drivers/usb/gadget/function/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/idr.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/sched.h>
  22 #include <linux/usb/g_hid.h>
  23
  24 #include "u_f.h"
  25 #include "u_hid.h"
  26
  27 #define HIDG_MINORS     4
  28
  29 static int major, minors;
  30 static struct class *hidg_class;
  31 static DEFINE_IDA(hidg_ida);
  32 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
  33
  34 /*-------------------------------------------------------------------------*/
  35 /*                            HID gadget struct                            */
  36
  37 struct f_hidg_req_list {
  38         struct usb_request      *req;
  39         unsigned int            pos;
  40         struct list_head        list;
  41 };
  42
  43 struct f_hidg {
  44         /* configuration */
  45         unsigned char                   bInterfaceSubClass;
  46         unsigned char                   bInterfaceProtocol;
  47         unsigned short                  report_desc_length;
  48         char                            *report_desc;
  49         unsigned short                  report_length;
  50
  51         /* recv report */
  52         struct list_head                completed_out_req;
  53         spinlock_t                      spinlock;
  54         wait_queue_head_t               read_queue;
  55         unsigned int                    qlen;
  56
  57         /* send report */
  58         struct mutex                    lock;
  59         bool                            write_pending;
  60         wait_queue_head_t               write_queue;
  61         struct usb_request              *req;
  62
  63         int                             minor;
  64         struct cdev                     cdev;
  65         struct usb_function             func;
  66
  67         struct usb_ep                   *in_ep;
  68         struct usb_ep                   *out_ep;
  69 };
  70
  71 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  72 {
  73         return container_of(f, struct f_hidg, func);
  74 }
  75
  76 /*-------------------------------------------------------------------------*/
  77 /*                           Static descriptors                            */
  78
  79 static struct usb_interface_descriptor hidg_interface_desc = {
  80         .bLength                = sizeof hidg_interface_desc,
  81         .bDescriptorType        = USB_DT_INTERFACE,
  82         /* .bInterfaceNumber    = DYNAMIC */
  83         .bAlternateSetting      = 0,
  84         .bNumEndpoints          = 2,
  85         .bInterfaceClass        = USB_CLASS_HID,
  86         /* .bInterfaceSubClass  = DYNAMIC */
  87         /* .bInterfaceProtocol  = DYNAMIC */
  88         /* .iInterface          = DYNAMIC */
  89 };
  90
  91 static struct hid_descriptor hidg_desc = {
  92         .bLength                        = sizeof hidg_desc,
  93         .bDescriptorType                = HID_DT_HID,
  94         .bcdHID                         = 0x0101,
  95         .bCountryCode                   = 0x00,
  96         .bNumDescriptors                = 0x1,
  97         /*.desc[0].bDescriptorType      = DYNAMIC */
  98         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  99 };
 100
 101 /* High-Speed Support */
 102
 103 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 104         .bLength                = USB_DT_ENDPOINT_SIZE,
 105         .bDescriptorType        = USB_DT_ENDPOINT,
 106         .bEndpointAddress       = USB_DIR_IN,
 107         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 108         /*.wMaxPacketSize       = DYNAMIC */
 109         .bInterval              = 4, /* FIXME: Add this field in the
 110                                       * HID gadget configuration?
 111                                       * (struct hidg_func_descriptor)
 112                                       */
 113 };
 114
 115 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 116         .bLength                = USB_DT_ENDPOINT_SIZE,
 117         .bDescriptorType        = USB_DT_ENDPOINT,
 118         .bEndpointAddress       = USB_DIR_OUT,
 119         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 120         /*.wMaxPacketSize       = DYNAMIC */
 121         .bInterval              = 4, /* FIXME: Add this field in the
 122                                       * HID gadget configuration?
 123                                       * (struct hidg_func_descriptor)
 124                                       */
 125 };
 126
 127 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 128         (struct usb_descriptor_header *)&hidg_interface_desc,
 129         (struct usb_descriptor_header *)&hidg_desc,
 130         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 131         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 132         NULL,
 133 };
 134
 135 /* Full-Speed Support */
 136
 137 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 138         .bLength                = USB_DT_ENDPOINT_SIZE,
 139         .bDescriptorType        = USB_DT_ENDPOINT,
 140         .bEndpointAddress       = USB_DIR_IN,
 141         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 142         /*.wMaxPacketSize       = DYNAMIC */
 143         .bInterval              = 10, /* FIXME: Add this field in the
 144                                        * HID gadget configuration?
 145                                        * (struct hidg_func_descriptor)
 146                                        */
 147 };
 148
 149 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 150         .bLength                = USB_DT_ENDPOINT_SIZE,
 151         .bDescriptorType        = USB_DT_ENDPOINT,
 152         .bEndpointAddress       = USB_DIR_OUT,
 153         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 154         /*.wMaxPacketSize       = DYNAMIC */
 155         .bInterval              = 10, /* FIXME: Add this field in the
 156                                        * HID gadget configuration?
 157                                        * (struct hidg_func_descriptor)
 158                                        */
 159 };
 160
 161 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 162         (struct usb_descriptor_header *)&hidg_interface_desc,
 163         (struct usb_descriptor_header *)&hidg_desc,
 164         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 165         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 166         NULL,
 167 };
 168
 169 /*-------------------------------------------------------------------------*/
 170 /*                                 Strings                                 */
 171
 172 #define CT_FUNC_HID_IDX 0
 173
 174 static struct usb_string ct_func_string_defs[] = {
 175         [CT_FUNC_HID_IDX].s     = "HID Interface",
 176         {},                     /* end of list */
 177 };
 178
 179 static struct usb_gadget_strings ct_func_string_table = {
 180         .language       = 0x0409,       /* en-US */
 181         .strings        = ct_func_string_defs,
 182 };
 183
 184 static struct usb_gadget_strings *ct_func_strings[] = {
 185         &ct_func_string_table,
 186         NULL,
 187 };
 188
 189 /*-------------------------------------------------------------------------*/
 190 /*                              Char Device                                */
 191
 192 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 193                         size_t count, loff_t *ptr)
 194 {
 195         struct f_hidg *hidg = file->private_data;
 196         struct f_hidg_req_list *list;
 197         struct usb_request *req;
 198         unsigned long flags;
 199         int ret;
 200
 201         if (!count)
 202                 return 0;
 203
 204         if (!access_ok(VERIFY_WRITE, buffer, count))
 205                 return -EFAULT;
 206
 207         spin_lock_irqsave(&hidg->spinlock, flags);
 208
 209 #define READ_COND (!list_empty(&hidg->completed_out_req))
 210
 211         /* wait for at least one buffer to complete */
 212         while (!READ_COND) {
 213                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 214                 if (file->f_flags & O_NONBLOCK)
 215                         return -EAGAIN;
 216
 217                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 218                         return -ERESTARTSYS;
 219
 220                 spin_lock_irqsave(&hidg->spinlock, flags);
 221         }
 222
 223         /* pick the first one */
 224         list = list_first_entry(&hidg->completed_out_req,
 225                                 struct f_hidg_req_list, list);
 226         req = list->req;
 227         count = min_t(unsigned int, count, req->actual - list->pos);
 228         spin_unlock_irqrestore(&hidg->spinlock, flags);
 229
 230         /* copy to user outside spinlock */
 231         count -= copy_to_user(buffer, req->buf + list->pos, count);
 232         list->pos += count;
 233
 234         /*
 235          * if this request is completely handled and transfered to
 236          * userspace, remove its entry from the list and requeue it
 237          * again. Otherwise, we will revisit it again upon the next
 238          * call, taking into account its current read position.
 239          */
 240         if (list->pos == req->actual) {
 241                 spin_lock_irqsave(&hidg->spinlock, flags);
 242                 list_del(&list->list);
 243                 kfree(list);
 244                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 245
 246                 req->length = hidg->report_length;
 247                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 248                 if (ret < 0)
 249                         return ret;
 250         }
 251
 252         return count;
 253 }
 254
 255 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 256 {
 257         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 258
 259         if (req->status != 0) {
 260                 ERROR(hidg->func.config->cdev,
 261                         "End Point Request ERROR: %d\n", req->status);
 262         }
 263
 264         hidg->write_pending = 0;
 265         wake_up(&hidg->write_queue);
 266 }
 267
 268 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 269                             size_t count, loff_t *offp)
 270 {
 271         struct f_hidg *hidg  = file->private_data;
 272         ssize_t status = -ENOMEM;
 273
 274         if (!access_ok(VERIFY_READ, buffer, count))
 275                 return -EFAULT;
 276
 277         mutex_lock(&hidg->lock);
 278
 279 #define WRITE_COND (!hidg->write_pending)
 280
 281         /* write queue */
 282         while (!WRITE_COND) {
 283                 mutex_unlock(&hidg->lock);
 284                 if (file->f_flags & O_NONBLOCK)
 285                         return -EAGAIN;
 286
 287                 if (wait_event_interruptible_exclusive(
 288                                 hidg->write_queue, WRITE_COND))
 289                         return -ERESTARTSYS;
 290
 291                 mutex_lock(&hidg->lock);
 292         }
 293
 294         count  = min_t(unsigned, count, hidg->report_length);
 295         status = copy_from_user(hidg->req->buf, buffer, count);
 296
 297         if (status != 0) {
 298                 ERROR(hidg->func.config->cdev,
 299                         "copy_from_user error\n");
 300                 mutex_unlock(&hidg->lock);
 301                 return -EINVAL;
 302         }
 303
 304         hidg->req->status   = 0;
 305         hidg->req->zero     = 0;
 306         hidg->req->length   = count;
 307         hidg->req->complete = f_hidg_req_complete;
 308         hidg->req->context  = hidg;
 309         hidg->write_pending = 1;
 310
 311         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 312         if (status < 0) {
 313                 ERROR(hidg->func.config->cdev,
 314                         "usb_ep_queue error on int endpoint %zd\n", status);
 315                 hidg->write_pending = 0;
 316                 wake_up(&hidg->write_queue);
 317         } else {
 318                 status = count;
 319         }
 320
 321         mutex_unlock(&hidg->lock);
 322
 323         return status;
 324 }
 325
 326 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 327 {
 328         struct f_hidg   *hidg  = file->private_data;
 329         unsigned int    ret = 0;
 330
 331         poll_wait(file, &hidg->read_queue, wait);
 332         poll_wait(file, &hidg->write_queue, wait);
 333
 334         if (WRITE_COND)
 335                 ret |= POLLOUT | POLLWRNORM;
 336
 337         if (READ_COND)
 338                 ret |= POLLIN | POLLRDNORM;
 339
 340         return ret;
 341 }
 342
 343 #undef WRITE_COND
 344 #undef READ_COND
 345
 346 static int f_hidg_release(struct inode *inode, struct file *fd)
 347 {
 348         fd->private_data = NULL;
 349         return 0;
 350 }
 351
 352 static int f_hidg_open(struct inode *inode, struct file *fd)
 353 {
 354         struct f_hidg *hidg =
 355                 container_of(inode->i_cdev, struct f_hidg, cdev);
 356
 357         fd->private_data = hidg;
 358
 359         return 0;
 360 }
 361
 362 /*-------------------------------------------------------------------------*/
 363 /*                                usb_function                             */
 364
 365 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 366                                                     unsigned length)
 367 {
 368         return alloc_ep_req(ep, length, length);
 369 }
 370
 371 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 372 {
 373         struct f_hidg *hidg = (struct f_hidg *) req->context;
 374         struct f_hidg_req_list *req_list;
 375         unsigned long flags;
 376
 377         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 378         if (!req_list)
 379                 return;
 380
 381         req_list->req = req;
 382
 383         spin_lock_irqsave(&hidg->spinlock, flags);
 384         list_add_tail(&req_list->list, &hidg->completed_out_req);
 385         spin_unlock_irqrestore(&hidg->spinlock, flags);
 386
 387         wake_up(&hidg->read_queue);
 388 }
 389
 390 static int hidg_setup(struct usb_function *f,
 391                 const struct usb_ctrlrequest *ctrl)
 392 {
 393         struct f_hidg                   *hidg = func_to_hidg(f);
 394         struct usb_composite_dev        *cdev = f->config->cdev;
 395         struct usb_request              *req  = cdev->req;
 396         int status = 0;
 397         __u16 value, length;
 398
 399         value   = __le16_to_cpu(ctrl->wValue);
 400         length  = __le16_to_cpu(ctrl->wLength);
 401
 402         VDBG(cdev,
 403              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 404              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 405
 406         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 407         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 408                   | HID_REQ_GET_REPORT):
 409                 VDBG(cdev, "get_report\n");
 410
 411                 /* send an empty report */
 412                 length = min_t(unsigned, length, hidg->report_length);
 413                 memset(req->buf, 0x0, length);
 414
 415                 goto respond;
 416                 break;
 417
 418         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 419                   | HID_REQ_GET_PROTOCOL):
 420                 VDBG(cdev, "get_protocol\n");
 421                 goto stall;
 422                 break;
 423
 424         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 425                   | HID_REQ_SET_REPORT):
 426                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 427                 goto stall;
 428                 break;
 429
 430         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 431                   | HID_REQ_SET_PROTOCOL):
 432                 VDBG(cdev, "set_protocol\n");
 433                 goto stall;
 434                 break;
 435
 436         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 437                   | USB_REQ_GET_DESCRIPTOR):
 438                 switch (value >> 8) {
 439                 case HID_DT_HID:
 440                 {
 441                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 442
 443                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 444                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 445                         hidg_desc_copy.desc[0].wDescriptorLength =
 446                                 cpu_to_le16(hidg->report_desc_length);
 447
 448                         length = min_t(unsigned short, length,
 449                                                    hidg_desc_copy.bLength);
 450                         memcpy(req->buf, &hidg_desc_copy, length);
 451                         goto respond;
 452                         break;
 453                 }
 454                 case HID_DT_REPORT:
 455                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 456                         length = min_t(unsigned short, length,
 457                                                    hidg->report_desc_length);
 458                         memcpy(req->buf, hidg->report_desc, length);
 459                         goto respond;
 460                         break;
 461
 462                 default:
 463                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 464                                  value >> 8);
 465                         goto stall;
 466                         break;
 467                 }
 468                 break;
 469
 470         default:
 471                 VDBG(cdev, "Unknown request 0x%x\n",
 472                          ctrl->bRequest);
 473                 goto stall;
 474                 break;
 475         }
 476
 477 stall:
 478         return -EOPNOTSUPP;
 479
 480 respond:
 481         req->zero = 0;
 482         req->length = length;
 483         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 484         if (status < 0)
 485                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 486         return status;
 487 }
 488
 489 static void hidg_disable(struct usb_function *f)
 490 {
 491         struct f_hidg *hidg = func_to_hidg(f);
 492         struct f_hidg_req_list *list, *next;
 493
 494         usb_ep_disable(hidg->in_ep);
 495         hidg->in_ep->driver_data = NULL;
 496
 497         usb_ep_disable(hidg->out_ep);
 498         hidg->out_ep->driver_data = NULL;
 499
 500         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 501                 list_del(&list->list);
 502                 kfree(list);
 503         }
 504 }
 505
 506 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 507 {
 508         struct usb_composite_dev                *cdev = f->config->cdev;
 509         struct f_hidg                           *hidg = func_to_hidg(f);
 510         int i, status = 0;
 511
 512         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 513
 514         if (hidg->in_ep != NULL) {
 515                 /* restart endpoint */
 516                 if (hidg->in_ep->driver_data != NULL)
 517                         usb_ep_disable(hidg->in_ep);
 518
 519                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 520                                             hidg->in_ep);
 521                 if (status) {
 522                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 523                         goto fail;
 524                 }
 525                 status = usb_ep_enable(hidg->in_ep);
 526                 if (status < 0) {
 527                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 528                         goto fail;
 529                 }
 530                 hidg->in_ep->driver_data = hidg;
 531         }
 532
 533
 534         if (hidg->out_ep != NULL) {
 535                 /* restart endpoint */
 536                 if (hidg->out_ep->driver_data != NULL)
 537                         usb_ep_disable(hidg->out_ep);
 538
 539                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 540                                             hidg->out_ep);
 541                 if (status) {
 542                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 543                         goto fail;
 544                 }
 545                 status = usb_ep_enable(hidg->out_ep);
 546                 if (status < 0) {
 547                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 548                         goto fail;
 549                 }
 550                 hidg->out_ep->driver_data = hidg;
 551
 552                 /*
 553                  * allocate a bunch of read buffers and queue them all at once.
 554                  */
 555                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 556                         struct usb_request *req =
 557                                         hidg_alloc_ep_req(hidg->out_ep,
 558                                                           hidg->report_length);
 559                         if (req) {
 560                                 req->complete = hidg_set_report_complete;
 561                                 req->context  = hidg;
 562                                 status = usb_ep_queue(hidg->out_ep, req,
 563                                                       GFP_ATOMIC);
 564                                 if (status)
 565                                         ERROR(cdev, "%s queue req --> %d\n",
 566                                                 hidg->out_ep->name, status);
 567                         } else {
 568                                 usb_ep_disable(hidg->out_ep);
 569                                 hidg->out_ep->driver_data = NULL;
 570                                 status = -ENOMEM;
 571                                 goto fail;
 572                         }
 573                 }
 574         }
 575
 576 fail:
 577         return status;
 578 }
 579
 580 static const struct file_operations f_hidg_fops = {
 581         .owner          = THIS_MODULE,
 582         .open           = f_hidg_open,
 583         .release        = f_hidg_release,
 584         .write          = f_hidg_write,
 585         .read           = f_hidg_read,
 586         .poll           = f_hidg_poll,
 587         .llseek         = noop_llseek,
 588 };
 589
 590 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 591 {
 592         struct usb_ep           *ep;
 593         struct f_hidg           *hidg = func_to_hidg(f);
 594         struct usb_string       *us;
 595         struct device           *device;
 596         int                     status;
 597         dev_t                   dev;
 598
 599         /* maybe allocate device-global string IDs, and patch descriptors */
 600         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 601                                  ARRAY_SIZE(ct_func_string_defs));
 602         if (IS_ERR(us))
 603                 return PTR_ERR(us);
 604         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 605
 606         /* allocate instance-specific interface IDs, and patch descriptors */
 607         status = usb_interface_id(c, f);
 608         if (status < 0)
 609                 goto fail;
 610         hidg_interface_desc.bInterfaceNumber = status;
 611
 612         /* allocate instance-specific endpoints */
 613         status = -ENODEV;
 614         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 615         if (!ep)
 616                 goto fail;
 617         ep->driver_data = c->cdev;      /* claim */
 618         hidg->in_ep = ep;
 619
 620         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 621         if (!ep)
 622                 goto fail;
 623         ep->driver_data = c->cdev;      /* claim */
 624         hidg->out_ep = ep;
 625
 626         /* preallocate request and buffer */
 627         status = -ENOMEM;
 628         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 629         if (!hidg->req)
 630                 goto fail;
 631
 632         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 633         if (!hidg->req->buf)
 634                 goto fail;
 635
 636         /* set descriptor dynamic values */
 637         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 638         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 639         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 640         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 641         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 642         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 643         /*
 644          * We can use hidg_desc struct here but we should not relay
 645          * that its content won't change after returning from this function.
 646          */
 647         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 648         hidg_desc.desc[0].wDescriptorLength =
 649                 cpu_to_le16(hidg->report_desc_length);
 650
 651         hidg_hs_in_ep_desc.bEndpointAddress =
 652                 hidg_fs_in_ep_desc.bEndpointAddress;
 653         hidg_hs_out_ep_desc.bEndpointAddress =
 654                 hidg_fs_out_ep_desc.bEndpointAddress;
 655
 656         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 657                         hidg_hs_descriptors, NULL);
 658         if (status)
 659                 goto fail;
 660
 661         mutex_init(&hidg->lock);
 662         spin_lock_init(&hidg->spinlock);
 663         init_waitqueue_head(&hidg->write_queue);
 664         init_waitqueue_head(&hidg->read_queue);
 665         INIT_LIST_HEAD(&hidg->completed_out_req);
 666
 667         /* create char device */
 668         cdev_init(&hidg->cdev, &f_hidg_fops);
 669         dev = MKDEV(major, hidg->minor);
 670         status = cdev_add(&hidg->cdev, dev, 1);
 671         if (status)
 672                 goto fail_free_descs;
 673
 674         device = device_create(hidg_class, NULL, dev, NULL,
 675                                "%s%d", "hidg", hidg->minor);
 676         if (IS_ERR(device)) {
 677                 status = PTR_ERR(device);
 678                 goto del;
 679         }
 680
 681         return 0;
 682 del:
 683         cdev_del(&hidg->cdev);
 684 fail_free_descs:
 685         usb_free_all_descriptors(f);
 686 fail:
 687         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 688         if (hidg->req != NULL) {
 689                 kfree(hidg->req->buf);
 690                 if (hidg->in_ep != NULL)
 691                         usb_ep_free_request(hidg->in_ep, hidg->req);
 692         }
 693
 694         return status;
 695 }
 696
 697 static inline int hidg_get_minor(void)
 698 {
 699         int ret;
 700
 701         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 702         if (ret >= HIDG_MINORS) {
 703                 ida_simple_remove(&hidg_ida, ret);
 704                 ret = -ENODEV;
 705         }
 706
 707         return ret;
 708 }
 709
 710 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 711 {
 712         return container_of(to_config_group(item), struct f_hid_opts,
 713                             func_inst.group);
 714 }
 715
 716 static void hid_attr_release(struct config_item *item)
 717 {
 718         struct f_hid_opts *opts = to_f_hid_opts(item);
 719
 720         usb_put_function_instance(&opts->func_inst);
 721 }
 722
 723 static struct configfs_item_operations hidg_item_ops = {
 724         .release        = hid_attr_release,
 725 };
 726
 727 #define F_HID_OPT(name, prec, limit)                                    \
 728 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 729 {                                                                       \
 730         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 731         int result;                                                     \
 732                                                                         \
 733         mutex_lock(&opts->lock);                                        \
 734         result = sprintf(page, "%d\n", opts->name);                     \
 735         mutex_unlock(&opts->lock);                                      \
 736                                                                         \
 737         return result;                                                  \
 738 }                                                                       \
 739                                                                         \
 740 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 741                                          const char *page, size_t len)  \
 742 {                                                                       \
 743         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 744         int ret;                                                        \
 745         u##prec num;                                                    \
 746                                                                         \
 747         mutex_lock(&opts->lock);                                        \
 748         if (opts->refcnt) {                                             \
 749                 ret = -EBUSY;                                           \
 750                 goto end;                                               \
 751         }                                                               \
 752                                                                         \
 753         ret = kstrtou##prec(page, 0, &num);                             \
 754         if (ret)                                                        \
 755                 goto end;                                               \
 756                                                                         \
 757         if (num > limit) {                                              \
 758                 ret = -EINVAL;                                          \
 759                 goto end;                                               \
 760         }                                                               \
 761         opts->name = num;                                               \
 762         ret = len;                                                      \
 763                                                                         \
 764 end:                                                                    \
 765         mutex_unlock(&opts->lock);                                      \
 766         return ret;                                                     \
 767 }                                                                       \
 768                                                                         \
 769 CONFIGFS_ATTR(f_hid_opts_, name)
 770
 771 F_HID_OPT(subclass, 8, 255);
 772 F_HID_OPT(protocol, 8, 255);
 773 F_HID_OPT(report_length, 16, 65535);
 774
 775 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 776 {
 777         struct f_hid_opts *opts = to_f_hid_opts(item);
 778         int result;
 779
 780         mutex_lock(&opts->lock);
 781         result = opts->report_desc_length;
 782         memcpy(page, opts->report_desc, opts->report_desc_length);
 783         mutex_unlock(&opts->lock);
 784
 785         return result;
 786 }
 787
 788 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 789                                             const char *page, size_t len)
 790 {
 791         struct f_hid_opts *opts = to_f_hid_opts(item);
 792         int ret = -EBUSY;
 793         char *d;
 794
 795         mutex_lock(&opts->lock);
 796
 797         if (opts->refcnt)
 798                 goto end;
 799         if (len > PAGE_SIZE) {
 800                 ret = -ENOSPC;
 801                 goto end;
 802         }
 803         d = kmemdup(page, len, GFP_KERNEL);
 804         if (!d) {
 805                 ret = -ENOMEM;
 806                 goto end;
 807         }
 808         kfree(opts->report_desc);
 809         opts->report_desc = d;
 810         opts->report_desc_length = len;
 811         opts->report_desc_alloc = true;
 812         ret = len;
 813 end:
 814         mutex_unlock(&opts->lock);
 815         return ret;
 816 }
 817
 818 CONFIGFS_ATTR(f_hid_opts_, report_desc);
 819
 820 static struct configfs_attribute *hid_attrs[] = {
 821         &f_hid_opts_attr_subclass,
 822         &f_hid_opts_attr_protocol,
 823         &f_hid_opts_attr_report_length,
 824         &f_hid_opts_attr_report_desc,
 825         NULL,
 826 };
 827
 828 static struct config_item_type hid_func_type = {
 829         .ct_item_ops    = &hidg_item_ops,
 830         .ct_attrs       = hid_attrs,
 831         .ct_owner       = THIS_MODULE,
 832 };
 833
 834 static inline void hidg_put_minor(int minor)
 835 {
 836         ida_simple_remove(&hidg_ida, minor);
 837 }
 838
 839 static void hidg_free_inst(struct usb_function_instance *f)
 840 {
 841         struct f_hid_opts *opts;
 842
 843         opts = container_of(f, struct f_hid_opts, func_inst);
 844
 845         mutex_lock(&hidg_ida_lock);
 846
 847         hidg_put_minor(opts->minor);
 848         if (idr_is_empty(&hidg_ida.idr))
 849                 ghid_cleanup();
 850
 851         mutex_unlock(&hidg_ida_lock);
 852
 853         if (opts->report_desc_alloc)
 854                 kfree(opts->report_desc);
 855
 856         kfree(opts);
 857 }
 858
 859 static struct usb_function_instance *hidg_alloc_inst(void)
 860 {
 861         struct f_hid_opts *opts;
 862         struct usb_function_instance *ret;
 863         int status = 0;
 864
 865         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 866         if (!opts)
 867                 return ERR_PTR(-ENOMEM);
 868         mutex_init(&opts->lock);
 869         opts->func_inst.free_func_inst = hidg_free_inst;
 870         ret = &opts->func_inst;
 871
 872         mutex_lock(&hidg_ida_lock);
 873
 874         if (idr_is_empty(&hidg_ida.idr)) {
 875                 status = ghid_setup(NULL, HIDG_MINORS);
 876                 if (status)  {
 877                         ret = ERR_PTR(status);
 878                         kfree(opts);
 879                         goto unlock;
 880                 }
 881         }
 882
 883         opts->minor = hidg_get_minor();
 884         if (opts->minor < 0) {
 885                 ret = ERR_PTR(opts->minor);
 886                 kfree(opts);
 887                 if (idr_is_empty(&hidg_ida.idr))
 888                         ghid_cleanup();
 889                 goto unlock;
 890         }
 891         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
 892
 893 unlock:
 894         mutex_unlock(&hidg_ida_lock);
 895         return ret;
 896 }
 897
 898 static void hidg_free(struct usb_function *f)
 899 {
 900         struct f_hidg *hidg;
 901         struct f_hid_opts *opts;
 902
 903         hidg = func_to_hidg(f);
 904         opts = container_of(f->fi, struct f_hid_opts, func_inst);
 905         kfree(hidg->report_desc);
 906         kfree(hidg);
 907         mutex_lock(&opts->lock);
 908         --opts->refcnt;
 909         mutex_unlock(&opts->lock);
 910 }
 911
 912 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 913 {
 914         struct f_hidg *hidg = func_to_hidg(f);
 915
 916         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 917         cdev_del(&hidg->cdev);
 918
 919         /* disable/free request and end point */
 920         usb_ep_disable(hidg->in_ep);
 921         kfree(hidg->req->buf);
 922         usb_ep_free_request(hidg->in_ep, hidg->req);
 923
 924         usb_free_all_descriptors(f);
 925 }
 926
 927 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 928 {
 929         struct f_hidg *hidg;
 930         struct f_hid_opts *opts;
 931
 932         /* allocate and initialize one new instance */
 933         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 934         if (!hidg)
 935                 return ERR_PTR(-ENOMEM);
 936
 937         opts = container_of(fi, struct f_hid_opts, func_inst);
 938
 939         mutex_lock(&opts->lock);
 940         ++opts->refcnt;
 941
 942         hidg->minor = opts->minor;
 943         hidg->bInterfaceSubClass = opts->subclass;
 944         hidg->bInterfaceProtocol = opts->protocol;
 945         hidg->report_length = opts->report_length;
 946         hidg->report_desc_length = opts->report_desc_length;
 947         if (opts->report_desc) {
 948                 hidg->report_desc = kmemdup(opts->report_desc,
 949                                             opts->report_desc_length,
 950                                             GFP_KERNEL);
 951                 if (!hidg->report_desc) {
 952                         kfree(hidg);
 953                         mutex_unlock(&opts->lock);
 954                         return ERR_PTR(-ENOMEM);
 955                 }
 956         }
 957
 958         mutex_unlock(&opts->lock);
 959
 960         hidg->func.name    = "hid";
 961         hidg->func.bind    = hidg_bind;
 962         hidg->func.unbind  = hidg_unbind;
 963         hidg->func.set_alt = hidg_set_alt;
 964         hidg->func.disable = hidg_disable;
 965         hidg->func.setup   = hidg_setup;
 966         hidg->func.free_func = hidg_free;
 967
 968         /* this could me made configurable at some point */
 969         hidg->qlen         = 4;
 970
 971         return &hidg->func;
 972 }
 973
 974 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
 975 MODULE_LICENSE("GPL");
 976 MODULE_AUTHOR("Fabien Chouteau");
 977
 978 int ghid_setup(struct usb_gadget *g, int count)
 979 {
 980         int status;
 981         dev_t dev;
 982
 983         hidg_class = class_create(THIS_MODULE, "hidg");
 984         if (IS_ERR(hidg_class)) {
 985                 status = PTR_ERR(hidg_class);
 986                 hidg_class = NULL;
 987                 return status;
 988         }
 989
 990         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 991         if (status) {
 992                 class_destroy(hidg_class);
 993                 hidg_class = NULL;
 994                 return status;
 995         }
 996
 997         major = MAJOR(dev);
 998         minors = count;
 999
1000         return 0;
1001 }
1002
1003 void ghid_cleanup(void)
1004 {
1005         if (major) {
1006                 unregister_chrdev_region(MKDEV(major, 0), minors);
1007                 major = minors = 0;
1008         }
1009
1010         class_destroy(hidg_class);
1011         hidg_class = NULL;
1012 }