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