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
  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 /**
  32  * next_ep_desc() - advance to the next EP descriptor
  33  * @t: currect pointer within descriptor array
  34  *
  35  * Return: next EP descriptor or NULL
  36  *
  37  * Iterate over @t until either EP descriptor found or
  38  * NULL (that indicates end of list) encountered
  39  */
  40 static struct usb_descriptor_header**
  41 next_ep_desc(struct usb_descriptor_header **t)
  42 {
  43         for (; *t; t++) {
  44                 if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
  45                         return t;
  46         }
  47         return NULL;
  48 }
  49
  50 /*
  51  * for_each_ep_desc()- iterate over endpoint descriptors in the
  52  *              descriptors list
  53  * @start:      pointer within descriptor array.
  54  * @ep_desc:    endpoint descriptor to use as the loop cursor
  55  */
  56 #define for_each_ep_desc(start, ep_desc) \
  57         for (ep_desc = next_ep_desc(start); \
  58               ep_desc; ep_desc = next_ep_desc(ep_desc+1))
  59
  60 /**
  61  * config_ep_by_speed() - configures the given endpoint
  62  * according to gadget speed.
  63  * @g: pointer to the gadget
  64  * @f: usb function
  65  * @_ep: the endpoint to configure
  66  *
  67  * Return: error code, 0 on success
  68  *
  69  * This function chooses the right descriptors for a given
  70  * endpoint according to gadget speed and saves it in the
  71  * endpoint desc field. If the endpoint already has a descriptor
  72  * assigned to it - overwrites it with currently corresponding
  73  * descriptor. The endpoint maxpacket field is updated according
  74  * to the chosen descriptor.
  75  * Note: the supplied function should hold all the descriptors
  76  * for supported speeds
  77  */
  78 int config_ep_by_speed(struct usb_gadget *g,
  79                         struct usb_function *f,
  80                         struct usb_ep *_ep)
  81 {
  82         struct usb_composite_dev        *cdev = get_gadget_data(g);
  83         struct usb_endpoint_descriptor *chosen_desc = NULL;
  84         struct usb_descriptor_header **speed_desc = NULL;
  85
  86         struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
  87         int want_comp_desc = 0;
  88
  89         struct usb_descriptor_header **d_spd; /* cursor for speed desc */
  90
  91         if (!g || !f || !_ep)
  92                 return -EIO;
  93
  94         /* select desired speed */
  95         switch (g->speed) {
  96         case USB_SPEED_SUPER:
  97                 if (gadget_is_superspeed(g)) {
  98                         speed_desc = f->ss_descriptors;
  99                         want_comp_desc = 1;
 100                         break;
 101                 }
 102                 /* else: Fall trough */
 103         case USB_SPEED_HIGH:
 104                 if (gadget_is_dualspeed(g)) {
 105                         speed_desc = f->hs_descriptors;
 106                         break;
 107                 }
 108                 /* else: fall through */
 109         default:
 110                 speed_desc = f->fs_descriptors;
 111         }
 112         /* find descriptors */
 113         for_each_ep_desc(speed_desc, d_spd) {
 114                 chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 115                 if (chosen_desc->bEndpointAddress == _ep->address)
 116                         goto ep_found;
 117         }
 118         return -EIO;
 119
 120 ep_found:
 121         /* commit results */
 122         _ep->maxpacket = usb_endpoint_maxp(chosen_desc);
 123         _ep->desc = chosen_desc;
 124         _ep->comp_desc = NULL;
 125         _ep->maxburst = 0;
 126         _ep->mult = 0;
 127         if (!want_comp_desc)
 128                 return 0;
 129
 130         /*
 131          * Companion descriptor should follow EP descriptor
 132          * USB 3.0 spec, #9.6.7
 133          */
 134         comp_desc = (struct usb_ss_ep_comp_descriptor *)*(++d_spd);
 135         if (!comp_desc ||
 136             (comp_desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP))
 137                 return -EIO;
 138         _ep->comp_desc = comp_desc;
 139         if (g->speed == USB_SPEED_SUPER) {
 140                 switch (usb_endpoint_type(_ep->desc)) {
 141                 case USB_ENDPOINT_XFER_ISOC:
 142                         /* mult: bits 1:0 of bmAttributes */
 143                         _ep->mult = comp_desc->bmAttributes & 0x3;
 144                 case USB_ENDPOINT_XFER_BULK:
 145                 case USB_ENDPOINT_XFER_INT:
 146                         _ep->maxburst = comp_desc->bMaxBurst + 1;
 147                         break;
 148                 default:
 149                         if (comp_desc->bMaxBurst != 0)
 150                                 ERROR(cdev, "ep0 bMaxBurst must be 0\n");
 151                         _ep->maxburst = 1;
 152                         break;
 153                 }
 154         }
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(config_ep_by_speed);
 158
 159 /**
 160  * usb_add_function() - add a function to a configuration
 161  * @config: the configuration
 162  * @function: the function being added
 163  * Context: single threaded during gadget setup
 164  *
 165  * After initialization, each configuration must have one or more
 166  * functions added to it.  Adding a function involves calling its @bind()
 167  * method to allocate resources such as interface and string identifiers
 168  * and endpoints.
 169  *
 170  * This function returns the value of the function's bind(), which is
 171  * zero for success else a negative errno value.
 172  */
 173 int usb_add_function(struct usb_configuration *config,
 174                 struct usb_function *function)
 175 {
 176         int     value = -EINVAL;
 177
 178         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
 179                         function->name, function,
 180                         config->label, config);
 181
 182         if (!function->set_alt || !function->disable)
 183                 goto done;
 184
 185         function->config = config;
 186         list_add_tail(&function->list, &config->functions);
 187
 188         /* REVISIT *require* function->bind? */
 189         if (function->bind) {
 190                 value = function->bind(config, function);
 191                 if (value < 0) {
 192                         list_del(&function->list);
 193                         function->config = NULL;
 194                 }
 195         } else
 196                 value = 0;
 197
 198         /* We allow configurations that don't work at both speeds.
 199          * If we run into a lowspeed Linux system, treat it the same
 200          * as full speed ... it's the function drivers that will need
 201          * to avoid bulk and ISO transfers.
 202          */
 203         if (!config->fullspeed && function->fs_descriptors)
 204                 config->fullspeed = true;
 205         if (!config->highspeed && function->hs_descriptors)
 206                 config->highspeed = true;
 207         if (!config->superspeed && function->ss_descriptors)
 208                 config->superspeed = true;
 209
 210 done:
 211         if (value)
 212                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 213                                 function->name, function, value);
 214         return value;
 215 }
 216 EXPORT_SYMBOL_GPL(usb_add_function);
 217
 218 /**
 219  * usb_function_deactivate - prevent function and gadget enumeration
 220  * @function: the function that isn't yet ready to respond
 221  *
 222  * Blocks response of the gadget driver to host enumeration by
 223  * preventing the data line pullup from being activated.  This is
 224  * normally called during @bind() processing to change from the
 225  * initial "ready to respond" state, or when a required resource
 226  * becomes available.
 227  *
 228  * For example, drivers that serve as a passthrough to a userspace
 229  * daemon can block enumeration unless that daemon (such as an OBEX,
 230  * MTP, or print server) is ready to handle host requests.
 231  *
 232  * Not all systems support software control of their USB peripheral
 233  * data pullups.
 234  *
 235  * Returns zero on success, else negative errno.
 236  */
 237 int usb_function_deactivate(struct usb_function *function)
 238 {
 239         struct usb_composite_dev        *cdev = function->config->cdev;
 240         unsigned long                   flags;
 241         int                             status = 0;
 242
 243         spin_lock_irqsave(&cdev->lock, flags);
 244
 245         if (cdev->deactivations == 0)
 246                 status = usb_gadget_disconnect(cdev->gadget);
 247         if (status == 0)
 248                 cdev->deactivations++;
 249
 250         spin_unlock_irqrestore(&cdev->lock, flags);
 251         return status;
 252 }
 253 EXPORT_SYMBOL_GPL(usb_function_deactivate);
 254
 255 /**
 256  * usb_function_activate - allow function and gadget enumeration
 257  * @function: function on which usb_function_activate() was called
 258  *
 259  * Reverses effect of usb_function_deactivate().  If no more functions
 260  * are delaying their activation, the gadget driver will respond to
 261  * host enumeration procedures.
 262  *
 263  * Returns zero on success, else negative errno.
 264  */
 265 int usb_function_activate(struct usb_function *function)
 266 {
 267         struct usb_composite_dev        *cdev = function->config->cdev;
 268         unsigned long                   flags;
 269         int                             status = 0;
 270
 271         spin_lock_irqsave(&cdev->lock, flags);
 272
 273         if (WARN_ON(cdev->deactivations == 0))
 274                 status = -EINVAL;
 275         else {
 276                 cdev->deactivations--;
 277                 if (cdev->deactivations == 0)
 278                         status = usb_gadget_connect(cdev->gadget);
 279         }
 280
 281         spin_unlock_irqrestore(&cdev->lock, flags);
 282         return status;
 283 }
 284 EXPORT_SYMBOL_GPL(usb_function_activate);
 285
 286 /**
 287  * usb_interface_id() - allocate an unused interface ID
 288  * @config: configuration associated with the interface
 289  * @function: function handling the interface
 290  * Context: single threaded during gadget setup
 291  *
 292  * usb_interface_id() is called from usb_function.bind() callbacks to
 293  * allocate new interface IDs.  The function driver will then store that
 294  * ID in interface, association, CDC union, and other descriptors.  It
 295  * will also handle any control requests targeted at that interface,
 296  * particularly changing its altsetting via set_alt().  There may
 297  * also be class-specific or vendor-specific requests to handle.
 298  *
 299  * All interface identifier should be allocated using this routine, to
 300  * ensure that for example different functions don't wrongly assign
 301  * different meanings to the same identifier.  Note that since interface
 302  * identifiers are configuration-specific, functions used in more than
 303  * one configuration (or more than once in a given configuration) need
 304  * multiple versions of the relevant descriptors.
 305  *
 306  * Returns the interface ID which was allocated; or -ENODEV if no
 307  * more interface IDs can be allocated.
 308  */
 309 int usb_interface_id(struct usb_configuration *config,
 310                 struct usb_function *function)
 311 {
 312         unsigned id = config->next_interface_id;
 313
 314         if (id < MAX_CONFIG_INTERFACES) {
 315                 config->interface[id] = function;
 316                 config->next_interface_id = id + 1;
 317                 return id;
 318         }
 319         return -ENODEV;
 320 }
 321 EXPORT_SYMBOL_GPL(usb_interface_id);
 322
 323 static u8 encode_bMaxPower(enum usb_device_speed speed,
 324                 struct usb_configuration *c)
 325 {
 326         unsigned val;
 327
 328         if (c->MaxPower)
 329                 val = c->MaxPower;
 330         else
 331                 val = CONFIG_USB_GADGET_VBUS_DRAW;
 332         if (!val)
 333                 return 0;
 334         switch (speed) {
 335         case USB_SPEED_SUPER:
 336                 return DIV_ROUND_UP(val, 8);
 337         default:
 338                 return DIV_ROUND_UP(val, 2);
 339         };
 340 }
 341
 342 static int config_buf(struct usb_configuration *config,
 343                 enum usb_device_speed speed, void *buf, u8 type)
 344 {
 345         struct usb_config_descriptor    *c = buf;
 346         void                            *next = buf + USB_DT_CONFIG_SIZE;
 347         int                             len;
 348         struct usb_function             *f;
 349         int                             status;
 350
 351         len = USB_COMP_EP0_BUFSIZ - USB_DT_CONFIG_SIZE;
 352         /* write the config descriptor */
 353         c = buf;
 354         c->bLength = USB_DT_CONFIG_SIZE;
 355         c->bDescriptorType = type;
 356         /* wTotalLength is written later */
 357         c->bNumInterfaces = config->next_interface_id;
 358         c->bConfigurationValue = config->bConfigurationValue;
 359         c->iConfiguration = config->iConfiguration;
 360         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 361         c->bMaxPower = encode_bMaxPower(speed, config);
 362
 363         /* There may be e.g. OTG descriptors */
 364         if (config->descriptors) {
 365                 status = usb_descriptor_fillbuf(next, len,
 366                                 config->descriptors);
 367                 if (status < 0)
 368                         return status;
 369                 len -= status;
 370                 next += status;
 371         }
 372
 373         /* add each function's descriptors */
 374         list_for_each_entry(f, &config->functions, list) {
 375                 struct usb_descriptor_header **descriptors;
 376
 377                 switch (speed) {
 378                 case USB_SPEED_SUPER:
 379                         descriptors = f->ss_descriptors;
 380                         break;
 381                 case USB_SPEED_HIGH:
 382                         descriptors = f->hs_descriptors;
 383                         break;
 384                 default:
 385                         descriptors = f->fs_descriptors;
 386                 }
 387
 388                 if (!descriptors)
 389                         continue;
 390                 status = usb_descriptor_fillbuf(next, len,
 391                         (const struct usb_descriptor_header **) descriptors);
 392                 if (status < 0)
 393                         return status;
 394                 len -= status;
 395                 next += status;
 396         }
 397
 398         len = next - buf;
 399         c->wTotalLength = cpu_to_le16(len);
 400         return len;
 401 }
 402
 403 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 404 {
 405         struct usb_gadget               *gadget = cdev->gadget;
 406         struct usb_configuration        *c;
 407         u8                              type = w_value >> 8;
 408         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 409
 410         if (gadget->speed == USB_SPEED_SUPER)
 411                 speed = gadget->speed;
 412         else if (gadget_is_dualspeed(gadget)) {
 413                 int     hs = 0;
 414                 if (gadget->speed == USB_SPEED_HIGH)
 415                         hs = 1;
 416                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 417                         hs = !hs;
 418                 if (hs)
 419                         speed = USB_SPEED_HIGH;
 420
 421         }
 422
 423         /* This is a lookup by config *INDEX* */
 424         w_value &= 0xff;
 425         list_for_each_entry(c, &cdev->configs, list) {
 426                 /* ignore configs that won't work at this speed */
 427                 switch (speed) {
 428                 case USB_SPEED_SUPER:
 429                         if (!c->superspeed)
 430                                 continue;
 431                         break;
 432                 case USB_SPEED_HIGH:
 433                         if (!c->highspeed)
 434                                 continue;
 435                         break;
 436                 default:
 437                         if (!c->fullspeed)
 438                                 continue;
 439                 }
 440
 441                 if (w_value == 0)
 442                         return config_buf(c, speed, cdev->req->buf, type);
 443                 w_value--;
 444         }
 445         return -EINVAL;
 446 }
 447
 448 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 449 {
 450         struct usb_gadget               *gadget = cdev->gadget;
 451         struct usb_configuration        *c;
 452         unsigned                        count = 0;
 453         int                             hs = 0;
 454         int                             ss = 0;
 455
 456         if (gadget_is_dualspeed(gadget)) {
 457                 if (gadget->speed == USB_SPEED_HIGH)
 458                         hs = 1;
 459                 if (gadget->speed == USB_SPEED_SUPER)
 460                         ss = 1;
 461                 if (type == USB_DT_DEVICE_QUALIFIER)
 462                         hs = !hs;
 463         }
 464         list_for_each_entry(c, &cdev->configs, list) {
 465                 /* ignore configs that won't work at this speed */
 466                 if (ss) {
 467                         if (!c->superspeed)
 468                                 continue;
 469                 } else if (hs) {
 470                         if (!c->highspeed)
 471                                 continue;
 472                 } else {
 473                         if (!c->fullspeed)
 474                                 continue;
 475                 }
 476                 count++;
 477         }
 478         return count;
 479 }
 480
 481 /**
 482  * bos_desc() - prepares the BOS descriptor.
 483  * @cdev: pointer to usb_composite device to generate the bos
 484  *      descriptor for
 485  *
 486  * This function generates the BOS (Binary Device Object)
 487  * descriptor and its device capabilities descriptors. The BOS
 488  * descriptor should be supported by a SuperSpeed device.
 489  */
 490 static int bos_desc(struct usb_composite_dev *cdev)
 491 {
 492         struct usb_ext_cap_descriptor   *usb_ext;
 493         struct usb_ss_cap_descriptor    *ss_cap;
 494         struct usb_dcd_config_params    dcd_config_params;
 495         struct usb_bos_descriptor       *bos = cdev->req->buf;
 496
 497         bos->bLength = USB_DT_BOS_SIZE;
 498         bos->bDescriptorType = USB_DT_BOS;
 499
 500         bos->wTotalLength = cpu_to_le16(USB_DT_BOS_SIZE);
 501         bos->bNumDeviceCaps = 0;
 502
 503         /*
 504          * A SuperSpeed device shall include the USB2.0 extension descriptor
 505          * and shall support LPM when operating in USB2.0 HS mode.
 506          */
 507         usb_ext = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 508         bos->bNumDeviceCaps++;
 509         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_EXT_CAP_SIZE);
 510         usb_ext->bLength = USB_DT_USB_EXT_CAP_SIZE;
 511         usb_ext->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 512         usb_ext->bDevCapabilityType = USB_CAP_TYPE_EXT;
 513         usb_ext->bmAttributes = cpu_to_le32(USB_LPM_SUPPORT);
 514
 515         /*
 516          * The Superspeed USB Capability descriptor shall be implemented by all
 517          * SuperSpeed devices.
 518          */
 519         ss_cap = cdev->req->buf + le16_to_cpu(bos->wTotalLength);
 520         bos->bNumDeviceCaps++;
 521         le16_add_cpu(&bos->wTotalLength, USB_DT_USB_SS_CAP_SIZE);
 522         ss_cap->bLength = USB_DT_USB_SS_CAP_SIZE;
 523         ss_cap->bDescriptorType = USB_DT_DEVICE_CAPABILITY;
 524         ss_cap->bDevCapabilityType = USB_SS_CAP_TYPE;
 525         ss_cap->bmAttributes = 0; /* LTM is not supported yet */
 526         ss_cap->wSpeedSupported = cpu_to_le16(USB_LOW_SPEED_OPERATION |
 527                                 USB_FULL_SPEED_OPERATION |
 528                                 USB_HIGH_SPEED_OPERATION |
 529                                 USB_5GBPS_OPERATION);
 530         ss_cap->bFunctionalitySupport = USB_LOW_SPEED_OPERATION;
 531
 532         /* Get Controller configuration */
 533         if (cdev->gadget->ops->get_config_params)
 534                 cdev->gadget->ops->get_config_params(&dcd_config_params);
 535         else {
 536                 dcd_config_params.bU1devExitLat = USB_DEFAULT_U1_DEV_EXIT_LAT;
 537                 dcd_config_params.bU2DevExitLat =
 538                         cpu_to_le16(USB_DEFAULT_U2_DEV_EXIT_LAT);
 539         }
 540         ss_cap->bU1devExitLat = dcd_config_params.bU1devExitLat;
 541         ss_cap->bU2DevExitLat = dcd_config_params.bU2DevExitLat;
 542
 543         return le16_to_cpu(bos->wTotalLength);
 544 }
 545
 546 static void device_qual(struct usb_composite_dev *cdev)
 547 {
 548         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 549
 550         qual->bLength = sizeof(*qual);
 551         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 552         /* POLICY: same bcdUSB and device type info at both speeds */
 553         qual->bcdUSB = cdev->desc.bcdUSB;
 554         qual->bDeviceClass = cdev->desc.bDeviceClass;
 555         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 556         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 557         /* ASSUME same EP0 fifo size at both speeds */
 558         qual->bMaxPacketSize0 = cdev->gadget->ep0->maxpacket;
 559         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 560         qual->bRESERVED = 0;
 561 }
 562
 563 /*-------------------------------------------------------------------------*/
 564
 565 static void reset_config(struct usb_composite_dev *cdev)
 566 {
 567         struct usb_function             *f;
 568
 569         DBG(cdev, "reset config\n");
 570
 571         list_for_each_entry(f, &cdev->config->functions, list) {
 572                 if (f->disable)
 573                         f->disable(f);
 574
 575                 bitmap_zero(f->endpoints, 32);
 576         }
 577         cdev->config = NULL;
 578 }
 579
 580 static int set_config(struct usb_composite_dev *cdev,
 581                 const struct usb_ctrlrequest *ctrl, unsigned number)
 582 {
 583         struct usb_gadget       *gadget = cdev->gadget;
 584         struct usb_configuration *c = NULL;
 585         int                     result = -EINVAL;
 586         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 587         int                     tmp;
 588
 589         if (number) {
 590                 list_for_each_entry(c, &cdev->configs, list) {
 591                         if (c->bConfigurationValue == number) {
 592                                 /*
 593                                  * We disable the FDs of the previous
 594                                  * configuration only if the new configuration
 595                                  * is a valid one
 596                                  */
 597                                 if (cdev->config)
 598                                         reset_config(cdev);
 599                                 result = 0;
 600                                 break;
 601                         }
 602                 }
 603                 if (result < 0)
 604                         goto done;
 605         } else { /* Zero configuration value - need to reset the config */
 606                 if (cdev->config)
 607                         reset_config(cdev);
 608                 result = 0;
 609         }
 610
 611         INFO(cdev, "%s config #%d: %s\n",
 612              usb_speed_string(gadget->speed),
 613              number, c ? c->label : "unconfigured");
 614
 615         if (!c)
 616                 goto done;
 617
 618         cdev->config = c;
 619
 620         /* Initialize all interfaces by setting them to altsetting zero. */
 621         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 622                 struct usb_function     *f = c->interface[tmp];
 623                 struct usb_descriptor_header **descriptors;
 624
 625                 if (!f)
 626                         break;
 627
 628                 /*
 629                  * Record which endpoints are used by the function. This is used
 630                  * to dispatch control requests targeted at that endpoint to the
 631                  * function's setup callback instead of the current
 632                  * configuration's setup callback.
 633                  */
 634                 switch (gadget->speed) {
 635                 case USB_SPEED_SUPER:
 636                         descriptors = f->ss_descriptors;
 637                         break;
 638                 case USB_SPEED_HIGH:
 639                         descriptors = f->hs_descriptors;
 640                         break;
 641                 default:
 642                         descriptors = f->fs_descriptors;
 643                 }
 644
 645                 for (; *descriptors; ++descriptors) {
 646                         struct usb_endpoint_descriptor *ep;
 647                         int addr;
 648
 649                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 650                                 continue;
 651
 652                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 653                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 654                              |  (ep->bEndpointAddress & 0x0f);
 655                         set_bit(addr, f->endpoints);
 656                 }
 657
 658                 result = f->set_alt(f, tmp, 0);
 659                 if (result < 0) {
 660                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 661                                         tmp, f->name, f, result);
 662
 663                         reset_config(cdev);
 664                         goto done;
 665                 }
 666
 667                 if (result == USB_GADGET_DELAYED_STATUS) {
 668                         DBG(cdev,
 669                          "%s: interface %d (%s) requested delayed status\n",
 670                                         __func__, tmp, f->name);
 671                         cdev->delayed_status++;
 672                         DBG(cdev, "delayed_status count %d\n",
 673                                         cdev->delayed_status);
 674                 }
 675         }
 676
 677         /* when we return, be sure our power usage is valid */
 678         power = c->MaxPower ? c->MaxPower : CONFIG_USB_GADGET_VBUS_DRAW;
 679 done:
 680         usb_gadget_vbus_draw(gadget, power);
 681         if (result >= 0 && cdev->delayed_status)
 682                 result = USB_GADGET_DELAYED_STATUS;
 683         return result;
 684 }
 685
 686 /**
 687  * usb_add_config() - add a configuration to a device.
 688  * @cdev: wraps the USB gadget
 689  * @config: the configuration, with bConfigurationValue assigned
 690  * @bind: the configuration's bind function
 691  * Context: single threaded during gadget setup
 692  *
 693  * One of the main tasks of a composite @bind() routine is to
 694  * add each of the configurations it supports, using this routine.
 695  *
 696  * This function returns the value of the configuration's @bind(), which
 697  * is zero for success else a negative errno value.  Binding configurations
 698  * assigns global resources including string IDs, and per-configuration
 699  * resources such as interface IDs and endpoints.
 700  */
 701 int usb_add_config(struct usb_composite_dev *cdev,
 702                 struct usb_configuration *config,
 703                 int (*bind)(struct usb_configuration *))
 704 {
 705         int                             status = -EINVAL;
 706         struct usb_configuration        *c;
 707
 708         DBG(cdev, "adding config #%u '%s'/%p\n",
 709                         config->bConfigurationValue,
 710                         config->label, config);
 711
 712         if (!config->bConfigurationValue || !bind)
 713                 goto done;
 714
 715         /* Prevent duplicate configuration identifiers */
 716         list_for_each_entry(c, &cdev->configs, list) {
 717                 if (c->bConfigurationValue == config->bConfigurationValue) {
 718                         status = -EBUSY;
 719                         goto done;
 720                 }
 721         }
 722
 723         config->cdev = cdev;
 724         list_add_tail(&config->list, &cdev->configs);
 725
 726         INIT_LIST_HEAD(&config->functions);
 727         config->next_interface_id = 0;
 728         memset(config->interface, 0, sizeof(config->interface));
 729
 730         status = bind(config);
 731         if (status < 0) {
 732                 while (!list_empty(&config->functions)) {
 733                         struct usb_function             *f;
 734
 735                         f = list_first_entry(&config->functions,
 736                                         struct usb_function, list);
 737                         list_del(&f->list);
 738                         if (f->unbind) {
 739                                 DBG(cdev, "unbind function '%s'/%p\n",
 740                                         f->name, f);
 741                                 f->unbind(config, f);
 742                                 /* may free memory for "f" */
 743                         }
 744                 }
 745                 list_del(&config->list);
 746                 config->cdev = NULL;
 747         } else {
 748                 unsigned        i;
 749
 750                 DBG(cdev, "cfg %d/%p speeds:%s%s%s\n",
 751                         config->bConfigurationValue, config,
 752                         config->superspeed ? " super" : "",
 753                         config->highspeed ? " high" : "",
 754                         config->fullspeed
 755                                 ? (gadget_is_dualspeed(cdev->gadget)
 756                                         ? " full"
 757                                         : " full/low")
 758                                 : "");
 759
 760                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 761                         struct usb_function     *f = config->interface[i];
 762
 763                         if (!f)
 764                                 continue;
 765                         DBG(cdev, "  interface %d = %s/%p\n",
 766                                 i, f->name, f);
 767                 }
 768         }
 769
 770         /* set_alt(), or next bind(), sets up
 771          * ep->driver_data as needed.
 772          */
 773         usb_ep_autoconfig_reset(cdev->gadget);
 774
 775 done:
 776         if (status)
 777                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 778                                 config->bConfigurationValue, status);
 779         return status;
 780 }
 781 EXPORT_SYMBOL_GPL(usb_add_config);
 782
 783 static void remove_config(struct usb_composite_dev *cdev,
 784                               struct usb_configuration *config)
 785 {
 786         while (!list_empty(&config->functions)) {
 787                 struct usb_function             *f;
 788
 789                 f = list_first_entry(&config->functions,
 790                                 struct usb_function, list);
 791                 list_del(&f->list);
 792                 if (f->unbind) {
 793                         DBG(cdev, "unbind function '%s'/%p\n", f->name, f);
 794                         f->unbind(config, f);
 795                         /* may free memory for "f" */
 796                 }
 797         }
 798         list_del(&config->list);
 799         if (config->unbind) {
 800                 DBG(cdev, "unbind config '%s'/%p\n", config->label, config);
 801                 config->unbind(config);
 802                         /* may free memory for "c" */
 803         }
 804 }
 805
 806 /**
 807  * usb_remove_config() - remove a configuration from a device.
 808  * @cdev: wraps the USB gadget
 809  * @config: the configuration
 810  *
 811  * Drivers must call usb_gadget_disconnect before calling this function
 812  * to disconnect the device from the host and make sure the host will not
 813  * try to enumerate the device while we are changing the config list.
 814  */
 815 void usb_remove_config(struct usb_composite_dev *cdev,
 816                       struct usb_configuration *config)
 817 {
 818         unsigned long flags;
 819
 820         spin_lock_irqsave(&cdev->lock, flags);
 821
 822         if (cdev->config == config)
 823                 reset_config(cdev);
 824
 825         spin_unlock_irqrestore(&cdev->lock, flags);
 826
 827         remove_config(cdev, config);
 828 }
 829
 830 /*-------------------------------------------------------------------------*/
 831
 832 /* We support strings in multiple languages ... string descriptor zero
 833  * says which languages are supported.  The typical case will be that
 834  * only one language (probably English) is used, with I18N handled on
 835  * the host side.
 836  */
 837
 838 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 839 {
 840         const struct usb_gadget_strings *s;
 841         __le16                          language;
 842         __le16                          *tmp;
 843
 844         while (*sp) {
 845                 s = *sp;
 846                 language = cpu_to_le16(s->language);
 847                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 848                         if (*tmp == language)
 849                                 goto repeat;
 850                 }
 851                 *tmp++ = language;
 852 repeat:
 853                 sp++;
 854         }
 855 }
 856
 857 static int lookup_string(
 858         struct usb_gadget_strings       **sp,
 859         void                            *buf,
 860         u16                             language,
 861         int                             id
 862 )
 863 {
 864         struct usb_gadget_strings       *s;
 865         int                             value;
 866
 867         while (*sp) {
 868                 s = *sp++;
 869                 if (s->language != language)
 870                         continue;
 871                 value = usb_gadget_get_string(s, id, buf);
 872                 if (value > 0)
 873                         return value;
 874         }
 875         return -EINVAL;
 876 }
 877
 878 static int get_string(struct usb_composite_dev *cdev,
 879                 void *buf, u16 language, int id)
 880 {
 881         struct usb_composite_driver     *composite = cdev->driver;
 882         struct usb_configuration        *c;
 883         struct usb_function             *f;
 884         int                             len;
 885
 886         /* Yes, not only is USB's I18N support probably more than most
 887          * folk will ever care about ... also, it's all supported here.
 888          * (Except for UTF8 support for Unicode's "Astral Planes".)
 889          */
 890
 891         /* 0 == report all available language codes */
 892         if (id == 0) {
 893                 struct usb_string_descriptor    *s = buf;
 894                 struct usb_gadget_strings       **sp;
 895
 896                 memset(s, 0, 256);
 897                 s->bDescriptorType = USB_DT_STRING;
 898
 899                 sp = composite->strings;
 900                 if (sp)
 901                         collect_langs(sp, s->wData);
 902
 903                 list_for_each_entry(c, &cdev->configs, list) {
 904                         sp = c->strings;
 905                         if (sp)
 906                                 collect_langs(sp, s->wData);
 907
 908                         list_for_each_entry(f, &c->functions, list) {
 909                                 sp = f->strings;
 910                                 if (sp)
 911                                         collect_langs(sp, s->wData);
 912                         }
 913                 }
 914
 915                 for (len = 0; len <= 126 && s->wData[len]; len++)
 916                         continue;
 917                 if (!len)
 918                         return -EINVAL;
 919
 920                 s->bLength = 2 * (len + 1);
 921                 return s->bLength;
 922         }
 923
 924         /* String IDs are device-scoped, so we look up each string
 925          * table we're told about.  These lookups are infrequent;
 926          * simpler-is-better here.
 927          */
 928         if (composite->strings) {
 929                 len = lookup_string(composite->strings, buf, language, id);
 930                 if (len > 0)
 931                         return len;
 932         }
 933         list_for_each_entry(c, &cdev->configs, list) {
 934                 if (c->strings) {
 935                         len = lookup_string(c->strings, buf, language, id);
 936                         if (len > 0)
 937                                 return len;
 938                 }
 939                 list_for_each_entry(f, &c->functions, list) {
 940                         if (!f->strings)
 941                                 continue;
 942                         len = lookup_string(f->strings, buf, language, id);
 943                         if (len > 0)
 944                                 return len;
 945                 }
 946         }
 947         return -EINVAL;
 948 }
 949
 950 /**
 951  * usb_string_id() - allocate an unused string ID
 952  * @cdev: the device whose string descriptor IDs are being allocated
 953  * Context: single threaded during gadget setup
 954  *
 955  * @usb_string_id() is called from bind() callbacks to allocate
 956  * string IDs.  Drivers for functions, configurations, or gadgets will
 957  * then store that ID in the appropriate descriptors and string table.
 958  *
 959  * All string identifier should be allocated using this,
 960  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 961  * that for example different functions don't wrongly assign different
 962  * meanings to the same identifier.
 963  */
 964 int usb_string_id(struct usb_composite_dev *cdev)
 965 {
 966         if (cdev->next_string_id < 254) {
 967                 /* string id 0 is reserved by USB spec for list of
 968                  * supported languages */
 969                 /* 255 reserved as well? -- mina86 */
 970                 cdev->next_string_id++;
 971                 return cdev->next_string_id;
 972         }
 973         return -ENODEV;
 974 }
 975 EXPORT_SYMBOL_GPL(usb_string_id);
 976
 977 /**
 978  * usb_string_ids() - allocate unused string IDs in batch
 979  * @cdev: the device whose string descriptor IDs are being allocated
 980  * @str: an array of usb_string objects to assign numbers to
 981  * Context: single threaded during gadget setup
 982  *
 983  * @usb_string_ids() is called from bind() callbacks to allocate
 984  * string IDs.  Drivers for functions, configurations, or gadgets will
 985  * then copy IDs from the string table to the appropriate descriptors
 986  * and string table for other languages.
 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  */
 993 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 994 {
 995         int next = cdev->next_string_id;
 996
 997         for (; str->s; ++str) {
 998                 if (unlikely(next >= 254))
 999                         return -ENODEV;
1000                 str->id = ++next;
1001         }
1002
1003         cdev->next_string_id = next;
1004
1005         return 0;
1006 }
1007 EXPORT_SYMBOL_GPL(usb_string_ids_tab);
1008
1009 /**
1010  * usb_string_ids_n() - allocate unused string IDs in batch
1011  * @c: the device whose string descriptor IDs are being allocated
1012  * @n: number of string IDs to allocate
1013  * Context: single threaded during gadget setup
1014  *
1015  * Returns the first requested ID.  This ID and next @n-1 IDs are now
1016  * valid IDs.  At least provided that @n is non-zero because if it
1017  * is, returns last requested ID which is now very useful information.
1018  *
1019  * @usb_string_ids_n() is called from bind() callbacks to allocate
1020  * string IDs.  Drivers for functions, configurations, or gadgets will
1021  * then store that ID in the appropriate descriptors and string table.
1022  *
1023  * All string identifier should be allocated using this,
1024  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
1025  * example different functions don't wrongly assign different meanings
1026  * to the same identifier.
1027  */
1028 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
1029 {
1030         unsigned next = c->next_string_id;
1031         if (unlikely(n > 254 || (unsigned)next + n > 254))
1032                 return -ENODEV;
1033         c->next_string_id += n;
1034         return next + 1;
1035 }
1036 EXPORT_SYMBOL_GPL(usb_string_ids_n);
1037
1038 /*-------------------------------------------------------------------------*/
1039
1040 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
1041 {
1042         if (req->status || req->actual != req->length)
1043                 DBG((struct usb_composite_dev *) ep->driver_data,
1044                                 "setup complete --> %d, %d/%d\n",
1045                                 req->status, req->actual, req->length);
1046 }
1047
1048 /*
1049  * The setup() callback implements all the ep0 functionality that's
1050  * not handled lower down, in hardware or the hardware driver(like
1051  * device and endpoint feature flags, and their status).  It's all
1052  * housekeeping for the gadget function we're implementing.  Most of
1053  * the work is in config and function specific setup.
1054  */
1055 static int
1056 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1057 {
1058         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1059         struct usb_request              *req = cdev->req;
1060         int                             value = -EOPNOTSUPP;
1061         int                             status = 0;
1062         u16                             w_index = le16_to_cpu(ctrl->wIndex);
1063         u8                              intf = w_index & 0xFF;
1064         u16                             w_value = le16_to_cpu(ctrl->wValue);
1065         u16                             w_length = le16_to_cpu(ctrl->wLength);
1066         struct usb_function             *f = NULL;
1067         u8                              endp;
1068
1069         /* partial re-init of the response message; the function or the
1070          * gadget might need to intercept e.g. a control-OUT completion
1071          * when we delegate to it.
1072          */
1073         req->zero = 0;
1074         req->complete = composite_setup_complete;
1075         req->length = 0;
1076         gadget->ep0->driver_data = cdev;
1077
1078         switch (ctrl->bRequest) {
1079
1080         /* we handle all standard USB descriptors */
1081         case USB_REQ_GET_DESCRIPTOR:
1082                 if (ctrl->bRequestType != USB_DIR_IN)
1083                         goto unknown;
1084                 switch (w_value >> 8) {
1085
1086                 case USB_DT_DEVICE:
1087                         cdev->desc.bNumConfigurations =
1088                                 count_configs(cdev, USB_DT_DEVICE);
1089                         cdev->desc.bMaxPacketSize0 =
1090                                 cdev->gadget->ep0->maxpacket;
1091                         if (gadget_is_superspeed(gadget)) {
1092                                 if (gadget->speed >= USB_SPEED_SUPER) {
1093                                         cdev->desc.bcdUSB = cpu_to_le16(0x0300);
1094                                         cdev->desc.bMaxPacketSize0 = 9;
1095                                 } else {
1096                                         cdev->desc.bcdUSB = cpu_to_le16(0x0210);
1097                                 }
1098                         }
1099
1100                         value = min(w_length, (u16) sizeof cdev->desc);
1101                         memcpy(req->buf, &cdev->desc, value);
1102                         break;
1103                 case USB_DT_DEVICE_QUALIFIER:
1104                         if (!gadget_is_dualspeed(gadget) ||
1105                             gadget->speed >= USB_SPEED_SUPER)
1106                                 break;
1107                         device_qual(cdev);
1108                         value = min_t(int, w_length,
1109                                 sizeof(struct usb_qualifier_descriptor));
1110                         break;
1111                 case USB_DT_OTHER_SPEED_CONFIG:
1112                         if (!gadget_is_dualspeed(gadget) ||
1113                             gadget->speed >= USB_SPEED_SUPER)
1114                                 break;
1115                         /* FALLTHROUGH */
1116                 case USB_DT_CONFIG:
1117                         value = config_desc(cdev, w_value);
1118                         if (value >= 0)
1119                                 value = min(w_length, (u16) value);
1120                         break;
1121                 case USB_DT_STRING:
1122                         value = get_string(cdev, req->buf,
1123                                         w_index, w_value & 0xff);
1124                         if (value >= 0)
1125                                 value = min(w_length, (u16) value);
1126                         break;
1127                 case USB_DT_BOS:
1128                         if (gadget_is_superspeed(gadget)) {
1129                                 value = bos_desc(cdev);
1130                                 value = min(w_length, (u16) value);
1131                         }
1132                         break;
1133                 }
1134                 break;
1135
1136         /* any number of configs can work */
1137         case USB_REQ_SET_CONFIGURATION:
1138                 if (ctrl->bRequestType != 0)
1139                         goto unknown;
1140                 if (gadget_is_otg(gadget)) {
1141                         if (gadget->a_hnp_support)
1142                                 DBG(cdev, "HNP available\n");
1143                         else if (gadget->a_alt_hnp_support)
1144                                 DBG(cdev, "HNP on another port\n");
1145                         else
1146                                 VDBG(cdev, "HNP inactive\n");
1147                 }
1148                 spin_lock(&cdev->lock);
1149                 value = set_config(cdev, ctrl, w_value);
1150                 spin_unlock(&cdev->lock);
1151                 break;
1152         case USB_REQ_GET_CONFIGURATION:
1153                 if (ctrl->bRequestType != USB_DIR_IN)
1154                         goto unknown;
1155                 if (cdev->config)
1156                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
1157                 else
1158                         *(u8 *)req->buf = 0;
1159                 value = min(w_length, (u16) 1);
1160                 break;
1161
1162         /* function drivers must handle get/set altsetting; if there's
1163          * no get() method, we know only altsetting zero works.
1164          */
1165         case USB_REQ_SET_INTERFACE:
1166                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
1167                         goto unknown;
1168                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1169                         break;
1170                 f = cdev->config->interface[intf];
1171                 if (!f)
1172                         break;
1173                 if (w_value && !f->set_alt)
1174                         break;
1175                 value = f->set_alt(f, w_index, w_value);
1176                 if (value == USB_GADGET_DELAYED_STATUS) {
1177                         DBG(cdev,
1178                          "%s: interface %d (%s) requested delayed status\n",
1179                                         __func__, intf, f->name);
1180                         cdev->delayed_status++;
1181                         DBG(cdev, "delayed_status count %d\n",
1182                                         cdev->delayed_status);
1183                 }
1184                 break;
1185         case USB_REQ_GET_INTERFACE:
1186                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
1187                         goto unknown;
1188                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1189                         break;
1190                 f = cdev->config->interface[intf];
1191                 if (!f)
1192                         break;
1193                 /* lots of interfaces only need altsetting zero... */
1194                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
1195                 if (value < 0)
1196                         break;
1197                 *((u8 *)req->buf) = value;
1198                 value = min(w_length, (u16) 1);
1199                 break;
1200
1201         /*
1202          * USB 3.0 additions:
1203          * Function driver should handle get_status request. If such cb
1204          * wasn't supplied we respond with default value = 0
1205          * Note: function driver should supply such cb only for the first
1206          * interface of the function
1207          */
1208         case USB_REQ_GET_STATUS:
1209                 if (!gadget_is_superspeed(gadget))
1210                         goto unknown;
1211                 if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
1212                         goto unknown;
1213                 value = 2;      /* This is the length of the get_status reply */
1214                 put_unaligned_le16(0, req->buf);
1215                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1216                         break;
1217                 f = cdev->config->interface[intf];
1218                 if (!f)
1219                         break;
1220                 status = f->get_status ? f->get_status(f) : 0;
1221                 if (status < 0)
1222                         break;
1223                 put_unaligned_le16(status & 0x0000ffff, req->buf);
1224                 break;
1225         /*
1226          * Function drivers should handle SetFeature/ClearFeature
1227          * (FUNCTION_SUSPEND) request. function_suspend cb should be supplied
1228          * only for the first interface of the function
1229          */
1230         case USB_REQ_CLEAR_FEATURE:
1231         case USB_REQ_SET_FEATURE:
1232                 if (!gadget_is_superspeed(gadget))
1233                         goto unknown;
1234                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_RECIP_INTERFACE))
1235                         goto unknown;
1236                 switch (w_value) {
1237                 case USB_INTRF_FUNC_SUSPEND:
1238                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1239                                 break;
1240                         f = cdev->config->interface[intf];
1241                         if (!f)
1242                                 break;
1243                         value = 0;
1244                         if (f->func_suspend)
1245                                 value = f->func_suspend(f, w_index >> 8);
1246                         if (value < 0) {
1247                                 ERROR(cdev,
1248                                       "func_suspend() returned error %d\n",
1249                                       value);
1250                                 value = 0;
1251                         }
1252                         break;
1253                 }
1254                 break;
1255         default:
1256 unknown:
1257                 VDBG(cdev,
1258                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
1259                         ctrl->bRequestType, ctrl->bRequest,
1260                         w_value, w_index, w_length);
1261
1262                 /* functions always handle their interfaces and endpoints...
1263                  * punt other recipients (other, WUSB, ...) to the current
1264                  * configuration code.
1265                  *
1266                  * REVISIT it could make sense to let the composite device
1267                  * take such requests too, if that's ever needed:  to work
1268                  * in config 0, etc.
1269                  */
1270                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
1271                 case USB_RECIP_INTERFACE:
1272                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
1273                                 break;
1274                         f = cdev->config->interface[intf];
1275                         break;
1276
1277                 case USB_RECIP_ENDPOINT:
1278                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
1279                         list_for_each_entry(f, &cdev->config->functions, list) {
1280                                 if (test_bit(endp, f->endpoints))
1281                                         break;
1282                         }
1283                         if (&f->list == &cdev->config->functions)
1284                                 f = NULL;
1285                         break;
1286                 }
1287
1288                 if (f && f->setup)
1289                         value = f->setup(f, ctrl);
1290                 else {
1291                         struct usb_configuration        *c;
1292
1293                         c = cdev->config;
1294                         if (c && c->setup)
1295                                 value = c->setup(c, ctrl);
1296                 }
1297
1298                 goto done;
1299         }
1300
1301         /* respond with data transfer before status phase? */
1302         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
1303                 req->length = value;
1304                 req->zero = value < w_length;
1305                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
1306                 if (value < 0) {
1307                         DBG(cdev, "ep_queue --> %d\n", value);
1308                         req->status = 0;
1309                         composite_setup_complete(gadget->ep0, req);
1310                 }
1311         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
1312                 WARN(cdev,
1313                         "%s: Delayed status not supported for w_length != 0",
1314                         __func__);
1315         }
1316
1317 done:
1318         /* device either stalls (value < 0) or reports success */
1319         return value;
1320 }
1321
1322 static void composite_disconnect(struct usb_gadget *gadget)
1323 {
1324         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1325         unsigned long                   flags;
1326
1327         /* REVISIT:  should we have config and device level
1328          * disconnect callbacks?
1329          */
1330         spin_lock_irqsave(&cdev->lock, flags);
1331         if (cdev->config)
1332                 reset_config(cdev);
1333         if (cdev->driver->disconnect)
1334                 cdev->driver->disconnect(cdev);
1335         spin_unlock_irqrestore(&cdev->lock, flags);
1336 }
1337
1338 /*-------------------------------------------------------------------------*/
1339
1340 static ssize_t composite_show_suspended(struct device *dev,
1341                                         struct device_attribute *attr,
1342                                         char *buf)
1343 {
1344         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1345         struct usb_composite_dev *cdev = get_gadget_data(gadget);
1346
1347         return sprintf(buf, "%d\n", cdev->suspended);
1348 }
1349
1350 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1351
1352 static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
1353 {
1354         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1355
1356         /* composite_disconnect() must already have been called
1357          * by the underlying peripheral controller driver!
1358          * so there's no i/o concurrency that could affect the
1359          * state protected by cdev->lock.
1360          */
1361         WARN_ON(cdev->config);
1362
1363         while (!list_empty(&cdev->configs)) {
1364                 struct usb_configuration        *c;
1365                 c = list_first_entry(&cdev->configs,
1366                                 struct usb_configuration, list);
1367                 remove_config(cdev, c);
1368         }
1369         if (cdev->driver->unbind && unbind_driver)
1370                 cdev->driver->unbind(cdev);
1371
1372         if (cdev->req) {
1373                 kfree(cdev->req->buf);
1374                 usb_ep_free_request(gadget->ep0, cdev->req);
1375         }
1376         device_remove_file(&gadget->dev, &dev_attr_suspended);
1377         kfree(cdev->def_manufacturer);
1378         kfree(cdev);
1379         set_gadget_data(gadget, NULL);
1380 }
1381
1382 static void composite_unbind(struct usb_gadget *gadget)
1383 {
1384         __composite_unbind(gadget, true);
1385 }
1386
1387 static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
1388                 const struct usb_device_descriptor *old)
1389 {
1390         __le16 idVendor;
1391         __le16 idProduct;
1392         __le16 bcdDevice;
1393         u8 iSerialNumber;
1394         u8 iManufacturer;
1395         u8 iProduct;
1396
1397         /*
1398          * these variables may have been set in
1399          * usb_composite_overwrite_options()
1400          */
1401         idVendor = new->idVendor;
1402         idProduct = new->idProduct;
1403         bcdDevice = new->bcdDevice;
1404         iSerialNumber = new->iSerialNumber;
1405         iManufacturer = new->iManufacturer;
1406         iProduct = new->iProduct;
1407
1408         *new = *old;
1409         if (idVendor)
1410                 new->idVendor = idVendor;
1411         if (idProduct)
1412                 new->idProduct = idProduct;
1413         if (bcdDevice)
1414                 new->bcdDevice = bcdDevice;
1415         else
1416                 new->bcdDevice = cpu_to_le16(get_default_bcdDevice());
1417         if (iSerialNumber)
1418                 new->iSerialNumber = iSerialNumber;
1419         if (iManufacturer)
1420                 new->iManufacturer = iManufacturer;
1421         if (iProduct)
1422                 new->iProduct = iProduct;
1423 }
1424
1425 static struct usb_composite_driver *to_cdriver(struct usb_gadget_driver *gdrv)
1426 {
1427         return container_of(gdrv, struct usb_composite_driver, gadget_driver);
1428 }
1429
1430 static int composite_bind(struct usb_gadget *gadget,
1431                 struct usb_gadget_driver *gdriver)
1432 {
1433         struct usb_composite_dev        *cdev;
1434         struct usb_composite_driver     *composite = to_cdriver(gdriver);
1435         int                             status = -ENOMEM;
1436
1437         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1438         if (!cdev)
1439                 return status;
1440
1441         spin_lock_init(&cdev->lock);
1442         cdev->gadget = gadget;
1443         set_gadget_data(gadget, cdev);
1444         INIT_LIST_HEAD(&cdev->configs);
1445
1446         /* preallocate control response and buffer */
1447         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1448         if (!cdev->req)
1449                 goto fail;
1450         cdev->req->buf = kmalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
1451         if (!cdev->req->buf)
1452                 goto fail;
1453         cdev->req->complete = composite_setup_complete;
1454         gadget->ep0->driver_data = cdev;
1455
1456         cdev->driver = composite;
1457
1458         /*
1459          * As per USB compliance update, a device that is actively drawing
1460          * more than 100mA from USB must report itself as bus-powered in
1461          * the GetStatus(DEVICE) call.
1462          */
1463         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
1464                 usb_gadget_set_selfpowered(gadget);
1465
1466         /* interface and string IDs start at zero via kzalloc.
1467          * we force endpoints to start unassigned; few controller
1468          * drivers will zero ep->driver_data.
1469          */
1470         usb_ep_autoconfig_reset(cdev->gadget);
1471
1472         /* composite gadget needs to assign strings for whole device (like
1473          * serial number), register function drivers, potentially update
1474          * power state and consumption, etc
1475          */
1476         status = composite->bind(cdev);
1477         if (status < 0)
1478                 goto fail;
1479
1480         update_unchanged_dev_desc(&cdev->desc, composite->dev);
1481
1482         /* has userspace failed to provide a serial number? */
1483         if (composite->needs_serial && !cdev->desc.iSerialNumber)
1484                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
1485
1486         /* finish up */
1487         status = device_create_file(&gadget->dev, &dev_attr_suspended);
1488         if (status)
1489                 goto fail;
1490
1491         INFO(cdev, "%s ready\n", composite->name);
1492         return 0;
1493
1494 fail:
1495         __composite_unbind(gadget, false);
1496         return status;
1497 }
1498
1499 /*-------------------------------------------------------------------------*/
1500
1501 static void
1502 composite_suspend(struct usb_gadget *gadget)
1503 {
1504         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1505         struct usb_function             *f;
1506
1507         /* REVISIT:  should we have config level
1508          * suspend/resume callbacks?
1509          */
1510         DBG(cdev, "suspend\n");
1511         if (cdev->config) {
1512                 list_for_each_entry(f, &cdev->config->functions, list) {
1513                         if (f->suspend)
1514                                 f->suspend(f);
1515                 }
1516         }
1517         if (cdev->driver->suspend)
1518                 cdev->driver->suspend(cdev);
1519
1520         cdev->suspended = 1;
1521
1522         usb_gadget_vbus_draw(gadget, 2);
1523 }
1524
1525 static void
1526 composite_resume(struct usb_gadget *gadget)
1527 {
1528         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1529         struct usb_function             *f;
1530         u8                              maxpower;
1531
1532         /* REVISIT:  should we have config level
1533          * suspend/resume callbacks?
1534          */
1535         DBG(cdev, "resume\n");
1536         if (cdev->driver->resume)
1537                 cdev->driver->resume(cdev);
1538         if (cdev->config) {
1539                 list_for_each_entry(f, &cdev->config->functions, list) {
1540                         if (f->resume)
1541                                 f->resume(f);
1542                 }
1543
1544                 maxpower = cdev->config->MaxPower;
1545
1546                 usb_gadget_vbus_draw(gadget, maxpower ?
1547                         maxpower : CONFIG_USB_GADGET_VBUS_DRAW);
1548         }
1549
1550         cdev->suspended = 0;
1551 }
1552
1553 /*-------------------------------------------------------------------------*/
1554
1555 static const struct usb_gadget_driver composite_driver_template = {
1556         .bind           = composite_bind,
1557         .unbind         = composite_unbind,
1558
1559         .setup          = composite_setup,
1560         .disconnect     = composite_disconnect,
1561
1562         .suspend        = composite_suspend,
1563         .resume         = composite_resume,
1564
1565         .driver = {
1566                 .owner          = THIS_MODULE,
1567         },
1568 };
1569
1570 /**
1571  * usb_composite_probe() - register a composite driver
1572  * @driver: the driver to register
1573  * @bind: the callback used to allocate resources that are shared across the
1574  *      whole device, such as string IDs, and add its configurations using
1575  *      @usb_add_config().  This may fail by returning a negative errno
1576  *      value; it should return zero on successful initialization.
1577  * Context: single threaded during gadget setup
1578  *
1579  * This function is used to register drivers using the composite driver
1580  * framework.  The return value is zero, or a negative errno value.
1581  * Those values normally come from the driver's @bind method, which does
1582  * all the work of setting up the driver to match the hardware.
1583  *
1584  * On successful return, the gadget is ready to respond to requests from
1585  * the host, unless one of its components invokes usb_gadget_disconnect()
1586  * while it was binding.  That would usually be done in order to wait for
1587  * some userspace participation.
1588  */
1589 int usb_composite_probe(struct usb_composite_driver *driver)
1590 {
1591         struct usb_gadget_driver *gadget_driver;
1592
1593         if (!driver || !driver->dev || !driver->bind)
1594                 return -EINVAL;
1595
1596         if (!driver->name)
1597                 driver->name = "composite";
1598
1599         driver->gadget_driver = composite_driver_template;
1600         gadget_driver = &driver->gadget_driver;
1601
1602         gadget_driver->function =  (char *) driver->name;
1603         gadget_driver->driver.name = driver->name;
1604         gadget_driver->max_speed = driver->max_speed;
1605
1606         return usb_gadget_probe_driver(gadget_driver);
1607 }
1608 EXPORT_SYMBOL_GPL(usb_composite_probe);
1609
1610 /**
1611  * usb_composite_unregister() - unregister a composite driver
1612  * @driver: the driver to unregister
1613  *
1614  * This function is used to unregister drivers using the composite
1615  * driver framework.
1616  */
1617 void usb_composite_unregister(struct usb_composite_driver *driver)
1618 {
1619         usb_gadget_unregister_driver(&driver->gadget_driver);
1620 }
1621 EXPORT_SYMBOL_GPL(usb_composite_unregister);
1622
1623 /**
1624  * usb_composite_setup_continue() - Continue with the control transfer
1625  * @cdev: the composite device who's control transfer was kept waiting
1626  *
1627  * This function must be called by the USB function driver to continue
1628  * with the control transfer's data/status stage in case it had requested to
1629  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
1630  * can request the composite framework to delay the setup request's data/status
1631  * stages by returning USB_GADGET_DELAYED_STATUS.
1632  */
1633 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
1634 {
1635         int                     value;
1636         struct usb_request      *req = cdev->req;
1637         unsigned long           flags;
1638
1639         DBG(cdev, "%s\n", __func__);
1640         spin_lock_irqsave(&cdev->lock, flags);
1641
1642         if (cdev->delayed_status == 0) {
1643                 WARN(cdev, "%s: Unexpected call\n", __func__);
1644
1645         } else if (--cdev->delayed_status == 0) {
1646                 DBG(cdev, "%s: Completing delayed status\n", __func__);
1647                 req->length = 0;
1648                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1649                 if (value < 0) {
1650                         DBG(cdev, "ep_queue --> %d\n", value);
1651                         req->status = 0;
1652                         composite_setup_complete(cdev->gadget->ep0, req);
1653                 }
1654         }
1655
1656         spin_unlock_irqrestore(&cdev->lock, flags);
1657 }
1658 EXPORT_SYMBOL_GPL(usb_composite_setup_continue);
1659
1660 static char *composite_default_mfr(struct usb_gadget *gadget)
1661 {
1662         char *mfr;
1663         int len;
1664
1665         len = snprintf(NULL, 0, "%s %s with %s", init_utsname()->sysname,
1666                         init_utsname()->release, gadget->name);
1667         len++;
1668         mfr = kmalloc(len, GFP_KERNEL);
1669         if (!mfr)
1670                 return NULL;
1671         snprintf(mfr, len, "%s %s with %s", init_utsname()->sysname,
1672                         init_utsname()->release, gadget->name);
1673         return mfr;
1674 }
1675
1676 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
1677                 struct usb_composite_overwrite *covr)
1678 {
1679         struct usb_device_descriptor    *desc = &cdev->desc;
1680         struct usb_gadget_strings       *gstr = cdev->driver->strings[0];
1681         struct usb_string               *dev_str = gstr->strings;
1682
1683         if (covr->idVendor)
1684                 desc->idVendor = cpu_to_le16(covr->idVendor);
1685
1686         if (covr->idProduct)
1687                 desc->idProduct = cpu_to_le16(covr->idProduct);
1688
1689         if (covr->bcdDevice)
1690                 desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
1691
1692         if (covr->serial_number) {
1693                 desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
1694                 dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
1695         }
1696         if (covr->manufacturer) {
1697                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
1698                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = covr->manufacturer;
1699
1700         } else if (!strlen(dev_str[USB_GADGET_MANUFACTURER_IDX].s)) {
1701                 desc->iManufacturer = dev_str[USB_GADGET_MANUFACTURER_IDX].id;
1702                 cdev->def_manufacturer = composite_default_mfr(cdev->gadget);
1703                 dev_str[USB_GADGET_MANUFACTURER_IDX].s = cdev->def_manufacturer;
1704         }
1705
1706         if (covr->product) {
1707                 desc->iProduct = dev_str[USB_GADGET_PRODUCT_IDX].id;
1708                 dev_str[USB_GADGET_PRODUCT_IDX].s = covr->product;
1709         }
1710 }
1711 EXPORT_SYMBOL_GPL(usb_composite_overwrite_options);
1712
1713 MODULE_LICENSE("GPL");
1714 MODULE_AUTHOR("David Brownell");