drivers/usb/gadget/f_hid.c

   1 /*
   2  * f_hid.c -- USB HID function driver
   3  *
   4  * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
   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 #include <linux/kernel.h>
  22 #include <linux/utsname.h>
  23 #include <linux/module.h>
  24 #include <linux/hid.h>
  25 #include <linux/cdev.h>
  26 #include <linux/mutex.h>
  27 #include <linux/poll.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/wait.h>
  31 #include <linux/usb/g_hid.h>
  32
  33 static int major, minors;
  34 static struct class *hidg_class;
  35
  36 /*-------------------------------------------------------------------------*/
  37 /*                            HID gadget struct                            */
  38
  39 struct f_hidg {
  40         /* configuration */
  41         unsigned char                   bInterfaceSubClass;
  42         unsigned char                   bInterfaceProtocol;
  43         unsigned short                  report_desc_length;
  44         char                            *report_desc;
  45         unsigned short                  report_length;
  46
  47         /* recv report */
  48         char                            *set_report_buff;
  49         unsigned short                  set_report_length;
  50         spinlock_t                      spinlock;
  51         wait_queue_head_t               read_queue;
  52
  53         /* send report */
  54         struct mutex                    lock;
  55         bool                            write_pending;
  56         wait_queue_head_t               write_queue;
  57         struct usb_request              *req;
  58
  59         int                             minor;
  60         struct cdev                     cdev;
  61         struct usb_function             func;
  62         struct usb_ep                   *in_ep;
  63         struct usb_endpoint_descriptor  *fs_in_ep_desc;
  64         struct usb_endpoint_descriptor  *hs_in_ep_desc;
  65 };
  66
  67 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  68 {
  69         return container_of(f, struct f_hidg, func);
  70 }
  71
  72 /*-------------------------------------------------------------------------*/
  73 /*                           Static descriptors                            */
  74
  75 static struct usb_interface_descriptor hidg_interface_desc = {
  76         .bLength                = sizeof hidg_interface_desc,
  77         .bDescriptorType        = USB_DT_INTERFACE,
  78         /* .bInterfaceNumber    = DYNAMIC */
  79         .bAlternateSetting      = 0,
  80         .bNumEndpoints          = 1,
  81         .bInterfaceClass        = USB_CLASS_HID,
  82         /* .bInterfaceSubClass  = DYNAMIC */
  83         /* .bInterfaceProtocol  = DYNAMIC */
  84         /* .iInterface          = DYNAMIC */
  85 };
  86
  87 static struct hid_descriptor hidg_desc = {
  88         .bLength                        = sizeof hidg_desc,
  89         .bDescriptorType                = HID_DT_HID,
  90         .bcdHID                         = 0x0101,
  91         .bCountryCode                   = 0x00,
  92         .bNumDescriptors                = 0x1,
  93         /*.desc[0].bDescriptorType      = DYNAMIC */
  94         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  95 };
  96
  97 /* High-Speed Support */
  98
  99 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 100         .bLength                = USB_DT_ENDPOINT_SIZE,
 101         .bDescriptorType        = USB_DT_ENDPOINT,
 102         .bEndpointAddress       = USB_DIR_IN,
 103         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 104         /*.wMaxPacketSize       = DYNAMIC */
 105         .bInterval              = 4, /* FIXME: Add this field in the
 106                                       * HID gadget configuration?
 107                                       * (struct hidg_func_descriptor)
 108                                       */
 109 };
 110
 111 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 112         (struct usb_descriptor_header *)&hidg_interface_desc,
 113         (struct usb_descriptor_header *)&hidg_desc,
 114         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 115         NULL,
 116 };
 117
 118 /* Full-Speed Support */
 119
 120 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 121         .bLength                = USB_DT_ENDPOINT_SIZE,
 122         .bDescriptorType        = USB_DT_ENDPOINT,
 123         .bEndpointAddress       = USB_DIR_IN,
 124         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 125         /*.wMaxPacketSize       = DYNAMIC */
 126         .bInterval              = 10, /* FIXME: Add this field in the
 127                                        * HID gadget configuration?
 128                                        * (struct hidg_func_descriptor)
 129                                        */
 130 };
 131
 132 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 133         (struct usb_descriptor_header *)&hidg_interface_desc,
 134         (struct usb_descriptor_header *)&hidg_desc,
 135         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 136         NULL,
 137 };
 138
 139 /*-------------------------------------------------------------------------*/
 140 /*                              Char Device                                */
 141
 142 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 143                         size_t count, loff_t *ptr)
 144 {
 145         struct f_hidg   *hidg     = file->private_data;
 146         char            *tmp_buff = NULL;
 147         unsigned long   flags;
 148
 149         if (!count)
 150                 return 0;
 151
 152         if (!access_ok(VERIFY_WRITE, buffer, count))
 153                 return -EFAULT;
 154
 155         spin_lock_irqsave(&hidg->spinlock, flags);
 156
 157 #define READ_COND (hidg->set_report_buff != NULL)
 158
 159         while (!READ_COND) {
 160                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 161                 if (file->f_flags & O_NONBLOCK)
 162                         return -EAGAIN;
 163
 164                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 165                         return -ERESTARTSYS;
 166
 167                 spin_lock_irqsave(&hidg->spinlock, flags);
 168         }
 169
 170
 171         count = min_t(unsigned, count, hidg->set_report_length);
 172         tmp_buff = hidg->set_report_buff;
 173         hidg->set_report_buff = NULL;
 174
 175         spin_unlock_irqrestore(&hidg->spinlock, flags);
 176
 177         if (tmp_buff != NULL) {
 178                 /* copy to user outside spinlock */
 179                 count -= copy_to_user(buffer, tmp_buff, count);
 180                 kfree(tmp_buff);
 181         } else
 182                 count = -ENOMEM;
 183
 184         return count;
 185 }
 186
 187 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 188 {
 189         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 190
 191         if (req->status != 0) {
 192                 ERROR(hidg->func.config->cdev,
 193                         "End Point Request ERROR: %d\n", req->status);
 194         }
 195
 196         hidg->write_pending = 0;
 197         wake_up(&hidg->write_queue);
 198 }
 199
 200 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 201                             size_t count, loff_t *offp)
 202 {
 203         struct f_hidg *hidg  = file->private_data;
 204         ssize_t status = -ENOMEM;
 205
 206         if (!access_ok(VERIFY_READ, buffer, count))
 207                 return -EFAULT;
 208
 209         mutex_lock(&hidg->lock);
 210
 211 #define WRITE_COND (!hidg->write_pending)
 212
 213         /* write queue */
 214         while (!WRITE_COND) {
 215                 mutex_unlock(&hidg->lock);
 216                 if (file->f_flags & O_NONBLOCK)
 217                         return -EAGAIN;
 218
 219                 if (wait_event_interruptible_exclusive(
 220                                 hidg->write_queue, WRITE_COND))
 221                         return -ERESTARTSYS;
 222
 223                 mutex_lock(&hidg->lock);
 224         }
 225
 226         count  = min_t(unsigned, count, hidg->report_length);
 227         status = copy_from_user(hidg->req->buf, buffer, count);
 228
 229         if (status != 0) {
 230                 ERROR(hidg->func.config->cdev,
 231                         "copy_from_user error\n");
 232                 mutex_unlock(&hidg->lock);
 233                 return -EINVAL;
 234         }
 235
 236         hidg->req->status   = 0;
 237         hidg->req->zero     = 0;
 238         hidg->req->length   = count;
 239         hidg->req->complete = f_hidg_req_complete;
 240         hidg->req->context  = hidg;
 241         hidg->write_pending = 1;
 242
 243         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 244         if (status < 0) {
 245                 ERROR(hidg->func.config->cdev,
 246                         "usb_ep_queue error on int endpoint %zd\n", status);
 247                 hidg->write_pending = 0;
 248                 wake_up(&hidg->write_queue);
 249         } else {
 250                 status = count;
 251         }
 252
 253         mutex_unlock(&hidg->lock);
 254
 255         return status;
 256 }
 257
 258 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 259 {
 260         struct f_hidg   *hidg  = file->private_data;
 261         unsigned int    ret = 0;
 262
 263         poll_wait(file, &hidg->read_queue, wait);
 264         poll_wait(file, &hidg->write_queue, wait);
 265
 266         if (WRITE_COND)
 267                 ret |= POLLOUT | POLLWRNORM;
 268
 269         if (READ_COND)
 270                 ret |= POLLIN | POLLRDNORM;
 271
 272         return ret;
 273 }
 274
 275 #undef WRITE_COND
 276 #undef READ_COND
 277
 278 static int f_hidg_release(struct inode *inode, struct file *fd)
 279 {
 280         fd->private_data = NULL;
 281         return 0;
 282 }
 283
 284 static int f_hidg_open(struct inode *inode, struct file *fd)
 285 {
 286         struct f_hidg *hidg =
 287                 container_of(inode->i_cdev, struct f_hidg, cdev);
 288
 289         fd->private_data = hidg;
 290
 291         return 0;
 292 }
 293
 294 /*-------------------------------------------------------------------------*/
 295 /*                                usb_function                             */
 296
 297 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 298 {
 299         struct f_hidg *hidg = (struct f_hidg *)req->context;
 300
 301         if (req->status != 0 || req->buf == NULL || req->actual == 0) {
 302                 ERROR(hidg->func.config->cdev, "%s FAILED\n", __func__);
 303                 return;
 304         }
 305
 306         spin_lock(&hidg->spinlock);
 307
 308         hidg->set_report_buff = krealloc(hidg->set_report_buff,
 309                                          req->actual, GFP_ATOMIC);
 310
 311         if (hidg->set_report_buff == NULL) {
 312                 spin_unlock(&hidg->spinlock);
 313                 return;
 314         }
 315         hidg->set_report_length = req->actual;
 316         memcpy(hidg->set_report_buff, req->buf, req->actual);
 317
 318         spin_unlock(&hidg->spinlock);
 319
 320         wake_up(&hidg->read_queue);
 321
 322         return;
 323 }
 324
 325 static int hidg_setup(struct usb_function *f,
 326                 const struct usb_ctrlrequest *ctrl)
 327 {
 328         struct f_hidg                   *hidg = func_to_hidg(f);
 329         struct usb_composite_dev        *cdev = f->config->cdev;
 330         struct usb_request              *req  = cdev->req;
 331         int status = 0;
 332         __u16 value, length;
 333
 334         value   = __le16_to_cpu(ctrl->wValue);
 335         length  = __le16_to_cpu(ctrl->wLength);
 336
 337         VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
 338                 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
 339
 340         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 341         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 342                   | HID_REQ_GET_REPORT):
 343                 VDBG(cdev, "get_report\n");
 344
 345                 /* send an empty report */
 346                 length = min_t(unsigned, length, hidg->report_length);
 347                 memset(req->buf, 0x0, length);
 348
 349                 goto respond;
 350                 break;
 351
 352         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 353                   | HID_REQ_GET_PROTOCOL):
 354                 VDBG(cdev, "get_protocol\n");
 355                 goto stall;
 356                 break;
 357
 358         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 359                   | HID_REQ_SET_REPORT):
 360                 VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
 361                 req->context  = hidg;
 362                 req->complete = hidg_set_report_complete;
 363                 goto respond;
 364                 break;
 365
 366         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 367                   | HID_REQ_SET_PROTOCOL):
 368                 VDBG(cdev, "set_protocol\n");
 369                 goto stall;
 370                 break;
 371
 372         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 373                   | USB_REQ_GET_DESCRIPTOR):
 374                 switch (value >> 8) {
 375                 case HID_DT_REPORT:
 376                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 377                         length = min_t(unsigned short, length,
 378                                                    hidg->report_desc_length);
 379                         memcpy(req->buf, hidg->report_desc, length);
 380                         goto respond;
 381                         break;
 382
 383                 default:
 384                         VDBG(cdev, "Unknown decriptor request 0x%x\n",
 385                                  value >> 8);
 386                         goto stall;
 387                         break;
 388                 }
 389                 break;
 390
 391         default:
 392                 VDBG(cdev, "Unknown request 0x%x\n",
 393                          ctrl->bRequest);
 394                 goto stall;
 395                 break;
 396         }
 397
 398 stall:
 399         return -EOPNOTSUPP;
 400
 401 respond:
 402         req->zero = 0;
 403         req->length = length;
 404         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 405         if (status < 0)
 406                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 407         return status;
 408 }
 409
 410 static void hidg_disable(struct usb_function *f)
 411 {
 412         struct f_hidg *hidg = func_to_hidg(f);
 413
 414         usb_ep_disable(hidg->in_ep);
 415         hidg->in_ep->driver_data = NULL;
 416
 417         return;
 418 }
 419
 420 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 421 {
 422         struct usb_composite_dev                *cdev = f->config->cdev;
 423         struct f_hidg                           *hidg = func_to_hidg(f);
 424         const struct usb_endpoint_descriptor    *ep_desc;
 425         int status = 0;
 426
 427         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 428
 429         if (hidg->in_ep != NULL) {
 430                 /* restart endpoint */
 431                 if (hidg->in_ep->driver_data != NULL)
 432                         usb_ep_disable(hidg->in_ep);
 433
 434                 ep_desc = ep_choose(f->config->cdev->gadget,
 435                                 hidg->hs_in_ep_desc, hidg->fs_in_ep_desc);
 436                 status = usb_ep_enable(hidg->in_ep, ep_desc);
 437                 if (status < 0) {
 438                         ERROR(cdev, "Enable endpoint FAILED!\n");
 439                         goto fail;
 440                 }
 441                 hidg->in_ep->driver_data = hidg;
 442         }
 443 fail:
 444         return status;
 445 }
 446
 447 const struct file_operations f_hidg_fops = {
 448         .owner          = THIS_MODULE,
 449         .open           = f_hidg_open,
 450         .release        = f_hidg_release,
 451         .write          = f_hidg_write,
 452         .read           = f_hidg_read,
 453         .poll           = f_hidg_poll,
 454         .llseek         = noop_llseek,
 455 };
 456
 457 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 458 {
 459         struct usb_ep           *ep;
 460         struct f_hidg           *hidg = func_to_hidg(f);
 461         int                     status;
 462         dev_t                   dev;
 463
 464         /* allocate instance-specific interface IDs, and patch descriptors */
 465         status = usb_interface_id(c, f);
 466         if (status < 0)
 467                 goto fail;
 468         hidg_interface_desc.bInterfaceNumber = status;
 469
 470
 471         /* allocate instance-specific endpoints */
 472         status = -ENODEV;
 473         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 474         if (!ep)
 475                 goto fail;
 476         ep->driver_data = c->cdev;      /* claim */
 477         hidg->in_ep = ep;
 478
 479         /* preallocate request and buffer */
 480         status = -ENOMEM;
 481         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 482         if (!hidg->req)
 483                 goto fail;
 484
 485
 486         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 487         if (!hidg->req->buf)
 488                 goto fail;
 489
 490         /* set descriptor dynamic values */
 491         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 492         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 493         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 494         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 495         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 496         hidg_desc.desc[0].wDescriptorLength =
 497                 cpu_to_le16(hidg->report_desc_length);
 498
 499         hidg->set_report_buff = NULL;
 500
 501         /* copy descriptors */
 502         f->descriptors = usb_copy_descriptors(hidg_fs_descriptors);
 503         if (!f->descriptors)
 504                 goto fail;
 505
 506         hidg->fs_in_ep_desc = usb_find_endpoint(hidg_fs_descriptors,
 507                                                 f->descriptors,
 508                                                 &hidg_fs_in_ep_desc);
 509
 510         if (gadget_is_dualspeed(c->cdev->gadget)) {
 511                 hidg_hs_in_ep_desc.bEndpointAddress =
 512                         hidg_fs_in_ep_desc.bEndpointAddress;
 513                 f->hs_descriptors = usb_copy_descriptors(hidg_hs_descriptors);
 514                 if (!f->hs_descriptors)
 515                         goto fail;
 516                 hidg->hs_in_ep_desc = usb_find_endpoint(hidg_hs_descriptors,
 517                                                         f->hs_descriptors,
 518                                                         &hidg_hs_in_ep_desc);
 519         } else {
 520                 hidg->hs_in_ep_desc = NULL;
 521         }
 522
 523         mutex_init(&hidg->lock);
 524         spin_lock_init(&hidg->spinlock);
 525         init_waitqueue_head(&hidg->write_queue);
 526         init_waitqueue_head(&hidg->read_queue);
 527
 528         /* create char device */
 529         cdev_init(&hidg->cdev, &f_hidg_fops);
 530         dev = MKDEV(major, hidg->minor);
 531         status = cdev_add(&hidg->cdev, dev, 1);
 532         if (status)
 533                 goto fail;
 534
 535         device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
 536
 537         return 0;
 538
 539 fail:
 540         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 541         if (hidg->req != NULL) {
 542                 kfree(hidg->req->buf);
 543                 if (hidg->in_ep != NULL)
 544                         usb_ep_free_request(hidg->in_ep, hidg->req);
 545         }
 546
 547         usb_free_descriptors(f->hs_descriptors);
 548         usb_free_descriptors(f->descriptors);
 549
 550         return status;
 551 }
 552
 553 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 554 {
 555         struct f_hidg *hidg = func_to_hidg(f);
 556
 557         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 558         cdev_del(&hidg->cdev);
 559
 560         /* disable/free request and end point */
 561         usb_ep_disable(hidg->in_ep);
 562         usb_ep_dequeue(hidg->in_ep, hidg->req);
 563         kfree(hidg->req->buf);
 564         usb_ep_free_request(hidg->in_ep, hidg->req);
 565
 566         /* free descriptors copies */
 567         usb_free_descriptors(f->hs_descriptors);
 568         usb_free_descriptors(f->descriptors);
 569
 570         kfree(hidg->report_desc);
 571         kfree(hidg->set_report_buff);
 572         kfree(hidg);
 573 }
 574
 575 /*-------------------------------------------------------------------------*/
 576 /*                                 Strings                                 */
 577
 578 #define CT_FUNC_HID_IDX 0
 579
 580 static struct usb_string ct_func_string_defs[] = {
 581         [CT_FUNC_HID_IDX].s     = "HID Interface",
 582         {},                     /* end of list */
 583 };
 584
 585 static struct usb_gadget_strings ct_func_string_table = {
 586         .language       = 0x0409,       /* en-US */
 587         .strings        = ct_func_string_defs,
 588 };
 589
 590 static struct usb_gadget_strings *ct_func_strings[] = {
 591         &ct_func_string_table,
 592         NULL,
 593 };
 594
 595 /*-------------------------------------------------------------------------*/
 596 /*                             usb_configuration                           */
 597
 598 int __init hidg_bind_config(struct usb_configuration *c,
 599                             struct hidg_func_descriptor *fdesc, int index)
 600 {
 601         struct f_hidg *hidg;
 602         int status;
 603
 604         if (index >= minors)
 605                 return -ENOENT;
 606
 607         /* maybe allocate device-global string IDs, and patch descriptors */
 608         if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
 609                 status = usb_string_id(c->cdev);
 610                 if (status < 0)
 611                         return status;
 612                 ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
 613                 hidg_interface_desc.iInterface = status;
 614         }
 615
 616         /* allocate and initialize one new instance */
 617         hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
 618         if (!hidg)
 619                 return -ENOMEM;
 620
 621         hidg->minor = index;
 622         hidg->bInterfaceSubClass = fdesc->subclass;
 623         hidg->bInterfaceProtocol = fdesc->protocol;
 624         hidg->report_length = fdesc->report_length;
 625         hidg->report_desc_length = fdesc->report_desc_length;
 626         hidg->report_desc = kmemdup(fdesc->report_desc,
 627                                     fdesc->report_desc_length,
 628                                     GFP_KERNEL);
 629         if (!hidg->report_desc) {
 630                 kfree(hidg);
 631                 return -ENOMEM;
 632         }
 633
 634         hidg->func.name    = "hid";
 635         hidg->func.strings = ct_func_strings;
 636         hidg->func.bind    = hidg_bind;
 637         hidg->func.unbind  = hidg_unbind;
 638         hidg->func.set_alt = hidg_set_alt;
 639         hidg->func.disable = hidg_disable;
 640         hidg->func.setup   = hidg_setup;
 641
 642         status = usb_add_function(c, &hidg->func);
 643         if (status)
 644                 kfree(hidg);
 645
 646         return status;
 647 }
 648
 649 int __init ghid_setup(struct usb_gadget *g, int count)
 650 {
 651         int status;
 652         dev_t dev;
 653
 654         hidg_class = class_create(THIS_MODULE, "hidg");
 655
 656         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 657         if (!status) {
 658                 major = MAJOR(dev);
 659                 minors = count;
 660         }
 661
 662         return status;
 663 }
 664
 665 void ghid_cleanup(void)
 666 {
 667         if (major) {
 668                 unregister_chrdev_region(MKDEV(major, 0), minors);
 669                 major = minors = 0;
 670         }
 671
 672         class_destroy(hidg_class);
 673         hidg_class = NULL;
 674 }