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