drivers/usb/gadget/composite.c

   1 /*
   2  * composite.c - infrastructure for Composite USB Gadgets
   3  *
   4  * Copyright (C) 2006-2008 David Brownell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /* #define VERBOSE_DEBUG */
  22
  23 #include <linux/kallsyms.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/device.h>
  27 #include <linux/utsname.h>
  28
  29 #include <linux/usb/composite.h>
  30
  31
  32 /*
  33  * The code in this file is utility code, used to build a gadget driver
  34  * from one or more "function" drivers, one or more "configuration"
  35  * objects, and a "usb_composite_driver" by gluing them together along
  36  * with the relevant device-wide data.
  37  */
  38
  39 /* big enough to hold our biggest descriptor */
  40 #define USB_BUFSIZ      1024
  41
  42 static struct usb_composite_driver *composite;
  43 static int (*composite_gadget_bind)(struct usb_composite_dev *cdev);
  44
  45 /* Some systems will need runtime overrides for the  product identifiers
  46  * published in the device descriptor, either numbers or strings or both.
  47  * String parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  48  */
  49
  50 static ushort idVendor;
  51 module_param(idVendor, ushort, 0);
  52 MODULE_PARM_DESC(idVendor, "USB Vendor ID");
  53
  54 static ushort idProduct;
  55 module_param(idProduct, ushort, 0);
  56 MODULE_PARM_DESC(idProduct, "USB Product ID");
  57
  58 static ushort bcdDevice;
  59 module_param(bcdDevice, ushort, 0);
  60 MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
  61
  62 static char *iManufacturer;
  63 module_param(iManufacturer, charp, 0);
  64 MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
  65
  66 static char *iProduct;
  67 module_param(iProduct, charp, 0);
  68 MODULE_PARM_DESC(iProduct, "USB Product string");
  69
  70 static char *iSerialNumber;
  71 module_param(iSerialNumber, charp, 0);
  72 MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
  73
  74 static char composite_manufacturer[50];
  75
  76 /*-------------------------------------------------------------------------*/
  77
  78 /**
  79  * usb_add_function() - add a function to a configuration
  80  * @config: the configuration
  81  * @function: the function being added
  82  * Context: single threaded during gadget setup
  83  *
  84  * After initialization, each configuration must have one or more
  85  * functions added to it.  Adding a function involves calling its @bind()
  86  * method to allocate resources such as interface and string identifiers
  87  * and endpoints.
  88  *
  89  * This function returns the value of the function's bind(), which is
  90  * zero for success else a negative errno value.
  91  */
  92 int usb_add_function(struct usb_configuration *config,
  93                 struct usb_function *function)
  94 {
  95         int     value = -EINVAL;
  96
  97         DBG(config->cdev, "adding '%s'/%p to config '%s'/%p\n",
  98                         function->name, function,
  99                         config->label, config);
 100
 101         if (!function->set_alt || !function->disable)
 102                 goto done;
 103
 104         function->config = config;
 105         list_add_tail(&function->list, &config->functions);
 106
 107         /* REVISIT *require* function->bind? */
 108         if (function->bind) {
 109                 value = function->bind(config, function);
 110                 if (value < 0) {
 111                         list_del(&function->list);
 112                         function->config = NULL;
 113                 }
 114         } else
 115                 value = 0;
 116
 117         /* We allow configurations that don't work at both speeds.
 118          * If we run into a lowspeed Linux system, treat it the same
 119          * as full speed ... it's the function drivers that will need
 120          * to avoid bulk and ISO transfers.
 121          */
 122         if (!config->fullspeed && function->descriptors)
 123                 config->fullspeed = true;
 124         if (!config->highspeed && function->hs_descriptors)
 125                 config->highspeed = true;
 126
 127 done:
 128         if (value)
 129                 DBG(config->cdev, "adding '%s'/%p --> %d\n",
 130                                 function->name, function, value);
 131         return value;
 132 }
 133
 134 /**
 135  * usb_function_deactivate - prevent function and gadget enumeration
 136  * @function: the function that isn't yet ready to respond
 137  *
 138  * Blocks response of the gadget driver to host enumeration by
 139  * preventing the data line pullup from being activated.  This is
 140  * normally called during @bind() processing to change from the
 141  * initial "ready to respond" state, or when a required resource
 142  * becomes available.
 143  *
 144  * For example, drivers that serve as a passthrough to a userspace
 145  * daemon can block enumeration unless that daemon (such as an OBEX,
 146  * MTP, or print server) is ready to handle host requests.
 147  *
 148  * Not all systems support software control of their USB peripheral
 149  * data pullups.
 150  *
 151  * Returns zero on success, else negative errno.
 152  */
 153 int usb_function_deactivate(struct usb_function *function)
 154 {
 155         struct usb_composite_dev        *cdev = function->config->cdev;
 156         unsigned long                   flags;
 157         int                             status = 0;
 158
 159         spin_lock_irqsave(&cdev->lock, flags);
 160
 161         if (cdev->deactivations == 0)
 162                 status = usb_gadget_disconnect(cdev->gadget);
 163         if (status == 0)
 164                 cdev->deactivations++;
 165
 166         spin_unlock_irqrestore(&cdev->lock, flags);
 167         return status;
 168 }
 169
 170 /**
 171  * usb_function_activate - allow function and gadget enumeration
 172  * @function: function on which usb_function_activate() was called
 173  *
 174  * Reverses effect of usb_function_deactivate().  If no more functions
 175  * are delaying their activation, the gadget driver will respond to
 176  * host enumeration procedures.
 177  *
 178  * Returns zero on success, else negative errno.
 179  */
 180 int usb_function_activate(struct usb_function *function)
 181 {
 182         struct usb_composite_dev        *cdev = function->config->cdev;
 183         int                             status = 0;
 184
 185         spin_lock(&cdev->lock);
 186
 187         if (WARN_ON(cdev->deactivations == 0))
 188                 status = -EINVAL;
 189         else {
 190                 cdev->deactivations--;
 191                 if (cdev->deactivations == 0)
 192                         status = usb_gadget_connect(cdev->gadget);
 193         }
 194
 195         spin_unlock(&cdev->lock);
 196         return status;
 197 }
 198
 199 /**
 200  * usb_interface_id() - allocate an unused interface ID
 201  * @config: configuration associated with the interface
 202  * @function: function handling the interface
 203  * Context: single threaded during gadget setup
 204  *
 205  * usb_interface_id() is called from usb_function.bind() callbacks to
 206  * allocate new interface IDs.  The function driver will then store that
 207  * ID in interface, association, CDC union, and other descriptors.  It
 208  * will also handle any control requests targeted at that interface,
 209  * particularly changing its altsetting via set_alt().  There may
 210  * also be class-specific or vendor-specific requests to handle.
 211  *
 212  * All interface identifier should be allocated using this routine, to
 213  * ensure that for example different functions don't wrongly assign
 214  * different meanings to the same identifier.  Note that since interface
 215  * identifiers are configuration-specific, functions used in more than
 216  * one configuration (or more than once in a given configuration) need
 217  * multiple versions of the relevant descriptors.
 218  *
 219  * Returns the interface ID which was allocated; or -ENODEV if no
 220  * more interface IDs can be allocated.
 221  */
 222 int usb_interface_id(struct usb_configuration *config,
 223                 struct usb_function *function)
 224 {
 225         unsigned id = config->next_interface_id;
 226
 227         if (id < MAX_CONFIG_INTERFACES) {
 228                 config->interface[id] = function;
 229                 config->next_interface_id = id + 1;
 230                 return id;
 231         }
 232         return -ENODEV;
 233 }
 234
 235 static int config_buf(struct usb_configuration *config,
 236                 enum usb_device_speed speed, void *buf, u8 type)
 237 {
 238         struct usb_config_descriptor    *c = buf;
 239         void                            *next = buf + USB_DT_CONFIG_SIZE;
 240         int                             len = USB_BUFSIZ - USB_DT_CONFIG_SIZE;
 241         struct usb_function             *f;
 242         int                             status;
 243
 244         /* write the config descriptor */
 245         c = buf;
 246         c->bLength = USB_DT_CONFIG_SIZE;
 247         c->bDescriptorType = type;
 248         /* wTotalLength is written later */
 249         c->bNumInterfaces = config->next_interface_id;
 250         c->bConfigurationValue = config->bConfigurationValue;
 251         c->iConfiguration = config->iConfiguration;
 252         c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
 253         c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 254
 255         /* There may be e.g. OTG descriptors */
 256         if (config->descriptors) {
 257                 status = usb_descriptor_fillbuf(next, len,
 258                                 config->descriptors);
 259                 if (status < 0)
 260                         return status;
 261                 len -= status;
 262                 next += status;
 263         }
 264
 265         /* add each function's descriptors */
 266         list_for_each_entry(f, &config->functions, list) {
 267                 struct usb_descriptor_header **descriptors;
 268
 269                 if (speed == USB_SPEED_HIGH)
 270                         descriptors = f->hs_descriptors;
 271                 else
 272                         descriptors = f->descriptors;
 273                 if (!descriptors)
 274                         continue;
 275                 status = usb_descriptor_fillbuf(next, len,
 276                         (const struct usb_descriptor_header **) descriptors);
 277                 if (status < 0)
 278                         return status;
 279                 len -= status;
 280                 next += status;
 281         }
 282
 283         len = next - buf;
 284         c->wTotalLength = cpu_to_le16(len);
 285         return len;
 286 }
 287
 288 static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
 289 {
 290         struct usb_gadget               *gadget = cdev->gadget;
 291         struct usb_configuration        *c;
 292         u8                              type = w_value >> 8;
 293         enum usb_device_speed           speed = USB_SPEED_UNKNOWN;
 294
 295         if (gadget_is_dualspeed(gadget)) {
 296                 int                     hs = 0;
 297
 298                 if (gadget->speed == USB_SPEED_HIGH)
 299                         hs = 1;
 300                 if (type == USB_DT_OTHER_SPEED_CONFIG)
 301                         hs = !hs;
 302                 if (hs)
 303                         speed = USB_SPEED_HIGH;
 304
 305         }
 306
 307         /* This is a lookup by config *INDEX* */
 308         w_value &= 0xff;
 309         list_for_each_entry(c, &cdev->configs, list) {
 310                 /* ignore configs that won't work at this speed */
 311                 if (speed == USB_SPEED_HIGH) {
 312                         if (!c->highspeed)
 313                                 continue;
 314                 } else {
 315                         if (!c->fullspeed)
 316                                 continue;
 317                 }
 318                 if (w_value == 0)
 319                         return config_buf(c, speed, cdev->req->buf, type);
 320                 w_value--;
 321         }
 322         return -EINVAL;
 323 }
 324
 325 static int count_configs(struct usb_composite_dev *cdev, unsigned type)
 326 {
 327         struct usb_gadget               *gadget = cdev->gadget;
 328         struct usb_configuration        *c;
 329         unsigned                        count = 0;
 330         int                             hs = 0;
 331
 332         if (gadget_is_dualspeed(gadget)) {
 333                 if (gadget->speed == USB_SPEED_HIGH)
 334                         hs = 1;
 335                 if (type == USB_DT_DEVICE_QUALIFIER)
 336                         hs = !hs;
 337         }
 338         list_for_each_entry(c, &cdev->configs, list) {
 339                 /* ignore configs that won't work at this speed */
 340                 if (hs) {
 341                         if (!c->highspeed)
 342                                 continue;
 343                 } else {
 344                         if (!c->fullspeed)
 345                                 continue;
 346                 }
 347                 count++;
 348         }
 349         return count;
 350 }
 351
 352 static void device_qual(struct usb_composite_dev *cdev)
 353 {
 354         struct usb_qualifier_descriptor *qual = cdev->req->buf;
 355
 356         qual->bLength = sizeof(*qual);
 357         qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
 358         /* POLICY: same bcdUSB and device type info at both speeds */
 359         qual->bcdUSB = cdev->desc.bcdUSB;
 360         qual->bDeviceClass = cdev->desc.bDeviceClass;
 361         qual->bDeviceSubClass = cdev->desc.bDeviceSubClass;
 362         qual->bDeviceProtocol = cdev->desc.bDeviceProtocol;
 363         /* ASSUME same EP0 fifo size at both speeds */
 364         qual->bMaxPacketSize0 = cdev->desc.bMaxPacketSize0;
 365         qual->bNumConfigurations = count_configs(cdev, USB_DT_DEVICE_QUALIFIER);
 366         qual->bRESERVED = 0;
 367 }
 368
 369 /*-------------------------------------------------------------------------*/
 370
 371 static void reset_config(struct usb_composite_dev *cdev)
 372 {
 373         struct usb_function             *f;
 374
 375         DBG(cdev, "reset config\n");
 376
 377         list_for_each_entry(f, &cdev->config->functions, list) {
 378                 if (f->disable)
 379                         f->disable(f);
 380
 381                 bitmap_zero(f->endpoints, 32);
 382         }
 383         cdev->config = NULL;
 384 }
 385
 386 static int set_config(struct usb_composite_dev *cdev,
 387                 const struct usb_ctrlrequest *ctrl, unsigned number)
 388 {
 389         struct usb_gadget       *gadget = cdev->gadget;
 390         struct usb_configuration *c = NULL;
 391         int                     result = -EINVAL;
 392         unsigned                power = gadget_is_otg(gadget) ? 8 : 100;
 393         int                     tmp;
 394
 395         if (cdev->config)
 396                 reset_config(cdev);
 397
 398         if (number) {
 399                 list_for_each_entry(c, &cdev->configs, list) {
 400                         if (c->bConfigurationValue == number) {
 401                                 result = 0;
 402                                 break;
 403                         }
 404                 }
 405                 if (result < 0)
 406                         goto done;
 407         } else
 408                 result = 0;
 409
 410         INFO(cdev, "%s speed config #%d: %s\n",
 411                 ({ char *speed;
 412                 switch (gadget->speed) {
 413                 case USB_SPEED_LOW:     speed = "low"; break;
 414                 case USB_SPEED_FULL:    speed = "full"; break;
 415                 case USB_SPEED_HIGH:    speed = "high"; break;
 416                 default:                speed = "?"; break;
 417                 } ; speed; }), number, c ? c->label : "unconfigured");
 418
 419         if (!c)
 420                 goto done;
 421
 422         cdev->config = c;
 423
 424         /* Initialize all interfaces by setting them to altsetting zero. */
 425         for (tmp = 0; tmp < MAX_CONFIG_INTERFACES; tmp++) {
 426                 struct usb_function     *f = c->interface[tmp];
 427                 struct usb_descriptor_header **descriptors;
 428
 429                 if (!f)
 430                         break;
 431
 432                 /*
 433                  * Record which endpoints are used by the function. This is used
 434                  * to dispatch control requests targeted at that endpoint to the
 435                  * function's setup callback instead of the current
 436                  * configuration's setup callback.
 437                  */
 438                 if (gadget->speed == USB_SPEED_HIGH)
 439                         descriptors = f->hs_descriptors;
 440                 else
 441                         descriptors = f->descriptors;
 442
 443                 for (; *descriptors; ++descriptors) {
 444                         struct usb_endpoint_descriptor *ep;
 445                         int addr;
 446
 447                         if ((*descriptors)->bDescriptorType != USB_DT_ENDPOINT)
 448                                 continue;
 449
 450                         ep = (struct usb_endpoint_descriptor *)*descriptors;
 451                         addr = ((ep->bEndpointAddress & 0x80) >> 3)
 452                              |  (ep->bEndpointAddress & 0x0f);
 453                         set_bit(addr, f->endpoints);
 454                 }
 455
 456                 result = f->set_alt(f, tmp, 0);
 457                 if (result < 0) {
 458                         DBG(cdev, "interface %d (%s/%p) alt 0 --> %d\n",
 459                                         tmp, f->name, f, result);
 460
 461                         reset_config(cdev);
 462                         goto done;
 463                 }
 464
 465                 if (result == USB_GADGET_DELAYED_STATUS) {
 466                         DBG(cdev,
 467                          "%s: interface %d (%s) requested delayed status\n",
 468                                         __func__, tmp, f->name);
 469                         cdev->delayed_status++;
 470                         DBG(cdev, "delayed_status count %d\n",
 471                                         cdev->delayed_status);
 472                 }
 473         }
 474
 475         /* when we return, be sure our power usage is valid */
 476         power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 477 done:
 478         usb_gadget_vbus_draw(gadget, power);
 479         if (result >= 0 && cdev->delayed_status)
 480                 result = USB_GADGET_DELAYED_STATUS;
 481         return result;
 482 }
 483
 484 /**
 485  * usb_add_config() - add a configuration to a device.
 486  * @cdev: wraps the USB gadget
 487  * @config: the configuration, with bConfigurationValue assigned
 488  * @bind: the configuration's bind function
 489  * Context: single threaded during gadget setup
 490  *
 491  * One of the main tasks of a composite @bind() routine is to
 492  * add each of the configurations it supports, using this routine.
 493  *
 494  * This function returns the value of the configuration's @bind(), which
 495  * is zero for success else a negative errno value.  Binding configurations
 496  * assigns global resources including string IDs, and per-configuration
 497  * resources such as interface IDs and endpoints.
 498  */
 499 int usb_add_config(struct usb_composite_dev *cdev,
 500                 struct usb_configuration *config,
 501                 int (*bind)(struct usb_configuration *))
 502 {
 503         int                             status = -EINVAL;
 504         struct usb_configuration        *c;
 505
 506         DBG(cdev, "adding config #%u '%s'/%p\n",
 507                         config->bConfigurationValue,
 508                         config->label, config);
 509
 510         if (!config->bConfigurationValue || !bind)
 511                 goto done;
 512
 513         /* Prevent duplicate configuration identifiers */
 514         list_for_each_entry(c, &cdev->configs, list) {
 515                 if (c->bConfigurationValue == config->bConfigurationValue) {
 516                         status = -EBUSY;
 517                         goto done;
 518                 }
 519         }
 520
 521         config->cdev = cdev;
 522         list_add_tail(&config->list, &cdev->configs);
 523
 524         INIT_LIST_HEAD(&config->functions);
 525         config->next_interface_id = 0;
 526
 527         status = bind(config);
 528         if (status < 0) {
 529                 list_del(&config->list);
 530                 config->cdev = NULL;
 531         } else {
 532                 unsigned        i;
 533
 534                 DBG(cdev, "cfg %d/%p speeds:%s%s\n",
 535                         config->bConfigurationValue, config,
 536                         config->highspeed ? " high" : "",
 537                         config->fullspeed
 538                                 ? (gadget_is_dualspeed(cdev->gadget)
 539                                         ? " full"
 540                                         : " full/low")
 541                                 : "");
 542
 543                 for (i = 0; i < MAX_CONFIG_INTERFACES; i++) {
 544                         struct usb_function     *f = config->interface[i];
 545
 546                         if (!f)
 547                                 continue;
 548                         DBG(cdev, "  interface %d = %s/%p\n",
 549                                 i, f->name, f);
 550                 }
 551         }
 552
 553         /* set_alt(), or next bind(), sets up
 554          * ep->driver_data as needed.
 555          */
 556         usb_ep_autoconfig_reset(cdev->gadget);
 557
 558 done:
 559         if (status)
 560                 DBG(cdev, "added config '%s'/%u --> %d\n", config->label,
 561                                 config->bConfigurationValue, status);
 562         return status;
 563 }
 564
 565 /*-------------------------------------------------------------------------*/
 566
 567 /* We support strings in multiple languages ... string descriptor zero
 568  * says which languages are supported.  The typical case will be that
 569  * only one language (probably English) is used, with I18N handled on
 570  * the host side.
 571  */
 572
 573 static void collect_langs(struct usb_gadget_strings **sp, __le16 *buf)
 574 {
 575         const struct usb_gadget_strings *s;
 576         u16                             language;
 577         __le16                          *tmp;
 578
 579         while (*sp) {
 580                 s = *sp;
 581                 language = cpu_to_le16(s->language);
 582                 for (tmp = buf; *tmp && tmp < &buf[126]; tmp++) {
 583                         if (*tmp == language)
 584                                 goto repeat;
 585                 }
 586                 *tmp++ = language;
 587 repeat:
 588                 sp++;
 589         }
 590 }
 591
 592 static int lookup_string(
 593         struct usb_gadget_strings       **sp,
 594         void                            *buf,
 595         u16                             language,
 596         int                             id
 597 )
 598 {
 599         struct usb_gadget_strings       *s;
 600         int                             value;
 601
 602         while (*sp) {
 603                 s = *sp++;
 604                 if (s->language != language)
 605                         continue;
 606                 value = usb_gadget_get_string(s, id, buf);
 607                 if (value > 0)
 608                         return value;
 609         }
 610         return -EINVAL;
 611 }
 612
 613 static int get_string(struct usb_composite_dev *cdev,
 614                 void *buf, u16 language, int id)
 615 {
 616         struct usb_configuration        *c;
 617         struct usb_function             *f;
 618         int                             len;
 619         const char                      *str;
 620
 621         /* Yes, not only is USB's I18N support probably more than most
 622          * folk will ever care about ... also, it's all supported here.
 623          * (Except for UTF8 support for Unicode's "Astral Planes".)
 624          */
 625
 626         /* 0 == report all available language codes */
 627         if (id == 0) {
 628                 struct usb_string_descriptor    *s = buf;
 629                 struct usb_gadget_strings       **sp;
 630
 631                 memset(s, 0, 256);
 632                 s->bDescriptorType = USB_DT_STRING;
 633
 634                 sp = composite->strings;
 635                 if (sp)
 636                         collect_langs(sp, s->wData);
 637
 638                 list_for_each_entry(c, &cdev->configs, list) {
 639                         sp = c->strings;
 640                         if (sp)
 641                                 collect_langs(sp, s->wData);
 642
 643                         list_for_each_entry(f, &c->functions, list) {
 644                                 sp = f->strings;
 645                                 if (sp)
 646                                         collect_langs(sp, s->wData);
 647                         }
 648                 }
 649
 650                 for (len = 0; len <= 126 && s->wData[len]; len++)
 651                         continue;
 652                 if (!len)
 653                         return -EINVAL;
 654
 655                 s->bLength = 2 * (len + 1);
 656                 return s->bLength;
 657         }
 658
 659         /* Otherwise, look up and return a specified string.  First
 660          * check if the string has not been overridden.
 661          */
 662         if (cdev->manufacturer_override == id)
 663                 str = iManufacturer ?: composite->iManufacturer ?:
 664                         composite_manufacturer;
 665         else if (cdev->product_override == id)
 666                 str = iProduct ?: composite->iProduct;
 667         else if (cdev->serial_override == id)
 668                 str = iSerialNumber;
 669         else
 670                 str = NULL;
 671         if (str) {
 672                 struct usb_gadget_strings strings = {
 673                         .language = language,
 674                         .strings  = &(struct usb_string) { 0xff, str }
 675                 };
 676                 return usb_gadget_get_string(&strings, 0xff, buf);
 677         }
 678
 679         /* String IDs are device-scoped, so we look up each string
 680          * table we're told about.  These lookups are infrequent;
 681          * simpler-is-better here.
 682          */
 683         if (composite->strings) {
 684                 len = lookup_string(composite->strings, buf, language, id);
 685                 if (len > 0)
 686                         return len;
 687         }
 688         list_for_each_entry(c, &cdev->configs, list) {
 689                 if (c->strings) {
 690                         len = lookup_string(c->strings, buf, language, id);
 691                         if (len > 0)
 692                                 return len;
 693                 }
 694                 list_for_each_entry(f, &c->functions, list) {
 695                         if (!f->strings)
 696                                 continue;
 697                         len = lookup_string(f->strings, buf, language, id);
 698                         if (len > 0)
 699                                 return len;
 700                 }
 701         }
 702         return -EINVAL;
 703 }
 704
 705 /**
 706  * usb_string_id() - allocate an unused string ID
 707  * @cdev: the device whose string descriptor IDs are being allocated
 708  * Context: single threaded during gadget setup
 709  *
 710  * @usb_string_id() is called from bind() callbacks to allocate
 711  * string IDs.  Drivers for functions, configurations, or gadgets will
 712  * then store that ID in the appropriate descriptors and string table.
 713  *
 714  * All string identifier should be allocated using this,
 715  * @usb_string_ids_tab() or @usb_string_ids_n() routine, to ensure
 716  * that for example different functions don't wrongly assign different
 717  * meanings to the same identifier.
 718  */
 719 int usb_string_id(struct usb_composite_dev *cdev)
 720 {
 721         if (cdev->next_string_id < 254) {
 722                 /* string id 0 is reserved by USB spec for list of
 723                  * supported languages */
 724                 /* 255 reserved as well? -- mina86 */
 725                 cdev->next_string_id++;
 726                 return cdev->next_string_id;
 727         }
 728         return -ENODEV;
 729 }
 730
 731 /**
 732  * usb_string_ids() - allocate unused string IDs in batch
 733  * @cdev: the device whose string descriptor IDs are being allocated
 734  * @str: an array of usb_string objects to assign numbers to
 735  * Context: single threaded during gadget setup
 736  *
 737  * @usb_string_ids() is called from bind() callbacks to allocate
 738  * string IDs.  Drivers for functions, configurations, or gadgets will
 739  * then copy IDs from the string table to the appropriate descriptors
 740  * and string table for other languages.
 741  *
 742  * All string identifier should be allocated using this,
 743  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 744  * example different functions don't wrongly assign different meanings
 745  * to the same identifier.
 746  */
 747 int usb_string_ids_tab(struct usb_composite_dev *cdev, struct usb_string *str)
 748 {
 749         int next = cdev->next_string_id;
 750
 751         for (; str->s; ++str) {
 752                 if (unlikely(next >= 254))
 753                         return -ENODEV;
 754                 str->id = ++next;
 755         }
 756
 757         cdev->next_string_id = next;
 758
 759         return 0;
 760 }
 761
 762 /**
 763  * usb_string_ids_n() - allocate unused string IDs in batch
 764  * @c: the device whose string descriptor IDs are being allocated
 765  * @n: number of string IDs to allocate
 766  * Context: single threaded during gadget setup
 767  *
 768  * Returns the first requested ID.  This ID and next @n-1 IDs are now
 769  * valid IDs.  At least provided that @n is non-zero because if it
 770  * is, returns last requested ID which is now very useful information.
 771  *
 772  * @usb_string_ids_n() is called from bind() callbacks to allocate
 773  * string IDs.  Drivers for functions, configurations, or gadgets will
 774  * then store that ID in the appropriate descriptors and string table.
 775  *
 776  * All string identifier should be allocated using this,
 777  * @usb_string_id() or @usb_string_ids_n() routine, to ensure that for
 778  * example different functions don't wrongly assign different meanings
 779  * to the same identifier.
 780  */
 781 int usb_string_ids_n(struct usb_composite_dev *c, unsigned n)
 782 {
 783         unsigned next = c->next_string_id;
 784         if (unlikely(n > 254 || (unsigned)next + n > 254))
 785                 return -ENODEV;
 786         c->next_string_id += n;
 787         return next + 1;
 788 }
 789
 790
 791 /*-------------------------------------------------------------------------*/
 792
 793 static void composite_setup_complete(struct usb_ep *ep, struct usb_request *req)
 794 {
 795         if (req->status || req->actual != req->length)
 796                 DBG((struct usb_composite_dev *) ep->driver_data,
 797                                 "setup complete --> %d, %d/%d\n",
 798                                 req->status, req->actual, req->length);
 799 }
 800
 801 /*
 802  * The setup() callback implements all the ep0 functionality that's
 803  * not handled lower down, in hardware or the hardware driver(like
 804  * device and endpoint feature flags, and their status).  It's all
 805  * housekeeping for the gadget function we're implementing.  Most of
 806  * the work is in config and function specific setup.
 807  */
 808 static int
 809 composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 810 {
 811         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
 812         struct usb_request              *req = cdev->req;
 813         int                             value = -EOPNOTSUPP;
 814         u16                             w_index = le16_to_cpu(ctrl->wIndex);
 815         u8                              intf = w_index & 0xFF;
 816         u16                             w_value = le16_to_cpu(ctrl->wValue);
 817         u16                             w_length = le16_to_cpu(ctrl->wLength);
 818         struct usb_function             *f = NULL;
 819         u8                              endp;
 820
 821         /* partial re-init of the response message; the function or the
 822          * gadget might need to intercept e.g. a control-OUT completion
 823          * when we delegate to it.
 824          */
 825         req->zero = 0;
 826         req->complete = composite_setup_complete;
 827         req->length = 0;
 828         gadget->ep0->driver_data = cdev;
 829
 830         switch (ctrl->bRequest) {
 831
 832         /* we handle all standard USB descriptors */
 833         case USB_REQ_GET_DESCRIPTOR:
 834                 if (ctrl->bRequestType != USB_DIR_IN)
 835                         goto unknown;
 836                 switch (w_value >> 8) {
 837
 838                 case USB_DT_DEVICE:
 839                         cdev->desc.bNumConfigurations =
 840                                 count_configs(cdev, USB_DT_DEVICE);
 841                         value = min(w_length, (u16) sizeof cdev->desc);
 842                         memcpy(req->buf, &cdev->desc, value);
 843                         break;
 844                 case USB_DT_DEVICE_QUALIFIER:
 845                         if (!gadget_is_dualspeed(gadget))
 846                                 break;
 847                         device_qual(cdev);
 848                         value = min_t(int, w_length,
 849                                 sizeof(struct usb_qualifier_descriptor));
 850                         break;
 851                 case USB_DT_OTHER_SPEED_CONFIG:
 852                         if (!gadget_is_dualspeed(gadget))
 853                                 break;
 854                         /* FALLTHROUGH */
 855                 case USB_DT_CONFIG:
 856                         value = config_desc(cdev, w_value);
 857                         if (value >= 0)
 858                                 value = min(w_length, (u16) value);
 859                         break;
 860                 case USB_DT_STRING:
 861                         value = get_string(cdev, req->buf,
 862                                         w_index, w_value & 0xff);
 863                         if (value >= 0)
 864                                 value = min(w_length, (u16) value);
 865                         break;
 866                 }
 867                 break;
 868
 869         /* any number of configs can work */
 870         case USB_REQ_SET_CONFIGURATION:
 871                 if (ctrl->bRequestType != 0)
 872                         goto unknown;
 873                 if (gadget_is_otg(gadget)) {
 874                         if (gadget->a_hnp_support)
 875                                 DBG(cdev, "HNP available\n");
 876                         else if (gadget->a_alt_hnp_support)
 877                                 DBG(cdev, "HNP on another port\n");
 878                         else
 879                                 VDBG(cdev, "HNP inactive\n");
 880                 }
 881                 spin_lock(&cdev->lock);
 882                 value = set_config(cdev, ctrl, w_value);
 883                 spin_unlock(&cdev->lock);
 884                 break;
 885         case USB_REQ_GET_CONFIGURATION:
 886                 if (ctrl->bRequestType != USB_DIR_IN)
 887                         goto unknown;
 888                 if (cdev->config)
 889                         *(u8 *)req->buf = cdev->config->bConfigurationValue;
 890                 else
 891                         *(u8 *)req->buf = 0;
 892                 value = min(w_length, (u16) 1);
 893                 break;
 894
 895         /* function drivers must handle get/set altsetting; if there's
 896          * no get() method, we know only altsetting zero works.
 897          */
 898         case USB_REQ_SET_INTERFACE:
 899                 if (ctrl->bRequestType != USB_RECIP_INTERFACE)
 900                         goto unknown;
 901                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
 902                         break;
 903                 f = cdev->config->interface[intf];
 904                 if (!f)
 905                         break;
 906                 if (w_value && !f->set_alt)
 907                         break;
 908                 value = f->set_alt(f, w_index, w_value);
 909                 if (value == USB_GADGET_DELAYED_STATUS) {
 910                         DBG(cdev,
 911                          "%s: interface %d (%s) requested delayed status\n",
 912                                         __func__, intf, f->name);
 913                         cdev->delayed_status++;
 914                         DBG(cdev, "delayed_status count %d\n",
 915                                         cdev->delayed_status);
 916                 }
 917                 break;
 918         case USB_REQ_GET_INTERFACE:
 919                 if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
 920                         goto unknown;
 921                 if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
 922                         break;
 923                 f = cdev->config->interface[intf];
 924                 if (!f)
 925                         break;
 926                 /* lots of interfaces only need altsetting zero... */
 927                 value = f->get_alt ? f->get_alt(f, w_index) : 0;
 928                 if (value < 0)
 929                         break;
 930                 *((u8 *)req->buf) = value;
 931                 value = min(w_length, (u16) 1);
 932                 break;
 933         default:
 934 unknown:
 935                 VDBG(cdev,
 936                         "non-core control req%02x.%02x v%04x i%04x l%d\n",
 937                         ctrl->bRequestType, ctrl->bRequest,
 938                         w_value, w_index, w_length);
 939
 940                 /* functions always handle their interfaces and endpoints...
 941                  * punt other recipients (other, WUSB, ...) to the current
 942                  * configuration code.
 943                  *
 944                  * REVISIT it could make sense to let the composite device
 945                  * take such requests too, if that's ever needed:  to work
 946                  * in config 0, etc.
 947                  */
 948                 switch (ctrl->bRequestType & USB_RECIP_MASK) {
 949                 case USB_RECIP_INTERFACE:
 950                         if (!cdev->config || intf >= MAX_CONFIG_INTERFACES)
 951                                 break;
 952                         f = cdev->config->interface[intf];
 953                         break;
 954
 955                 case USB_RECIP_ENDPOINT:
 956                         endp = ((w_index & 0x80) >> 3) | (w_index & 0x0f);
 957                         list_for_each_entry(f, &cdev->config->functions, list) {
 958                                 if (test_bit(endp, f->endpoints))
 959                                         break;
 960                         }
 961                         if (&f->list == &cdev->config->functions)
 962                                 f = NULL;
 963                         break;
 964                 }
 965
 966                 if (f && f->setup)
 967                         value = f->setup(f, ctrl);
 968                 else {
 969                         struct usb_configuration        *c;
 970
 971                         c = cdev->config;
 972                         if (c && c->setup)
 973                                 value = c->setup(c, ctrl);
 974                 }
 975
 976                 goto done;
 977         }
 978
 979         /* respond with data transfer before status phase? */
 980         if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
 981                 req->length = value;
 982                 req->zero = value < w_length;
 983                 value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
 984                 if (value < 0) {
 985                         DBG(cdev, "ep_queue --> %d\n", value);
 986                         req->status = 0;
 987                         composite_setup_complete(gadget->ep0, req);
 988                 }
 989         } else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
 990                 WARN(cdev,
 991                         "%s: Delayed status not supported for w_length != 0",
 992                         __func__);
 993         }
 994
 995 done:
 996         /* device either stalls (value < 0) or reports success */
 997         return value;
 998 }
 999
1000 static void composite_disconnect(struct usb_gadget *gadget)
1001 {
1002         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1003         unsigned long                   flags;
1004
1005         /* REVISIT:  should we have config and device level
1006          * disconnect callbacks?
1007          */
1008         spin_lock_irqsave(&cdev->lock, flags);
1009         if (cdev->config)
1010                 reset_config(cdev);
1011         if (composite->disconnect)
1012                 composite->disconnect(cdev);
1013         spin_unlock_irqrestore(&cdev->lock, flags);
1014 }
1015
1016 /*-------------------------------------------------------------------------*/
1017
1018 static ssize_t composite_show_suspended(struct device *dev,
1019                                         struct device_attribute *attr,
1020                                         char *buf)
1021 {
1022         struct usb_gadget *gadget = dev_to_usb_gadget(dev);
1023         struct usb_composite_dev *cdev = get_gadget_data(gadget);
1024
1025         return sprintf(buf, "%d\n", cdev->suspended);
1026 }
1027
1028 static DEVICE_ATTR(suspended, 0444, composite_show_suspended, NULL);
1029
1030 static void
1031 composite_unbind(struct usb_gadget *gadget)
1032 {
1033         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1034
1035         /* composite_disconnect() must already have been called
1036          * by the underlying peripheral controller driver!
1037          * so there's no i/o concurrency that could affect the
1038          * state protected by cdev->lock.
1039          */
1040         WARN_ON(cdev->config);
1041
1042         while (!list_empty(&cdev->configs)) {
1043                 struct usb_configuration        *c;
1044
1045                 c = list_first_entry(&cdev->configs,
1046                                 struct usb_configuration, list);
1047                 while (!list_empty(&c->functions)) {
1048                         struct usb_function             *f;
1049
1050                         f = list_first_entry(&c->functions,
1051                                         struct usb_function, list);
1052                         list_del(&f->list);
1053                         if (f->unbind) {
1054                                 DBG(cdev, "unbind function '%s'/%p\n",
1055                                                 f->name, f);
1056                                 f->unbind(c, f);
1057                                 /* may free memory for "f" */
1058                         }
1059                 }
1060                 list_del(&c->list);
1061                 if (c->unbind) {
1062                         DBG(cdev, "unbind config '%s'/%p\n", c->label, c);
1063                         c->unbind(c);
1064                         /* may free memory for "c" */
1065                 }
1066         }
1067         if (composite->unbind)
1068                 composite->unbind(cdev);
1069
1070         if (cdev->req) {
1071                 kfree(cdev->req->buf);
1072                 usb_ep_free_request(gadget->ep0, cdev->req);
1073         }
1074         device_remove_file(&gadget->dev, &dev_attr_suspended);
1075         kfree(cdev);
1076         set_gadget_data(gadget, NULL);
1077         composite = NULL;
1078 }
1079
1080 static u8 override_id(struct usb_composite_dev *cdev, u8 *desc)
1081 {
1082         if (!*desc) {
1083                 int ret = usb_string_id(cdev);
1084                 if (unlikely(ret < 0))
1085                         WARNING(cdev, "failed to override string ID\n");
1086                 else
1087                         *desc = ret;
1088         }
1089
1090         return *desc;
1091 }
1092
1093 static int composite_bind(struct usb_gadget *gadget)
1094 {
1095         struct usb_composite_dev        *cdev;
1096         int                             status = -ENOMEM;
1097
1098         cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
1099         if (!cdev)
1100                 return status;
1101
1102         spin_lock_init(&cdev->lock);
1103         cdev->gadget = gadget;
1104         set_gadget_data(gadget, cdev);
1105         INIT_LIST_HEAD(&cdev->configs);
1106
1107         /* preallocate control response and buffer */
1108         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
1109         if (!cdev->req)
1110                 goto fail;
1111         cdev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
1112         if (!cdev->req->buf)
1113                 goto fail;
1114         cdev->req->complete = composite_setup_complete;
1115         gadget->ep0->driver_data = cdev;
1116
1117         cdev->bufsiz = USB_BUFSIZ;
1118         cdev->driver = composite;
1119
1120         /*
1121          * As per USB compliance update, a device that is actively drawing
1122          * more than 100mA from USB must report itself as bus-powered in
1123          * the GetStatus(DEVICE) call.
1124          */
1125         if (CONFIG_USB_GADGET_VBUS_DRAW <= USB_SELF_POWER_VBUS_MAX_DRAW)
1126                 usb_gadget_set_selfpowered(gadget);
1127
1128         /* interface and string IDs start at zero via kzalloc.
1129          * we force endpoints to start unassigned; few controller
1130          * drivers will zero ep->driver_data.
1131          */
1132         usb_ep_autoconfig_reset(cdev->gadget);
1133
1134         /* composite gadget needs to assign strings for whole device (like
1135          * serial number), register function drivers, potentially update
1136          * power state and consumption, etc
1137          */
1138         status = composite_gadget_bind(cdev);
1139         if (status < 0)
1140                 goto fail;
1141
1142         cdev->desc = *composite->dev;
1143         cdev->desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
1144
1145         /* standardized runtime overrides for device ID data */
1146         if (idVendor)
1147                 cdev->desc.idVendor = cpu_to_le16(idVendor);
1148         if (idProduct)
1149                 cdev->desc.idProduct = cpu_to_le16(idProduct);
1150         if (bcdDevice)
1151                 cdev->desc.bcdDevice = cpu_to_le16(bcdDevice);
1152
1153         /* string overrides */
1154         if (iManufacturer || !cdev->desc.iManufacturer) {
1155                 if (!iManufacturer && !composite->iManufacturer &&
1156                     !*composite_manufacturer)
1157                         snprintf(composite_manufacturer,
1158                                  sizeof composite_manufacturer,
1159                                  "%s %s with %s",
1160                                  init_utsname()->sysname,
1161                                  init_utsname()->release,
1162                                  gadget->name);
1163
1164                 cdev->manufacturer_override =
1165                         override_id(cdev, &cdev->desc.iManufacturer);
1166         }
1167
1168         if (iProduct || (!cdev->desc.iProduct && composite->iProduct))
1169                 cdev->product_override =
1170                         override_id(cdev, &cdev->desc.iProduct);
1171
1172         if (iSerialNumber)
1173                 cdev->serial_override =
1174                         override_id(cdev, &cdev->desc.iSerialNumber);
1175
1176         /* has userspace failed to provide a serial number? */
1177         if (composite->needs_serial && !cdev->desc.iSerialNumber)
1178                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
1179
1180         /* finish up */
1181         status = device_create_file(&gadget->dev, &dev_attr_suspended);
1182         if (status)
1183                 goto fail;
1184
1185         INFO(cdev, "%s ready\n", composite->name);
1186         return 0;
1187
1188 fail:
1189         composite_unbind(gadget);
1190         return status;
1191 }
1192
1193 /*-------------------------------------------------------------------------*/
1194
1195 static void
1196 composite_suspend(struct usb_gadget *gadget)
1197 {
1198         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1199         struct usb_function             *f;
1200
1201         /* REVISIT:  should we have config level
1202          * suspend/resume callbacks?
1203          */
1204         DBG(cdev, "suspend\n");
1205         if (cdev->config) {
1206                 list_for_each_entry(f, &cdev->config->functions, list) {
1207                         if (f->suspend)
1208                                 f->suspend(f);
1209                 }
1210         }
1211         if (composite->suspend)
1212                 composite->suspend(cdev);
1213
1214         cdev->suspended = 1;
1215
1216         usb_gadget_vbus_draw(gadget, 2);
1217 }
1218
1219 static void
1220 composite_resume(struct usb_gadget *gadget)
1221 {
1222         struct usb_composite_dev        *cdev = get_gadget_data(gadget);
1223         struct usb_function             *f;
1224         u8                              maxpower;
1225
1226         /* REVISIT:  should we have config level
1227          * suspend/resume callbacks?
1228          */
1229         DBG(cdev, "resume\n");
1230         if (composite->resume)
1231                 composite->resume(cdev);
1232         if (cdev->config) {
1233                 list_for_each_entry(f, &cdev->config->functions, list) {
1234                         if (f->resume)
1235                                 f->resume(f);
1236                 }
1237
1238                 maxpower = cdev->config->bMaxPower;
1239
1240                 usb_gadget_vbus_draw(gadget, maxpower ?
1241                         (2 * maxpower) : CONFIG_USB_GADGET_VBUS_DRAW);
1242         }
1243
1244         cdev->suspended = 0;
1245 }
1246
1247 /*-------------------------------------------------------------------------*/
1248
1249 static struct usb_gadget_driver composite_driver = {
1250         .speed          = USB_SPEED_HIGH,
1251
1252         .unbind         = composite_unbind,
1253
1254         .setup          = composite_setup,
1255         .disconnect     = composite_disconnect,
1256
1257         .suspend        = composite_suspend,
1258         .resume         = composite_resume,
1259
1260         .driver = {
1261                 .owner          = THIS_MODULE,
1262         },
1263 };
1264
1265 /**
1266  * usb_composite_probe() - register a composite driver
1267  * @driver: the driver to register
1268  * @bind: the callback used to allocate resources that are shared across the
1269  *      whole device, such as string IDs, and add its configurations using
1270  *      @usb_add_config().  This may fail by returning a negative errno
1271  *      value; it should return zero on successful initialization.
1272  * Context: single threaded during gadget setup
1273  *
1274  * This function is used to register drivers using the composite driver
1275  * framework.  The return value is zero, or a negative errno value.
1276  * Those values normally come from the driver's @bind method, which does
1277  * all the work of setting up the driver to match the hardware.
1278  *
1279  * On successful return, the gadget is ready to respond to requests from
1280  * the host, unless one of its components invokes usb_gadget_disconnect()
1281  * while it was binding.  That would usually be done in order to wait for
1282  * some userspace participation.
1283  */
1284 int usb_composite_probe(struct usb_composite_driver *driver,
1285                                int (*bind)(struct usb_composite_dev *cdev))
1286 {
1287         if (!driver || !driver->dev || !bind || composite)
1288                 return -EINVAL;
1289
1290         if (!driver->name)
1291                 driver->name = "composite";
1292         if (!driver->iProduct)
1293                 driver->iProduct = driver->name;
1294         composite_driver.function =  (char *) driver->name;
1295         composite_driver.driver.name = driver->name;
1296         composite = driver;
1297         composite_gadget_bind = bind;
1298
1299         return usb_gadget_probe_driver(&composite_driver, composite_bind);
1300 }
1301
1302 /**
1303  * usb_composite_unregister() - unregister a composite driver
1304  * @driver: the driver to unregister
1305  *
1306  * This function is used to unregister drivers using the composite
1307  * driver framework.
1308  */
1309 void usb_composite_unregister(struct usb_composite_driver *driver)
1310 {
1311         if (composite != driver)
1312                 return;
1313         usb_gadget_unregister_driver(&composite_driver);
1314 }
1315
1316 /**
1317  * usb_composite_setup_continue() - Continue with the control transfer
1318  * @cdev: the composite device who's control transfer was kept waiting
1319  *
1320  * This function must be called by the USB function driver to continue
1321  * with the control transfer's data/status stage in case it had requested to
1322  * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
1323  * can request the composite framework to delay the setup request's data/status
1324  * stages by returning USB_GADGET_DELAYED_STATUS.
1325  */
1326 void usb_composite_setup_continue(struct usb_composite_dev *cdev)
1327 {
1328         int                     value;
1329         struct usb_request      *req = cdev->req;
1330         unsigned long           flags;
1331
1332         DBG(cdev, "%s\n", __func__);
1333         spin_lock_irqsave(&cdev->lock, flags);
1334
1335         if (cdev->delayed_status == 0) {
1336                 WARN(cdev, "%s: Unexpected call\n", __func__);
1337
1338         } else if (--cdev->delayed_status == 0) {
1339                 DBG(cdev, "%s: Completing delayed status\n", __func__);
1340                 req->length = 0;
1341                 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1342                 if (value < 0) {
1343                         DBG(cdev, "ep_queue --> %d\n", value);
1344                         req->status = 0;
1345                         composite_setup_complete(cdev->gadget->ep0, req);
1346                 }
1347         }
1348
1349         spin_unlock_irqrestore(&cdev->lock, flags);
1350 }
1351