linux/drivers/usb/gadget/composite.c
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   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
  12/* #define VERBOSE_DEBUG */
  13
  14#include <linux/kallsyms.h>
  15#include <linux/kernel.h>
  16#include <linux/slab.h>
  17#include <linux/module.h>
  18#include <linux/device.h>
  19#include <linux/utsname.h>
  20
  21#include <linux/usb/composite.h>
  22#include <asm/unaligned.h>
  23
  24/*
  25 * The code in this file is utility code, used to build a gadget driver
  26 * from one or more "function" drivers, one or more "configuration"
  27 * objects, and a "usb_composite_driver" by gluing them together along
  28 * with the relevant device-wide data.
  29 */
  30
  31/* big enough to hold our biggest descriptor */
  32#define USB_BUFSIZ      1024
  33
  34static struct usb_composite_driver *composite;
  35static int (*composite_gadget_bind)(struct usb_composite_dev *cdev);
  36
  37/* Some systems will need runtime overrides for the  product identifiers
  38 * published in the device descriptor, either numbers or strings or both.
  39 * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  40 */
  41
  42static ushort idVendor;
  43module_param(idVendor, ushort, 0);
  44MODULE_PARM_DESC(idVendor, "USB Vendor ID");
  45
  46static ushort idProduct;
  47module_param(idProduct, ushort, 0);
  48MODULE_PARM_DESC(idProduct, "USB Product ID");
  49
  50static ushort bcdDevice;
  51module_param(bcdDevice, ushort, 0);
  52MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
  53
  54static char *iManufacturer;
  55module_param(iManufacturer, charp, 0);
  56MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
  57
  58static char *iProduct;
  59module_param(iProduct, charp, 0);
  60MODULE_PARM_DESC(iProduct, "USB Product string");
  61
  62static char *iSerialNumber;
  63module_param(iSerialNumber, charp, 0);
  64MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
  65
  66static char composite_manufacturer[50];
  67
  68/*-------------------------------------------------------------------------*/
  69/**
  70 * next_ep_desc() - advance to the next EP descriptor
  71 * @t: currect pointer within descriptor array
  72 *
  73 * Return: next EP descriptor or NULL
  74 *
  75 * Iterate over @t until either EP descriptor found or
  76 * NULL (that indicates end of list) encountered
  77 */
  78static struct usb_descriptor_header**
  79next_ep_desc(struct usb_descriptor_header **t)
  80{
  81        for (; *t; t++) {
  82                if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
  83                        return t;
  84        }
  85        return NULL;
  86}
  87
  88/*
  89 * for_each_ep_desc()- iterate over endpoint descriptors in the
  90 *              descriptors list
  91 * @start:      pointer within descriptor array.
  92 * @ep_desc:    endpoint descriptor to use as the loop cursor
  93 */
  94#define for_each_ep_desc(start, ep_desc) \
  95        for (ep_desc = next_ep_desc(start); \
  96              ep_desc; ep_desc = next_ep_desc(ep_desc+1))
  97
  98/**
  99 * config_ep_by_speed() - configures the given endpoint
 100 * according to gadget speed.
 101 * @g: pointer to the gadget
 102 * @f: usb function
 103 * @_ep: the endpoint to configure
 104 *
 105 * Return: error code, 0 on success
 106 *
 107 * This function chooses the right descriptors for a given
 108 * endpoint according to gadget speed and saves it in the
 109 * endpoint desc field. If the endpoint already has a descriptor
 110 * assigned to it - overwrites it with currently corresponding
 111 * descriptor. The endpoint maxpacket field is updated according
 112 * to the chosen descriptor.
 113 * Note: the supplied function should hold all the descriptors
 114 * for supported speeds
 115 */
 116int config_ep_by_speed(struct usb_gadget *g,
 117                        struct usb_function *f,
 118                        struct usb_ep *_ep)
 119{
 120        struct usb_endpoint_descriptor *chosen_desc = NULL;
 121        struct usb_descriptor_header **speed_desc = NULL;
 122
 123        struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
 124        int want_comp_desc = 0;
 125
 126        struct usb_descriptor_header **d_spd; /* cursor for speed desc */
 127
 128        if (!g || !f || !_ep)
 129                return -EIO;
 130
 131        /* select desired speed */
 132        switch (g->speed) {
 133        case USB_SPEED_SUPER:
 134                if (gadget_is_superspeed(g)) {
 135                        speed_desc = f->ss_descriptors;
 136                        want_comp_desc = 1;
 137                        break;
 138                }
 139                /* else: Fall trough */
 140        case USB_SPEED_HIGH:
 141                if (gadget_is_dualspeed(g)) {
 142                        speed_desc = f->hs_descriptors;
 143                        break;
 144                }
 145                /* else: fall through */
 146        default:
 147                speed_desc = f->descriptors;
 148        }
 149        /* find descriptors */
 150        for_each_ep_desc(speed_desc, d_spd) {
 151                chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 152                if (chosen_desc->bEndpointAddress == _ep->address)
 153                        goto ep_found;
 154        }
 155        return -EIO;
 156
 157ep_found:
 158        /* commit results */
 159        _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 160        _ep->desc = chosen_desc;
 161        _ep->comp_desc = NULL;
 162        _ep->maxburst = 0;
 163        _ep->mult = 0;
 164        if (!want_comp_desc)
 165                return 0;
 166
 167        /*
 168         * Companion descriptor should follow EP descriptor
 169         * USB 3.0 spec, #9.6.7
 170         */
 171        comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 172        if (!comp_desc ||
 173            (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 174                return -EIO;
 175        _ep->comp_desc = comp_desc;
 176        if (g->speed == USB_SPEED_SUPER) {
 177                switch (usb_endpoint_type(_ep->desc)) {
 178                case USB_ENDPOINT_XFER_ISOC:
 179                        /* mult: bits 1:0 of bmAttributes */
 180                        _ep->mult = comp_desc->bmAttributes & 0x3;
 181                case USB_ENDPOINT_XFER_BULK:
 182                case USB_ENDPOINT_XFER_INT:
 183                        _ep->maxburst = comp_desc->bMaxBurst;
 184                        break;
 185                default:
 186                        /* Do nothing for control endpoints */
 187                        break;
 188                }
 189        }
 190        return 0;
 191}
 192
 193/**
 194 * usb_add_function() - add a function to a configuration
 195 * @config: the configuration
 196 * @function: the function being added
 197 * Context: single threaded during gadget setup
 198 *
 199 * After initialization, each configuration must have one or more
 200 * functions added to it.  Adding a function involves calling its @bind()
 201 * method to allocate resources such as interface and string identifiers
 202 * and endpoints.
 203 *
 204 * This function returns the value of the function's bind(), which is
 205 * zero for success else a negative errno value.
 206 */
 207int usb_add_function(struct usb_configuration *config,
 208                struct usb_function *function)
 209{
 210        int     value = -EINVAL;
 211
 212        DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 213                        function->name, function,
 214                        config->label, config);
 215
 216        if (!function->set_alt || !function->disable)
 217                goto done;
 218
 219        function->config = config;
 220        list_add_tail(&function->list, &config->functions);
 221
 222        /* REVISIT *require* function->bind? */
 223        if (function->bind) {
 224                value = function->bind(config, function);
 225                if (value < 0) {
 226                        list_del(&function->list);
 227                        function->config = NULL;
 228                }
 229        } else
 230                value = 0;
 231
 232        /* We allow configurations that don't work at both speeds.
 233         * If we run into a lowspeed Linux system, treat it the same
 234         * as full speed ... it's the function drivers that will need
 235         * to avoid bulk and ISO transfers.
 236         */
 237        if (!config->fullspeed && function->descriptors)
 238                config->fullspeed = true;
 239        if (!config->highspeed && function->hs_descriptors)
 240                config->highspeed = true;
 241        if (!config->superspeed && function->ss_descriptors)
 242                config->superspeed = true;
 243
 244done:
 245        if (value)
 246                DBG(config->cdev, "adding '%s'/%p --> %d\n",
 247                                function->name, function, value);
 248        return value;
 249}
 250
 251/**
 252 * usb_function_deactivate - prevent function and gadget enumeration
 253 * @function: the function that isn't yet ready to respond
 254 *
 255 * Blocks response of the gadget driver to host enumeration by
 256 * preventing the data line pullup from being activated.  This is
 257 * normally called during @bind() processing to change from the
 258 * initial "ready to respond" state, or when a required resource
 259 * becomes available.
 260 *
 261 * For example, drivers that serve as a passthrough to a userspace
 262 * daemon can block enumeration unless that daemon (such as an OBEX,
 263 * MTP, or print server) is ready to handle host requests.
 264 *
 265 * Not all systems support software control of their USB peripheral
 266 * data pullups.
 267 *
 268 * Returns zero on success, else negative errno.
 269 */
 270int usb_function_deactivate(struct usb_function *function)
 271{
 272        struct usb_composite_dev        *cdev = function->config->cdev;
 273        unsigned long                   flags;
 274        int                             status = 0;
 275
 276        spin_lock_irqsave(&cdev->lock, flags);
 277
 278        if (cdev->deactivations == 0)
 279                status = usb_gadget_disconnect(cdev->gadget);
 280        if (status == 0)
 281                cdev->deactivations++;
 282
 283        spin_unlock_irqrestore(&cdev->lock, flags);
 284        return status;
 285}
 286
 287/**
 288 * usb_function_activate - allow function and gadget enumeration
 289 * @function: function on which usb_function_activate() was called
 290 *
 291 * Reverses effect of usb_function_deactivate().  If no more functions
 292 * are delaying their activation, the gadget driver will respond to
 293 * host enumeration procedures.
 294 *
 295 * Returns zero on success, else negative errno.
 296 */
 297int usb_function_activate(struct usb_function *function)
 298{
 299        struct usb_composite_dev        *cdev = function->config->cdev;
 300        int                             status = 0;
 301
 302        spin_lock(&cdev->lock);
 303
 304        if (WARN_ON(cdev->deactivations == 0))
 305                status = -EINVAL;
 306        else {
 307                cdev->deactivations--;
 308                if (cdev->deactivations == 0)
 309                        status = usb_gadget_connect(cdev->gadget);
 310        }
 311
 312        spin_unlock(&cdev->lock);
 313        return status;
 314}
 315
 316/**
 317 * usb_interface_id() - allocate an unused interface ID
 318 * @config: configuration associated with the interface
 319 * @function: function handling the interface
 320 * Context: single threaded during gadget setup
 321 *
 322 * usb_interface_id() is called from usb_function.bind() callbacks to
 323 * allocate new interface IDs.  The function driver will then store that
 324 * ID in interface, association, CDC union, and other descriptors.  It
 325 * will also handle any control requests targeted at that interface,
 326 * particularly changing its altsetting via set_alt().  There may
 327 * also be class-specific or vendor-specific requests to handle.
 328 *
 329 * All interface identifier should be allocated using this routine, to
 330 * ensure that for example different functions don't wrongly assign
 331 * different meanings to the same identifier.  Note that since interface
 332 * identifiers are configuration-specific, functions used in more than
 333 * one configuration (or more than once in a given configuration) need
 334 * multiple versions of the relevant descriptors.
 335 *
 336 * Returns the interface ID which was allocated; or -ENODEV if no
 337 * more interface IDs can be allocated.
 338 */
 339int usb_interface_id(struct usb_configuration *config,
 340                struct usb_function *function)
 341{
 342        unsigned id = config->next_interface_id;
 343
 344        if (id < MAX_CONFIG_INTERFACES) {
 345                config->interface[id] = function;
 346                config->next_interface_id = id + 1;
 347                return id;
 348        }
 349        return -ENODEV;
 350}
 351
 352static int config_buf(struct usb_configuration *config,
 353                enum usb_device_speed speed, void *buf, u8 type)
 354{
 355        struct usb_config_descriptor    *c = buf;
 356        void                            *next = buf + USB_DT_CONFIG_SIZE;
 357        int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 358        struct usb_function             *f;
 359        int                             status;
 360
 361        /* write the config descriptor */
 362        c = buf;
 363        c->bLength = USB_DT_CONFIG_SIZE;
 364        c->bDescriptorType = type;
 365        /* wTotalLength is written later */
 366        c->bNumInterfaces = config->next_interface_id;
 367        c->bConfigurationValue = config->bConfigurationValue;
 368        c->iConfiguration = config->iConfiguration;
 369        c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 370        c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 371
 372        /* There may be e.g. OTG descriptors */
 373        if (config->descriptors) {
 374                status = usb_descriptor_fillbuf(next, len,
 375                                config->descriptors);
 376                if (status < 0)
 377                        return status;
 378                len -= status;
 379                next += status;
 380        }
 381
 382        /* add each function's descriptors */
 383        list_for_each_entry(f, &config->functions, list) {
 384                struct usb_descriptor_header **descriptors;
 385
 386                switch (speed) {
 387                case USB_SPEED_SUPER:
 388                        descriptors = f->ss_descriptors;
 389                        break;
 390                case USB_SPEED_HIGH:
 391                        descriptors = f->hs_descriptors;
 392                        break;
 393                default:
 394                        descriptors = f->descriptors;
 395                }
 396
 397                if (!descriptors)
 398                        continue;
 399                status = usb_descriptor_fillbuf(next, len,
 400                        (const struct usb_descriptor_header **) descriptors);
 401                if (status < 0)
 402                        return status;
 403                len -= status;
 404                next += status;
 405        }
 406
 407        len = next - buf;
 408        c->wTotalLength = cpu_to_le16(len);
 409        return len;
 410}
 411
 412static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 413{
 414        struct usb_gadget               *gadget = cdev->gadget;
 415        struct usb_configuration        *c;
 416        u8                              type = w_value >> 8;
 417        enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 418
 419        if (gadget->speed == USB_SPEED_SUPER)
 420                speed = gadget->speed;
 421        else if (gadget_is_dualspeed(gadget)) {
 422                int     hs = 0;
 423                if (gadget->speed == USB_SPEED_HIGH)
 424                        hs = 1;
 425                if (type == USB_DT_OTHER_SPEED_CONFIG)
 426                        hs = !hs;
 427                if (hs)
 428                        speed = USB_SPEED_HIGH;
 429
 430        }
 431
 432        /* This is a lookup by config *INDEX* */
 433        w_value &= 0xff;
 434        list_for_each_entry(c, &cdev->configs, list) {
 435                /* ignore configs that won't work at this speed */
 436                switch (speed) {
 437                case USB_SPEED_SUPER:
 438                        if (!c->superspeed)
 439                                continue;
 440                        break;
 441                case USB_SPEED_HIGH:
 442                        if (!c->highspeed)
 443                                continue;
 444                        break;
 445                default:
 446                        if (!c->fullspeed)
 447                                continue;
 448                }
 449
 450                if (w_value == 0)
 451                        return config_buf(c, speed, cdev->req->buf, type);
 452                w_value--;
 453        }
 454        return -EINVAL;
 455}
 456
 457static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 458{
 459        struct usb_gadget               *gadget = cdev->gadget;
 460        struct usb_configuration        *c;
 461        unsigned                        count = 0;
 462        int                             hs = 0;
 463        int                             ss = 0;
 464
 465        if (gadget_is_dualspeed(gadget)) {
 466                if (gadget->speed == USB_SPEED_HIGH)
 467                        hs = 1;
 468                if (gadget->speed == USB_SPEED_SUPER)
 469                        ss = 1;
 470                if (type == USB_DT_DEVICE_QUALIFIER)
 471                        hs = !hs;
 472        }
 473        list_for_each_entry(c, &cdev->configs, list) {
 474                /* ignore configs that won't work at this speed */
 475                if (ss) {
 476                        if (!c->superspeed)
 477                                continue;
 478                } else if (hs) {
 479                        if (!c->highspeed)
 480                                continue;
 481                } else {
 482                        if (!c->fullspeed)
 483                                continue;
 484                }
 485                count++;
 486        }
 487        return count;
 488}
 489
 490/**
 491 * bos_desc() - prepares the BOS descriptor.
 492 * @cdev: pointer to usb_composite device to generate the bos
 493 *      descriptor for
 494 *
 495 * This function generates the BOS (Binary Device Object)
 496 * descriptor and its device capabilities descriptors. The BOS
 497 * descriptor should be supported by a SuperSpeed device.
 498 */
 499static int bos_desc(struct usb_composite_dev *cdev)
 500{
 501        struct usb_ext_cap_descriptor   *usb_ext;
 502        struct usb_ss_cap_descriptor    *ss_cap;
 503        struct usb_dcd_config_params    dcd_config_params;
 504        struct usb_bos_descriptor       *bos = cdev->req->buf;
 505
 506        bos->bLength = USB_DT_BOS_SIZE;
 507        bos->bDescriptorType = USB_DT_BOS;
 508
 509        bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 510        bos->bNumDeviceCaps = 0;
 511
 512        /*
 513         * A SuperSpeed device shall include the USB2.0 extension descriptor
 514         * and shall support LPM when operating in USB2.0 HS mode.
 515         */
 516        usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 517        bos->bNumDeviceCaps++;
 518        le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 519        usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 520        usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 521        usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 522        usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT);
 523
 524        /*
 525         * The Superspeed USB Capability descriptor shall be implemented by all
 526         * SuperSpeed devices.
 527         */
 528        ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 529        bos->bNumDeviceCaps++;
 530        le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 531        ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 532        ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 533        ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 534        ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 535        ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 536                                USB_FULL_SPEED_OPERATION |
 537                                USB_HIGH_SPEED_OPERATION |
 538                                USB_5GBPS_OPERATION);
 539        ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 540
 541        /* Get Controller configuration */
 542        if (cdev->gadget->ops->get_config_params)
 543                cdev->gadget->ops->get_config_params(&dcd_config_params);
 544        else {
 545                dcd_config_params.bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT;
 546                dcd_config_params.bU2DevExitLat =
 547                        cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
 548        }
 549        ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 550        ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 551
 552        return le16_to_cpu(bos->wTotalLength);
 553}
 554
 555static void device_qual(struct usb_composite_dev *cdev)
 556{
 557        struct usb_qualifier_descriptor *qual = cdev->req->buf;
 558
 559        qual->bLength = sizeof(*qual);
 560        qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 561        /* POLICY: same bcdUSB and device type info at both speeds */
 562        qual->bcdUSB = cdev->desc.bcdUSB;
 563        qual->bDeviceClass = cdev->desc.bDeviceClass;
 564        qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 565        qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 566        /* ASSUME same EP0 fifo size at both speeds */
 567        qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 568        qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 569        qual->bRESERVED = 0;
 570}
 571
 572/*-------------------------------------------------------------------------*/
 573
 574static void reset_config(struct usb_composite_dev *cdev)
 575{
 576        struct usb_function             *f;
 577
 578        DBG(cdev, "reset config\n");
 579
 580        list_for_each_entry(f, &cdev->config->functions, list) {
 581                if (f->disable)
 582                        f->disable(f);
 583
 584                bitmap_zero(f->endpoints, 32);
 585        }
 586        cdev->config = NULL;
 587}
 588
 589static int set_config(struct usb_composite_dev *cdev,
 590                const struct usb_ctrlrequest *ctrl, unsigned number)
 591{
 592        struct usb_gadget       *gadget = cdev->gadget;
 593        struct usb_configuration *c = NULL;
 594        int                     result = -EINVAL;
 595        unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 596        int                     tmp;
 597
 598        if (number) {
 599                list_for_each_entry(c, &cdev->configs, list) {
 600                        if (c->bConfigurationValue == number) {
 601                                /*
 602                                 * We disable the FDs of the previous
 603                                 * configuration only if the new configuration
 604                                 * is a valid one
 605                                 */
 606                                if (cdev->config)
 607                                        reset_config(cdev);
 608                                result = 0;
 609                                break;
 610                        }
 611                }
 612                if (result < 0)
 613                        goto done;
 614        } else { /* Zero configuration value - need to reset the config */
 615                if (cdev->config)
 616                        reset_config(cdev);
 617                result = 0;
 618        }
 619
 620        INFO(cdev, "%s config #%d: %s\n",
 621             usb_speed_string(gadget->speed),
 622             number, c ? c->label : "unconfigured");
 623
 624        if (!c)
 625                goto done;
 626
 627        cdev->config = c;
 628
 629        /* Initialize all interfaces by setting them to altsetting zero. */
 630        for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 631                struct usb_function     *f = c->interface[tmp];
 632                struct usb_descriptor_header **descriptors;
 633
 634                if (!f)
 635                        break;
 636
 637                /*
 638                 * Record which endpoints are used by the function. This is used
 639                 * to dispatch control requests targeted at that endpoint to the
 640                 * function's setup callback instead of the current
 641                 * configuration's setup callback.
 642                 */
 643                switch (gadget->speed) {
 644                case USB_SPEED_SUPER:
 645                        descriptors = f->ss_descriptors;
 646                        break;
 647                case USB_SPEED_HIGH:
 648                        descriptors = f->hs_descriptors;
 649                        break;
 650                default:
 651                        descriptors = f->descriptors;
 652                }
 653
 654                for (; *descriptors; ++descriptors) {
 655                        struct usb_endpoint_descriptor *ep;
 656                        int addr;
 657
 658                        if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 659                                continue;
 660
 661                        ep = (struct usb_endpoint_descriptor *)*descriptors;
 662                        addr = ((ep->bEndpointAddress & 0x80) >> 3)
 663                             |  (ep->bEndpointAddress & 0x0f);
 664                        set_bit(addr, f->endpoints);
 665                }
 666
 667                result = f->set_alt(f, tmp, 0);
 668                if (result < 0) {
 669                        DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 670                                        tmp, f->name, f, result);
 671
 672                        reset_config(cdev);
 673                        goto done;
 674                }
 675
 676                if (result == USB_GADGET_DELAYED_STATUS) {
 677                        DBG(cdev,
 678                         "%s: interface %d (%s) requested delayed status\n",
 679                                        __func__, tmp, f->name);
 680                        cdev->delayed_status++;
 681                        DBG(cdev, "delayed_status count %d\n",
 682                                        cdev->delayed_status);
 683                }
 684        }
 685
 686        /* when we return, be sure our power usage is valid */
 687        power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 688done:
 689        usb_gadget_vbus_draw(gadget, power);
 690        if (result >= 0 && cdev->delayed_status)
 691                result = USB_GADGET_DELAYED_STATUS;
 692        return result;
 693}
 694
 695/**
 696 * usb_add_config() - add a configuration to a device.
 697 * @cdev: wraps the USB gadget
 698 * @config: the configuration, with bConfigurationValue assigned
 699 * @bind: the configuration's bind function
 700 * Context: single threaded during gadget setup
 701 *
 702 * One of the main tasks of a composite @bind() routine is to
 703 * add each of the configurations it supports, using this routine.
 704 *
 705 * This function returns the value of the configuration's @bind(), which
 706 * is zero for success else a negative errno value.  Binding configurations
 707 * assigns global resources including string IDs, and per-configuration
 708 * resources such as interface IDs and endpoints.
 709 */
 710int usb_add_config(struct usb_composite_dev *cdev,
 711                struct usb_configuration *config,
 712                int (*bind)(struct usb_configuration *))
 713{
 714        int                             status = -EINVAL;
 715        struct usb_configuration        *c;
 716
 717        DBG(cdev, "adding config #%u '%s'/%p\n",
 718                        config->bConfigurationValue,
 719                        config->label, config);
 720
 721        if (!config->bConfigurationValue || !bind)
 722                goto done;
 723
 724        /* Prevent duplicate configuration identifiers */
 725        list_for_each_entry(c, &cdev->configs, list) {
 726                if (c->bConfigurationValue == config->bConfigurationValue) {
 727                        status = -EBUSY;
 728                        goto done;
 729                }
 730        }
 731
 732        config->cdev = cdev;
 733        list_add_tail(&config->list, &cdev->configs);
 734
 735        INIT_LIST_HEAD(&config->functions);
 736        config->next_interface_id = 0;
 737
 738        status = bind(config);
 739        if (status < 0) {
 740                list_del(&config->list);
 741                config->cdev = NULL;
 742        } else {
 743                unsigned        i;
 744
 745                DBG(cdev, "cfg %d/%p speeds:%s%s%s\n",
 746                        config->bConfigurationValue, config,
 747                        config->superspeed ? " super" : "",
 748                        config->highspeed ? " high" : "",
 749                        config->fullspeed
 750                                ? (gadget_is_dualspeed(cdev->gadget)
 751                                        ? " full"
 752                                        : " full/low")
 753                                : "");
 754
 755                for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 756                        struct usb_function     *f = config->interface[i];
 757
 758                        if (!f)
 759                                continue;
 760                        DBG(cdev, "  interface %d = %s/%p\n",
 761                                i, f->name, f);
 762                }
 763        }
 764
 765        /* set_alt(), or next bind(), sets up
 766         * ep->driver_data as needed.
 767         */
 768        usb_ep_autoconfig_reset(cdev->gadget);
 769
 770done:
 771        if (status)
 772                DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 773                                config->bConfigurationValue, status);
 774        return status;
 775}
 776
 777/*-------------------------------------------------------------------------*/
 778
 779/* We support strings in multiple languages ... string descriptor zero
 780 * says which languages are supported.  The typical case will be that
 781 * only one language (probably English) is used, with I18N handled on
 782 * the host side.
 783 */
 784
 785static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 786{
 787        const struct usb_gadget_strings *s;
 788        u16                             language;
 789        __le16                          *tmp;
 790
 791        while (*sp) {
 792                s = *sp;
 793                language = cpu_to_le16(s->language);
 794                for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 795                        if (*tmp == language)
 796                                goto repeat;
 797                }
 798                *tmp++ = language;
 799repeat:
 800                sp++;
 801        }
 802}
 803
 804static int lookup_string(
 805        struct usb_gadget_strings       **sp,
 806        void                            *buf,
 807        u16                             language,
 808        int                             id
 809)
 810{
 811        struct usb_gadget_strings       *s;
 812        int                             value;
 813
 814        while (*sp) {
 815                s = *sp++;
 816                if (s->language != language)
 817                        continue;
 818                value = usb_gadget_get_string(s, id, buf);
 819                if (value > 0)
 820                        return value;
 821        }
 822        return -EINVAL;
 823}
 824
 825static int get_string(struct usb_composite_dev *cdev,
 826                void *buf, u16 language, int id)
 827{
 828        struct usb_configuration        *c;
 829        struct usb_function             *f;
 830        int                             len;
 831        const char                      *str;
 832
 833        /* Yes, not only is USB's I18N support probably more than most
 834         * folk will ever care about ... also, it's all supported here.
 835         * (Except for UTF8 support for Unicode's "Astral Planes".)
 836         */
 837
 838        /* 0 == report all available language codes */
 839        if (id == 0) {
 840                struct usb_string_descriptor    *s = buf;
 841                struct usb_gadget_strings       **sp;
 842
 843                memset(s, 0, 256);
 844                s->bDescriptorType = USB_DT_STRING;
 845
 846                sp = composite->strings;
 847                if (sp)
 848                        collect_langs(sp, s->wData);
 849
 850                list_for_each_entry(c, &cdev->configs, list) {
 851                        sp = c->strings;
 852                        if (sp)
 853                                collect_langs(sp, s->wData);
 854
 855                        list_for_each_entry(f, &c->functions, list) {
 856                                sp = f->strings;
 857                                if (sp)
 858                                        collect_langs(sp, s->wData);
 859                        }
 860                }
 861
 862                for (len = 0; len <= 126 && s->wData[len]; len++)
 863                        continue;
 864                if (!len)
 865                        return -EINVAL;
 866
 867                s->bLength = 2 * (len + 1);
 868                return s->bLength;
 869        }
 870
 871        /* Otherwise, look up and return a specified string.  First
 872         * check if the string has not been overridden.
 873         */
 874        if (cdev->manufacturer_override == id)
 875                str = iManufacturer ?: composite->iManufacturer ?:
 876                        composite_manufacturer;
 877        else if (cdev->product_override == id)
 878                str = iProduct ?: composite->iProduct;
 879        else if (cdev->serial_override == id)
 880                str = iSerialNumber;
 881        else
 882                str = NULL;
 883        if (str) {
 884                struct usb_gadget_strings strings = {
 885                        .language = language,
 886                        .strings  = &(struct usb_string) { 0xff, str }
 887                };
 888                return usb_gadget_get_string(&strings, 0xff, buf);
 889        }
 890
 891        /* String IDs are device-scoped, so we look up each string
 892         * table we're told about.  These lookups are infrequent;
 893         * simpler-is-better here.
 894         */
 895        if (composite->strings) {
 896                len = lookup_string(composite->strings, buf, language, id);
 897                if (len > 0)
 898                        return len;
 899        }
 900        list_for_each_entry(c, &cdev->configs, list) {
 901                if (c->strings) {
 902                        len = lookup_string(c->strings, buf, language, id);
 903                        if (len > 0)
 904                                return len;
 905                }
 906                list_for_each_entry(f, &c->functions, list) {
 907                        if (!f->strings)
 908                                continue;
 909                        len = lookup_string(f->strings, buf, language, id);
 910                        if (len > 0)
 911                                return len;
 912                }
 913        }
 914        return -EINVAL;
 915}
 916
 917/**
 918 * usb_string_id() - allocate an unused string ID
 919 * @cdev: the device whose string descriptor IDs are being allocated
 920 * Context: single threaded during gadget setup
 921 *
 922 * @usb_string_id() is called from bind() callbacks to allocate
 923 * string IDs.  Drivers for functions, configurations, or gadgets will
 924 * then store that ID in the appropriate descriptors and string table.
 925 *
 926 * All string identifier should be allocated using this,
 927 * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 928 * that for example different functions don't wrongly assign different
 929 * meanings to the same identifier.
 930 */
 931int usb_string_id(struct usb_composite_dev *cdev)
 932{
 933        if (cdev->next_string_id < 254) {
 934                /* string id 0 is reserved by USB spec for list of
 935                 * supported languages */
 936                /* 255 reserved as well? -- mina86 */
 937                cdev->next_string_id++;
 938                return cdev->next_string_id;
 939        }
 940        return -ENODEV;
 941}
 942
 943/**
 944 * usb_string_ids() - allocate unused string IDs in batch
 945 * @cdev: the device whose string descriptor IDs are being allocated
 946 * @str: an array of usb_string objects to assign numbers to
 947 * Context: single threaded during gadget setup
 948 *
 949 * @usb_string_ids() is called from bind() callbacks to allocate
 950 * string IDs.  Drivers for functions, configurations, or gadgets will
 951 * then copy IDs from the string table to the appropriate descriptors
 952 * and string table for other languages.
 953 *
 954 * All string identifier should be allocated using this,
 955 * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 956 * example different functions don't wrongly assign different meanings
 957 * to the same identifier.
 958 */
 959int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 960{
 961        int next = cdev->next_string_id;
 962
 963        for (; str->s; ++str) {
 964                if (unlikely(next >= 254))
 965                        return -ENODEV;
 966                str->id = ++next;
 967        }
 968
 969        cdev->next_string_id = next;
 970
 971        return 0;
 972}
 973
 974/**
 975 * usb_string_ids_n() - allocate unused string IDs in batch
 976 * @c: the device whose string descriptor IDs are being allocated
 977 * @n: number of string IDs to allocate
 978 * Context: single threaded during gadget setup
 979 *
 980 * Returns the first requested ID.  This ID and next @n-1 IDs are now
 981 * valid IDs.  At least provided that @n is non-zero because if it
 982 * is, returns last requested ID which is now very useful information.
 983 *
 984 * @usb_string_ids_n() is called from bind() callbacks to allocate
 985 * string IDs.  Drivers for functions, configurations, or gadgets will
 986 * then store that ID in the appropriate descriptors and string table.
 987 *
 988 * All string identifier should be allocated using this,
 989 * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 990 * example different functions don't wrongly assign different meanings
 991 * to the same identifier.
 992 */
 993int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
 994{
 995        unsigned next = c->next_string_id;
 996        if (unlikely(n > 254 || (unsigned)next + n > 254))
 997                return -ENODEV;
 998        c->next_string_id += n;
 999        return next + 1;
1000}
1001
1002
1003/*-------------------------------------------------------------------------*/
1004
1005static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1006{
1007        if (req->status || req->actual != req->length)
1008                DBG((struct usb_composite_dev *) ep->driver_data,
1009                                "setup complete --> %d, %d/%d\n",
1010                                req->status, req->actual, req->length);
1011}
1012
1013/*
1014 * The setup() callback implements all the ep0 functionality that's
1015 * not handled lower down, in hardware or the hardware driver(like
1016 * device and endpoint feature flags, and their status).  It's all
1017 * housekeeping for the gadget function we're implementing.  Most of
1018 * the work is in config and function specific setup.
1019 */
1020static int
1021composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1022{
1023        struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1024        struct usb_request              *req = cdev->req;
1025        int                             value = -EOPNOTSUPP;
1026        int                             status = 0;
1027        u16                             w_index = le16_to_cpu(ctrl->wIndex);
1028        u8                              intf = w_index & 0xFF;
1029        u16                             w_value = le16_to_cpu(ctrl->wValue);
1030        u16                             w_length = le16_to_cpu(ctrl->wLength);
1031        struct usb_function             *f = NULL;
1032        u8                              endp;
1033
1034        /* partial re-init of the response message; the function or the
1035         * gadget might need to intercept e.g. a control-OUT completion
1036         * when we delegate to it.
1037         */
1038        req->zero = 0;
1039        req->complete = composite_setup_complete;
1040        req->length = 0;
1041        gadget->ep0->driver_data = cdev;
1042
1043        switch (ctrl->bRequest) {
1044
1045        /* we handle all standard USB descriptors */
1046        case USB_REQ_GET_DESCRIPTOR:
1047                if (ctrl->bRequestType != USB_DIR_IN)
1048                        goto unknown;
1049                switch (w_value >> 8) {
1050
1051                case USB_DT_DEVICE:
1052                        cdev->desc.bNumConfigurations =
1053                                count_configs(cdev, USB_DT_DEVICE);
1054                        cdev->desc.bMaxPacketSize0 =
1055                                cdev->gadget->ep0->maxpacket;
1056                        if (gadget_is_superspeed(gadget)) {
1057                                if (gadget->speed >= USB_SPEED_SUPER) {
1058                                        cdev->desc.bcdUSB = cpu_to_le16(0x0300);
1059                                        cdev->desc.bMaxPacketSize0 = 9;
1060                                } else {
1061                                        cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1062                                }
1063                        }
1064
1065                        value = min(w_length, (u16) sizeof cdev->desc);
1066                        memcpy(req->buf, &cdev->desc, value);
1067                        break;
1068                case USB_DT_DEVICE_QUALIFIER:
1069                        if (!gadget_is_dualspeed(gadget) ||
1070                            gadget->speed >= USB_SPEED_SUPER)
1071                                break;
1072                        device_qual(cdev);
1073                        value = min_t(int, w_length,
1074                                sizeof(struct usb_qualifier_descriptor));
1075                        break;
1076                case USB_DT_OTHER_SPEED_CONFIG:
1077                        if (!gadget_is_dualspeed(gadget) ||
1078                            gadget->speed >= USB_SPEED_SUPER)
1079                                break;
1080                        /* FALLTHROUGH */
1081                case USB_DT_CONFIG:
1082                        value = config_desc(cdev, w_value);
1083                        if (value >= 0)
1084                                value = min(w_length, (u16) value);
1085                        break;
1086                case USB_DT_STRING:
1087                        value = get_string(cdev, req->buf,
1088                                        w_index, w_value & 0xff);
1089                        if (value >= 0)
1090                                value = min(w_length, (u16) value);
1091                        break;
1092                case USB_DT_BOS:
1093                        if (gadget_is_superspeed(gadget)) {
1094                                value = bos_desc(cdev);
1095                                value = min(w_length, (u16) value);
1096                        }
1097                        break;
1098                }
1099                break;
1100
1101        /* any number of configs can work */
1102        case USB_REQ_SET_CONFIGURATION:
1103                if (ctrl->bRequestType != 0)
1104                        goto unknown;
1105                if (gadget_is_otg(gadget)) {
1106                        if (gadget->a_hnp_support)
1107                                DBG(cdev, "HNP available\n");
1108                        else if (gadget->a_alt_hnp_support)
1109                                DBG(cdev, "HNP on another port\n");
1110                        else
1111                                VDBG(cdev, "HNP inactive\n");
1112                }
1113                spin_lock(&cdev->lock);
1114                value = set_config(cdev, ctrl, w_value);
1115                spin_unlock(&cdev->lock);
1116                break;
1117        case USB_REQ_GET_CONFIGURATION:
1118                if (ctrl->bRequestType != USB_DIR_IN)
1119                        goto unknown;
1120                if (cdev->config)
1121                        *(u8 *)req->buf = cdev->config->bConfigurationValue;
1122                else
1123                        *(u8 *)req->buf = 0;
1124                value = min(w_length, (u16) 1);
1125                break;
1126
1127        /* function drivers must handle get/set altsetting; if there's
1128         * no get() method, we know only altsetting zero works.
1129         */
1130        case USB_REQ_SET_INTERFACE:
1131                if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1132                        goto unknown;
1133                if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1134                        break;
1135                f = cdev->config->interface[intf];
1136                if (!f)
1137                        break;
1138                if (w_value && !f->set_alt)
1139                        break;
1140                value = f->set_alt(f, w_index, w_value);
1141                if (value == USB_GADGET_DELAYED_STATUS) {
1142                        DBG(cdev,
1143                         "%s: interface %d (%s) requested delayed status\n",
1144                                        __func__, intf, f->name);
1145                        cdev->delayed_status++;
1146                        DBG(cdev, "delayed_status count %d\n",
1147                                        cdev->delayed_status);
1148                }
1149                break;
1150        case USB_REQ_GET_INTERFACE:
1151                if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1152                        goto unknown;
1153                if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1154                        break;
1155                f = cdev->config->interface[intf];
1156                if (!f)
1157                        break;
1158                /* lots of interfaces only need altsetting zero... */
1159                value = f->get_alt ? f->get_alt(f, w_index) : 0;
1160                if (value < 0)
1161                        break;
1162                *((u8 *)req->buf) = value;
1163                value = min(w_length, (u16) 1);
1164                break;
1165
1166        /*
1167         * USB 3.0 additions:
1168         * Function driver should handle get_status request. If such cb
1169         * wasn't supplied we respond with default value = 0
1170         * Note: function driver should supply such cb only for the first
1171         * interface of the function
1172         */
1173        case USB_REQ_GET_STATUS:
1174                if (!gadget_is_superspeed(gadget))
1175                        goto unknown;
1176                if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1177                        goto unknown;
1178                value = 2;      /* This is the length of the get_status reply */
1179                put_unaligned_le16(0, req->buf);
1180                if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1181                        break;
1182                f = cdev->config->interface[intf];
1183                if (!f)
1184                        break;
1185                status = f->get_status ? f->get_status(f) : 0;
1186                if (status < 0)
1187                        break;
1188                put_unaligned_le16(status & 0x0000ffff, req->buf);
1189                break;
1190        /*
1191         * Function drivers should handle SetFeature/ClearFeature
1192         * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1193         * only for the first interface of the function
1194         */
1195        case USB_REQ_CLEAR_FEATURE:
1196        case USB_REQ_SET_FEATURE:
1197                if (!gadget_is_superspeed(gadget))
1198                        goto unknown;
1199                if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1200                        goto unknown;
1201                switch (w_value) {
1202                case USB_INTRF_FUNC_SUSPEND:
1203                        if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1204                                break;
1205                        f = cdev->config->interface[intf];
1206                        if (!f)
1207                                break;
1208                        value = 0;
1209                        if (f->func_suspend)
1210                                value = f->func_suspend(f, w_index >> 8);
1211                        if (value < 0) {
1212                                ERROR(cdev,
1213                                      "func_suspend() returned error %d\n",
1214                                      value);
1215                                value = 0;
1216                        }
1217                        break;
1218                }
1219                break;
1220        default:
1221unknown:
1222                VDBG(cdev,
1223                        "non-core control req%02x.%02x v%04x i%04x l%d\n",
1224                        ctrl->bRequestType, ctrl->bRequest,
1225                        w_value, w_index, w_length);
1226
1227                /* functions always handle their interfaces and endpoints...
1228                 * punt other recipients (other, WUSB, ...) to the current
1229                 * configuration code.
1230                 *
1231                 * REVISIT it could make sense to let the composite device
1232                 * take such requests too, if that's ever needed:  to work
1233                 * in config 0, etc.
1234                 */
1235                switch (ctrl->bRequestType & USB_RECIP_MASK) {
1236                case USB_RECIP_INTERFACE:
1237                        if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1238                                break;
1239                        f = cdev->config->interface[intf];
1240                        break;
1241
1242                case USB_RECIP_ENDPOINT:
1243                        endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1244                        list_for_each_entry(f, &cdev->config->functions, list) {
1245                                if (test_bit(endp, f->endpoints))
1246                                        break;
1247                        }
1248                        if (&f->list == &cdev->config->functions)
1249                                f = NULL;
1250                        break;
1251                }
1252
1253                if (f && f->setup)
1254                        value = f->setup(f, ctrl);
1255                else {
1256                        struct usb_configuration        *c;
1257
1258                        c = cdev->config;
1259                        if (c && c->setup)
1260                                value = c->setup(c, ctrl);
1261                }
1262
1263                goto done;
1264        }
1265
1266        /* respond with data transfer before status phase? */
1267        if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
1268                req->length = value;
1269                req->zero = value < w_length;
1270                value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
1271                if (value < 0) {
1272                        DBG(cdev, "ep_queue --> %d\n", value);
1273                        req->status = 0;
1274                        composite_setup_complete(gadget->ep0, req);
1275                }
1276        } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
1277                WARN(cdev,
1278                        "%s: Delayed status not supported for w_length != 0",
1279                        __func__);
1280        }
1281
1282done:
1283        /* device either stalls (value < 0) or reports success */
1284        return value;
1285}
1286
1287static void composite_disconnect(struct usb_gadget *gadget)
1288{
1289        struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1290        unsigned long                   flags;
1291
1292        /* REVISIT:  should we have config and device level
1293         * disconnect callbacks?
1294         */
1295        spin_lock_irqsave(&cdev->lock, flags);
1296        if (cdev->config)
1297                reset_config(cdev);
1298        if (composite->disconnect)
1299                composite->disconnect(cdev);
1300        spin_unlock_irqrestore(&cdev->lock, flags);
1301}
1302
1303/*-------------------------------------------------------------------------*/
1304
1305static ssize_t composite_show_suspended(struct device *dev,
1306                                        struct device_attribute *attr,
1307                                        char *buf)
1308{
1309        struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1310        struct usb_composite_dev *cdev = get_gadget_data(gadget);
1311
1312        return sprintf(buf, "%d\n", cdev->suspended);
1313}
1314
1315static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1316
1317static void
1318composite_unbind(struct usb_gadget *gadget)
1319{
1320        struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1321
1322        /* composite_disconnect() must already have been called
1323         * by the underlying peripheral controller driver!
1324         * so there's no i/o concurrency that could affect the
1325         * state protected by cdev->lock.
1326         */
1327        WARN_ON(cdev->config);
1328
1329        while (!list_empty(&cdev->configs)) {
1330                struct usb_configuration        *c;
1331
1332                c = list_first_entry(&cdev->configs,
1333                                struct usb_configuration, list);
1334                while (!list_empty(&c->functions)) {
1335                        struct usb_function             *f;
1336
1337                        f = list_first_entry(&c->functions,
1338                                        struct usb_function, list);
1339                        list_del(&f->list);
1340                        if (f->unbind) {
1341                                DBG(cdev, "unbind function '%s'/%p\n",
1342                                                f->name, f);
1343                                f->unbind(c, f);
1344                                /* may free memory for "f" */
1345                        }
1346                }
1347                list_del(&c->list);
1348                if (c->unbind) {
1349                        DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
1350                        c->unbind(c);
1351                        /* may free memory for "c" */
1352                }
1353        }
1354        if (composite->unbind)
1355                composite->unbind(cdev);
1356
1357        if (cdev->req) {
1358                kfree(cdev->req->buf);
1359                usb_ep_free_request(gadget->ep0, cdev->req);
1360        }
1361        device_remove_file(&gadget->dev, &dev_attr_suspended);
1362        kfree(cdev);
1363        set_gadget_data(gadget, NULL);
1364        composite = NULL;
1365}
1366
1367static u8 override_id(struct usb_composite_dev *cdev, u8 *desc)
1368{
1369        if (!*desc) {
1370                int ret = usb_string_id(cdev);
1371                if (unlikely(ret < 0))
1372                        WARNING(cdev, "failed to override string ID\n");
1373                else
1374                        *desc = ret;
1375        }
1376
1377        return *desc;
1378}
1379
1380static int composite_bind(struct usb_gadget *gadget)
1381{
1382        struct usb_composite_dev        *cdev;
1383        int                             status = -ENOMEM;
1384
1385        cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1386        if (!cdev)
1387                return status;
1388
1389        spin_lock_init(&cdev->lock);
1390        cdev->gadget = gadget;
1391        set_gadget_data(gadget, cdev);
1392        INIT_LIST_HEAD(&cdev->configs);
1393
1394        /* preallocate control response and buffer */
1395        cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1396        if (!cdev->req)
1397                goto fail;
1398        cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
1399        if (!cdev->req->buf)
1400                goto fail;
1401        cdev->req->complete = composite_setup_complete;
1402        gadget->ep0->driver_data = cdev;
1403
1404        cdev->bufsiz = USB_BUFSIZ;
1405        cdev->driver = composite;
1406
1407        /*
1408         * As per USB compliance update, a device that is actively drawing
1409         * more than 100mA from USB must report itself as bus-powered in
1410         * the GetStatus(DEVICE) call.
1411         */
1412        if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
1413                usb_gadget_set_selfpowered(gadget);
1414
1415        /* interface and string IDs start at zero via kzalloc.
1416         * we force endpoints to start unassigned; few controller
1417         * drivers will zero ep->driver_data.
1418         */
1419        usb_ep_autoconfig_reset(cdev->gadget);
1420
1421        /* composite gadget needs to assign strings for whole device (like
1422         * serial number), register function drivers, potentially update
1423         * power state and consumption, etc
1424         */
1425        status = composite_gadget_bind(cdev);
1426        if (status < 0)
1427                goto fail;
1428
1429        cdev->desc = *composite->dev;
1430
1431        /* standardized runtime overrides for device ID data */
1432        if (idVendor)
1433                cdev->desc.idVendor = cpu_to_le16(idVendor);
1434        if (idProduct)
1435                cdev->desc.idProduct = cpu_to_le16(idProduct);
1436        if (bcdDevice)
1437                cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1438
1439        /* string overrides */
1440        if (iManufacturer || !cdev->desc.iManufacturer) {
1441                if (!iManufacturer && !composite->iManufacturer &&
1442                    !*composite_manufacturer)
1443                        snprintf(composite_manufacturer,
1444                                 sizeof composite_manufacturer,
1445                                 "%s %s with %s",
1446                                 init_utsname()->sysname,
1447                                 init_utsname()->release,
1448                                 gadget->name);
1449
1450                cdev->manufacturer_override =
1451                        override_id(cdev, &cdev->desc.iManufacturer);
1452        }
1453
1454        if (iProduct || (!cdev->desc.iProduct && composite->iProduct))
1455                cdev->product_override =
1456                        override_id(cdev, &cdev->desc.iProduct);
1457
1458        if (iSerialNumber)
1459                cdev->serial_override =
1460                        override_id(cdev, &cdev->desc.iSerialNumber);
1461
1462        /* has userspace failed to provide a serial number? */
1463        if (composite->needs_serial && !cdev->desc.iSerialNumber)
1464                WARNING(cdev, "userspace failed to provide iSerialNumber\n");
1465
1466        /* finish up */
1467        status = device_create_file(&gadget->dev, &dev_attr_suspended);
1468        if (status)
1469                goto fail;
1470
1471        INFO(cdev, "%s ready\n", composite->name);
1472        return 0;
1473
1474fail:
1475        composite_unbind(gadget);
1476        return status;
1477}
1478
1479/*-------------------------------------------------------------------------*/
1480
1481static void
1482composite_suspend(struct usb_gadget *gadget)
1483{
1484        struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1485        struct usb_function             *f;
1486
1487        /* REVISIT:  should we have config level
1488         * suspend/resume callbacks?
1489         */
1490        DBG(cdev, "suspend\n");
1491        if (cdev->config) {
1492                list_for_each_entry(f, &cdev->config->functions, list) {
1493                        if (f->suspend)
1494                                f->suspend(f);
1495                }
1496        }
1497        if (composite->suspend)
1498                composite->suspend(cdev);
1499
1500        cdev->suspended = 1;
1501
1502        usb_gadget_vbus_draw(gadget, 2);
1503}
1504
1505static void
1506composite_resume(struct usb_gadget *gadget)
1507{
1508        struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1509        struct usb_function             *f;
1510        u8                              maxpower;
1511
1512        /* REVISIT:  should we have config level
1513         * suspend/resume callbacks?
1514         */
1515        DBG(cdev, "resume\n");
1516        if (composite->resume)
1517                composite->resume(cdev);
1518        if (cdev->config) {
1519                list_for_each_entry(f, &cdev->config->functions, list) {
1520                        if (f->resume)
1521                                f->resume(f);
1522                }
1523
1524                maxpower = cdev->config->bMaxPower;
1525
1526                usb_gadget_vbus_draw(gadget, maxpower ?
1527                        (2 * maxpower) : CONFIG_USB_GADGET_VBUS_DRAW);
1528        }
1529
1530        cdev->suspended = 0;
1531}
1532
1533/*-------------------------------------------------------------------------*/
1534
1535static struct usb_gadget_driver composite_driver = {
1536#ifdef CONFIG_USB_GADGET_SUPERSPEED
1537        .max_speed      = USB_SPEED_SUPER,
1538#else
1539        .max_speed      = USB_SPEED_HIGH,
1540#endif
1541
1542        .unbind         = composite_unbind,
1543
1544        .setup          = composite_setup,
1545        .disconnect     = composite_disconnect,
1546
1547        .suspend        = composite_suspend,
1548        .resume         = composite_resume,
1549
1550        .driver = {
1551                .owner          = THIS_MODULE,
1552        },
1553};
1554
1555/**
1556 * usb_composite_probe() - register a composite driver
1557 * @driver: the driver to register
1558 * @bind: the callback used to allocate resources that are shared across the
1559 *      whole device, such as string IDs, and add its configurations using
1560 *      @usb_add_config().  This may fail by returning a negative errno
1561 *      value; it should return zero on successful initialization.
1562 * Context: single threaded during gadget setup
1563 *
1564 * This function is used to register drivers using the composite driver
1565 * framework.  The return value is zero, or a negative errno value.
1566 * Those values normally come from the driver's @bind method, which does
1567 * all the work of setting up the driver to match the hardware.
1568 *
1569 * On successful return, the gadget is ready to respond to requests from
1570 * the host, unless one of its components invokes usb_gadget_disconnect()
1571 * while it was binding.  That would usually be done in order to wait for
1572 * some userspace participation.
1573 */
1574int usb_composite_probe(struct usb_composite_driver *driver,
1575                               int (*bind)(struct usb_composite_dev *cdev))
1576{
1577        if (!driver || !driver->dev || !bind || composite)
1578                return -EINVAL;
1579
1580        if (!driver->name)
1581                driver->name = "composite";
1582        if (!driver->iProduct)
1583                driver->iProduct = driver->name;
1584        composite_driver.function =  (char *) driver->name;
1585        composite_driver.driver.name = driver->name;
1586        composite_driver.max_speed =
1587                min_t(u8, composite_driver.max_speed, driver->max_speed);
1588        composite = driver;
1589        composite_gadget_bind = bind;
1590
1591        return usb_gadget_probe_driver(&composite_driver, composite_bind);
1592}
1593
1594/**
1595 * usb_composite_unregister() - unregister a composite driver
1596 * @driver: the driver to unregister
1597 *
1598 * This function is used to unregister drivers using the composite
1599 * driver framework.
1600 */
1601void usb_composite_unregister(struct usb_composite_driver *driver)
1602{
1603        if (composite != driver)
1604                return;
1605        usb_gadget_unregister_driver(&composite_driver);
1606}
1607
1608/**
1609 * usb_composite_setup_continue() - Continue with the control transfer
1610 * @cdev: the composite device who's control transfer was kept waiting
1611 *
1612 * This function must be called by the USB function driver to continue
1613 * with the control transfer's data/status stage in case it had requested to
1614 * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
1615 * can request the composite framework to delay the setup request's data/status
1616 * stages by returning USB_GADGET_DELAYED_STATUS.
1617 */
1618void usb_composite_setup_continue(struct usb_composite_dev *cdev)
1619{
1620        int                     value;
1621        struct usb_request      *req = cdev->req;
1622        unsigned long           flags;
1623
1624        DBG(cdev, "%s\n", __func__);
1625        spin_lock_irqsave(&cdev->lock, flags);
1626
1627        if (cdev->delayed_status == 0) {
1628                WARN(cdev, "%s: Unexpected call\n", __func__);
1629
1630        } else if (--cdev->delayed_status == 0) {
1631                DBG(cdev, "%s: Completing delayed status\n", __func__);
1632                req->length = 0;
1633                value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1634                if (value < 0) {
1635                        DBG(cdev, "ep_queue --> %d\n", value);
1636                        req->status = 0;
1637                        composite_setup_complete(cdev->gadget->ep0, req);
1638                }
1639        }
1640
1641        spin_unlock_irqrestore(&cdev->lock, flags);
1642}
1643
1644