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 #include "u_f.h"
  24
  25 static int major, minors;
  26 static struct class *hidg_class;
  27
  28 /*-------------------------------------------------------------------------*/
  29 /*                            HID gadget struct                            */
  30
  31 struct f_hidg_req_list {
  32         struct usb_request      *req;
  33         unsigned int            pos;
  34         struct list_head        list;
  35 };
  36
  37 struct f_hidg {
  38         /* configuration */
  39         unsigned char                   bInterfaceSubClass;
  40         unsigned char                   bInterfaceProtocol;
  41         unsigned short                  report_desc_length;
  42         char                            *report_desc;
  43         unsigned short                  report_length;
  44
  45         /* recv report */
  46         struct list_head                completed_out_req;
  47         spinlock_t                      spinlock;
  48         wait_queue_head_t               read_queue;
  49         unsigned int                    qlen;
  50
  51         /* send report */
  52         struct mutex                    lock;
  53         bool                            write_pending;
  54         wait_queue_head_t               write_queue;
  55         struct usb_request              *req;
  56
  57         int                             minor;
  58         struct cdev                     cdev;
  59         struct usb_function             func;
  60
  61         struct usb_ep                   *in_ep;
  62         struct usb_ep                   *out_ep;
  63 };
  64
  65 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  66 {
  67         return container_of(f, struct f_hidg, func);
  68 }
  69
  70 /*-------------------------------------------------------------------------*/
  71 /*                           Static descriptors                            */
  72
  73 static struct usb_interface_descriptor hidg_interface_desc = {
  74         .bLength                = sizeof hidg_interface_desc,
  75         .bDescriptorType        = USB_DT_INTERFACE,
  76         /* .bInterfaceNumber    = DYNAMIC */
  77         .bAlternateSetting      = 0,
  78         .bNumEndpoints          = 2,
  79         .bInterfaceClass        = USB_CLASS_HID,
  80         /* .bInterfaceSubClass  = DYNAMIC */
  81         /* .bInterfaceProtocol  = DYNAMIC */
  82         /* .iInterface          = DYNAMIC */
  83 };
  84
  85 static struct hid_descriptor hidg_desc = {
  86         .bLength                        = sizeof hidg_desc,
  87         .bDescriptorType                = HID_DT_HID,
  88         .bcdHID                         = 0x0101,
  89         .bCountryCode                   = 0x00,
  90         .bNumDescriptors                = 0x1,
  91         /*.desc[0].bDescriptorType      = DYNAMIC */
  92         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  93 };
  94
  95 /* High-Speed Support */
  96
  97 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
  98         .bLength                = USB_DT_ENDPOINT_SIZE,
  99         .bDescriptorType        = USB_DT_ENDPOINT,
 100         .bEndpointAddress       = USB_DIR_IN,
 101         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 102         /*.wMaxPacketSize       = DYNAMIC */
 103         .bInterval              = 4, /* FIXME: Add this field in the
 104                                       * HID gadget configuration?
 105                                       * (struct hidg_func_descriptor)
 106                                       */
 107 };
 108
 109 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 110         .bLength                = USB_DT_ENDPOINT_SIZE,
 111         .bDescriptorType        = USB_DT_ENDPOINT,
 112         .bEndpointAddress       = USB_DIR_OUT,
 113         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 114         /*.wMaxPacketSize       = DYNAMIC */
 115         .bInterval              = 4, /* FIXME: Add this field in the
 116                                       * HID gadget configuration?
 117                                       * (struct hidg_func_descriptor)
 118                                       */
 119 };
 120
 121 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 122         (struct usb_descriptor_header *)&hidg_interface_desc,
 123         (struct usb_descriptor_header *)&hidg_desc,
 124         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 125         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 126         NULL,
 127 };
 128
 129 /* Full-Speed Support */
 130
 131 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 132         .bLength                = USB_DT_ENDPOINT_SIZE,
 133         .bDescriptorType        = USB_DT_ENDPOINT,
 134         .bEndpointAddress       = USB_DIR_IN,
 135         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 136         /*.wMaxPacketSize       = DYNAMIC */
 137         .bInterval              = 10, /* FIXME: Add this field in the
 138                                        * HID gadget configuration?
 139                                        * (struct hidg_func_descriptor)
 140                                        */
 141 };
 142
 143 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 144         .bLength                = USB_DT_ENDPOINT_SIZE,
 145         .bDescriptorType        = USB_DT_ENDPOINT,
 146         .bEndpointAddress       = USB_DIR_OUT,
 147         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 148         /*.wMaxPacketSize       = DYNAMIC */
 149         .bInterval              = 10, /* FIXME: Add this field in the
 150                                        * HID gadget configuration?
 151                                        * (struct hidg_func_descriptor)
 152                                        */
 153 };
 154
 155 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 156         (struct usb_descriptor_header *)&hidg_interface_desc,
 157         (struct usb_descriptor_header *)&hidg_desc,
 158         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 159         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 160         NULL,
 161 };
 162
 163 /*-------------------------------------------------------------------------*/
 164 /*                              Char Device                                */
 165
 166 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 167                         size_t count, loff_t *ptr)
 168 {
 169         struct f_hidg *hidg = file->private_data;
 170         struct f_hidg_req_list *list;
 171         struct usb_request *req;
 172         unsigned long flags;
 173         int ret;
 174
 175         if (!count)
 176                 return 0;
 177
 178         if (!access_ok(VERIFY_WRITE, buffer, count))
 179                 return -EFAULT;
 180
 181         spin_lock_irqsave(&hidg->spinlock, flags);
 182
 183 #define READ_COND (!list_empty(&hidg->completed_out_req))
 184
 185         /* wait for at least one buffer to complete */
 186         while (!READ_COND) {
 187                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 188                 if (file->f_flags & O_NONBLOCK)
 189                         return -EAGAIN;
 190
 191                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 192                         return -ERESTARTSYS;
 193
 194                 spin_lock_irqsave(&hidg->spinlock, flags);
 195         }
 196
 197         /* pick the first one */
 198         list = list_first_entry(&hidg->completed_out_req,
 199                                 struct f_hidg_req_list, list);
 200         req = list->req;
 201         count = min_t(unsigned int, count, req->actual - list->pos);
 202         spin_unlock_irqrestore(&hidg->spinlock, flags);
 203
 204         /* copy to user outside spinlock */
 205         count -= copy_to_user(buffer, req->buf + list->pos, count);
 206         list->pos += count;
 207
 208         /*
 209          * if this request is completely handled and transfered to
 210          * userspace, remove its entry from the list and requeue it
 211          * again. Otherwise, we will revisit it again upon the next
 212          * call, taking into account its current read position.
 213          */
 214         if (list->pos == req->actual) {
 215                 spin_lock_irqsave(&hidg->spinlock, flags);
 216                 list_del(&list->list);
 217                 kfree(list);
 218                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 219
 220                 req->length = hidg->report_length;
 221                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 222                 if (ret < 0)
 223                         return ret;
 224         }
 225
 226         return count;
 227 }
 228
 229 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 230 {
 231         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 232
 233         if (req->status != 0) {
 234                 ERROR(hidg->func.config->cdev,
 235                         "End Point Request ERROR: %d\n", req->status);
 236         }
 237
 238         hidg->write_pending = 0;
 239         wake_up(&hidg->write_queue);
 240 }
 241
 242 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 243                             size_t count, loff_t *offp)
 244 {
 245         struct f_hidg *hidg  = file->private_data;
 246         ssize_t status = -ENOMEM;
 247
 248         if (!access_ok(VERIFY_READ, buffer, count))
 249                 return -EFAULT;
 250
 251         mutex_lock(&hidg->lock);
 252
 253 #define WRITE_COND (!hidg->write_pending)
 254
 255         /* write queue */
 256         while (!WRITE_COND) {
 257                 mutex_unlock(&hidg->lock);
 258                 if (file->f_flags & O_NONBLOCK)
 259                         return -EAGAIN;
 260
 261                 if (wait_event_interruptible_exclusive(
 262                                 hidg->write_queue, WRITE_COND))
 263                         return -ERESTARTSYS;
 264
 265                 mutex_lock(&hidg->lock);
 266         }
 267
 268         count  = min_t(unsigned, count, hidg->report_length);
 269         status = copy_from_user(hidg->req->buf, buffer, count);
 270
 271         if (status != 0) {
 272                 ERROR(hidg->func.config->cdev,
 273                         "copy_from_user error\n");
 274                 mutex_unlock(&hidg->lock);
 275                 return -EINVAL;
 276         }
 277
 278         hidg->req->status   = 0;
 279         hidg->req->zero     = 0;
 280         hidg->req->length   = count;
 281         hidg->req->complete = f_hidg_req_complete;
 282         hidg->req->context  = hidg;
 283         hidg->write_pending = 1;
 284
 285         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 286         if (status < 0) {
 287                 ERROR(hidg->func.config->cdev,
 288                         "usb_ep_queue error on int endpoint %zd\n", status);
 289                 hidg->write_pending = 0;
 290                 wake_up(&hidg->write_queue);
 291         } else {
 292                 status = count;
 293         }
 294
 295         mutex_unlock(&hidg->lock);
 296
 297         return status;
 298 }
 299
 300 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 301 {
 302         struct f_hidg   *hidg  = file->private_data;
 303         unsigned int    ret = 0;
 304
 305         poll_wait(file, &hidg->read_queue, wait);
 306         poll_wait(file, &hidg->write_queue, wait);
 307
 308         if (WRITE_COND)
 309                 ret |= POLLOUT | POLLWRNORM;
 310
 311         if (READ_COND)
 312                 ret |= POLLIN | POLLRDNORM;
 313
 314         return ret;
 315 }
 316
 317 #undef WRITE_COND
 318 #undef READ_COND
 319
 320 static int f_hidg_release(struct inode *inode, struct file *fd)
 321 {
 322         fd->private_data = NULL;
 323         return 0;
 324 }
 325
 326 static int f_hidg_open(struct inode *inode, struct file *fd)
 327 {
 328         struct f_hidg *hidg =
 329                 container_of(inode->i_cdev, struct f_hidg, cdev);
 330
 331         fd->private_data = hidg;
 332
 333         return 0;
 334 }
 335
 336 /*-------------------------------------------------------------------------*/
 337 /*                                usb_function                             */
 338
 339 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 340                                                     unsigned length)
 341 {
 342         return alloc_ep_req(ep, length, length);
 343 }
 344
 345 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 346 {
 347         struct f_hidg *hidg = (struct f_hidg *) req->context;
 348         struct f_hidg_req_list *req_list;
 349         unsigned long flags;
 350
 351         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 352         if (!req_list)
 353                 return;
 354
 355         req_list->req = req;
 356
 357         spin_lock_irqsave(&hidg->spinlock, flags);
 358         list_add_tail(&req_list->list, &hidg->completed_out_req);
 359         spin_unlock_irqrestore(&hidg->spinlock, flags);
 360
 361         wake_up(&hidg->read_queue);
 362 }
 363
 364 static int hidg_setup(struct usb_function *f,
 365                 const struct usb_ctrlrequest *ctrl)
 366 {
 367         struct f_hidg                   *hidg = func_to_hidg(f);
 368         struct usb_composite_dev        *cdev = f->config->cdev;
 369         struct usb_request              *req  = cdev->req;
 370         int status = 0;
 371         __u16 value, length;
 372
 373         value   = __le16_to_cpu(ctrl->wValue);
 374         length  = __le16_to_cpu(ctrl->wLength);
 375
 376         VDBG(cdev, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
 377                 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
 378
 379         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 380         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 381                   | HID_REQ_GET_REPORT):
 382                 VDBG(cdev, "get_report\n");
 383
 384                 /* send an empty report */
 385                 length = min_t(unsigned, length, hidg->report_length);
 386                 memset(req->buf, 0x0, length);
 387
 388                 goto respond;
 389                 break;
 390
 391         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 392                   | HID_REQ_GET_PROTOCOL):
 393                 VDBG(cdev, "get_protocol\n");
 394                 goto stall;
 395                 break;
 396
 397         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 398                   | HID_REQ_SET_REPORT):
 399                 VDBG(cdev, "set_report | wLenght=%d\n", ctrl->wLength);
 400                 goto stall;
 401                 break;
 402
 403         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 404                   | HID_REQ_SET_PROTOCOL):
 405                 VDBG(cdev, "set_protocol\n");
 406                 goto stall;
 407                 break;
 408
 409         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 410                   | USB_REQ_GET_DESCRIPTOR):
 411                 switch (value >> 8) {
 412                 case HID_DT_HID:
 413                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 414                         length = min_t(unsigned short, length,
 415                                                    hidg_desc.bLength);
 416                         memcpy(req->buf, &hidg_desc, length);
 417                         goto respond;
 418                         break;
 419                 case HID_DT_REPORT:
 420                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 421                         length = min_t(unsigned short, length,
 422                                                    hidg->report_desc_length);
 423                         memcpy(req->buf, hidg->report_desc, length);
 424                         goto respond;
 425                         break;
 426
 427                 default:
 428                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 429                                  value >> 8);
 430                         goto stall;
 431                         break;
 432                 }
 433                 break;
 434
 435         default:
 436                 VDBG(cdev, "Unknown request 0x%x\n",
 437                          ctrl->bRequest);
 438                 goto stall;
 439                 break;
 440         }
 441
 442 stall:
 443         return -EOPNOTSUPP;
 444
 445 respond:
 446         req->zero = 0;
 447         req->length = length;
 448         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 449         if (status < 0)
 450                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 451         return status;
 452 }
 453
 454 static void hidg_disable(struct usb_function *f)
 455 {
 456         struct f_hidg *hidg = func_to_hidg(f);
 457         struct f_hidg_req_list *list, *next;
 458
 459         usb_ep_disable(hidg->in_ep);
 460         hidg->in_ep->driver_data = NULL;
 461
 462         usb_ep_disable(hidg->out_ep);
 463         hidg->out_ep->driver_data = NULL;
 464
 465         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 466                 list_del(&list->list);
 467                 kfree(list);
 468         }
 469 }
 470
 471 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 472 {
 473         struct usb_composite_dev                *cdev = f->config->cdev;
 474         struct f_hidg                           *hidg = func_to_hidg(f);
 475         int i, status = 0;
 476
 477         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 478
 479         if (hidg->in_ep != NULL) {
 480                 /* restart endpoint */
 481                 if (hidg->in_ep->driver_data != NULL)
 482                         usb_ep_disable(hidg->in_ep);
 483
 484                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 485                                             hidg->in_ep);
 486                 if (status) {
 487                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 488                         goto fail;
 489                 }
 490                 status = usb_ep_enable(hidg->in_ep);
 491                 if (status < 0) {
 492                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 493                         goto fail;
 494                 }
 495                 hidg->in_ep->driver_data = hidg;
 496         }
 497
 498
 499         if (hidg->out_ep != NULL) {
 500                 /* restart endpoint */
 501                 if (hidg->out_ep->driver_data != NULL)
 502                         usb_ep_disable(hidg->out_ep);
 503
 504                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 505                                             hidg->out_ep);
 506                 if (status) {
 507                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 508                         goto fail;
 509                 }
 510                 status = usb_ep_enable(hidg->out_ep);
 511                 if (status < 0) {
 512                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 513                         goto fail;
 514                 }
 515                 hidg->out_ep->driver_data = hidg;
 516
 517                 /*
 518                  * allocate a bunch of read buffers and queue them all at once.
 519                  */
 520                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 521                         struct usb_request *req =
 522                                         hidg_alloc_ep_req(hidg->out_ep,
 523                                                           hidg->report_length);
 524                         if (req) {
 525                                 req->complete = hidg_set_report_complete;
 526                                 req->context  = hidg;
 527                                 status = usb_ep_queue(hidg->out_ep, req,
 528                                                       GFP_ATOMIC);
 529                                 if (status)
 530                                         ERROR(cdev, "%s queue req --> %d\n",
 531                                                 hidg->out_ep->name, status);
 532                         } else {
 533                                 usb_ep_disable(hidg->out_ep);
 534                                 hidg->out_ep->driver_data = NULL;
 535                                 status = -ENOMEM;
 536                                 goto fail;
 537                         }
 538                 }
 539         }
 540
 541 fail:
 542         return status;
 543 }
 544
 545 const struct file_operations f_hidg_fops = {
 546         .owner          = THIS_MODULE,
 547         .open           = f_hidg_open,
 548         .release        = f_hidg_release,
 549         .write          = f_hidg_write,
 550         .read           = f_hidg_read,
 551         .poll           = f_hidg_poll,
 552         .llseek         = noop_llseek,
 553 };
 554
 555 static int __init hidg_bind(struct usb_configuration *c, struct usb_function *f)
 556 {
 557         struct usb_ep           *ep;
 558         struct f_hidg           *hidg = func_to_hidg(f);
 559         int                     status;
 560         dev_t                   dev;
 561
 562         /* allocate instance-specific interface IDs, and patch descriptors */
 563         status = usb_interface_id(c, f);
 564         if (status < 0)
 565                 goto fail;
 566         hidg_interface_desc.bInterfaceNumber = status;
 567
 568         /* allocate instance-specific endpoints */
 569         status = -ENODEV;
 570         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 571         if (!ep)
 572                 goto fail;
 573         ep->driver_data = c->cdev;      /* claim */
 574         hidg->in_ep = ep;
 575
 576         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 577         if (!ep)
 578                 goto fail;
 579         ep->driver_data = c->cdev;      /* claim */
 580         hidg->out_ep = ep;
 581
 582         /* preallocate request and buffer */
 583         status = -ENOMEM;
 584         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 585         if (!hidg->req)
 586                 goto fail;
 587
 588         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 589         if (!hidg->req->buf)
 590                 goto fail;
 591
 592         /* set descriptor dynamic values */
 593         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 594         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 595         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 596         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 597         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 598         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 599         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 600         hidg_desc.desc[0].wDescriptorLength =
 601                 cpu_to_le16(hidg->report_desc_length);
 602
 603         hidg_hs_in_ep_desc.bEndpointAddress =
 604                 hidg_fs_in_ep_desc.bEndpointAddress;
 605         hidg_hs_out_ep_desc.bEndpointAddress =
 606                 hidg_fs_out_ep_desc.bEndpointAddress;
 607
 608         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 609                         hidg_hs_descriptors, NULL);
 610         if (status)
 611                 goto fail;
 612
 613         mutex_init(&hidg->lock);
 614         spin_lock_init(&hidg->spinlock);
 615         init_waitqueue_head(&hidg->write_queue);
 616         init_waitqueue_head(&hidg->read_queue);
 617         INIT_LIST_HEAD(&hidg->completed_out_req);
 618
 619         /* create char device */
 620         cdev_init(&hidg->cdev, &f_hidg_fops);
 621         dev = MKDEV(major, hidg->minor);
 622         status = cdev_add(&hidg->cdev, dev, 1);
 623         if (status)
 624                 goto fail;
 625
 626         device_create(hidg_class, NULL, dev, NULL, "%s%d", "hidg", hidg->minor);
 627
 628         return 0;
 629
 630 fail:
 631         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 632         if (hidg->req != NULL) {
 633                 kfree(hidg->req->buf);
 634                 if (hidg->in_ep != NULL)
 635                         usb_ep_free_request(hidg->in_ep, hidg->req);
 636         }
 637
 638         usb_free_all_descriptors(f);
 639         return status;
 640 }
 641
 642 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 643 {
 644         struct f_hidg *hidg = func_to_hidg(f);
 645
 646         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 647         cdev_del(&hidg->cdev);
 648
 649         /* disable/free request and end point */
 650         usb_ep_disable(hidg->in_ep);
 651         usb_ep_dequeue(hidg->in_ep, hidg->req);
 652         kfree(hidg->req->buf);
 653         usb_ep_free_request(hidg->in_ep, hidg->req);
 654
 655         usb_free_all_descriptors(f);
 656
 657         kfree(hidg->report_desc);
 658         kfree(hidg);
 659 }
 660
 661 /*-------------------------------------------------------------------------*/
 662 /*                                 Strings                                 */
 663
 664 #define CT_FUNC_HID_IDX 0
 665
 666 static struct usb_string ct_func_string_defs[] = {
 667         [CT_FUNC_HID_IDX].s     = "HID Interface",
 668         {},                     /* end of list */
 669 };
 670
 671 static struct usb_gadget_strings ct_func_string_table = {
 672         .language       = 0x0409,       /* en-US */
 673         .strings        = ct_func_string_defs,
 674 };
 675
 676 static struct usb_gadget_strings *ct_func_strings[] = {
 677         &ct_func_string_table,
 678         NULL,
 679 };
 680
 681 /*-------------------------------------------------------------------------*/
 682 /*                             usb_configuration                           */
 683
 684 int __init hidg_bind_config(struct usb_configuration *c,
 685                             struct hidg_func_descriptor *fdesc, int index)
 686 {
 687         struct f_hidg *hidg;
 688         int status;
 689
 690         if (index >= minors)
 691                 return -ENOENT;
 692
 693         /* maybe allocate device-global string IDs, and patch descriptors */
 694         if (ct_func_string_defs[CT_FUNC_HID_IDX].id == 0) {
 695                 status = usb_string_id(c->cdev);
 696                 if (status < 0)
 697                         return status;
 698                 ct_func_string_defs[CT_FUNC_HID_IDX].id = status;
 699                 hidg_interface_desc.iInterface = status;
 700         }
 701
 702         /* allocate and initialize one new instance */
 703         hidg = kzalloc(sizeof *hidg, GFP_KERNEL);
 704         if (!hidg)
 705                 return -ENOMEM;
 706
 707         hidg->minor = index;
 708         hidg->bInterfaceSubClass = fdesc->subclass;
 709         hidg->bInterfaceProtocol = fdesc->protocol;
 710         hidg->report_length = fdesc->report_length;
 711         hidg->report_desc_length = fdesc->report_desc_length;
 712         hidg->report_desc = kmemdup(fdesc->report_desc,
 713                                     fdesc->report_desc_length,
 714                                     GFP_KERNEL);
 715         if (!hidg->report_desc) {
 716                 kfree(hidg);
 717                 return -ENOMEM;
 718         }
 719
 720         hidg->func.name    = "hid";
 721         hidg->func.strings = ct_func_strings;
 722         hidg->func.bind    = hidg_bind;
 723         hidg->func.unbind  = hidg_unbind;
 724         hidg->func.set_alt = hidg_set_alt;
 725         hidg->func.disable = hidg_disable;
 726         hidg->func.setup   = hidg_setup;
 727
 728         /* this could me made configurable at some point */
 729         hidg->qlen         = 4;
 730
 731         status = usb_add_function(c, &hidg->func);
 732         if (status)
 733                 kfree(hidg);
 734
 735         return status;
 736 }
 737
 738 int __init ghid_setup(struct usb_gadget *g, int count)
 739 {
 740         int status;
 741         dev_t dev;
 742
 743         hidg_class = class_create(THIS_MODULE, "hidg");
 744
 745         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 746         if (!status) {
 747                 major = MAJOR(dev);
 748                 minors = count;
 749         }
 750
 751         return status;
 752 }
 753
 754 void ghid_cleanup(void)
 755 {
 756         if (major) {
 757                 unregister_chrdev_region(MKDEV(major, 0), minors);
 758                 major = minors = 0;
 759         }
 760
 761         class_destroy(hidg_class);
 762         hidg_class = NULL;
 763 }