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/module.h>
  27 #include <linux/device.h>
  28 #include <linux/utsname.h>
  29
  30 #include <linux/usb/composite.h>
  31 #include <asm/unaligned.h>
  32
  33 /*
  34  * The code in this file is utility code, used to build a gadget driver
  35  * from one or more "function" drivers, one or more "configuration"
  36  * objects, and a "usb_composite_driver" by gluing them together along
  37  * with the relevant device-wide data.
  38  */
  39
  40 /* big enough to hold our biggest descriptor */
  41 #define USB_BUFSIZ      1024
  42
  43 static struct usb_composite_driver *composite;
  44 static int (*composite_gadget_bind)(struct usb_composite_dev *cdev);
  45
  46 /* Some systems will need runtime overrides for the  product identifiers
  47  * published in the device descriptor, either numbers or strings or both.
  48  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  49  */
  50
  51 static ushort idVendor;
  52 module_param(idVendor, ushort, 0);
  53 MODULE_PARM_DESC(idVendor, "USB Vendor ID");
  54
  55 static ushort idProduct;
  56 module_param(idProduct, ushort, 0);
  57 MODULE_PARM_DESC(idProduct, "USB Product ID");
  58
  59 static ushort bcdDevice;
  60 module_param(bcdDevice, ushort, 0);
  61 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
  62
  63 static char *iManufacturer;
  64 module_param(iManufacturer, charp, 0);
  65 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
  66
  67 static char *iProduct;
  68 module_param(iProduct, charp, 0);
  69 MODULE_PARM_DESC(iProduct, "USB Product string");
  70
  71 static char *iSerialNumber;
  72 module_param(iSerialNumber, charp, 0);
  73 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
  74
  75 static char composite_manufacturer[50];
  76
  77 /*-------------------------------------------------------------------------*/
  78 /**
  79  * next_ep_desc() - advance to the next EP descriptor
  80  * @t: currect pointer within descriptor array
  81  *
  82  * Return: next EP descriptor or NULL
  83  *
  84  * Iterate over @t until either EP descriptor found or
  85  * NULL (that indicates end of list) encountered
  86  */
  87 static struct usb_descriptor_header**
  88 next_ep_desc(struct usb_descriptor_header **t)
  89 {
  90         for (; *t; t++) {
  91                 if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
  92                         return t;
  93         }
  94         return NULL;
  95 }
  96
  97 /*
  98  * for_each_ep_desc()- iterate over endpoint descriptors in the
  99  *              descriptors list
 100  * @start:      pointer within descriptor array.
 101  * @ep_desc:    endpoint descriptor to use as the loop cursor
 102  */
 103 #define for_each_ep_desc(start, ep_desc) \
 104         for (ep_desc = next_ep_desc(start); \
 105               ep_desc; ep_desc = next_ep_desc(ep_desc+1))
 106
 107 /**
 108  * config_ep_by_speed() - configures the given endpoint
 109  * according to gadget speed.
 110  * @g: pointer to the gadget
 111  * @f: usb function
 112  * @_ep: the endpoint to configure
 113  *
 114  * Return: error code, 0 on success
 115  *
 116  * This function chooses the right descriptors for a given
 117  * endpoint according to gadget speed and saves it in the
 118  * endpoint desc field. If the endpoint already has a descriptor
 119  * assigned to it - overwrites it with currently corresponding
 120  * descriptor. The endpoint maxpacket field is updated according
 121  * to the chosen descriptor.
 122  * Note: the supplied function should hold all the descriptors
 123  * for supported speeds
 124  */
 125 int config_ep_by_speed(struct usb_gadget *g,
 126                         struct usb_function *f,
 127                         struct usb_ep *_ep)
 128 {
 129         struct usb_endpoint_descriptor *chosen_desc = NULL;
 130         struct usb_descriptor_header **speed_desc = NULL;
 131
 132         struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
 133         int want_comp_desc = 0;
 134
 135         struct usb_descriptor_header **d_spd; /* cursor for speed desc */
 136
 137         if (!g || !f || !_ep)
 138                 return -EIO;
 139
 140         /* select desired speed */
 141         switch (g->speed) {
 142         case USB_SPEED_SUPER:
 143                 if (gadget_is_superspeed(g)) {
 144                         speed_desc = f->ss_descriptors;
 145                         want_comp_desc = 1;
 146                         break;
 147                 }
 148                 /* else: Fall trough */
 149         case USB_SPEED_HIGH:
 150                 if (gadget_is_dualspeed(g)) {
 151                         speed_desc = f->hs_descriptors;
 152                         break;
 153                 }
 154                 /* else: fall through */
 155         default:
 156                 speed_desc = f->descriptors;
 157         }
 158         /* find descriptors */
 159         for_each_ep_desc(speed_desc, d_spd) {
 160                 chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 161                 if (chosen_desc->bEndpointAddress == _ep->address)
 162                         goto ep_found;
 163         }
 164         return -EIO;
 165
 166 ep_found:
 167         /* commit results */
 168         _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 169         _ep->desc = chosen_desc;
 170         _ep->comp_desc = NULL;
 171         _ep->maxburst = 0;
 172         _ep->mult = 0;
 173         if (!want_comp_desc)
 174                 return 0;
 175
 176         /*
 177          * Companion descriptor should follow EP descriptor
 178          * USB 3.0 spec, #9.6.7
 179          */
 180         comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 181         if (!comp_desc ||
 182             (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 183                 return -EIO;
 184         _ep->comp_desc = comp_desc;
 185         if (g->speed == USB_SPEED_SUPER) {
 186                 switch (usb_endpoint_type(_ep->desc)) {
 187                 case USB_ENDPOINT_XFER_BULK:
 188                 case USB_ENDPOINT_XFER_INT:
 189                         _ep->maxburst = comp_desc->bMaxBurst;
 190                         break;
 191                 case USB_ENDPOINT_XFER_ISOC:
 192                         /* mult: bits 1:0 of bmAttributes */
 193                         _ep->mult = comp_desc->bmAttributes & 0x3;
 194                         break;
 195                 default:
 196                         /* Do nothing for control endpoints */
 197                         break;
 198                 }
 199         }
 200         return 0;
 201 }
 202
 203 /**
 204  * usb_add_function() - add a function to a configuration
 205  * @config: the configuration
 206  * @function: the function being added
 207  * Context: single threaded during gadget setup
 208  *
 209  * After initialization, each configuration must have one or more
 210  * functions added to it.  Adding a function involves calling its @bind()
 211  * method to allocate resources such as interface and string identifiers
 212  * and endpoints.
 213  *
 214  * This function returns the value of the function's bind(), which is
 215  * zero for success else a negative errno value.
 216  */
 217 int usb_add_function(struct usb_configuration *config,
 218                 struct usb_function *function)
 219 {
 220         int     value = -EINVAL;
 221
 222         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 223                         function->name, function,
 224                         config->label, config);
 225
 226         if (!function->set_alt || !function->disable)
 227                 goto done;
 228
 229         function->config = config;
 230         list_add_tail(&function->list, &config->functions);
 231
 232         /* REVISIT *require* function->bind? */
 233         if (function->bind) {
 234                 value = function->bind(config, function);
 235                 if (value < 0) {
 236                         list_del(&function->list);
 237                         function->config = NULL;
 238                 }
 239         } else
 240                 value = 0;
 241
 242         /* We allow configurations that don't work at both speeds.
 243          * If we run into a lowspeed Linux system, treat it the same
 244          * as full speed ... it's the function drivers that will need
 245          * to avoid bulk and ISO transfers.
 246          */
 247         if (!config->fullspeed && function->descriptors)
 248                 config->fullspeed = true;
 249         if (!config->highspeed && function->hs_descriptors)
 250                 config->highspeed = true;
 251         if (!config->superspeed && function->ss_descriptors)
 252                 config->superspeed = true;
 253
 254 done:
 255         if (value)
 256                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 257                                 function->name, function, value);
 258         return value;
 259 }
 260
 261 /**
 262  * usb_function_deactivate - prevent function and gadget enumeration
 263  * @function: the function that isn't yet ready to respond
 264  *
 265  * Blocks response of the gadget driver to host enumeration by
 266  * preventing the data line pullup from being activated.  This is
 267  * normally called during @bind() processing to change from the
 268  * initial "ready to respond" state, or when a required resource
 269  * becomes available.
 270  *
 271  * For example, drivers that serve as a passthrough to a userspace
 272  * daemon can block enumeration unless that daemon (such as an OBEX,
 273  * MTP, or print server) is ready to handle host requests.
 274  *
 275  * Not all systems support software control of their USB peripheral
 276  * data pullups.
 277  *
 278  * Returns zero on success, else negative errno.
 279  */
 280 int usb_function_deactivate(struct usb_function *function)
 281 {
 282         struct usb_composite_dev        *cdev = function->config->cdev;
 283         unsigned long                   flags;
 284         int                             status = 0;
 285
 286         spin_lock_irqsave(&cdev->lock, flags);
 287
 288         if (cdev->deactivations == 0)
 289                 status = usb_gadget_disconnect(cdev->gadget);
 290         if (status == 0)
 291                 cdev->deactivations++;
 292
 293         spin_unlock_irqrestore(&cdev->lock, flags);
 294         return status;
 295 }
 296
 297 /**
 298  * usb_function_activate - allow function and gadget enumeration
 299  * @function: function on which usb_function_activate() was called
 300  *
 301  * Reverses effect of usb_function_deactivate().  If no more functions
 302  * are delaying their activation, the gadget driver will respond to
 303  * host enumeration procedures.
 304  *
 305  * Returns zero on success, else negative errno.
 306  */
 307 int usb_function_activate(struct usb_function *function)
 308 {
 309         struct usb_composite_dev        *cdev = function->config->cdev;
 310         int                             status = 0;
 311
 312         spin_lock(&cdev->lock);
 313
 314         if (WARN_ON(cdev->deactivations == 0))
 315                 status = -EINVAL;
 316         else {
 317                 cdev->deactivations--;
 318                 if (cdev->deactivations == 0)
 319                         status = usb_gadget_connect(cdev->gadget);
 320         }
 321
 322         spin_unlock(&cdev->lock);
 323         return status;
 324 }
 325
 326 /**
 327  * usb_interface_id() - allocate an unused interface ID
 328  * @config: configuration associated with the interface
 329  * @function: function handling the interface
 330  * Context: single threaded during gadget setup
 331  *
 332  * usb_interface_id() is called from usb_function.bind() callbacks to
 333  * allocate new interface IDs.  The function driver will then store that
 334  * ID in interface, association, CDC union, and other descriptors.  It
 335  * will also handle any control requests targeted at that interface,
 336  * particularly changing its altsetting via set_alt().  There may
 337  * also be class-specific or vendor-specific requests to handle.
 338  *
 339  * All interface identifier should be allocated using this routine, to
 340  * ensure that for example different functions don't wrongly assign
 341  * different meanings to the same identifier.  Note that since interface
 342  * identifiers are configuration-specific, functions used in more than
 343  * one configuration (or more than once in a given configuration) need
 344  * multiple versions of the relevant descriptors.
 345  *
 346  * Returns the interface ID which was allocated; or -ENODEV if no
 347  * more interface IDs can be allocated.
 348  */
 349 int usb_interface_id(struct usb_configuration *config,
 350                 struct usb_function *function)
 351 {
 352         unsigned id = config->next_interface_id;
 353
 354         if (id < MAX_CONFIG_INTERFACES) {
 355                 config->interface[id] = function;
 356                 config->next_interface_id = id + 1;
 357                 return id;
 358         }
 359         return -ENODEV;
 360 }
 361
 362 static int config_buf(struct usb_configuration *config,
 363                 enum usb_device_speed speed, void *buf, u8 type)
 364 {
 365         struct usb_config_descriptor    *c = buf;
 366         void                            *next = buf + USB_DT_CONFIG_SIZE;
 367         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 368         struct usb_function             *f;
 369         int                             status;
 370
 371         /* write the config descriptor */
 372         c = buf;
 373         c->bLength = USB_DT_CONFIG_SIZE;
 374         c->bDescriptorType = type;
 375         /* wTotalLength is written later */
 376         c->bNumInterfaces = config->next_interface_id;
 377         c->bConfigurationValue = config->bConfigurationValue;
 378         c->iConfiguration = config->iConfiguration;
 379         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 380         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 381
 382         /* There may be e.g. OTG descriptors */
 383         if (config->descriptors) {
 384                 status = usb_descriptor_fillbuf(next, len,
 385                                 config->descriptors);
 386                 if (status < 0)
 387                         return status;
 388                 len -= status;
 389                 next += status;
 390         }
 391
 392         /* add each function's descriptors */
 393         list_for_each_entry(f, &config->functions, list) {
 394                 struct usb_descriptor_header **descriptors;
 395
 396                 switch (speed) {
 397                 case USB_SPEED_SUPER:
 398                         descriptors = f->ss_descriptors;
 399                         break;
 400                 case USB_SPEED_HIGH:
 401                         descriptors = f->hs_descriptors;
 402                         break;
 403                 default:
 404                         descriptors = f->descriptors;
 405                 }
 406
 407                 if (!descriptors)
 408                         continue;
 409                 status = usb_descriptor_fillbuf(next, len,
 410                         (const struct usb_descriptor_header **) descriptors);
 411                 if (status < 0)
 412                         return status;
 413                 len -= status;
 414                 next += status;
 415         }
 416
 417         len = next - buf;
 418         c->wTotalLength = cpu_to_le16(len);
 419         return len;
 420 }
 421
 422 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 423 {
 424         struct usb_gadget               *gadget = cdev->gadget;
 425         struct usb_configuration        *c;
 426         u8                              type = w_value >> 8;
 427         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 428
 429         if (gadget->speed == USB_SPEED_SUPER)
 430                 speed = gadget->speed;
 431         else if (gadget_is_dualspeed(gadget)) {
 432                 int     hs = 0;
 433                 if (gadget->speed == USB_SPEED_HIGH)
 434                         hs = 1;
 435                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 436                         hs = !hs;
 437                 if (hs)
 438                         speed = USB_SPEED_HIGH;
 439
 440         }
 441
 442         /* This is a lookup by config *INDEX* */
 443         w_value &= 0xff;
 444         list_for_each_entry(c, &cdev->configs, list) {
 445                 /* ignore configs that won't work at this speed */
 446                 switch (speed) {
 447                 case USB_SPEED_SUPER:
 448                         if (!c->superspeed)
 449                                 continue;
 450                         break;
 451                 case USB_SPEED_HIGH:
 452                         if (!c->highspeed)
 453                                 continue;
 454                         break;
 455                 default:
 456                         if (!c->fullspeed)
 457                                 continue;
 458                 }
 459
 460                 if (w_value == 0)
 461                         return config_buf(c, speed, cdev->req->buf, type);
 462                 w_value--;
 463         }
 464         return -EINVAL;
 465 }
 466
 467 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 468 {
 469         struct usb_gadget               *gadget = cdev->gadget;
 470         struct usb_configuration        *c;
 471         unsigned                        count = 0;
 472         int                             hs = 0;
 473         int                             ss = 0;
 474
 475         if (gadget_is_dualspeed(gadget)) {
 476                 if (gadget->speed == USB_SPEED_HIGH)
 477                         hs = 1;
 478                 if (gadget->speed == USB_SPEED_SUPER)
 479                         ss = 1;
 480                 if (type == USB_DT_DEVICE_QUALIFIER)
 481                         hs = !hs;
 482         }
 483         list_for_each_entry(c, &cdev->configs, list) {
 484                 /* ignore configs that won't work at this speed */
 485                 if (ss) {
 486                         if (!c->superspeed)
 487                                 continue;
 488                 } else if (hs) {
 489                         if (!c->highspeed)
 490                                 continue;
 491                 } else {
 492                         if (!c->fullspeed)
 493                                 continue;
 494                 }
 495                 count++;
 496         }
 497         return count;
 498 }
 499
 500 /**
 501  * bos_desc() - prepares the BOS descriptor.
 502  * @cdev: pointer to usb_composite device to generate the bos
 503  *      descriptor for
 504  *
 505  * This function generates the BOS (Binary Device Object)
 506  * descriptor and its device capabilities descriptors. The BOS
 507  * descriptor should be supported by a SuperSpeed device.
 508  */
 509 static int bos_desc(struct usb_composite_dev *cdev)
 510 {
 511         struct usb_ext_cap_descriptor   *usb_ext;
 512         struct usb_ss_cap_descriptor    *ss_cap;
 513         struct usb_dcd_config_params    dcd_config_params;
 514         struct usb_bos_descriptor       *bos = cdev->req->buf;
 515
 516         bos->bLength = USB_DT_BOS_SIZE;
 517         bos->bDescriptorType = USB_DT_BOS;
 518
 519         bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 520         bos->bNumDeviceCaps = 0;
 521
 522         /*
 523          * A SuperSpeed device shall include the USB2.0 extension descriptor
 524          * and shall support LPM when operating in USB2.0 HS mode.
 525          */
 526         usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 527         bos->bNumDeviceCaps++;
 528         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 529         usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 530         usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 531         usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 532         usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT);
 533
 534         /*
 535          * The Superspeed USB Capability descriptor shall be implemented by all
 536          * SuperSpeed devices.
 537          */
 538         ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 539         bos->bNumDeviceCaps++;
 540         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 541         ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 542         ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 543         ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 544         ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 545         ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 546                                 USB_FULL_SPEED_OPERATION |
 547                                 USB_HIGH_SPEED_OPERATION |
 548                                 USB_5GBPS_OPERATION);
 549         ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 550
 551         /* Get Controller configuration */
 552         if (cdev->gadget->ops->get_config_params)
 553                 cdev->gadget->ops->get_config_params(&dcd_config_params);
 554         else {
 555                 dcd_config_params.bU1devExitLat = USB_DEFULT_U1_DEV_EXIT_LAT;
 556                 dcd_config_params.bU2DevExitLat =
 557                         cpu_to_le16(USB_DEFULT_U2_DEV_EXIT_LAT);
 558         }
 559         ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 560         ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 561
 562         return le16_to_cpu(bos->wTotalLength);
 563 }
 564
 565 static void device_qual(struct usb_composite_dev *cdev)
 566 {
 567         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 568
 569         qual->bLength = sizeof(*qual);
 570         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 571         /* POLICY: same bcdUSB and device type info at both speeds */
 572         qual->bcdUSB = cdev->desc.bcdUSB;
 573         qual->bDeviceClass = cdev->desc.bDeviceClass;
 574         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 575         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 576         /* ASSUME same EP0 fifo size at both speeds */
 577         qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 578         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 579         qual->bRESERVED = 0;
 580 }
 581
 582 /*-------------------------------------------------------------------------*/
 583
 584 static void reset_config(struct usb_composite_dev *cdev)
 585 {
 586         struct usb_function             *f;
 587
 588         DBG(cdev, "reset config\n");
 589
 590         list_for_each_entry(f, &cdev->config->functions, list) {
 591                 if (f->disable)
 592                         f->disable(f);
 593
 594                 bitmap_zero(f->endpoints, 32);
 595         }
 596         cdev->config = NULL;
 597 }
 598
 599 static int set_config(struct usb_composite_dev *cdev,
 600                 const struct usb_ctrlrequest *ctrl, unsigned number)
 601 {
 602         struct usb_gadget       *gadget = cdev->gadget;
 603         struct usb_configuration *c = NULL;
 604         int                     result = -EINVAL;
 605         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 606         int                     tmp;
 607
 608         if (number) {
 609                 list_for_each_entry(c, &cdev->configs, list) {
 610                         if (c->bConfigurationValue == number) {
 611                                 /*
 612                                  * We disable the FDs of the previous
 613                                  * configuration only if the new configuration
 614                                  * is a valid one
 615                                  */
 616                                 if (cdev->config)
 617                                         reset_config(cdev);
 618                                 result = 0;
 619                                 break;
 620                         }
 621                 }
 622                 if (result < 0)
 623                         goto done;
 624         } else { /* Zero configuration value - need to reset the config */
 625                 if (cdev->config)
 626                         reset_config(cdev);
 627                 result = 0;
 628         }
 629
 630         INFO(cdev, "%s speed config #%d: %s\n",
 631                 ({ char *speed;
 632                 switch (gadget->speed) {
 633                 case USB_SPEED_LOW:
 634                         speed = "low";
 635                         break;
 636                 case USB_SPEED_FULL:
 637                         speed = "full";
 638                         break;
 639                 case USB_SPEED_HIGH:
 640                         speed = "high";
 641                         break;
 642                 case USB_SPEED_SUPER:
 643                         speed = "super";
 644                         break;
 645                 default:
 646                         speed = "?";
 647                         break;
 648                 } ; speed; }), number, c ? c->label : "unconfigured");
 649
 650         if (!c)
 651                 goto done;
 652
 653         cdev->config = c;
 654
 655         /* Initialize all interfaces by setting them to altsetting zero. */
 656         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 657                 struct usb_function     *f = c->interface[tmp];
 658                 struct usb_descriptor_header **descriptors;
 659
 660                 if (!f)
 661                         break;
 662
 663                 /*
 664                  * Record which endpoints are used by the function. This is used
 665                  * to dispatch control requests targeted at that endpoint to the
 666                  * function's setup callback instead of the current
 667                  * configuration's setup callback.
 668                  */
 669                 switch (gadget->speed) {
 670                 case USB_SPEED_SUPER:
 671                         descriptors = f->ss_descriptors;
 672                         break;
 673                 case USB_SPEED_HIGH:
 674                         descriptors = f->hs_descriptors;
 675                         break;
 676                 default:
 677                         descriptors = f->descriptors;
 678                 }
 679
 680                 for (; *descriptors; ++descriptors) {
 681                         struct usb_endpoint_descriptor *ep;
 682                         int addr;
 683
 684                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 685                                 continue;
 686
 687                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 688                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 689                              |  (ep->bEndpointAddress & 0x0f);
 690                         set_bit(addr, f->endpoints);
 691                 }
 692
 693                 result = f->set_alt(f, tmp, 0);
 694                 if (result < 0) {
 695                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 696                                         tmp, f->name, f, result);
 697
 698                         reset_config(cdev);
 699                         goto done;
 700                 }
 701
 702                 if (result == USB_GADGET_DELAYED_STATUS) {
 703                         DBG(cdev,
 704                          "%s: interface %d (%s) requested delayed status\n",
 705                                         __func__, tmp, f->name);
 706                         cdev->delayed_status++;
 707                         DBG(cdev, "delayed_status count %d\n",
 708                                         cdev->delayed_status);
 709                 }
 710         }
 711
 712         /* when we return, be sure our power usage is valid */
 713         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 714 done:
 715         usb_gadget_vbus_draw(gadget, power);
 716         if (result >= 0 && cdev->delayed_status)
 717                 result = USB_GADGET_DELAYED_STATUS;
 718         return result;
 719 }
 720
 721 /**
 722  * usb_add_config() - add a configuration to a device.
 723  * @cdev: wraps the USB gadget
 724  * @config: the configuration, with bConfigurationValue assigned
 725  * @bind: the configuration's bind function
 726  * Context: single threaded during gadget setup
 727  *
 728  * One of the main tasks of a composite @bind() routine is to
 729  * add each of the configurations it supports, using this routine.
 730  *
 731  * This function returns the value of the configuration's @bind(), which
 732  * is zero for success else a negative errno value.  Binding configurations
 733  * assigns global resources including string IDs, and per-configuration
 734  * resources such as interface IDs and endpoints.
 735  */
 736 int usb_add_config(struct usb_composite_dev *cdev,
 737                 struct usb_configuration *config,
 738                 int (*bind)(struct usb_configuration *))
 739 {
 740         int                             status = -EINVAL;
 741         struct usb_configuration        *c;
 742
 743         DBG(cdev, "adding config #%u '%s'/%p\n",
 744                         config->bConfigurationValue,
 745                         config->label, config);
 746
 747         if (!config->bConfigurationValue || !bind)
 748                 goto done;
 749
 750         /* Prevent duplicate configuration identifiers */
 751         list_for_each_entry(c, &cdev->configs, list) {
 752                 if (c->bConfigurationValue == config->bConfigurationValue) {
 753                         status = -EBUSY;
 754                         goto done;
 755                 }
 756         }
 757
 758         config->cdev = cdev;
 759         list_add_tail(&config->list, &cdev->configs);
 760
 761         INIT_LIST_HEAD(&config->functions);
 762         config->next_interface_id = 0;
 763
 764         status = bind(config);
 765         if (status < 0) {
 766                 list_del(&config->list);
 767                 config->cdev = NULL;
 768         } else {
 769                 unsigned        i;
 770
 771                 DBG(cdev, "cfg %d/%p speeds:%s%s%s\n",
 772                         config->bConfigurationValue, config,
 773                         config->superspeed ? " super" : "",
 774                         config->highspeed ? " high" : "",
 775                         config->fullspeed
 776                                 ? (gadget_is_dualspeed(cdev->gadget)
 777                                         ? " full"
 778                                         : " full/low")
 779                                 : "");
 780
 781                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 782                         struct usb_function     *f = config->interface[i];
 783
 784                         if (!f)
 785                                 continue;
 786                         DBG(cdev, "  interface %d = %s/%p\n",
 787                                 i, f->name, f);
 788                 }
 789         }
 790
 791         /* set_alt(), or next bind(), sets up
 792          * ep->driver_data as needed.
 793          */
 794         usb_ep_autoconfig_reset(cdev->gadget);
 795
 796 done:
 797         if (status)
 798                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 799                                 config->bConfigurationValue, status);
 800         return status;
 801 }
 802
 803 /*-------------------------------------------------------------------------*/
 804
 805 /* We support strings in multiple languages ... string descriptor zero
 806  * says which languages are supported.  The typical case will be that
 807  * only one language (probably English) is used, with I18N handled on
 808  * the host side.
 809  */
 810
 811 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 812 {
 813         const struct usb_gadget_strings *s;
 814         u16                             language;
 815         __le16                          *tmp;
 816
 817         while (*sp) {
 818                 s = *sp;
 819                 language = cpu_to_le16(s->language);
 820                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 821                         if (*tmp == language)
 822                                 goto repeat;
 823                 }
 824                 *tmp++ = language;
 825 repeat:
 826                 sp++;
 827         }
 828 }
 829
 830 static int lookup_string(
 831         struct usb_gadget_strings       **sp,
 832         void                            *buf,
 833         u16                             language,
 834         int                             id
 835 )
 836 {
 837         struct usb_gadget_strings       *s;
 838         int                             value;
 839
 840         while (*sp) {
 841                 s = *sp++;
 842                 if (s->language != language)
 843                         continue;
 844                 value = usb_gadget_get_string(s, id, buf);
 845                 if (value > 0)
 846                         return value;
 847         }
 848         return -EINVAL;
 849 }
 850
 851 static int get_string(struct usb_composite_dev *cdev,
 852                 void *buf, u16 language, int id)
 853 {
 854         struct usb_configuration        *c;
 855         struct usb_function             *f;
 856         int                             len;
 857         const char                      *str;
 858
 859         /* Yes, not only is USB's I18N support probably more than most
 860          * folk will ever care about ... also, it's all supported here.
 861          * (Except for UTF8 support for Unicode's "Astral Planes".)
 862          */
 863
 864         /* 0 == report all available language codes */
 865         if (id == 0) {
 866                 struct usb_string_descriptor    *s = buf;
 867                 struct usb_gadget_strings       **sp;
 868
 869                 memset(s, 0, 256);
 870                 s->bDescriptorType = USB_DT_STRING;
 871
 872                 sp = composite->strings;
 873                 if (sp)
 874                         collect_langs(sp, s->wData);
 875
 876                 list_for_each_entry(c, &cdev->configs, list) {
 877                         sp = c->strings;
 878                         if (sp)
 879                                 collect_langs(sp, s->wData);
 880
 881                         list_for_each_entry(f, &c->functions, list) {
 882                                 sp = f->strings;
 883                                 if (sp)
 884                                         collect_langs(sp, s->wData);
 885                         }
 886                 }
 887
 888                 for (len = 0; len <= 126 && s->wData[len]; len++)
 889                         continue;
 890                 if (!len)
 891                         return -EINVAL;
 892
 893                 s->bLength = 2 * (len + 1);
 894                 return s->bLength;
 895         }
 896
 897         /* Otherwise, look up and return a specified string.  First
 898          * check if the string has not been overridden.
 899          */
 900         if (cdev->manufacturer_override == id)
 901                 str = iManufacturer ?: composite->iManufacturer ?:
 902                         composite_manufacturer;
 903         else if (cdev->product_override == id)
 904                 str = iProduct ?: composite->iProduct;
 905         else if (cdev->serial_override == id)
 906                 str = iSerialNumber;
 907         else
 908                 str = NULL;
 909         if (str) {
 910                 struct usb_gadget_strings strings = {
 911                         .language = language,
 912                         .strings  = &(struct usb_string) { 0xff, str }
 913                 };
 914                 return usb_gadget_get_string(&strings, 0xff, buf);
 915         }
 916
 917         /* String IDs are device-scoped, so we look up each string
 918          * table we're told about.  These lookups are infrequent;
 919          * simpler-is-better here.
 920          */
 921         if (composite->strings) {
 922                 len = lookup_string(composite->strings, buf, language, id);
 923                 if (len > 0)
 924                         return len;
 925         }
 926         list_for_each_entry(c, &cdev->configs, list) {
 927                 if (c->strings) {
 928                         len = lookup_string(c->strings, buf, language, id);
 929                         if (len > 0)
 930                                 return len;
 931                 }
 932                 list_for_each_entry(f, &c->functions, list) {
 933                         if (!f->strings)
 934                                 continue;
 935                         len = lookup_string(f->strings, buf, language, id);
 936                         if (len > 0)
 937                                 return len;
 938                 }
 939         }
 940         return -EINVAL;
 941 }
 942
 943 /**
 944  * usb_string_id() - allocate an unused string ID
 945  * @cdev: the device whose string descriptor IDs are being allocated
 946  * Context: single threaded during gadget setup
 947  *
 948  * @usb_string_id() is called from bind() callbacks to allocate
 949  * string IDs.  Drivers for functions, configurations, or gadgets will
 950  * then store that ID in the appropriate descriptors and string table.
 951  *
 952  * All string identifier should be allocated using this,
 953  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 954  * that for example different functions don't wrongly assign different
 955  * meanings to the same identifier.
 956  */
 957 int usb_string_id(struct usb_composite_dev *cdev)
 958 {
 959         if (cdev->next_string_id < 254) {
 960                 /* string id 0 is reserved by USB spec for list of
 961                  * supported languages */
 962                 /* 255 reserved as well? -- mina86 */
 963                 cdev->next_string_id++;
 964                 return cdev->next_string_id;
 965         }
 966         return -ENODEV;
 967 }
 968
 969 /**
 970  * usb_string_ids() - allocate unused string IDs in batch
 971  * @cdev: the device whose string descriptor IDs are being allocated
 972  * @str: an array of usb_string objects to assign numbers to
 973  * Context: single threaded during gadget setup
 974  *
 975  * @usb_string_ids() is called from bind() callbacks to allocate
 976  * string IDs.  Drivers for functions, configurations, or gadgets will
 977  * then copy IDs from the string table to the appropriate descriptors
 978  * and string table for other languages.
 979  *
 980  * All string identifier should be allocated using this,
 981  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 982  * example different functions don't wrongly assign different meanings
 983  * to the same identifier.
 984  */
 985 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 986 {
 987         int next = cdev->next_string_id;
 988
 989         for (; str->s; ++str) {
 990                 if (unlikely(next >= 254))
 991                         return -ENODEV;
 992                 str->id = ++next;
 993         }
 994
 995         cdev->next_string_id = next;
 996
 997         return 0;
 998 }
 999
1000 /**
1001  * usb_string_ids_n() - allocate unused string IDs in batch
1002  * @c: the device whose string descriptor IDs are being allocated
1003  * @n: number of string IDs to allocate
1004  * Context: single threaded during gadget setup
1005  *
1006  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1007  * valid IDs.  At least provided that @n is non-zero because if it
1008  * is, returns last requested ID which is now very useful information.
1009  *
1010  * @usb_string_ids_n() is called from bind() callbacks to allocate
1011  * string IDs.  Drivers for functions, configurations, or gadgets will
1012  * then store that ID in the appropriate descriptors and string table.
1013  *
1014  * All string identifier should be allocated using this,
1015  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1016  * example different functions don't wrongly assign different meanings
1017  * to the same identifier.
1018  */
1019 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1020 {
1021         unsigned next = c->next_string_id;
1022         if (unlikely(n > 254 || (unsigned)next + n > 254))
1023                 return -ENODEV;
1024         c->next_string_id += n;
1025         return next + 1;
1026 }
1027
1028
1029 /*-------------------------------------------------------------------------*/
1030
1031 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1032 {
1033         if (req->status || req->actual != req->length)
1034                 DBG((struct usb_composite_dev *) ep->driver_data,
1035                                 "setup complete --> %d, %d/%d\n",
1036                                 req->status, req->actual, req->length);
1037 }
1038
1039 /*
1040  * The setup() callback implements all the ep0 functionality that's
1041  * not handled lower down, in hardware or the hardware driver(like
1042  * device and endpoint feature flags, and their status).  It's all
1043  * housekeeping for the gadget function we're implementing.  Most of
1044  * the work is in config and function specific setup.
1045  */
1046 static int
1047 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1048 {
1049         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1050         struct usb_request              *req = cdev->req;
1051         int                             value = -EOPNOTSUPP;
1052         int                             status = 0;
1053         u16                             w_index = le16_to_cpu(ctrl->wIndex);
1054         u8                              intf = w_index & 0xFF;
1055         u16                             w_value = le16_to_cpu(ctrl->wValue);
1056         u16                             w_length = le16_to_cpu(ctrl->wLength);
1057         struct usb_function             *f = NULL;
1058         u8                              endp;
1059
1060         /* partial re-init of the response message; the function or the
1061          * gadget might need to intercept e.g. a control-OUT completion
1062          * when we delegate to it.
1063          */
1064         req->zero = 0;
1065         req->complete = composite_setup_complete;
1066         req->length = 0;
1067         gadget->ep0->driver_data = cdev;
1068
1069         switch (ctrl->bRequest) {
1070
1071         /* we handle all standard USB descriptors */
1072         case USB_REQ_GET_DESCRIPTOR:
1073                 if (ctrl->bRequestType != USB_DIR_IN)
1074                         goto unknown;
1075                 switch (w_value >> 8) {
1076
1077                 case USB_DT_DEVICE:
1078                         cdev->desc.bNumConfigurations =
1079                                 count_configs(cdev, USB_DT_DEVICE);
1080                         cdev->desc.bMaxPacketSize0 =
1081                                 cdev->gadget->ep0->maxpacket;
1082                         if (gadget_is_superspeed(gadget)) {
1083                                 if (gadget->speed >= USB_SPEED_SUPER) {
1084                                         cdev->desc.bcdUSB = cpu_to_le16(0x0300);
1085                                         cdev->desc.bMaxPacketSize0 = 9;
1086                                 } else {
1087                                         cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1088                                 }
1089                         }
1090
1091                         value = min(w_length, (u16) sizeof cdev->desc);
1092                         memcpy(req->buf, &cdev->desc, value);
1093                         break;
1094                 case USB_DT_DEVICE_QUALIFIER:
1095                         if (!gadget_is_dualspeed(gadget) ||
1096                             gadget->speed >= USB_SPEED_SUPER)
1097                                 break;
1098                         device_qual(cdev);
1099                         value = min_t(int, w_length,
1100                                 sizeof(struct usb_qualifier_descriptor));
1101                         break;
1102                 case USB_DT_OTHER_SPEED_CONFIG:
1103                         if (!gadget_is_dualspeed(gadget) ||
1104                             gadget->speed >= USB_SPEED_SUPER)
1105                                 break;
1106                         /* FALLTHROUGH */
1107                 case USB_DT_CONFIG:
1108                         value = config_desc(cdev, w_value);
1109                         if (value >= 0)
1110                                 value = min(w_length, (u16) value);
1111                         break;
1112                 case USB_DT_STRING:
1113                         value = get_string(cdev, req->buf,
1114                                         w_index, w_value & 0xff);
1115                         if (value >= 0)
1116                                 value = min(w_length, (u16) value);
1117                         break;
1118                 case USB_DT_BOS:
1119                         if (gadget_is_superspeed(gadget)) {
1120                                 value = bos_desc(cdev);
1121                                 value = min(w_length, (u16) value);
1122                         }
1123                         break;
1124                 }
1125                 break;
1126
1127         /* any number of configs can work */
1128         case USB_REQ_SET_CONFIGURATION:
1129                 if (ctrl->bRequestType != 0)
1130                         goto unknown;
1131                 if (gadget_is_otg(gadget)) {
1132                         if (gadget->a_hnp_support)
1133                                 DBG(cdev, "HNP available\n");
1134                         else if (gadget->a_alt_hnp_support)
1135                                 DBG(cdev, "HNP on another port\n");
1136                         else
1137                                 VDBG(cdev, "HNP inactive\n");
1138                 }
1139                 spin_lock(&cdev->lock);
1140                 value = set_config(cdev, ctrl, w_value);
1141                 spin_unlock(&cdev->lock);
1142                 break;
1143         case USB_REQ_GET_CONFIGURATION:
1144                 if (ctrl->bRequestType != USB_DIR_IN)
1145                         goto unknown;
1146                 if (cdev->config)
1147                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
1148                 else
1149                         *(u8 *)req->buf = 0;
1150                 value = min(w_length, (u16) 1);
1151                 break;
1152
1153         /* function drivers must handle get/set altsetting; if there's
1154          * no get() method, we know only altsetting zero works.
1155          */
1156         case USB_REQ_SET_INTERFACE:
1157                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1158                         goto unknown;
1159                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1160                         break;
1161                 f = cdev->config->interface[intf];
1162                 if (!f)
1163                         break;
1164                 if (w_value && !f->set_alt)
1165                         break;
1166                 value = f->set_alt(f, w_index, w_value);
1167                 if (value == USB_GADGET_DELAYED_STATUS) {
1168                         DBG(cdev,
1169                          "%s: interface %d (%s) requested delayed status\n",
1170                                         __func__, intf, f->name);
1171                         cdev->delayed_status++;
1172                         DBG(cdev, "delayed_status count %d\n",
1173                                         cdev->delayed_status);
1174                 }
1175                 break;
1176         case USB_REQ_GET_INTERFACE:
1177                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1178                         goto unknown;
1179                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1180                         break;
1181                 f = cdev->config->interface[intf];
1182                 if (!f)
1183                         break;
1184                 /* lots of interfaces only need altsetting zero... */
1185                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1186                 if (value < 0)
1187                         break;
1188                 *((u8 *)req->buf) = value;
1189                 value = min(w_length, (u16) 1);
1190                 break;
1191
1192         /*
1193          * USB 3.0 additions:
1194          * Function driver should handle get_status request. If such cb
1195          * wasn't supplied we respond with default value = 0
1196          * Note: function driver should supply such cb only for the first
1197          * interface of the function
1198          */
1199         case USB_REQ_GET_STATUS:
1200                 if (!gadget_is_superspeed(gadget))
1201                         goto unknown;
1202                 if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1203                         goto unknown;
1204                 value = 2;      /* This is the length of the get_status reply */
1205                 put_unaligned_le16(0, req->buf);
1206                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1207                         break;
1208                 f = cdev->config->interface[intf];
1209                 if (!f)
1210                         break;
1211                 status = f->get_status ? f->get_status(f) : 0;
1212                 if (status < 0)
1213                         break;
1214                 put_unaligned_le16(status & 0x0000ffff, req->buf);
1215                 break;
1216         /*
1217          * Function drivers should handle SetFeature/ClearFeature
1218          * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1219          * only for the first interface of the function
1220          */
1221         case USB_REQ_CLEAR_FEATURE:
1222         case USB_REQ_SET_FEATURE:
1223                 if (!gadget_is_superspeed(gadget))
1224                         goto unknown;
1225                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1226                         goto unknown;
1227                 switch (w_value) {
1228                 case USB_INTRF_FUNC_SUSPEND:
1229                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1230                                 break;
1231                         f = cdev->config->interface[intf];
1232                         if (!f)
1233                                 break;
1234                         value = 0;
1235                         if (f->func_suspend)
1236                                 value = f->func_suspend(f, w_index >> 8);
1237                         if (value < 0) {
1238                                 ERROR(cdev,
1239                                       "func_suspend() returned error %d\n",
1240                                       value);
1241                                 value = 0;
1242                         }
1243                         break;
1244                 }
1245                 break;
1246         default:
1247 unknown:
1248                 VDBG(cdev,
1249                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
1250                         ctrl->bRequestType, ctrl->bRequest,
1251                         w_value, w_index, w_length);
1252
1253                 /* functions always handle their interfaces and endpoints...
1254                  * punt other recipients (other, WUSB, ...) to the current
1255                  * configuration code.
1256                  *
1257                  * REVISIT it could make sense to let the composite device
1258                  * take such requests too, if that's ever needed:  to work
1259                  * in config 0, etc.
1260                  */
1261                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
1262                 case USB_RECIP_INTERFACE:
1263                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1264                                 break;
1265                         f = cdev->config->interface[intf];
1266                         break;
1267
1268                 case USB_RECIP_ENDPOINT:
1269                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1270                         list_for_each_entry(f, &cdev->config->functions, list) {
1271                                 if (test_bit(endp, f->endpoints))
1272                                         break;
1273                         }
1274                         if (&f->list == &cdev->config->functions)
1275                                 f = NULL;
1276                         break;
1277                 }
1278
1279                 if (f && f->setup)
1280                         value = f->setup(f, ctrl);
1281                 else {
1282                         struct usb_configuration        *c;
1283
1284                         c = cdev->config;
1285                         if (c && c->setup)
1286                                 value = c->setup(c, ctrl);
1287                 }
1288
1289                 goto done;
1290         }
1291
1292         /* respond with data transfer before status phase? */
1293         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
1294                 req->length = value;
1295                 req->zero = value < w_length;
1296                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
1297                 if (value < 0) {
1298                         DBG(cdev, "ep_queue --> %d\n", value);
1299                         req->status = 0;
1300                         composite_setup_complete(gadget->ep0, req);
1301                 }
1302         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
1303                 WARN(cdev,
1304                         "%s: Delayed status not supported for w_length != 0",
1305                         __func__);
1306         }
1307
1308 done:
1309         /* device either stalls (value < 0) or reports success */
1310         return value;
1311 }
1312
1313 static void composite_disconnect(struct usb_gadget *gadget)
1314 {
1315         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1316         unsigned long                   flags;
1317
1318         /* REVISIT:  should we have config and device level
1319          * disconnect callbacks?
1320          */
1321         spin_lock_irqsave(&cdev->lock, flags);
1322         if (cdev->config)
1323                 reset_config(cdev);
1324         if (composite->disconnect)
1325                 composite->disconnect(cdev);
1326         spin_unlock_irqrestore(&cdev->lock, flags);
1327 }
1328
1329 /*-------------------------------------------------------------------------*/
1330
1331 static ssize_t composite_show_suspended(struct device *dev,
1332                                         struct device_attribute *attr,
1333                                         char *buf)
1334 {
1335         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1336         struct usb_composite_dev *cdev = get_gadget_data(gadget);
1337
1338         return sprintf(buf, "%d\n", cdev->suspended);
1339 }
1340
1341 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1342
1343 static void
1344 composite_unbind(struct usb_gadget *gadget)
1345 {
1346         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1347
1348         /* composite_disconnect() must already have been called
1349          * by the underlying peripheral controller driver!
1350          * so there's no i/o concurrency that could affect the
1351          * state protected by cdev->lock.
1352          */
1353         WARN_ON(cdev->config);
1354
1355         while (!list_empty(&cdev->configs)) {
1356                 struct usb_configuration        *c;
1357
1358                 c = list_first_entry(&cdev->configs,
1359                                 struct usb_configuration, list);
1360                 while (!list_empty(&c->functions)) {
1361                         struct usb_function             *f;
1362
1363                         f = list_first_entry(&c->functions,
1364                                         struct usb_function, list);
1365                         list_del(&f->list);
1366                         if (f->unbind) {
1367                                 DBG(cdev, "unbind function '%s'/%p\n",
1368                                                 f->name, f);
1369                                 f->unbind(c, f);
1370                                 /* may free memory for "f" */
1371                         }
1372                 }
1373                 list_del(&c->list);
1374                 if (c->unbind) {
1375                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
1376                         c->unbind(c);
1377                         /* may free memory for "c" */
1378                 }
1379         }
1380         if (composite->unbind)
1381                 composite->unbind(cdev);
1382
1383         if (cdev->req) {
1384                 kfree(cdev->req->buf);
1385                 usb_ep_free_request(gadget->ep0, cdev->req);
1386         }
1387         device_remove_file(&gadget->dev, &dev_attr_suspended);
1388         kfree(cdev);
1389         set_gadget_data(gadget, NULL);
1390         composite = NULL;
1391 }
1392
1393 static u8 override_id(struct usb_composite_dev *cdev, u8 *desc)
1394 {
1395         if (!*desc) {
1396                 int ret = usb_string_id(cdev);
1397                 if (unlikely(ret < 0))
1398                         WARNING(cdev, "failed to override string ID\n");
1399                 else
1400                         *desc = ret;
1401         }
1402
1403         return *desc;
1404 }
1405
1406 static int composite_bind(struct usb_gadget *gadget)
1407 {
1408         struct usb_composite_dev        *cdev;
1409         int                             status = -ENOMEM;
1410
1411         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1412         if (!cdev)
1413                 return status;
1414
1415         spin_lock_init(&cdev->lock);
1416         cdev->gadget = gadget;
1417         set_gadget_data(gadget, cdev);
1418         INIT_LIST_HEAD(&cdev->configs);
1419
1420         /* preallocate control response and buffer */
1421         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1422         if (!cdev->req)
1423                 goto fail;
1424         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
1425         if (!cdev->req->buf)
1426                 goto fail;
1427         cdev->req->complete = composite_setup_complete;
1428         gadget->ep0->driver_data = cdev;
1429
1430         cdev->bufsiz = USB_BUFSIZ;
1431         cdev->driver = composite;
1432
1433         /*
1434          * As per USB compliance update, a device that is actively drawing
1435          * more than 100mA from USB must report itself as bus-powered in
1436          * the GetStatus(DEVICE) call.
1437          */
1438         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
1439                 usb_gadget_set_selfpowered(gadget);
1440
1441         /* interface and string IDs start at zero via kzalloc.
1442          * we force endpoints to start unassigned; few controller
1443          * drivers will zero ep->driver_data.
1444          */
1445         usb_ep_autoconfig_reset(cdev->gadget);
1446
1447         /* composite gadget needs to assign strings for whole device (like
1448          * serial number), register function drivers, potentially update
1449          * power state and consumption, etc
1450          */
1451         status = composite_gadget_bind(cdev);
1452         if (status < 0)
1453                 goto fail;
1454
1455         cdev->desc = *composite->dev;
1456
1457         /* standardized runtime overrides for device ID data */
1458         if (idVendor)
1459                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1460         if (idProduct)
1461                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1462         if (bcdDevice)
1463                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1464
1465         /* string overrides */
1466         if (iManufacturer || !cdev->desc.iManufacturer) {
1467                 if (!iManufacturer && !composite->iManufacturer &&
1468                     !*composite_manufacturer)
1469                         snprintf(composite_manufacturer,
1470                                  sizeof composite_manufacturer,
1471                                  "%s %s with %s",
1472                                  init_utsname()->sysname,
1473                                  init_utsname()->release,
1474                                  gadget->name);
1475
1476                 cdev->manufacturer_override =
1477                         override_id(cdev, &cdev->desc.iManufacturer);
1478         }
1479
1480         if (iProduct || (!cdev->desc.iProduct && composite->iProduct))
1481                 cdev->product_override =
1482                         override_id(cdev, &cdev->desc.iProduct);
1483
1484         if (iSerialNumber)
1485                 cdev->serial_override =
1486                         override_id(cdev, &cdev->desc.iSerialNumber);
1487
1488         /* has userspace failed to provide a serial number? */
1489         if (composite->needs_serial && !cdev->desc.iSerialNumber)
1490                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
1491
1492         /* finish up */
1493         status = device_create_file(&gadget->dev, &dev_attr_suspended);
1494         if (status)
1495                 goto fail;
1496
1497         INFO(cdev, "%s ready\n", composite->name);
1498         return 0;
1499
1500 fail:
1501         composite_unbind(gadget);
1502         return status;
1503 }
1504
1505 /*-------------------------------------------------------------------------*/
1506
1507 static void
1508 composite_suspend(struct usb_gadget *gadget)
1509 {
1510         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1511         struct usb_function             *f;
1512
1513         /* REVISIT:  should we have config level
1514          * suspend/resume callbacks?
1515          */
1516         DBG(cdev, "suspend\n");
1517         if (cdev->config) {
1518                 list_for_each_entry(f, &cdev->config->functions, list) {
1519                         if (f->suspend)
1520                                 f->suspend(f);
1521                 }
1522         }
1523         if (composite->suspend)
1524                 composite->suspend(cdev);
1525
1526         cdev->suspended = 1;
1527
1528         usb_gadget_vbus_draw(gadget, 2);
1529 }
1530
1531 static void
1532 composite_resume(struct usb_gadget *gadget)
1533 {
1534         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1535         struct usb_function             *f;
1536         u8                              maxpower;
1537
1538         /* REVISIT:  should we have config level
1539          * suspend/resume callbacks?
1540          */
1541         DBG(cdev, "resume\n");
1542         if (composite->resume)
1543                 composite->resume(cdev);
1544         if (cdev->config) {
1545                 list_for_each_entry(f, &cdev->config->functions, list) {
1546                         if (f->resume)
1547                                 f->resume(f);
1548                 }
1549
1550                 maxpower = cdev->config->bMaxPower;
1551
1552                 usb_gadget_vbus_draw(gadget, maxpower ?
1553                         (2 * maxpower) : CONFIG_USB_GADGET_VBUS_DRAW);
1554         }
1555
1556         cdev->suspended = 0;
1557 }
1558
1559 /*-------------------------------------------------------------------------*/
1560
1561 static struct usb_gadget_driver composite_driver = {
1562 #ifdef CONFIG_USB_GADGET_SUPERSPEED
1563         .speed          = USB_SPEED_SUPER,
1564 #else
1565         .speed          = USB_SPEED_HIGH,
1566 #endif
1567
1568         .unbind         = composite_unbind,
1569
1570         .setup          = composite_setup,
1571         .disconnect     = composite_disconnect,
1572
1573         .suspend        = composite_suspend,
1574         .resume         = composite_resume,
1575
1576         .driver = {
1577                 .owner          = THIS_MODULE,
1578         },
1579 };
1580
1581 /**
1582  * usb_composite_probe() - register a composite driver
1583  * @driver: the driver to register
1584  * @bind: the callback used to allocate resources that are shared across the
1585  *      whole device, such as string IDs, and add its configurations using
1586  *      @usb_add_config().  This may fail by returning a negative errno
1587  *      value; it should return zero on successful initialization.
1588  * Context: single threaded during gadget setup
1589  *
1590  * This function is used to register drivers using the composite driver
1591  * framework.  The return value is zero, or a negative errno value.
1592  * Those values normally come from the driver's @bind method, which does
1593  * all the work of setting up the driver to match the hardware.
1594  *
1595  * On successful return, the gadget is ready to respond to requests from
1596  * the host, unless one of its components invokes usb_gadget_disconnect()
1597  * while it was binding.  That would usually be done in order to wait for
1598  * some userspace participation.
1599  */
1600 int usb_composite_probe(struct usb_composite_driver *driver,
1601                                int (*bind)(struct usb_composite_dev *cdev))
1602 {
1603         if (!driver || !driver->dev || !bind || composite)
1604                 return -EINVAL;
1605
1606         if (!driver->name)
1607                 driver->name = "composite";
1608         if (!driver->iProduct)
1609                 driver->iProduct = driver->name;
1610         composite_driver.function =  (char *) driver->name;
1611         composite_driver.driver.name = driver->name;
1612         composite_driver.speed = min((u8)composite_driver.speed,
1613                                      (u8)driver->max_speed);
1614         composite = driver;
1615         composite_gadget_bind = bind;
1616
1617         return usb_gadget_probe_driver(&composite_driver, composite_bind);
1618 }
1619
1620 /**
1621  * usb_composite_unregister() - unregister a composite driver
1622  * @driver: the driver to unregister
1623  *
1624  * This function is used to unregister drivers using the composite
1625  * driver framework.
1626  */
1627 void usb_composite_unregister(struct usb_composite_driver *driver)
1628 {
1629         if (composite != driver)
1630                 return;
1631         usb_gadget_unregister_driver(&composite_driver);
1632 }
1633
1634 /**
1635  * usb_composite_setup_continue() - Continue with the control transfer
1636  * @cdev: the composite device who's control transfer was kept waiting
1637  *
1638  * This function must be called by the USB function driver to continue
1639  * with the control transfer's data/status stage in case it had requested to
1640  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
1641  * can request the composite framework to delay the setup request's data/status
1642  * stages by returning USB_GADGET_DELAYED_STATUS.
1643  */
1644 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
1645 {
1646         int                     value;
1647         struct usb_request      *req = cdev->req;
1648         unsigned long           flags;
1649
1650         DBG(cdev, "%s\n", __func__);
1651         spin_lock_irqsave(&cdev->lock, flags);
1652
1653         if (cdev->delayed_status == 0) {
1654                 WARN(cdev, "%s: Unexpected call\n", __func__);
1655
1656         } else if (--cdev->delayed_status == 0) {
1657                 DBG(cdev, "%s: Completing delayed status\n", __func__);
1658                 req->length = 0;
1659                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1660                 if (value < 0) {
1661                         DBG(cdev, "ep_queue --> %d\n", value);
1662                         req->status = 0;
1663                         composite_setup_complete(cdev->gadget->ep0, req);
1664                 }
1665         }
1666
1667         spin_unlock_irqrestore(&cdev->lock, flags);
1668 }
1669