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, "hid_setup crtl_request : bRequestType:0x%x bRequest:0x%x "
 403                 "Value:0x%x\n", ctrl->bRequestType, ctrl->bRequest, value);
 404
 405         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 406         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 407                   | HID_REQ_GET_REPORT):
 408                 VDBG(cdev, "get_report\n");
 409
 410                 /* send an empty report */
 411                 length = min_t(unsigned, length, hidg->report_length);
 412                 memset(req->buf, 0x0, length);
 413
 414                 goto respond;
 415                 break;
 416
 417         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 418                   | HID_REQ_GET_PROTOCOL):
 419                 VDBG(cdev, "get_protocol\n");
 420                 goto stall;
 421                 break;
 422
 423         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 424                   | HID_REQ_SET_REPORT):
 425                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 426                 goto stall;
 427                 break;
 428
 429         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 430                   | HID_REQ_SET_PROTOCOL):
 431                 VDBG(cdev, "set_protocol\n");
 432                 goto stall;
 433                 break;
 434
 435         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 436                   | USB_REQ_GET_DESCRIPTOR):
 437                 switch (value >> 8) {
 438                 case HID_DT_HID:
 439                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 440                         length = min_t(unsigned short, length,
 441                                                    hidg_desc.bLength);
 442                         memcpy(req->buf, &hidg_desc, length);
 443                         goto respond;
 444                         break;
 445                 case HID_DT_REPORT:
 446                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 447                         length = min_t(unsigned short, length,
 448                                                    hidg->report_desc_length);
 449                         memcpy(req->buf, hidg->report_desc, length);
 450                         goto respond;
 451                         break;
 452
 453                 default:
 454                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 455                                  value >> 8);
 456                         goto stall;
 457                         break;
 458                 }
 459                 break;
 460
 461         default:
 462                 VDBG(cdev, "Unknown request 0x%x\n",
 463                          ctrl->bRequest);
 464                 goto stall;
 465                 break;
 466         }
 467
 468 stall:
 469         return -EOPNOTSUPP;
 470
 471 respond:
 472         req->zero = 0;
 473         req->length = length;
 474         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 475         if (status < 0)
 476                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 477         return status;
 478 }
 479
 480 static void hidg_disable(struct usb_function *f)
 481 {
 482         struct f_hidg *hidg = func_to_hidg(f);
 483         struct f_hidg_req_list *list, *next;
 484
 485         usb_ep_disable(hidg->in_ep);
 486         hidg->in_ep->driver_data = NULL;
 487
 488         usb_ep_disable(hidg->out_ep);
 489         hidg->out_ep->driver_data = NULL;
 490
 491         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 492                 list_del(&list->list);
 493                 kfree(list);
 494         }
 495 }
 496
 497 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 498 {
 499         struct usb_composite_dev                *cdev = f->config->cdev;
 500         struct f_hidg                           *hidg = func_to_hidg(f);
 501         int i, status = 0;
 502
 503         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 504
 505         if (hidg->in_ep != NULL) {
 506                 /* restart endpoint */
 507                 if (hidg->in_ep->driver_data != NULL)
 508                         usb_ep_disable(hidg->in_ep);
 509
 510                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 511                                             hidg->in_ep);
 512                 if (status) {
 513                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 514                         goto fail;
 515                 }
 516                 status = usb_ep_enable(hidg->in_ep);
 517                 if (status < 0) {
 518                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 519                         goto fail;
 520                 }
 521                 hidg->in_ep->driver_data = hidg;
 522         }
 523
 524
 525         if (hidg->out_ep != NULL) {
 526                 /* restart endpoint */
 527                 if (hidg->out_ep->driver_data != NULL)
 528                         usb_ep_disable(hidg->out_ep);
 529
 530                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 531                                             hidg->out_ep);
 532                 if (status) {
 533                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 534                         goto fail;
 535                 }
 536                 status = usb_ep_enable(hidg->out_ep);
 537                 if (status < 0) {
 538                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 539                         goto fail;
 540                 }
 541                 hidg->out_ep->driver_data = hidg;
 542
 543                 /*
 544                  * allocate a bunch of read buffers and queue them all at once.
 545                  */
 546                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 547                         struct usb_request *req =
 548                                         hidg_alloc_ep_req(hidg->out_ep,
 549                                                           hidg->report_length);
 550                         if (req) {
 551                                 req->complete = hidg_set_report_complete;
 552                                 req->context  = hidg;
 553                                 status = usb_ep_queue(hidg->out_ep, req,
 554                                                       GFP_ATOMIC);
 555                                 if (status)
 556                                         ERROR(cdev, "%s queue req --> %d\n",
 557                                                 hidg->out_ep->name, status);
 558                         } else {
 559                                 usb_ep_disable(hidg->out_ep);
 560                                 hidg->out_ep->driver_data = NULL;
 561                                 status = -ENOMEM;
 562                                 goto fail;
 563                         }
 564                 }
 565         }
 566
 567 fail:
 568         return status;
 569 }
 570
 571 const struct file_operations f_hidg_fops = {
 572         .owner          = THIS_MODULE,
 573         .open           = f_hidg_open,
 574         .release        = f_hidg_release,
 575         .write          = f_hidg_write,
 576         .read           = f_hidg_read,
 577         .poll           = f_hidg_poll,
 578         .llseek         = noop_llseek,
 579 };
 580
 581 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 582 {
 583         struct usb_ep           *ep;
 584         struct f_hidg           *hidg = func_to_hidg(f);
 585         struct usb_string       *us;
 586         struct device           *device;
 587         int                     status;
 588         dev_t                   dev;
 589
 590         /* maybe allocate device-global string IDs, and patch descriptors */
 591         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 592                                  ARRAY_SIZE(ct_func_string_defs));
 593         if (IS_ERR(us))
 594                 return PTR_ERR(us);
 595         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 596
 597         /* allocate instance-specific interface IDs, and patch descriptors */
 598         status = usb_interface_id(c, f);
 599         if (status < 0)
 600                 goto fail;
 601         hidg_interface_desc.bInterfaceNumber = status;
 602
 603         /* allocate instance-specific endpoints */
 604         status = -ENODEV;
 605         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 606         if (!ep)
 607                 goto fail;
 608         ep->driver_data = c->cdev;      /* claim */
 609         hidg->in_ep = ep;
 610
 611         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 612         if (!ep)
 613                 goto fail;
 614         ep->driver_data = c->cdev;      /* claim */
 615         hidg->out_ep = ep;
 616
 617         /* preallocate request and buffer */
 618         status = -ENOMEM;
 619         hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
 620         if (!hidg->req)
 621                 goto fail;
 622
 623         hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
 624         if (!hidg->req->buf)
 625                 goto fail;
 626
 627         /* set descriptor dynamic values */
 628         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 629         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 630         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 631         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 632         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 633         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 634         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 635         hidg_desc.desc[0].wDescriptorLength =
 636                 cpu_to_le16(hidg->report_desc_length);
 637
 638         hidg_hs_in_ep_desc.bEndpointAddress =
 639                 hidg_fs_in_ep_desc.bEndpointAddress;
 640         hidg_hs_out_ep_desc.bEndpointAddress =
 641                 hidg_fs_out_ep_desc.bEndpointAddress;
 642
 643         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 644                         hidg_hs_descriptors, NULL);
 645         if (status)
 646                 goto fail;
 647
 648         mutex_init(&hidg->lock);
 649         spin_lock_init(&hidg->spinlock);
 650         init_waitqueue_head(&hidg->write_queue);
 651         init_waitqueue_head(&hidg->read_queue);
 652         INIT_LIST_HEAD(&hidg->completed_out_req);
 653
 654         /* create char device */
 655         cdev_init(&hidg->cdev, &f_hidg_fops);
 656         dev = MKDEV(major, hidg->minor);
 657         status = cdev_add(&hidg->cdev, dev, 1);
 658         if (status)
 659                 goto fail_free_descs;
 660
 661         device = device_create(hidg_class, NULL, dev, NULL,
 662                                "%s%d", "hidg", hidg->minor);
 663         if (IS_ERR(device)) {
 664                 status = PTR_ERR(device);
 665                 goto del;
 666         }
 667
 668         return 0;
 669 del:
 670         cdev_del(&hidg->cdev);
 671 fail_free_descs:
 672         usb_free_all_descriptors(f);
 673 fail:
 674         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 675         if (hidg->req != NULL) {
 676                 kfree(hidg->req->buf);
 677                 if (hidg->in_ep != NULL)
 678                         usb_ep_free_request(hidg->in_ep, hidg->req);
 679         }
 680
 681         return status;
 682 }
 683
 684 static inline int hidg_get_minor(void)
 685 {
 686         int ret;
 687
 688         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 689
 690         return ret;
 691 }
 692
 693 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 694 {
 695         return container_of(to_config_group(item), struct f_hid_opts,
 696                             func_inst.group);
 697 }
 698
 699 CONFIGFS_ATTR_STRUCT(f_hid_opts);
 700 CONFIGFS_ATTR_OPS(f_hid_opts);
 701
 702 static void hid_attr_release(struct config_item *item)
 703 {
 704         struct f_hid_opts *opts = to_f_hid_opts(item);
 705
 706         usb_put_function_instance(&opts->func_inst);
 707 }
 708
 709 static struct configfs_item_operations hidg_item_ops = {
 710         .release        = hid_attr_release,
 711         .show_attribute = f_hid_opts_attr_show,
 712         .store_attribute = f_hid_opts_attr_store,
 713 };
 714
 715 #define F_HID_OPT(name, prec, limit)                                    \
 716 static ssize_t f_hid_opts_##name##_show(struct f_hid_opts *opts, char *page)\
 717 {                                                                       \
 718         int result;                                                     \
 719                                                                         \
 720         mutex_lock(&opts->lock);                                        \
 721         result = sprintf(page, "%d\n", opts->name);                     \
 722         mutex_unlock(&opts->lock);                                      \
 723                                                                         \
 724         return result;                                                  \
 725 }                                                                       \
 726                                                                         \
 727 static ssize_t f_hid_opts_##name##_store(struct f_hid_opts *opts,       \
 728                                          const char *page, size_t len)  \
 729 {                                                                       \
 730         int ret;                                                        \
 731         u##prec num;                                                    \
 732                                                                         \
 733         mutex_lock(&opts->lock);                                        \
 734         if (opts->refcnt) {                                             \
 735                 ret = -EBUSY;                                           \
 736                 goto end;                                               \
 737         }                                                               \
 738                                                                         \
 739         ret = kstrtou##prec(page, 0, &num);                             \
 740         if (ret)                                                        \
 741                 goto end;                                               \
 742                                                                         \
 743         if (num > limit) {                                              \
 744                 ret = -EINVAL;                                          \
 745                 goto end;                                               \
 746         }                                                               \
 747         opts->name = num;                                               \
 748         ret = len;                                                      \
 749                                                                         \
 750 end:                                                                    \
 751         mutex_unlock(&opts->lock);                                      \
 752         return ret;                                                     \
 753 }                                                                       \
 754                                                                         \
 755 static struct f_hid_opts_attribute f_hid_opts_##name =                  \
 756         __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_hid_opts_##name##_show,\
 757                         f_hid_opts_##name##_store)
 758
 759 F_HID_OPT(subclass, 8, 255);
 760 F_HID_OPT(protocol, 8, 255);
 761 F_HID_OPT(report_length, 16, 65536);
 762
 763 static ssize_t f_hid_opts_report_desc_show(struct f_hid_opts *opts, char *page)
 764 {
 765         int result;
 766
 767         mutex_lock(&opts->lock);
 768         result = opts->report_desc_length;
 769         memcpy(page, opts->report_desc, opts->report_desc_length);
 770         mutex_unlock(&opts->lock);
 771
 772         return result;
 773 }
 774
 775 static ssize_t f_hid_opts_report_desc_store(struct f_hid_opts *opts,
 776                                             const char *page, size_t len)
 777 {
 778         int ret = -EBUSY;
 779         char *d;
 780
 781         mutex_lock(&opts->lock);
 782
 783         if (opts->refcnt)
 784                 goto end;
 785         if (len > PAGE_SIZE) {
 786                 ret = -ENOSPC;
 787                 goto end;
 788         }
 789         d = kmemdup(page, len, GFP_KERNEL);
 790         if (!d) {
 791                 ret = -ENOMEM;
 792                 goto end;
 793         }
 794         kfree(opts->report_desc);
 795         opts->report_desc = d;
 796         opts->report_desc_length = len;
 797         opts->report_desc_alloc = true;
 798         ret = len;
 799 end:
 800         mutex_unlock(&opts->lock);
 801         return ret;
 802 }
 803
 804 static struct f_hid_opts_attribute f_hid_opts_report_desc =
 805         __CONFIGFS_ATTR(report_desc, S_IRUGO | S_IWUSR,
 806                         f_hid_opts_report_desc_show,
 807                         f_hid_opts_report_desc_store);
 808
 809 static struct configfs_attribute *hid_attrs[] = {
 810         &f_hid_opts_subclass.attr,
 811         &f_hid_opts_protocol.attr,
 812         &f_hid_opts_report_length.attr,
 813         &f_hid_opts_report_desc.attr,
 814         NULL,
 815 };
 816
 817 static struct config_item_type hid_func_type = {
 818         .ct_item_ops    = &hidg_item_ops,
 819         .ct_attrs       = hid_attrs,
 820         .ct_owner       = THIS_MODULE,
 821 };
 822
 823 static inline void hidg_put_minor(int minor)
 824 {
 825         ida_simple_remove(&hidg_ida, minor);
 826 }
 827
 828 static void hidg_free_inst(struct usb_function_instance *f)
 829 {
 830         struct f_hid_opts *opts;
 831
 832         opts = container_of(f, struct f_hid_opts, func_inst);
 833
 834         mutex_lock(&hidg_ida_lock);
 835
 836         hidg_put_minor(opts->minor);
 837         if (idr_is_empty(&hidg_ida.idr))
 838                 ghid_cleanup();
 839
 840         mutex_unlock(&hidg_ida_lock);
 841
 842         if (opts->report_desc_alloc)
 843                 kfree(opts->report_desc);
 844
 845         kfree(opts);
 846 }
 847
 848 static struct usb_function_instance *hidg_alloc_inst(void)
 849 {
 850         struct f_hid_opts *opts;
 851         struct usb_function_instance *ret;
 852         int status = 0;
 853
 854         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 855         if (!opts)
 856                 return ERR_PTR(-ENOMEM);
 857         mutex_init(&opts->lock);
 858         opts->func_inst.free_func_inst = hidg_free_inst;
 859         ret = &opts->func_inst;
 860
 861         mutex_lock(&hidg_ida_lock);
 862
 863         if (idr_is_empty(&hidg_ida.idr)) {
 864                 status = ghid_setup(NULL, HIDG_MINORS);
 865                 if (status)  {
 866                         ret = ERR_PTR(status);
 867                         kfree(opts);
 868                         goto unlock;
 869                 }
 870         }
 871
 872         opts->minor = hidg_get_minor();
 873         if (opts->minor < 0) {
 874                 ret = ERR_PTR(opts->minor);
 875                 kfree(opts);
 876                 if (idr_is_empty(&hidg_ida.idr))
 877                         ghid_cleanup();
 878                 goto unlock;
 879         }
 880         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
 881
 882 unlock:
 883         mutex_unlock(&hidg_ida_lock);
 884         return ret;
 885 }
 886
 887 static void hidg_free(struct usb_function *f)
 888 {
 889         struct f_hidg *hidg;
 890         struct f_hid_opts *opts;
 891
 892         hidg = func_to_hidg(f);
 893         opts = container_of(f->fi, struct f_hid_opts, func_inst);
 894         kfree(hidg->report_desc);
 895         kfree(hidg);
 896         mutex_lock(&opts->lock);
 897         --opts->refcnt;
 898         mutex_unlock(&opts->lock);
 899 }
 900
 901 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 902 {
 903         struct f_hidg *hidg = func_to_hidg(f);
 904
 905         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 906         cdev_del(&hidg->cdev);
 907
 908         /* disable/free request and end point */
 909         usb_ep_disable(hidg->in_ep);
 910         usb_ep_dequeue(hidg->in_ep, hidg->req);
 911         kfree(hidg->req->buf);
 912         usb_ep_free_request(hidg->in_ep, hidg->req);
 913
 914         usb_free_all_descriptors(f);
 915 }
 916
 917 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 918 {
 919         struct f_hidg *hidg;
 920         struct f_hid_opts *opts;
 921
 922         /* allocate and initialize one new instance */
 923         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 924         if (!hidg)
 925                 return ERR_PTR(-ENOMEM);
 926
 927         opts = container_of(fi, struct f_hid_opts, func_inst);
 928
 929         mutex_lock(&opts->lock);
 930         ++opts->refcnt;
 931
 932         hidg->minor = opts->minor;
 933         hidg->bInterfaceSubClass = opts->subclass;
 934         hidg->bInterfaceProtocol = opts->protocol;
 935         hidg->report_length = opts->report_length;
 936         hidg->report_desc_length = opts->report_desc_length;
 937         if (opts->report_desc) {
 938                 hidg->report_desc = kmemdup(opts->report_desc,
 939                                             opts->report_desc_length,
 940                                             GFP_KERNEL);
 941                 if (!hidg->report_desc) {
 942                         kfree(hidg);
 943                         mutex_unlock(&opts->lock);
 944                         return ERR_PTR(-ENOMEM);
 945                 }
 946         }
 947
 948         mutex_unlock(&opts->lock);
 949
 950         hidg->func.name    = "hid";
 951         hidg->func.bind    = hidg_bind;
 952         hidg->func.unbind  = hidg_unbind;
 953         hidg->func.set_alt = hidg_set_alt;
 954         hidg->func.disable = hidg_disable;
 955         hidg->func.setup   = hidg_setup;
 956         hidg->func.free_func = hidg_free;
 957
 958         /* this could me made configurable at some point */
 959         hidg->qlen         = 4;
 960
 961         return &hidg->func;
 962 }
 963
 964 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
 965 MODULE_LICENSE("GPL");
 966 MODULE_AUTHOR("Fabien Chouteau");
 967
 968 int ghid_setup(struct usb_gadget *g, int count)
 969 {
 970         int status;
 971         dev_t dev;
 972
 973         hidg_class = class_create(THIS_MODULE, "hidg");
 974         if (IS_ERR(hidg_class)) {
 975                 status = PTR_ERR(hidg_class);
 976                 hidg_class = NULL;
 977                 return status;
 978         }
 979
 980         status = alloc_chrdev_region(&dev, 0, count, "hidg");
 981         if (status) {
 982                 class_destroy(hidg_class);
 983                 hidg_class = NULL;
 984                 return status;
 985         }
 986
 987         major = MAJOR(dev);
 988         minors = count;
 989
 990         return 0;
 991 }
 992
 993 void ghid_cleanup(void)
 994 {
 995         if (major) {
 996                 unregister_chrdev_region(MKDEV(major, 0), minors);
 997                 major = minors = 0;
 998         }
 999
1000         class_destroy(hidg_class);
1001         hidg_class = NULL;
1002 }