805                  * configuration code.
 806                  *
 807                  * REVISIT it could make sense to let the composite device
 808                  * take such requests too, if that's ever needed:  to work
 809                  * in config 0, etc.
 810                  */
 811                 if ((ctrl->bRequestType & USB_RECIP_MASK)
 812                                 == USB_RECIP_INTERFACE) {
 813                         f = cdev->config->interface[intf];
 814                         if (f && f->setup)
 815                                 value = f->setup(f, ctrl);
 816                         else
 817                                 f = NULL;
 818                 }
 819                 if (value < 0 && !f) {
 820                         struct usb_configuration        *c;
 821
 822                         c = cdev->config;
 823                         if (c && c->setup)
 824                                 value = c->setup(c, ctrl);
 825                 }
 826
 827                 goto done;
 828         }
 829
 830         /* respond with data transfer before status phase? */
 831         if (value >= 0) {
 832                 req->length = value;
 833                 req->zero = value < w_length;
 834                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
 835                 if (value < 0) {
 836                         DBG(cdev, "ep_queue --> %d\n", value);
 837                         req->status = 0;
 838                         composite_setup_complete(gadget->ep0, req);
 839                 }
 840         }
 841
 842 done:
 843         /* device either stalls (value < 0) or reports success */
 844         return value;
 845 }
 846
 847 static void composite_disconnect(struct usb_gadget *gadget)
 848 {
 849         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 850         unsigned long                   flags;
 851
 852         /* REVISIT:  should we have config and device level
 853          * disconnect callbacks?
 854          */
 855         spin_lock_irqsave(&cdev->lock, flags);
 856         if (cdev->config)
 857                 reset_config(cdev);
 858         spin_unlock_irqrestore(&cdev->lock, flags);
 859 }
 860
 861 /*-------------------------------------------------------------------------*/
 862
 863 static void /* __init_or_exit */
 864 composite_unbind(struct usb_gadget *gadget)
 865 {
 866         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 867
 868         /* composite_disconnect() must already have been called
 869          * by the underlying peripheral controller driver!
 870          * so there's no i/o concurrency that could affect the
 871          * state protected by cdev->lock.
 872          */
 873         WARN_ON(cdev->config);
 874
 875         while (!list_empty(&cdev->configs)) {
 876                 struct usb_configuration        *c;
 877
 878                 c = list_first_entry(&cdev->configs,
 879                                 struct usb_configuration, list);
 880                 while (!list_empty(&c->functions)) {
 881                         struct usb_function             *f;
 882
 883                         f = list_first_entry(&c->functions,
 884                                         struct usb_function, list);
 885                         list_del(&f->list);
 886                         if (f->unbind) {
 887                                 DBG(cdev, "unbind function '%s'/%p\n",
 888                                                 f->name, f);
 889                                 f->unbind(c, f);
 890                                 /* may free memory for "f" */
 891                         }
 892                 }
 893                 list_del(&c->list);
 894                 if (c->unbind) {
 895                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
 896                         c->unbind(c);
 897                         /* may free memory for "c" */
 898                 }
 899         }
 900         if (composite->unbind)
 901                 composite->unbind(cdev);
 902
 903         if (cdev->req) {
 904                 kfree(cdev->req->buf);
 905                 usb_ep_free_request(gadget->ep0, cdev->req);
 906         }
 907         kfree(cdev);
 908         set_gadget_data(gadget, NULL);
 909         composite = NULL;
 910 }
 911
 912 static void __init
 913 string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
 914 {
 915         struct usb_string               *str = tab->strings;
 916
 917         for (str = tab->strings; str->s; str++) {
 918                 if (str->id == id) {
 919                         str->s = s;
 920                         return;
 921                 }
 922         }
 923 }
 924
 925 static void __init
 926 string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
 927 {
 928         while (*tab) {
 929                 string_override_one(*tab, id, s);
 930                 tab++;
 931         }
 932 }
 933
 934 static int __init composite_bind(struct usb_gadget *gadget)
 935 {
 936         struct usb_composite_dev        *cdev;
 937         int                             status = -ENOMEM;
 938
 939         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
 940         if (!cdev)
 941                 return status;
 942
 943         spin_lock_init(&cdev->lock);
 944         cdev->gadget = gadget;
 945         set_gadget_data(gadget, cdev);
 946         INIT_LIST_HEAD(&cdev->configs);
 947
 948         /* preallocate control response and buffer */
 949         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
 950         if (!cdev->req)
 951                 goto fail;
 952         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
 953         if (!cdev->req->buf)
 954                 goto fail;
 955         cdev->req->complete = composite_setup_complete;
 956         gadget->ep0->driver_data = cdev;
 957
 958         cdev->bufsiz = USB_BUFSIZ;
 959         cdev->driver = composite;
 960
 961         usb_gadget_set_selfpowered(gadget);
 962
 963         /* interface and string IDs start at zero via kzalloc.
 964          * we force endpoints to start unassigned; few controller
 965          * drivers will zero ep->driver_data.
 966          */
 967         usb_ep_autoconfig_reset(cdev->gadget);
 968
 969         /* composite gadget needs to assign strings for whole device (like
 970          * serial number), register function drivers, potentially update
 971          * power state and consumption, etc
 972          */
 973         status = composite->bind(cdev);
 974         if (status < 0)
 975                 goto fail;
 976
 977         cdev->desc = *composite->dev;
 978         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
 979
 980         /* standardized runtime overrides for device ID data */
 981         if (idVendor)
 982                 cdev->desc.idVendor = cpu_to_le16(idVendor);
 983         if (idProduct)
 984                 cdev->desc.idProduct = cpu_to_le16(idProduct);
 985         if (bcdDevice)
 986                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
 987
 988         /* strings can't be assigned before bind() allocates the
 989          * releavnt identifiers
 990          */
 991         if (cdev->desc.iManufacturer && iManufacturer)
 992                 string_override(composite->strings,
 993                         cdev->desc.iManufacturer, iManufacturer);
 994         if (cdev->desc.iProduct && iProduct)
 995                 string_override(composite->strings,
 996                         cdev->desc.iProduct, iProduct);
 997         if (cdev->desc.iSerialNumber && iSerialNumber)
 998                 string_override(composite->strings,
 999                         cdev->desc.iSerialNumber, iSerialNumber);
1000
1001         INFO(cdev, "%s ready\n", composite->name);
1002         return 0;
1003
1004 fail:
1005         composite_unbind(gadget);
1006         return status;
1007 }
1008
1009 /*-------------------------------------------------------------------------*/
1010
1011 static void
1012 composite_suspend(struct usb_gadget *gadget)
1013 {
1014         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1015         struct usb_function             *f;
1016
1017         /* REVISIT:  should we have config level
1018          * suspend/resume callbacks?
1019          */
1020         DBG(cdev, "suspend\n");
1021         if (cdev->config) {
1022                 list_for_each_entry(f, &cdev->config->functions, list) {
1023                         if (f->suspend)
1024                                 f->suspend(f);
1025                 }
1026         }
1027         if (composite->suspend)
1028                 composite->suspend(cdev);
1029 }
1030
1031 static void
1032 composite_resume(struct usb_gadget *gadget)
1033 {
1034         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1035         struct usb_function             *f;
1036
1037         /* REVISIT:  should we have config level
1038          * suspend/resume callbacks?
1039          */
1040         DBG(cdev, "resume\n");
1041         if (composite->resume)
1042                 composite->resume(cdev);
1043         if (cdev->config) {
1044                 list_for_each_entry(f, &cdev->config->functions, list) {
1045                         if (f->resume)
1046                                 f->resume(f);
1047                 }
1048         }
1049 }
1050
1051 /*-------------------------------------------------------------------------*/
1052
1053 static struct usb_gadget_driver composite_driver = {
1054         .speed          = USB_SPEED_HIGH,
1055
1056         .bind           = composite_bind,
1057         .unbind         = __exit_p(composite_unbind),
1058
1059         .setup          = composite_setup,
1060         .disconnect     = composite_disconnect,
1061
1062         .suspend        = composite_suspend,
1063         .resume         = composite_resume,
1064
1065         .driver = {
1066                 .owner          = THIS_MODULE,
1067         },
1068 };
1069
1070 /**
1071  * usb_composite_register() - register a composite driver
1072  * @driver: the driver to register
1073  * Context: single threaded during gadget setup
1074  *
1075  * This function is used to register drivers using the composite driver
1076  * framework.  The return value is zero, or a negative errno value.
1077  * Those values normally come from the driver's @bind method, which does
1078  * all the work of setting up the driver to match the hardware.
1079  *
1080  * On successful return, the gadget is ready to respond to requests from
1081  * the host, unless one of its components invokes usb_gadget_disconnect()
1082  * while it was binding.  That would usually be done in order to wait for
1083  * some userspace participation.
1084  */
1085 int __init usb_composite_register(struct usb_composite_driver *driver)
1086 {
1087         if (!driver || !driver->dev || !driver->bind || composite)
1088                 return -EINVAL;
1089
1090         if (!driver->name)
1091                 driver->name = "composite";
1092         composite_driver.function =  (char *) driver->name;
1093         composite_driver.driver.name = driver->name;
1094         composite = driver;
1095
1096         return usb_gadget_register_driver(&composite_driver);
1097 }
1098
1099 /**
1100  * usb_composite_unregister() - unregister a composite driver
1101  * @driver: the driver to unregister
1102  *
1103  * This function is used to unregister drivers using the composite
1104  * driver framework.
1105  */
1106 void __exit usb_composite_unregister(struct usb_composite_driver *driver)
1107 {
1108         if (composite != driver)
1109                 return;
1110         usb_gadget_unregister_driver(&composite_driver);
1111 }