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/module.h>
  14 #include <linux/hid.h>
  15 #include <linux/cdev.h>
  16 #include <linux/mutex.h>
  17 #include <linux/poll.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/wait.h>
  20 #include <linux/sched.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_req_list {
  30         struct usb_request      *req;
  31         unsigned int            pos;
  32         struct list_head        list;
  33 };
  34
  35 struct f_hidg {
  36         /* configuration */
  37         unsigned char                   bInterfaceSubClass;
  38         unsigned char                   bInterfaceProtocol;
  39         unsigned short                  report_desc_length;
  40         char                            *report_desc;
  41         unsigned short                  report_length;
  42
  43         /* recv report */
  44         struct list_head                completed_out_req;
  45         spinlock_t                      spinlock;
  46         wait_queue_head_t               read_queue;
  47         unsigned int                    qlen;
  48
  49         /* send report */
  50         struct mutex                    lock;
  51         bool                            write_pending;
  52         wait_queue_head_t               write_queue;
  53         struct usb_request              *req;
  54
  55         int                             minor;
  56         struct cdev                     cdev;
  57         struct usb_function             func;
  58
  59         struct usb_ep                   *in_ep;
  60         struct usb_ep                   *out_ep;
  61 };
  62
  63 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  64 {
  65         return container_of(f, struct f_hidg, func);
  66 }
  67
  68 /*-------------------------------------------------------------------------*/
  69 /*                           Static descriptors                            */
  70
  71 static struct usb_interface_descriptor hidg_interface_desc = {
  72         .bLength                = sizeof hidg_interface_desc,
  73         .bDescriptorType        = USB_DT_INTERFACE,
  74         /* .bInterfaceNumber    = DYNAMIC */
  75         .bAlternateSetting      = 0,
  76         .bNumEndpoints          = 2,
  77         .bInterfaceClass        = USB_CLASS_HID,
  78         /* .bInterfaceSubClass  = DYNAMIC */
  79         /* .bInterfaceProtocol  = DYNAMIC */
  80         /* .iInterface          = DYNAMIC */
  81 };
  82
  83 static struct hid_descriptor hidg_desc = {
  84         .bLength                        = sizeof hidg_desc,
  85         .bDescriptorType                = HID_DT_HID,
  86         .bcdHID                         = 0x0101,
  87         .bCountryCode                   = 0x00,
  88         .bNumDescriptors                = 0x1,
  89         /*.desc[0].bDescriptorType      = DYNAMIC */
  90         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  91 };
  92
  93 /* High-Speed Support */
  94
  95 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
  96         .bLength                = USB_DT_ENDPOINT_SIZE,
  97         .bDescriptorType        = USB_DT_ENDPOINT,
  98         .bEndpointAddress       = USB_DIR_IN,
  99         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 100         /*.wMaxPacketSize       = DYNAMIC */
 101         .bInterval              = 4, /* FIXME: Add this field in the
 102                                       * HID gadget configuration?
 103                                       * (struct hidg_func_descriptor)
 104                                       */
 105 };
 106
 107 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 108         .bLength                = USB_DT_ENDPOINT_SIZE,
 109         .bDescriptorType        = USB_DT_ENDPOINT,
 110         .bEndpointAddress       = USB_DIR_OUT,
 111         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 112         /*.wMaxPacketSize       = DYNAMIC */
 113         .bInterval              = 4, /* FIXME: Add this field in the
 114                                       * HID gadget configuration?
 115                                       * (struct hidg_func_descriptor)
 116                                       */
 117 };
 118
 119 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 120         (struct usb_descriptor_header *)&hidg_interface_desc,
 121         (struct usb_descriptor_header *)&hidg_desc,
 122         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 123         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 124         NULL,
 125 };
 126
 127 /* Full-Speed Support */
 128
 129 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 130         .bLength                = USB_DT_ENDPOINT_SIZE,
 131         .bDescriptorType        = USB_DT_ENDPOINT,
 132         .bEndpointAddress       = USB_DIR_IN,
 133         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 134         /*.wMaxPacketSize       = DYNAMIC */
 135         .bInterval              = 10, /* FIXME: Add this field in the
 136                                        * HID gadget configuration?
 137                                        * (struct hidg_func_descriptor)
 138                                        */
 139 };
 140
 141 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 142         .bLength                = USB_DT_ENDPOINT_SIZE,
 143         .bDescriptorType        = USB_DT_ENDPOINT,
 144         .bEndpointAddress       = USB_DIR_OUT,
 145         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 146         /*.wMaxPacketSize       = DYNAMIC */
 147         .bInterval              = 10, /* FIXME: Add this field in the
 148                                        * HID gadget configuration?
 149                                        * (struct hidg_func_descriptor)
 150                                        */
 151 };
 152
 153 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 154         (struct usb_descriptor_header *)&hidg_interface_desc,
 155         (struct usb_descriptor_header *)&hidg_desc,
 156         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 157         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 158         NULL,
 159 };
 160
 161 /*-------------------------------------------------------------------------*/
 162 /*                              Char Device                                */
 163
 164 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 165                         size_t count, loff_t *ptr)
 166 {
 167         struct f_hidg *hidg = file->private_data;
 168         struct f_hidg_req_list *list;
 169         struct usb_request *req;
 170         unsigned long flags;
 171         int ret;
 172
 173         if (!count)
 174                 return 0;
 175
 176         if (!access_ok(VERIFY_WRITE, buffer, count))
 177                 return -EFAULT;
 178
 179         spin_lock_irqsave(&hidg->spinlock, flags);
 180
 181 #define READ_COND (!list_empty(&hidg->completed_out_req))
 182
 183         /* wait for at least one buffer to complete */
 184         while (!READ_COND) {
 185                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 186                 if (file->f_flags & O_NONBLOCK)
 187                         return -EAGAIN;
 188
 189                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 190                         return -ERESTARTSYS;
 191
 192                 spin_lock_irqsave(&hidg->spinlock, flags);
 193         }
 194
 195         /* pick the first one */
 196         list = list_first_entry(&hidg->completed_out_req,
 197                                 struct f_hidg_req_list, list);
 198         req = list->req;
 199         count = min_t(unsigned int, count, req->actual - list->pos);
 200         spin_unlock_irqrestore(&hidg->spinlock, flags);
 201
 202         /* copy to user outside spinlock */
 203         count -= copy_to_user(buffer, req->buf + list->pos, count);
 204         list->pos += count;
 205
 206         /*
 207          * if this request is completely handled and transfered to
 208          * userspace, remove its entry from the list and requeue it
 209          * again. Otherwise, we will revisit it again upon the next
 210          * call, taking into account its current read position.
 211          */
 212         if (list->pos == req->actual) {
 213                 spin_lock_irqsave(&hidg->spinlock, flags);
 214                 list_del(&list->list);
 215                 kfree(list);
 216                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 217
 218                 req->length = hidg->report_length;
 219                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 220                 if (ret < 0)
 221                         return ret;
 222         }
 223
 224         return count;
 225 }
 226
 227 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 228 {
 229         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 230
 231         if (req->status != 0) {
 232                 ERROR(hidg->func.config->cdev,
 233                         "End Point Request ERROR: %d\n", req->status);
 234         }
 235
 236         hidg->write_pending = 0;
 237         wake_up(&hidg->write_queue);
 238 }
 239
 240 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 241                             size_t count, loff_t *offp)
 242 {
 243         struct f_hidg *hidg  = file->private_data;
 244         ssize_t status = -ENOMEM;
 245
 246         if (!access_ok(VERIFY_READ, buffer, count))
 247                 return -EFAULT;
 248
 249         mutex_lock(&hidg->lock);
 250
 251 #define WRITE_COND (!hidg->write_pending)
 252
 253         /* write queue */
 254         while (!WRITE_COND) {
 255                 mutex_unlock(&hidg->lock);
 256                 if (file->f_flags & O_NONBLOCK)
 257                         return -EAGAIN;
 258
 259                 if (wait_event_interruptible_exclusive(
 260                                 hidg->write_queue, WRITE_COND))
 261                         return -ERESTARTSYS;
 262
 263                 mutex_lock(&hidg->lock);
 264         }
 265
 266         count  = min_t(unsigned, count, hidg->report_length);
 267         status = copy_from_user(hidg->req->buf, buffer, count);
 268
 269         if (status != 0) {
 270                 ERROR(hidg->func.config->cdev,
 271                         "copy_from_user error\n");
 272                 mutex_unlock(&hidg->lock);
 273                 return -EINVAL;
 274         }
 275
 276         hidg->req->status   = 0;
 277         hidg->req->zero     = 0;
 278         hidg->req->length   = count;
 279         hidg->req->complete = f_hidg_req_complete;
 280         hidg->req->context  = hidg;
 281         hidg->write_pending = 1;
 282
 283         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 284         if (status < 0) {
 285                 ERROR(hidg->func.config->cdev,
 286                         "usb_ep_queue error on int endpoint %zd\n", status);
 287                 hidg->write_pending = 0;
 288                 wake_up(&hidg->write_queue);
 289         } else {
 290                 status = count;
 291         }
 292
 293         mutex_unlock(&hidg->lock);
 294
 295         return status;
 296 }
 297
 298 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 299 {
 300         struct f_hidg   *hidg  = file->private_data;
 301         unsigned int    ret = 0;
 302
 303         poll_wait(file, &hidg->read_queue, wait);
 304         poll_wait(file, &hidg->write_queue, wait);
 305
 306         if (WRITE_COND)
 307                 ret |= POLLOUT | POLLWRNORM;
 308
 309         if (READ_COND)
 310                 ret |= POLLIN | POLLRDNORM;
 311
 312         return ret;
 313 }
 314
 315 #undef WRITE_COND
 316 #undef READ_COND
 317
 318 static int f_hidg_release(struct inode *inode, struct file *fd)
 319 {
 320         fd->private_data = NULL;
 321         return 0;
 322 }
 323
 324 static int f_hidg_open(struct inode *inode, struct file *fd)
 325 {
 326         struct f_hidg *hidg =
 327                 container_of(inode->i_cdev, struct f_hidg, cdev);
 328
 329         fd->private_data = hidg;
 330
 331         return 0;
 332 }
 333
 334 /*-------------------------------------------------------------------------*/
 335 /*                                usb_function                             */
 336
 337 static struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep, unsigned length)
 338 {
 339         struct usb_request *req;
 340
 341         req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 342         if (req) {
 343                 req->length = length;
 344                 req->buf = kmalloc(length, GFP_ATOMIC);
 345                 if (!req->buf) {
 346                         usb_ep_free_request(ep, req);
 347                         req = NULL;
 348                 }
 349         }
 350         return req;
 351 }
 352
 353 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 354 {
 355         struct f_hidg *hidg = (struct f_hidg *) req->context;
 356         struct f_hidg_req_list *req_list;
 357         unsigned long flags;
 358
 359         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 360         if (!req_list)
 361                 return;
 362
 363         req_list->req = req;
 364
 365         spin_lock_irqsave(&hidg->spinlock, flags);
 366         list_add_tail(&req_list->list, &hidg->completed_out_req);
 367         spin_unlock_irqrestore(&hidg->spinlock, flags);
 368
 369         wake_up(&hidg->read_queue);
 370 }
 371
 372 static int hidg_setup(struct usb_function *f,
 373                 const struct usb_ctrlrequest *ctrl)
 374 {
 375         struct f_hidg                   *hidg = func_to_hidg(f);
 376         struct usb_composite_dev        *cdev = f->config->cdev;
 377         struct usb_request              *req  = cdev->req;
 378         int status = 0;
 379         __u16 value, length;
 380
 381         value   = __le16_to_cpu(ctrl->wValue);
 382         length  = __le16_to_cpu(ctrl->wLength);
 383
 384         VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
 385                 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
 386
 387         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 388         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 389                   | HID_REQ_GET_REPORT):
 390                 VDBG(cdev, "get_report\n");
 391
 392                 /* send an empty report */
 393                 length = min_t(unsigned, length, hidg->report_length);
 394                 memset(req->buf, 0x0, length);
 395
 396                 goto respond;
 397                 break;
 398
 399         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 400                   | HID_REQ_GET_PROTOCOL):
 401                 VDBG(cdev, "get_protocol\n");
 402                 goto stall;
 403                 break;
 404
 405         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 406                   | HID_REQ_SET_REPORT):
 407                 VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
 408                 goto stall;
 409                 break;
 410
 411         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 412                   | HID_REQ_SET_PROTOCOL):
 413                 VDBG(cdev, "set_protocol\n");
 414                 goto stall;
 415                 break;
 416
 417         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 418                   | USB_REQ_GET_DESCRIPTOR):
 419                 switch (value >> 8) {
 420                 case HID_DT_HID:
 421                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 422                         length = min_t(unsigned short, length,
 423                                                    hidg_desc.bLength);
 424                         memcpy(req->buf, &hidg_desc, length);
 425                         goto respond;
 426                         break;
 427                 case HID_DT_REPORT:
 428                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 429                         length = min_t(unsigned short, length,
 430                                                    hidg->report_desc_length);
 431                         memcpy(req->buf, hidg->report_desc, length);
 432                         goto respond;
 433                         break;
 434
 435                 default:
 436                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 437                                  value >> 8);
 438                         goto stall;
 439                         break;
 440                 }
 441                 break;
 442
 443         default:
 444                 VDBG(cdev, "Unknown request 0x%x\n",
 445                          ctrl->bRequest);
 446                 goto stall;
 447                 break;
 448         }
 449
 450 stall:
 451         return -EOPNOTSUPP;
 452
 453 respond:
 454         req->zero = 0;
 455         req->length = length;
 456         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 457         if (status < 0)
 458                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 459         return status;
 460 }
 461
 462 static void hidg_disable(struct usb_function *f)
 463 {
 464         struct f_hidg *hidg = func_to_hidg(f);
 465         struct f_hidg_req_list *list, *next;
 466
 467         usb_ep_disable(hidg->in_ep);
 468         hidg->in_ep->driver_data = NULL;
 469
 470         usb_ep_disable(hidg->out_ep);
 471         hidg->out_ep->driver_data = NULL;
 472
 473         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 474                 list_del(&list->list);
 475                 kfree(list);
 476         }
 477 }
 478
 479 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 480 {
 481         struct usb_composite_dev                *cdev = f->config->cdev;
 482         struct f_hidg                           *hidg = func_to_hidg(f);
 483         int i, status = 0;
 484
 485         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 486
 487         if (hidg->in_ep != NULL) {
 488                 /* restart endpoint */
 489                 if (hidg->in_ep->driver_data != NULL)
 490                         usb_ep_disable(hidg->in_ep);
 491
 492                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 493                                             hidg->in_ep);
 494                 if (status) {
 495                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 496                         goto fail;
 497                 }
 498                 status = usb_ep_enable(hidg->in_ep);
 499                 if (status < 0) {
 500                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 501                         goto fail;
 502                 }
 503                 hidg->in_ep->driver_data = hidg;
 504         }
 505
 506
 507         if (hidg->out_ep != NULL) {
 508                 /* restart endpoint */
 509                 if (hidg->out_ep->driver_data != NULL)
 510                         usb_ep_disable(hidg->out_ep);
 511
 512                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 513                                             hidg->out_ep);
 514                 if (status) {
 515                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 516                         goto fail;
 517                 }
 518                 status = usb_ep_enable(hidg->out_ep);
 519                 if (status < 0) {
 520                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 521                         goto fail;
 522                 }
 523                 hidg->out_ep->driver_data = hidg;
 524
 525                 /*
 526                  * allocate a bunch of read buffers and queue them all at once.
 527                  */
 528                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 529                         struct usb_request *req =
 530                                         hidg_alloc_ep_req(hidg->out_ep,
 531                                                           hidg->report_length);
 532                         if (req) {
 533                                 req->complete = hidg_set_report_complete;
 534                                 req->context  = hidg;
 535                                 status = usb_ep_queue(hidg->out_ep, req,
 536                                                       GFP_ATOMIC);
 537                                 if (status)
 538                                         ERROR(cdev, "%s queue req --> %d\n",
 539                                                 hidg->out_ep->name, status);
 540                         } else {
 541                                 usb_ep_disable(hidg->out_ep);
 542                                 hidg->out_ep->driver_data = NULL;
 543                                 status = -ENOMEM;
 544                                 goto fail;
 545                         }
 546                 }
 547         }
 548
 549 fail:
 550         return status;
 551 }
 552
 553 const struct file_operations f_hidg_fops = {
 554         .owner          = THIS_MODULE,
 555         .open           = f_hidg_open,
 556         .release        = f_hidg_release,
 557         .write          = f_hidg_write,
 558         .read           = f_hidg_read,
 559         .poll           = f_hidg_poll,
 560         .llseek         = noop_llseek,
 561 };
 562
 563 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 564 {
 565         struct usb_ep           *ep;
 566         struct f_hidg           *hidg = func_to_hidg(f);
 567         int                     status;
 568         dev_t                   dev;
 569
 570         /* allocate instance-specific interface IDs, and patch descriptors */
 571         status = usb_interface_id(c, f);
 572         if (status < 0)
 573                 goto fail;
 574         hidg_interface_desc.bInterfaceNumber = status;
 575
 576         /* allocate instance-specific endpoints */
 577         status = -ENODEV;
 578         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 579         if (!ep)
 580                 goto fail;
 581         ep->driver_data = c->cdev;      /* claim */
 582         hidg->in_ep = ep;
 583
 584         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 585         if (!ep)
 586                 goto fail;
 587         ep->driver_data = c->cdev;      /* claim */
 588         hidg->out_ep = ep;
 589
 590         /* preallocate request and buffer */
 591         status = -ENOMEM;
 592         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 593         if (!hidg->req)
 594                 goto fail;
 595
 596         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 597         if (!hidg->req->buf)
 598                 goto fail;
 599
 600         /* set descriptor dynamic values */
 601         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 602         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 603         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 604         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 605         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 606         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 607         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 608         hidg_desc.desc[0].wDescriptorLength =
 609                 cpu_to_le16(hidg->report_desc_length);
 610
 611         hidg_hs_in_ep_desc.bEndpointAddress =
 612                 hidg_fs_in_ep_desc.bEndpointAddress;
 613         hidg_hs_out_ep_desc.bEndpointAddress =
 614                 hidg_fs_out_ep_desc.bEndpointAddress;
 615
 616         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 617                         hidg_hs_descriptors, NULL);
 618         if (status)
 619                 goto fail;
 620
 621         mutex_init(&hidg->lock);
 622         spin_lock_init(&hidg->spinlock);
 623         init_waitqueue_head(&hidg->write_queue);
 624         init_waitqueue_head(&hidg->read_queue);
 625         INIT_LIST_HEAD(&hidg->completed_out_req);
 626
 627         /* create char device */
 628         cdev_init(&hidg->cdev, &f_hidg_fops);
 629         dev = MKDEV(major, hidg->minor);
 630         status = cdev_add(&hidg->cdev, dev, 1);
 631         if (status)
 632                 goto fail;
 633
 634         device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
 635
 636         return 0;
 637
 638 fail:
 639         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 640         if (hidg->req != NULL) {
 641                 kfree(hidg->req->buf);
 642                 if (hidg->in_ep != NULL)
 643                         usb_ep_free_request(hidg->in_ep, hidg->req);
 644         }
 645
 646         usb_free_all_descriptors(f);
 647         return status;
 648 }
 649
 650 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 651 {
 652         struct f_hidg *hidg = func_to_hidg(f);
 653
 654         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 655         cdev_del(&hidg->cdev);
 656
 657         /* disable/free request and end point */
 658         usb_ep_disable(hidg->in_ep);
 659         usb_ep_dequeue(hidg->in_ep, hidg->req);
 660         kfree(hidg->req->buf);
 661         usb_ep_free_request(hidg->in_ep, hidg->req);
 662
 663         usb_free_all_descriptors(f);
 664
 665         kfree(hidg->report_desc);
 666         kfree(hidg);
 667 }
 668
 669 /*-------------------------------------------------------------------------*/
 670 /*                                 Strings                                 */
 671
 672 #define CT_FUNC_HID_IDX 0
 673
 674 static struct usb_string ct_func_string_defs[] = {
 675         [CT_FUNC_HID_IDX].s     = "HID Interface",
 676         {},                     /* end of list */
 677 };
 678
 679 static struct usb_gadget_strings ct_func_string_table = {
 680         .language       = 0x0409,       /* en-US */
 681         .strings        = ct_func_string_defs,
 682 };
 683
 684 static struct usb_gadget_strings *ct_func_strings[] = {
 685         &ct_func_string_table,
 686         NULL,
 687 };
 688
 689 /*-------------------------------------------------------------------------*/
 690 /*                             usb_configuration                           */
 691
 692 int __init hidg_bind_config(struct usb_configuration *c,
 693                             struct hidg_func_descriptor *fdesc, int index)
 694 {
 695         struct f_hidg *hidg;
 696         int status;
 697
 698         if (index >= minors)
 699                 return -ENOENT;
 700
 701         /* maybe allocate device-global string IDs, and patch descriptors */
 702         if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
 703                 status = usb_string_id(c->cdev);
 704                 if (status < 0)
 705                         return status;
 706                 ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
 707                 hidg_interface_desc.iInterface = status;
 708         }
 709
 710         /* allocate and initialize one new instance */
 711         hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
 712         if (!hidg)
 713                 return -ENOMEM;
 714
 715         hidg->minor = index;
 716         hidg->bInterfaceSubClass = fdesc->subclass;
 717         hidg->bInterfaceProtocol = fdesc->protocol;
 718         hidg->report_length = fdesc->report_length;
 719         hidg->report_desc_length = fdesc->report_desc_length;
 720         hidg->report_desc = kmemdup(fdesc->report_desc,
 721                                     fdesc->report_desc_length,
 722                                     GFP_KERNEL);
 723         if (!hidg->report_desc) {
 724                 kfree(hidg);
 725                 return -ENOMEM;
 726         }
 727
 728         hidg->func.name    = "hid";
 729         hidg->func.strings = ct_func_strings;
 730         hidg->func.bind    = hidg_bind;
 731         hidg->func.unbind  = hidg_unbind;
 732         hidg->func.set_alt = hidg_set_alt;
 733         hidg->func.disable = hidg_disable;
 734         hidg->func.setup   = hidg_setup;
 735
 736         /* this could me made configurable at some point */
 737         hidg->qlen         = 4;
 738
 739         status = usb_add_function(c, &hidg->func);
 740         if (status)
 741                 kfree(hidg);
 742
 743         return status;
 744 }
 745
 746 int __init ghid_setup(struct usb_gadget *g, int count)
 747 {
 748         int status;
 749         dev_t dev;
 750
 751         hidg_class = class_create(THIS_MODULE, "hidg");
 752
 753         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 754         if (!status) {
 755                 major = MAJOR(dev);
 756                 minors = count;
 757         }
 758
 759         return status;
 760 }
 761
 762 void ghid_cleanup(void)
 763 {
 764         if (major) {
 765                 unregister_chrdev_region(MKDEV(major, 0), minors);
 766                 major = minors = 0;
 767         }
 768
 769         class_destroy(hidg_class);
 770         hidg_class = NULL;
 771 }