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                 bitmap_zero(f->endpoints, 32);
 378         }
 379         cdev->config = NULL;
 380 }
 381
 382 static int set_config(struct usb_composite_dev *cdev,
 383                 const struct usb_ctrlrequest *ctrl, unsigned number)
 384 {
 385         struct usb_gadget       *gadget = cdev->gadget;
 386         struct usb_configuration *c = NULL;
 387         int                     result = -EINVAL;
 388         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 389         int                     tmp;
 390
 391         if (cdev->config)
 392                 reset_config(cdev);
 393
 394         if (number) {
 395                 list_for_each_entry(c, &cdev->configs, list) {
 396                         if (c->bConfigurationValue == number) {
 397                                 result = 0;
 398                                 break;
 399                         }
 400                 }
 401                 if (result < 0)
 402                         goto done;
 403         } else
 404                 result = 0;
 405
 406         INFO(cdev, "%s speed config #%d: %s\n",
 407                 ({ char *speed;
 408                 switch (gadget->speed) {
 409                 case USB_SPEED_LOW:     speed = "low"; break;
 410                 case USB_SPEED_FULL:    speed = "full"; break;
 411                 case USB_SPEED_HIGH:    speed = "high"; break;
 412                 default:                speed = "?"; break;
 413                 } ; speed; }), number, c ? c->label : "unconfigured");
 414
 415         if (!c)
 416                 goto done;
 417
 418         cdev->config = c;
 419
 420         /* Initialize all interfaces by setting them to altsetting zero. */
 421         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 422                 struct usb_function     *f = c->interface[tmp];
 423                 struct usb_descriptor_header **descriptors;
 424
 425                 if (!f)
 426                         break;
 427
 428                 /*
 429                  * Record which endpoints are used by the function. This is used
 430                  * to dispatch control requests targeted at that endpoint to the
 431                  * function's setup callback instead of the current
 432                  * configuration's setup callback.
 433                  */
 434                 if (gadget->speed == USB_SPEED_HIGH)
 435                         descriptors = f->hs_descriptors;
 436                 else
 437                         descriptors = f->descriptors;
 438
 439                 for (; *descriptors; ++descriptors) {
 440                         struct usb_endpoint_descriptor *ep;
 441                         int addr;
 442
 443                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 444                                 continue;
 445
 446                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 447                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 448                              |  (ep->bEndpointAddress & 0x0f);
 449                         set_bit(addr, f->endpoints);
 450                 }
 451
 452                 result = f->set_alt(f, tmp, 0);
 453                 if (result < 0) {
 454                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 455                                         tmp, f->name, f, result);
 456
 457                         reset_config(cdev);
 458                         goto done;
 459                 }
 460         }
 461
 462         /* when we return, be sure our power usage is valid */
 463         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 464 done:
 465         usb_gadget_vbus_draw(gadget, power);
 466         return result;
 467 }
 468
 469 /**
 470  * usb_add_config() - add a configuration to a device.
 471  * @cdev: wraps the USB gadget
 472  * @config: the configuration, with bConfigurationValue assigned
 473  * Context: single threaded during gadget setup
 474  *
 475  * One of the main tasks of a composite driver's bind() routine is to
 476  * add each of the configurations it supports, using this routine.
 477  *
 478  * This function returns the value of the configuration's bind(), which
 479  * is zero for success else a negative errno value.  Binding configurations
 480  * assigns global resources including string IDs, and per-configuration
 481  * resources such as interface IDs and endpoints.
 482  */
 483 int __init usb_add_config(struct usb_composite_dev *cdev,
 484                 struct usb_configuration *config)
 485 {
 486         int                             status = -EINVAL;
 487         struct usb_configuration        *c;
 488
 489         DBG(cdev, "adding config #%u '%s'/%p\n",
 490                         config->bConfigurationValue,
 491                         config->label, config);
 492
 493         if (!config->bConfigurationValue || !config->bind)
 494                 goto done;
 495
 496         /* Prevent duplicate configuration identifiers */
 497         list_for_each_entry(c, &cdev->configs, list) {
 498                 if (c->bConfigurationValue == config->bConfigurationValue) {
 499                         status = -EBUSY;
 500                         goto done;
 501                 }
 502         }
 503
 504         config->cdev = cdev;
 505         list_add_tail(&config->list, &cdev->configs);
 506
 507         INIT_LIST_HEAD(&config->functions);
 508         config->next_interface_id = 0;
 509
 510         status = config->bind(config);
 511         if (status < 0) {
 512                 list_del(&config->list);
 513                 config->cdev = NULL;
 514         } else {
 515                 unsigned        i;
 516
 517                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
 518                         config->bConfigurationValue, config,
 519                         config->highspeed ? " high" : "",
 520                         config->fullspeed
 521                                 ? (gadget_is_dualspeed(cdev->gadget)
 522                                         ? " full"
 523                                         : " full/low")
 524                                 : "");
 525
 526                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 527                         struct usb_function     *f = config->interface[i];
 528
 529                         if (!f)
 530                                 continue;
 531                         DBG(cdev, "  interface %d = %s/%p\n",
 532                                 i, f->name, f);
 533                 }
 534         }
 535
 536         /* set_alt(), or next config->bind(), sets up
 537          * ep->driver_data as needed.
 538          */
 539         usb_ep_autoconfig_reset(cdev->gadget);
 540
 541 done:
 542         if (status)
 543                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 544                                 config->bConfigurationValue, status);
 545         return status;
 546 }
 547
 548 /*-------------------------------------------------------------------------*/
 549
 550 /* We support strings in multiple languages ... string descriptor zero
 551  * says which languages are supported.  The typical case will be that
 552  * only one language (probably English) is used, with I18N handled on
 553  * the host side.
 554  */
 555
 556 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 557 {
 558         const struct usb_gadget_strings *s;
 559         u16                             language;
 560         __le16                          *tmp;
 561
 562         while (*sp) {
 563                 s = *sp;
 564                 language = cpu_to_le16(s->language);
 565                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 566                         if (*tmp == language)
 567                                 goto repeat;
 568                 }
 569                 *tmp++ = language;
 570 repeat:
 571                 sp++;
 572         }
 573 }
 574
 575 static int lookup_string(
 576         struct usb_gadget_strings       **sp,
 577         void                            *buf,
 578         u16                             language,
 579         int                             id
 580 )
 581 {
 582         struct usb_gadget_strings       *s;
 583         int                             value;
 584
 585         while (*sp) {
 586                 s = *sp++;
 587                 if (s->language != language)
 588                         continue;
 589                 value = usb_gadget_get_string(s, id, buf);
 590                 if (value > 0)
 591                         return value;
 592         }
 593         return -EINVAL;
 594 }
 595
 596 static int get_string(struct usb_composite_dev *cdev,
 597                 void *buf, u16 language, int id)
 598 {
 599         struct usb_configuration        *c;
 600         struct usb_function             *f;
 601         int                             len;
 602
 603         /* Yes, not only is USB's I18N support probably more than most
 604          * folk will ever care about ... also, it's all supported here.
 605          * (Except for UTF8 support for Unicode's "Astral Planes".)
 606          */
 607
 608         /* 0 == report all available language codes */
 609         if (id == 0) {
 610                 struct usb_string_descriptor    *s = buf;
 611                 struct usb_gadget_strings       **sp;
 612
 613                 memset(s, 0, 256);
 614                 s->bDescriptorType = USB_DT_STRING;
 615
 616                 sp = composite->strings;
 617                 if (sp)
 618                         collect_langs(sp, s->wData);
 619
 620                 list_for_each_entry(c, &cdev->configs, list) {
 621                         sp = c->strings;
 622                         if (sp)
 623                                 collect_langs(sp, s->wData);
 624
 625                         list_for_each_entry(f, &c->functions, list) {
 626                                 sp = f->strings;
 627                                 if (sp)
 628                                         collect_langs(sp, s->wData);
 629                         }
 630                 }
 631
 632                 for (len = 0; len <= 126 && s->wData[len]; len++)
 633                         continue;
 634                 if (!len)
 635                         return -EINVAL;
 636
 637                 s->bLength = 2 * (len + 1);
 638                 return s->bLength;
 639         }
 640
 641         /* Otherwise, look up and return a specified string.  String IDs
 642          * are device-scoped, so we look up each string table we're told
 643          * about.  These lookups are infrequent; simpler-is-better here.
 644          */
 645         if (composite->strings) {
 646                 len = lookup_string(composite->strings, buf, language, id);
 647                 if (len > 0)
 648                         return len;
 649         }
 650         list_for_each_entry(c, &cdev->configs, list) {
 651                 if (c->strings) {
 652                         len = lookup_string(c->strings, buf, language, id);
 653                         if (len > 0)
 654                                 return len;
 655                 }
 656                 list_for_each_entry(f, &c->functions, list) {
 657                         if (!f->strings)
 658                                 continue;
 659                         len = lookup_string(f->strings, buf, language, id);
 660                         if (len > 0)
 661                                 return len;
 662                 }
 663         }
 664         return -EINVAL;
 665 }
 666
 667 /**
 668  * usb_string_id() - allocate an unused string ID
 669  * @cdev: the device whose string descriptor IDs are being allocated
 670  * Context: single threaded during gadget setup
 671  *
 672  * @usb_string_id() is called from bind() callbacks to allocate
 673  * string IDs.  Drivers for functions, configurations, or gadgets will
 674  * then store that ID in the appropriate descriptors and string table.
 675  *
 676  * All string identifier should be allocated using this routine, to
 677  * ensure that for example different functions don't wrongly assign
 678  * different meanings to the same identifier.
 679  */
 680 int __init usb_string_id(struct usb_composite_dev *cdev)
 681 {
 682         if (cdev->next_string_id < 254) {
 683                 /* string id 0 is reserved */
 684                 cdev->next_string_id++;
 685                 return cdev->next_string_id;
 686         }
 687         return -ENODEV;
 688 }
 689
 690 /*-------------------------------------------------------------------------*/
 691
 692 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 693 {
 694         if (req->status || req->actual != req->length)
 695                 DBG((struct usb_composite_dev *) ep->driver_data,
 696                                 "setup complete --> %d, %d/%d\n",
 697                                 req->status, req->actual, req->length);
 698 }
 699
 700 /*
 701  * The setup() callback implements all the ep0 functionality that's
 702  * not handled lower down, in hardware or the hardware driver(like
 703  * device and endpoint feature flags, and their status).  It's all
 704  * housekeeping for the gadget function we're implementing.  Most of
 705  * the work is in config and function specific setup.
 706  */
 707 static int
 708 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 709 {
 710         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 711         struct usb_request              *req = cdev->req;
 712         int                             value = -EOPNOTSUPP;
 713         u16                             w_index = le16_to_cpu(ctrl->wIndex);
 714         u8                              intf = w_index & 0xFF;
 715         u16                             w_value = le16_to_cpu(ctrl->wValue);
 716         u16                             w_length = le16_to_cpu(ctrl->wLength);
 717         struct usb_function             *f = NULL;
 718         u8                              endp;
 719
 720         /* partial re-init of the response message; the function or the
 721          * gadget might need to intercept e.g. a control-OUT completion
 722          * when we delegate to it.
 723          */
 724         req->zero = 0;
 725         req->complete = composite_setup_complete;
 726         req->length = USB_BUFSIZ;
 727         gadget->ep0->driver_data = cdev;
 728
 729         switch (ctrl->bRequest) {
 730
 731         /* we handle all standard USB descriptors */
 732         case USB_REQ_GET_DESCRIPTOR:
 733                 if (ctrl->bRequestType != USB_DIR_IN)
 734                         goto unknown;
 735                 switch (w_value >> 8) {
 736
 737                 case USB_DT_DEVICE:
 738                         cdev->desc.bNumConfigurations =
 739                                 count_configs(cdev, USB_DT_DEVICE);
 740                         value = min(w_length, (u16) sizeof cdev->desc);
 741                         memcpy(req->buf, &cdev->desc, value);
 742                         break;
 743                 case USB_DT_DEVICE_QUALIFIER:
 744                         if (!gadget_is_dualspeed(gadget))
 745                                 break;
 746                         device_qual(cdev);
 747                         value = min_t(int, w_length,
 748                                 sizeof(struct usb_qualifier_descriptor));
 749                         break;
 750                 case USB_DT_OTHER_SPEED_CONFIG:
 751                         if (!gadget_is_dualspeed(gadget))
 752                                 break;
 753                         /* FALLTHROUGH */
 754                 case USB_DT_CONFIG:
 755                         value = config_desc(cdev, w_value);
 756                         if (value >= 0)
 757                                 value = min(w_length, (u16) value);
 758                         break;
 759                 case USB_DT_STRING:
 760                         value = get_string(cdev, req->buf,
 761                                         w_index, w_value & 0xff);
 762                         if (value >= 0)
 763                                 value = min(w_length, (u16) value);
 764                         break;
 765                 }
 766                 break;
 767
 768         /* any number of configs can work */
 769         case USB_REQ_SET_CONFIGURATION:
 770                 if (ctrl->bRequestType != 0)
 771                         goto unknown;
 772                 if (gadget_is_otg(gadget)) {
 773                         if (gadget->a_hnp_support)
 774                                 DBG(cdev, "HNP available\n");
 775                         else if (gadget->a_alt_hnp_support)
 776                                 DBG(cdev, "HNP on another port\n");
 777                         else
 778                                 VDBG(cdev, "HNP inactive\n");
 779                 }
 780                 spin_lock(&cdev->lock);
 781                 value = set_config(cdev, ctrl, w_value);
 782                 spin_unlock(&cdev->lock);
 783                 break;
 784         case USB_REQ_GET_CONFIGURATION:
 785                 if (ctrl->bRequestType != USB_DIR_IN)
 786                         goto unknown;
 787                 if (cdev->config)
 788                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
 789                 else
 790                         *(u8 *)req->buf = 0;
 791                 value = min(w_length, (u16) 1);
 792                 break;
 793
 794         /* function drivers must handle get/set altsetting; if there's
 795          * no get() method, we know only altsetting zero works.
 796          */
 797         case USB_REQ_SET_INTERFACE:
 798                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
 799                         goto unknown;
 800                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
 801                         break;
 802                 f = cdev->config->interface[intf];
 803                 if (!f)
 804                         break;
 805                 if (w_value && !f->set_alt)
 806                         break;
 807                 value = f->set_alt(f, w_index, w_value);
 808                 break;
 809         case USB_REQ_GET_INTERFACE:
 810                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
 811                         goto unknown;
 812                 if (!cdev->config || w_index >= MAX_CONFIG_INTERFACES)
 813                         break;
 814                 f = cdev->config->interface[intf];
 815                 if (!f)
 816                         break;
 817                 /* lots of interfaces only need altsetting zero... */
 818                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
 819                 if (value < 0)
 820                         break;
 821                 *((u8 *)req->buf) = value;
 822                 value = min(w_length, (u16) 1);
 823                 break;
 824         default:
 825 unknown:
 826                 VDBG(cdev,
 827                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
 828                         ctrl->bRequestType, ctrl->bRequest,
 829                         w_value, w_index, w_length);
 830
 831                 /* functions always handle their interfaces and endpoints...
 832                  * punt other recipients (other, WUSB, ...) to the current
 833                  * configuration code.
 834                  *
 835                  * REVISIT it could make sense to let the composite device
 836                  * take such requests too, if that's ever needed:  to work
 837                  * in config 0, etc.
 838                  */
 839                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
 840                 case USB_RECIP_INTERFACE:
 841                         f = cdev->config->interface[intf];
 842                         break;
 843
 844                 case USB_RECIP_ENDPOINT:
 845                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
 846                         list_for_each_entry(f, &cdev->config->functions, list) {
 847                                 if (test_bit(endp, f->endpoints))
 848                                         break;
 849                         }
 850                         if (&f->list == &cdev->config->functions)
 851                                 f = NULL;
 852                         break;
 853                 }
 854
 855                 if (f && f->setup)
 856                         value = f->setup(f, ctrl);
 857                 else {
 858                         struct usb_configuration        *c;
 859
 860                         c = cdev->config;
 861                         if (c && c->setup)
 862                                 value = c->setup(c, ctrl);
 863                 }
 864
 865                 goto done;
 866         }
 867
 868         /* respond with data transfer before status phase? */
 869         if (value >= 0) {
 870                 req->length = value;
 871                 req->zero = value < w_length;
 872                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
 873                 if (value < 0) {
 874                         DBG(cdev, "ep_queue --> %d\n", value);
 875                         req->status = 0;
 876                         composite_setup_complete(gadget->ep0, req);
 877                 }
 878         }
 879
 880 done:
 881         /* device either stalls (value < 0) or reports success */
 882         return value;
 883 }
 884
 885 static void composite_disconnect(struct usb_gadget *gadget)
 886 {
 887         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 888         unsigned long                   flags;
 889
 890         /* REVISIT:  should we have config and device level
 891          * disconnect callbacks?
 892          */
 893         spin_lock_irqsave(&cdev->lock, flags);
 894         if (cdev->config)
 895                 reset_config(cdev);
 896         spin_unlock_irqrestore(&cdev->lock, flags);
 897 }
 898
 899 /*-------------------------------------------------------------------------*/
 900
 901 static void /* __init_or_exit */
 902 composite_unbind(struct usb_gadget *gadget)
 903 {
 904         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 905
 906         /* composite_disconnect() must already have been called
 907          * by the underlying peripheral controller driver!
 908          * so there's no i/o concurrency that could affect the
 909          * state protected by cdev->lock.
 910          */
 911         WARN_ON(cdev->config);
 912
 913         while (!list_empty(&cdev->configs)) {
 914                 struct usb_configuration        *c;
 915
 916                 c = list_first_entry(&cdev->configs,
 917                                 struct usb_configuration, list);
 918                 while (!list_empty(&c->functions)) {
 919                         struct usb_function             *f;
 920
 921                         f = list_first_entry(&c->functions,
 922                                         struct usb_function, list);
 923                         list_del(&f->list);
 924                         if (f->unbind) {
 925                                 DBG(cdev, "unbind function '%s'/%p\n",
 926                                                 f->name, f);
 927                                 f->unbind(c, f);
 928                                 /* may free memory for "f" */
 929                         }
 930                 }
 931                 list_del(&c->list);
 932                 if (c->unbind) {
 933                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
 934                         c->unbind(c);
 935                         /* may free memory for "c" */
 936                 }
 937         }
 938         if (composite->unbind)
 939                 composite->unbind(cdev);
 940
 941         if (cdev->req) {
 942                 kfree(cdev->req->buf);
 943                 usb_ep_free_request(gadget->ep0, cdev->req);
 944         }
 945         kfree(cdev);
 946         set_gadget_data(gadget, NULL);
 947         composite = NULL;
 948 }
 949
 950 static void __init
 951 string_override_one(struct usb_gadget_strings *tab, u8 id, const char *s)
 952 {
 953         struct usb_string               *str = tab->strings;
 954
 955         for (str = tab->strings; str->s; str++) {
 956                 if (str->id == id) {
 957                         str->s = s;
 958                         return;
 959                 }
 960         }
 961 }
 962
 963 static void __init
 964 string_override(struct usb_gadget_strings **tab, u8 id, const char *s)
 965 {
 966         while (*tab) {
 967                 string_override_one(*tab, id, s);
 968                 tab++;
 969         }
 970 }
 971
 972 static int __init composite_bind(struct usb_gadget *gadget)
 973 {
 974         struct usb_composite_dev        *cdev;
 975         int                             status = -ENOMEM;
 976
 977         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
 978         if (!cdev)
 979                 return status;
 980
 981         spin_lock_init(&cdev->lock);
 982         cdev->gadget = gadget;
 983         set_gadget_data(gadget, cdev);
 984         INIT_LIST_HEAD(&cdev->configs);
 985
 986         /* preallocate control response and buffer */
 987         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
 988         if (!cdev->req)
 989                 goto fail;
 990         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
 991         if (!cdev->req->buf)
 992                 goto fail;
 993         cdev->req->complete = composite_setup_complete;
 994         gadget->ep0->driver_data = cdev;
 995
 996         cdev->bufsiz = USB_BUFSIZ;
 997         cdev->driver = composite;
 998
 999         usb_gadget_set_selfpowered(gadget);
1000
1001         /* interface and string IDs start at zero via kzalloc.
1002          * we force endpoints to start unassigned; few controller
1003          * drivers will zero ep->driver_data.
1004          */
1005         usb_ep_autoconfig_reset(cdev->gadget);
1006
1007         /* composite gadget needs to assign strings for whole device (like
1008          * serial number), register function drivers, potentially update
1009          * power state and consumption, etc
1010          */
1011         status = composite->bind(cdev);
1012         if (status < 0)
1013                 goto fail;
1014
1015         cdev->desc = *composite->dev;
1016         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
1017
1018         /* standardized runtime overrides for device ID data */
1019         if (idVendor)
1020                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1021         if (idProduct)
1022                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1023         if (bcdDevice)
1024                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1025
1026         /* strings can't be assigned before bind() allocates the
1027          * releavnt identifiers
1028          */
1029         if (cdev->desc.iManufacturer && iManufacturer)
1030                 string_override(composite->strings,
1031                         cdev->desc.iManufacturer, iManufacturer);
1032         if (cdev->desc.iProduct && iProduct)
1033                 string_override(composite->strings,
1034                         cdev->desc.iProduct, iProduct);
1035         if (cdev->desc.iSerialNumber && iSerialNumber)
1036                 string_override(composite->strings,
1037                         cdev->desc.iSerialNumber, iSerialNumber);
1038
1039         INFO(cdev, "%s ready\n", composite->name);
1040         return 0;
1041
1042 fail:
1043         composite_unbind(gadget);
1044         return status;
1045 }
1046
1047 /*-------------------------------------------------------------------------*/
1048
1049 static void
1050 composite_suspend(struct usb_gadget *gadget)
1051 {
1052         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1053         struct usb_function             *f;
1054
1055         /* REVISIT:  should we have config level
1056          * suspend/resume callbacks?
1057          */
1058         DBG(cdev, "suspend\n");
1059         if (cdev->config) {
1060                 list_for_each_entry(f, &cdev->config->functions, list) {
1061                         if (f->suspend)
1062                                 f->suspend(f);
1063                 }
1064         }
1065         if (composite->suspend)
1066                 composite->suspend(cdev);
1067 }
1068
1069 static void
1070 composite_resume(struct usb_gadget *gadget)
1071 {
1072         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1073         struct usb_function             *f;
1074
1075         /* REVISIT:  should we have config level
1076          * suspend/resume callbacks?
1077          */
1078         DBG(cdev, "resume\n");
1079         if (composite->resume)
1080                 composite->resume(cdev);
1081         if (cdev->config) {
1082                 list_for_each_entry(f, &cdev->config->functions, list) {
1083                         if (f->resume)
1084                                 f->resume(f);
1085                 }
1086         }
1087 }
1088
1089 /*-------------------------------------------------------------------------*/
1090
1091 static struct usb_gadget_driver composite_driver = {
1092         .speed          = USB_SPEED_HIGH,
1093
1094         .bind           = composite_bind,
1095         /* .unbind              = __exit_p(composite_unbind), */
1096         .unbind         = composite_unbind,
1097
1098         .setup          = composite_setup,
1099         .disconnect     = composite_disconnect,
1100
1101         .suspend        = composite_suspend,
1102         .resume         = composite_resume,
1103
1104         .driver = {
1105                 .owner          = THIS_MODULE,
1106         },
1107 };
1108
1109 /**
1110  * usb_composite_register() - register a composite driver
1111  * @driver: the driver to register
1112  * Context: single threaded during gadget setup
1113  *
1114  * This function is used to register drivers using the composite driver
1115  * framework.  The return value is zero, or a negative errno value.
1116  * Those values normally come from the driver's @bind method, which does
1117  * all the work of setting up the driver to match the hardware.
1118  *
1119  * On successful return, the gadget is ready to respond to requests from
1120  * the host, unless one of its components invokes usb_gadget_disconnect()
1121  * while it was binding.  That would usually be done in order to wait for
1122  * some userspace participation.
1123  */
1124 int __init usb_composite_register(struct usb_composite_driver *driver)
1125 {
1126         if (!driver || !driver->dev || !driver->bind || composite)
1127                 return -EINVAL;
1128
1129         if (!driver->name)
1130                 driver->name = "composite";
1131         composite_driver.function =  (char *) driver->name;
1132         composite_driver.driver.name = driver->name;
1133         composite = driver;
1134
1135         return usb_gadget_register_driver(&composite_driver);
1136 }
1137
1138 /**
1139  * usb_composite_unregister() - unregister a composite driver
1140  * @driver: the driver to unregister
1141  *
1142  * This function is used to unregister drivers using the composite
1143  * driver framework.
1144  */
1145 void /* __exit */ usb_composite_unregister(struct usb_composite_driver *driver)
1146 {
1147         if (composite != driver)
1148                 return;
1149         usb_gadget_unregister_driver(&composite_driver);
1150 }