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                         = cpu_to_le16(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
 227         /*
 228          * Remove this from list to protect it from beign free()
 229          * while host disables our function
 230          */
 231         list_del(&list->list);
 232
 233         req = list->req;
 234         count = min_t(unsigned int, count, req->actual - list->pos);
 235         spin_unlock_irqrestore(&hidg->spinlock, flags);
 236
 237         /* copy to user outside spinlock */
 238         count -= copy_to_user(buffer, req->buf + list->pos, count);
 239         list->pos += count;
 240
 241         /*
 242          * if this request is completely handled and transfered to
 243          * userspace, remove its entry from the list and requeue it
 244          * again. Otherwise, we will revisit it again upon the next
 245          * call, taking into account its current read position.
 246          */
 247         if (list->pos == req->actual) {
 248                 kfree(list);
 249
 250                 req->length = hidg->report_length;
 251                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 252                 if (ret < 0) {
 253                         free_ep_req(hidg->out_ep, req);
 254                         return ret;
 255                 }
 256         } else {
 257                 spin_lock_irqsave(&hidg->spinlock, flags);
 258                 list_add(&list->list, &hidg->completed_out_req);
 259                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 260
 261                 wake_up(&hidg->read_queue);
 262         }
 263
 264         return count;
 265 }
 266
 267 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 268 {
 269         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 270
 271         if (req->status != 0) {
 272                 ERROR(hidg->func.config->cdev,
 273                         "End Point Request ERROR: %d\n", req->status);
 274         }
 275
 276         hidg->write_pending = 0;
 277         wake_up(&hidg->write_queue);
 278 }
 279
 280 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 281                             size_t count, loff_t *offp)
 282 {
 283         struct f_hidg *hidg  = file->private_data;
 284         ssize_t status = -ENOMEM;
 285
 286         if (!access_ok(VERIFY_READ, buffer, count))
 287                 return -EFAULT;
 288
 289         mutex_lock(&hidg->lock);
 290
 291 #define WRITE_COND (!hidg->write_pending)
 292
 293         /* write queue */
 294         while (!WRITE_COND) {
 295                 mutex_unlock(&hidg->lock);
 296                 if (file->f_flags & O_NONBLOCK)
 297                         return -EAGAIN;
 298
 299                 if (wait_event_interruptible_exclusive(
 300                                 hidg->write_queue, WRITE_COND))
 301                         return -ERESTARTSYS;
 302
 303                 mutex_lock(&hidg->lock);
 304         }
 305
 306         count  = min_t(unsigned, count, hidg->report_length);
 307         status = copy_from_user(hidg->req->buf, buffer, count);
 308
 309         if (status != 0) {
 310                 ERROR(hidg->func.config->cdev,
 311                         "copy_from_user error\n");
 312                 mutex_unlock(&hidg->lock);
 313                 return -EINVAL;
 314         }
 315
 316         hidg->req->status   = 0;
 317         hidg->req->zero     = 0;
 318         hidg->req->length   = count;
 319         hidg->req->complete = f_hidg_req_complete;
 320         hidg->req->context  = hidg;
 321         hidg->write_pending = 1;
 322
 323         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 324         if (status < 0) {
 325                 ERROR(hidg->func.config->cdev,
 326                         "usb_ep_queue error on int endpoint %zd\n", status);
 327                 hidg->write_pending = 0;
 328                 wake_up(&hidg->write_queue);
 329         } else {
 330                 status = count;
 331         }
 332
 333         mutex_unlock(&hidg->lock);
 334
 335         return status;
 336 }
 337
 338 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 339 {
 340         struct f_hidg   *hidg  = file->private_data;
 341         unsigned int    ret = 0;
 342
 343         poll_wait(file, &hidg->read_queue, wait);
 344         poll_wait(file, &hidg->write_queue, wait);
 345
 346         if (WRITE_COND)
 347                 ret |= POLLOUT | POLLWRNORM;
 348
 349         if (READ_COND)
 350                 ret |= POLLIN | POLLRDNORM;
 351
 352         return ret;
 353 }
 354
 355 #undef WRITE_COND
 356 #undef READ_COND
 357
 358 static int f_hidg_release(struct inode *inode, struct file *fd)
 359 {
 360         fd->private_data = NULL;
 361         return 0;
 362 }
 363
 364 static int f_hidg_open(struct inode *inode, struct file *fd)
 365 {
 366         struct f_hidg *hidg =
 367                 container_of(inode->i_cdev, struct f_hidg, cdev);
 368
 369         fd->private_data = hidg;
 370
 371         return 0;
 372 }
 373
 374 /*-------------------------------------------------------------------------*/
 375 /*                                usb_function                             */
 376
 377 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 378                                                     unsigned length)
 379 {
 380         return alloc_ep_req(ep, length, length);
 381 }
 382
 383 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 384 {
 385         struct f_hidg *hidg = (struct f_hidg *) req->context;
 386         struct f_hidg_req_list *req_list;
 387         unsigned long flags;
 388
 389         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 390         if (!req_list)
 391                 return;
 392
 393         req_list->req = req;
 394
 395         spin_lock_irqsave(&hidg->spinlock, flags);
 396         list_add_tail(&req_list->list, &hidg->completed_out_req);
 397         spin_unlock_irqrestore(&hidg->spinlock, flags);
 398
 399         wake_up(&hidg->read_queue);
 400 }
 401
 402 static int hidg_setup(struct usb_function *f,
 403                 const struct usb_ctrlrequest *ctrl)
 404 {
 405         struct f_hidg                   *hidg = func_to_hidg(f);
 406         struct usb_composite_dev        *cdev = f->config->cdev;
 407         struct usb_request              *req  = cdev->req;
 408         int status = 0;
 409         __u16 value, length;
 410
 411         value   = __le16_to_cpu(ctrl->wValue);
 412         length  = __le16_to_cpu(ctrl->wLength);
 413
 414         VDBG(cdev,
 415              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 416              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 417
 418         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 419         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 420                   | HID_REQ_GET_REPORT):
 421                 VDBG(cdev, "get_report\n");
 422
 423                 /* send an empty report */
 424                 length = min_t(unsigned, length, hidg->report_length);
 425                 memset(req->buf, 0x0, length);
 426
 427                 goto respond;
 428                 break;
 429
 430         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 431                   | HID_REQ_GET_PROTOCOL):
 432                 VDBG(cdev, "get_protocol\n");
 433                 goto stall;
 434                 break;
 435
 436         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 437                   | HID_REQ_SET_REPORT):
 438                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 439                 goto stall;
 440                 break;
 441
 442         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 443                   | HID_REQ_SET_PROTOCOL):
 444                 VDBG(cdev, "set_protocol\n");
 445                 goto stall;
 446                 break;
 447
 448         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 449                   | USB_REQ_GET_DESCRIPTOR):
 450                 switch (value >> 8) {
 451                 case HID_DT_HID:
 452                 {
 453                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 454
 455                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 456                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 457                         hidg_desc_copy.desc[0].wDescriptorLength =
 458                                 cpu_to_le16(hidg->report_desc_length);
 459
 460                         length = min_t(unsigned short, length,
 461                                                    hidg_desc_copy.bLength);
 462                         memcpy(req->buf, &hidg_desc_copy, length);
 463                         goto respond;
 464                         break;
 465                 }
 466                 case HID_DT_REPORT:
 467                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 468                         length = min_t(unsigned short, length,
 469                                                    hidg->report_desc_length);
 470                         memcpy(req->buf, hidg->report_desc, length);
 471                         goto respond;
 472                         break;
 473
 474                 default:
 475                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 476                                  value >> 8);
 477                         goto stall;
 478                         break;
 479                 }
 480                 break;
 481
 482         default:
 483                 VDBG(cdev, "Unknown request 0x%x\n",
 484                          ctrl->bRequest);
 485                 goto stall;
 486                 break;
 487         }
 488
 489 stall:
 490         return -EOPNOTSUPP;
 491
 492 respond:
 493         req->zero = 0;
 494         req->length = length;
 495         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 496         if (status < 0)
 497                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 498         return status;
 499 }
 500
 501 static void hidg_disable(struct usb_function *f)
 502 {
 503         struct f_hidg *hidg = func_to_hidg(f);
 504         struct f_hidg_req_list *list, *next;
 505         unsigned long flags;
 506
 507         usb_ep_disable(hidg->in_ep);
 508         usb_ep_disable(hidg->out_ep);
 509
 510         spin_lock_irqsave(&hidg->spinlock, flags);
 511         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 512                 free_ep_req(hidg->out_ep, list->req);
 513                 list_del(&list->list);
 514                 kfree(list);
 515         }
 516         spin_unlock_irqrestore(&hidg->spinlock, flags);
 517 }
 518
 519 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 520 {
 521         struct usb_composite_dev                *cdev = f->config->cdev;
 522         struct f_hidg                           *hidg = func_to_hidg(f);
 523         int i, status = 0;
 524
 525         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 526
 527         if (hidg->in_ep != NULL) {
 528                 /* restart endpoint */
 529                 usb_ep_disable(hidg->in_ep);
 530
 531                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 532                                             hidg->in_ep);
 533                 if (status) {
 534                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 535                         goto fail;
 536                 }
 537                 status = usb_ep_enable(hidg->in_ep);
 538                 if (status < 0) {
 539                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 540                         goto fail;
 541                 }
 542                 hidg->in_ep->driver_data = hidg;
 543         }
 544
 545
 546         if (hidg->out_ep != NULL) {
 547                 /* restart endpoint */
 548                 usb_ep_disable(hidg->out_ep);
 549
 550                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 551                                             hidg->out_ep);
 552                 if (status) {
 553                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 554                         goto fail;
 555                 }
 556                 status = usb_ep_enable(hidg->out_ep);
 557                 if (status < 0) {
 558                         ERROR(cdev, "Enable OUT endpoint FAILED!\n");
 559                         goto fail;
 560                 }
 561                 hidg->out_ep->driver_data = hidg;
 562
 563                 /*
 564                  * allocate a bunch of read buffers and queue them all at once.
 565                  */
 566                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 567                         struct usb_request *req =
 568                                         hidg_alloc_ep_req(hidg->out_ep,
 569                                                           hidg->report_length);
 570                         if (req) {
 571                                 req->complete = hidg_set_report_complete;
 572                                 req->context  = hidg;
 573                                 status = usb_ep_queue(hidg->out_ep, req,
 574                                                       GFP_ATOMIC);
 575                                 if (status)
 576                                         ERROR(cdev, "%s queue req --> %d\n",
 577                                                 hidg->out_ep->name, status);
 578                         } else {
 579                                 usb_ep_disable(hidg->out_ep);
 580                                 status = -ENOMEM;
 581                                 goto fail;
 582                         }
 583                 }
 584         }
 585
 586 fail:
 587         return status;
 588 }
 589
 590 static const struct file_operations f_hidg_fops = {
 591         .owner          = THIS_MODULE,
 592         .open           = f_hidg_open,
 593         .release        = f_hidg_release,
 594         .write          = f_hidg_write,
 595         .read           = f_hidg_read,
 596         .poll           = f_hidg_poll,
 597         .llseek         = noop_llseek,
 598 };
 599
 600 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 601 {
 602         struct usb_ep           *ep;
 603         struct f_hidg           *hidg = func_to_hidg(f);
 604         struct usb_string       *us;
 605         struct device           *device;
 606         int                     status;
 607         dev_t                   dev;
 608
 609         /* maybe allocate device-global string IDs, and patch descriptors */
 610         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 611                                  ARRAY_SIZE(ct_func_string_defs));
 612         if (IS_ERR(us))
 613                 return PTR_ERR(us);
 614         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 615
 616         /* allocate instance-specific interface IDs, and patch descriptors */
 617         status = usb_interface_id(c, f);
 618         if (status < 0)
 619                 goto fail;
 620         hidg_interface_desc.bInterfaceNumber = status;
 621
 622         /* allocate instance-specific endpoints */
 623         status = -ENODEV;
 624         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 625         if (!ep)
 626                 goto fail;
 627         hidg->in_ep = ep;
 628
 629         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 630         if (!ep)
 631                 goto fail;
 632         hidg->out_ep = ep;
 633
 634         /* preallocate request and buffer */
 635         status = -ENOMEM;
 636         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 637         if (!hidg->req)
 638                 goto fail;
 639
 640         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 641         if (!hidg->req->buf)
 642                 goto fail;
 643
 644         /* set descriptor dynamic values */
 645         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 646         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 647         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 648         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 649         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 650         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 651         /*
 652          * We can use hidg_desc struct here but we should not relay
 653          * that its content won't change after returning from this function.
 654          */
 655         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 656         hidg_desc.desc[0].wDescriptorLength =
 657                 cpu_to_le16(hidg->report_desc_length);
 658
 659         hidg_hs_in_ep_desc.bEndpointAddress =
 660                 hidg_fs_in_ep_desc.bEndpointAddress;
 661         hidg_hs_out_ep_desc.bEndpointAddress =
 662                 hidg_fs_out_ep_desc.bEndpointAddress;
 663
 664         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 665                         hidg_hs_descriptors, NULL);
 666         if (status)
 667                 goto fail;
 668
 669         mutex_init(&hidg->lock);
 670         spin_lock_init(&hidg->spinlock);
 671         init_waitqueue_head(&hidg->write_queue);
 672         init_waitqueue_head(&hidg->read_queue);
 673         INIT_LIST_HEAD(&hidg->completed_out_req);
 674
 675         /* create char device */
 676         cdev_init(&hidg->cdev, &f_hidg_fops);
 677         dev = MKDEV(major, hidg->minor);
 678         status = cdev_add(&hidg->cdev, dev, 1);
 679         if (status)
 680                 goto fail_free_descs;
 681
 682         device = device_create(hidg_class, NULL, dev, NULL,
 683                                "%s%d", "hidg", hidg->minor);
 684         if (IS_ERR(device)) {
 685                 status = PTR_ERR(device);
 686                 goto del;
 687         }
 688
 689         return 0;
 690 del:
 691         cdev_del(&hidg->cdev);
 692 fail_free_descs:
 693         usb_free_all_descriptors(f);
 694 fail:
 695         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 696         if (hidg->req != NULL) {
 697                 kfree(hidg->req->buf);
 698                 if (hidg->in_ep != NULL)
 699                         usb_ep_free_request(hidg->in_ep, hidg->req);
 700         }
 701
 702         return status;
 703 }
 704
 705 static inline int hidg_get_minor(void)
 706 {
 707         int ret;
 708
 709         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 710         if (ret >= HIDG_MINORS) {
 711                 ida_simple_remove(&hidg_ida, ret);
 712                 ret = -ENODEV;
 713         }
 714
 715         return ret;
 716 }
 717
 718 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 719 {
 720         return container_of(to_config_group(item), struct f_hid_opts,
 721                             func_inst.group);
 722 }
 723
 724 static void hid_attr_release(struct config_item *item)
 725 {
 726         struct f_hid_opts *opts = to_f_hid_opts(item);
 727
 728         usb_put_function_instance(&opts->func_inst);
 729 }
 730
 731 static struct configfs_item_operations hidg_item_ops = {
 732         .release        = hid_attr_release,
 733 };
 734
 735 #define F_HID_OPT(name, prec, limit)                                    \
 736 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 737 {                                                                       \
 738         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 739         int result;                                                     \
 740                                                                         \
 741         mutex_lock(&opts->lock);                                        \
 742         result = sprintf(page, "%d\n", opts->name);                     \
 743         mutex_unlock(&opts->lock);                                      \
 744                                                                         \
 745         return result;                                                  \
 746 }                                                                       \
 747                                                                         \
 748 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 749                                          const char *page, size_t len)  \
 750 {                                                                       \
 751         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 752         int ret;                                                        \
 753         u##prec num;                                                    \
 754                                                                         \
 755         mutex_lock(&opts->lock);                                        \
 756         if (opts->refcnt) {                                             \
 757                 ret = -EBUSY;                                           \
 758                 goto end;                                               \
 759         }                                                               \
 760                                                                         \
 761         ret = kstrtou##prec(page, 0, &num);                             \
 762         if (ret)                                                        \
 763                 goto end;                                               \
 764                                                                         \
 765         if (num > limit) {                                              \
 766                 ret = -EINVAL;                                          \
 767                 goto end;                                               \
 768         }                                                               \
 769         opts->name = num;                                               \
 770         ret = len;                                                      \
 771                                                                         \
 772 end:                                                                    \
 773         mutex_unlock(&opts->lock);                                      \
 774         return ret;                                                     \
 775 }                                                                       \
 776                                                                         \
 777 CONFIGFS_ATTR(f_hid_opts_, name)
 778
 779 F_HID_OPT(subclass, 8, 255);
 780 F_HID_OPT(protocol, 8, 255);
 781 F_HID_OPT(report_length, 16, 65535);
 782
 783 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 784 {
 785         struct f_hid_opts *opts = to_f_hid_opts(item);
 786         int result;
 787
 788         mutex_lock(&opts->lock);
 789         result = opts->report_desc_length;
 790         memcpy(page, opts->report_desc, opts->report_desc_length);
 791         mutex_unlock(&opts->lock);
 792
 793         return result;
 794 }
 795
 796 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 797                                             const char *page, size_t len)
 798 {
 799         struct f_hid_opts *opts = to_f_hid_opts(item);
 800         int ret = -EBUSY;
 801         char *d;
 802
 803         mutex_lock(&opts->lock);
 804
 805         if (opts->refcnt)
 806                 goto end;
 807         if (len > PAGE_SIZE) {
 808                 ret = -ENOSPC;
 809                 goto end;
 810         }
 811         d = kmemdup(page, len, GFP_KERNEL);
 812         if (!d) {
 813                 ret = -ENOMEM;
 814                 goto end;
 815         }
 816         kfree(opts->report_desc);
 817         opts->report_desc = d;
 818         opts->report_desc_length = len;
 819         opts->report_desc_alloc = true;
 820         ret = len;
 821 end:
 822         mutex_unlock(&opts->lock);
 823         return ret;
 824 }
 825
 826 CONFIGFS_ATTR(f_hid_opts_, report_desc);
 827
 828 static struct configfs_attribute *hid_attrs[] = {
 829         &f_hid_opts_attr_subclass,
 830         &f_hid_opts_attr_protocol,
 831         &f_hid_opts_attr_report_length,
 832         &f_hid_opts_attr_report_desc,
 833         NULL,
 834 };
 835
 836 static struct config_item_type hid_func_type = {
 837         .ct_item_ops    = &hidg_item_ops,
 838         .ct_attrs       = hid_attrs,
 839         .ct_owner       = THIS_MODULE,
 840 };
 841
 842 static inline void hidg_put_minor(int minor)
 843 {
 844         ida_simple_remove(&hidg_ida, minor);
 845 }
 846
 847 static void hidg_free_inst(struct usb_function_instance *f)
 848 {
 849         struct f_hid_opts *opts;
 850
 851         opts = container_of(f, struct f_hid_opts, func_inst);
 852
 853         mutex_lock(&hidg_ida_lock);
 854
 855         hidg_put_minor(opts->minor);
 856         if (idr_is_empty(&hidg_ida.idr))
 857                 ghid_cleanup();
 858
 859         mutex_unlock(&hidg_ida_lock);
 860
 861         if (opts->report_desc_alloc)
 862                 kfree(opts->report_desc);
 863
 864         kfree(opts);
 865 }
 866
 867 static struct usb_function_instance *hidg_alloc_inst(void)
 868 {
 869         struct f_hid_opts *opts;
 870         struct usb_function_instance *ret;
 871         int status = 0;
 872
 873         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 874         if (!opts)
 875                 return ERR_PTR(-ENOMEM);
 876         mutex_init(&opts->lock);
 877         opts->func_inst.free_func_inst = hidg_free_inst;
 878         ret = &opts->func_inst;
 879
 880         mutex_lock(&hidg_ida_lock);
 881
 882         if (idr_is_empty(&hidg_ida.idr)) {
 883                 status = ghid_setup(NULL, HIDG_MINORS);
 884                 if (status)  {
 885                         ret = ERR_PTR(status);
 886                         kfree(opts);
 887                         goto unlock;
 888                 }
 889         }
 890
 891         opts->minor = hidg_get_minor();
 892         if (opts->minor < 0) {
 893                 ret = ERR_PTR(opts->minor);
 894                 kfree(opts);
 895                 if (idr_is_empty(&hidg_ida.idr))
 896                         ghid_cleanup();
 897                 goto unlock;
 898         }
 899         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
 900
 901 unlock:
 902         mutex_unlock(&hidg_ida_lock);
 903         return ret;
 904 }
 905
 906 static void hidg_free(struct usb_function *f)
 907 {
 908         struct f_hidg *hidg;
 909         struct f_hid_opts *opts;
 910
 911         hidg = func_to_hidg(f);
 912         opts = container_of(f->fi, struct f_hid_opts, func_inst);
 913         kfree(hidg->report_desc);
 914         kfree(hidg);
 915         mutex_lock(&opts->lock);
 916         --opts->refcnt;
 917         mutex_unlock(&opts->lock);
 918 }
 919
 920 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 921 {
 922         struct f_hidg *hidg = func_to_hidg(f);
 923
 924         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 925         cdev_del(&hidg->cdev);
 926
 927         /* disable/free request and end point */
 928         usb_ep_disable(hidg->in_ep);
 929         kfree(hidg->req->buf);
 930         usb_ep_free_request(hidg->in_ep, hidg->req);
 931
 932         usb_free_all_descriptors(f);
 933 }
 934
 935 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 936 {
 937         struct f_hidg *hidg;
 938         struct f_hid_opts *opts;
 939
 940         /* allocate and initialize one new instance */
 941         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 942         if (!hidg)
 943                 return ERR_PTR(-ENOMEM);
 944
 945         opts = container_of(fi, struct f_hid_opts, func_inst);
 946
 947         mutex_lock(&opts->lock);
 948         ++opts->refcnt;
 949
 950         hidg->minor = opts->minor;
 951         hidg->bInterfaceSubClass = opts->subclass;
 952         hidg->bInterfaceProtocol = opts->protocol;
 953         hidg->report_length = opts->report_length;
 954         hidg->report_desc_length = opts->report_desc_length;
 955         if (opts->report_desc) {
 956                 hidg->report_desc = kmemdup(opts->report_desc,
 957                                             opts->report_desc_length,
 958                                             GFP_KERNEL);
 959                 if (!hidg->report_desc) {
 960                         kfree(hidg);
 961                         mutex_unlock(&opts->lock);
 962                         return ERR_PTR(-ENOMEM);
 963                 }
 964         }
 965
 966         mutex_unlock(&opts->lock);
 967
 968         hidg->func.name    = "hid";
 969         hidg->func.bind    = hidg_bind;
 970         hidg->func.unbind  = hidg_unbind;
 971         hidg->func.set_alt = hidg_set_alt;
 972         hidg->func.disable = hidg_disable;
 973         hidg->func.setup   = hidg_setup;
 974         hidg->func.free_func = hidg_free;
 975
 976         /* this could me made configurable at some point */
 977         hidg->qlen         = 4;
 978
 979         return &hidg->func;
 980 }
 981
 982 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
 983 MODULE_LICENSE("GPL");
 984 MODULE_AUTHOR("Fabien Chouteau");
 985
 986 int ghid_setup(struct usb_gadget *g, int count)
 987 {
 988         int status;
 989         dev_t dev;
 990
 991         hidg_class = class_create(THIS_MODULE, "hidg");
 992         if (IS_ERR(hidg_class)) {
 993                 status = PTR_ERR(hidg_class);
 994                 hidg_class = NULL;
 995                 return status;
 996         }
 997
 998         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 999         if (status) {
1000                 class_destroy(hidg_class);
1001                 hidg_class = NULL;
1002                 return status;
1003         }
1004
1005         major = MAJOR(dev);
1006         minors = count;
1007
1008         return 0;
1009 }
1010
1011 void ghid_cleanup(void)
1012 {
1013         if (major) {
1014                 unregister_chrdev_region(MKDEV(major, 0), minors);
1015                 major = minors = 0;
1016         }
1017
1018         class_destroy(hidg_class);
1019         hidg_class = NULL;
1020 }