drivers/usb/gadget/function/f_hid.c

   1 /*
   2  * f_hid.c -- USB HID function driver
   3  *
   4  * Copyright (C) 2010 Fabien Chouteau <[email protected]>
   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 /* Super-Speed Support */
 102
 103 static struct usb_endpoint_descriptor hidg_ss_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_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
 116         .bLength                = sizeof(hidg_ss_in_comp_desc),
 117         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 118
 119         /* .bMaxBurst           = 0, */
 120         /* .bmAttributes        = 0, */
 121         /* .wBytesPerInterval   = DYNAMIC */
 122 };
 123
 124 static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
 125         .bLength                = USB_DT_ENDPOINT_SIZE,
 126         .bDescriptorType        = USB_DT_ENDPOINT,
 127         .bEndpointAddress       = USB_DIR_OUT,
 128         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 129         /*.wMaxPacketSize       = DYNAMIC */
 130         .bInterval              = 4, /* FIXME: Add this field in the
 131                                       * HID gadget configuration?
 132                                       * (struct hidg_func_descriptor)
 133                                       */
 134 };
 135
 136 static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
 137         .bLength                = sizeof(hidg_ss_out_comp_desc),
 138         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 139
 140         /* .bMaxBurst           = 0, */
 141         /* .bmAttributes        = 0, */
 142         /* .wBytesPerInterval   = DYNAMIC */
 143 };
 144
 145 static struct usb_descriptor_header *hidg_ss_descriptors[] = {
 146         (struct usb_descriptor_header *)&hidg_interface_desc,
 147         (struct usb_descriptor_header *)&hidg_desc,
 148         (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
 149         (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
 150         (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
 151         (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
 152         NULL,
 153 };
 154
 155 /* High-Speed Support */
 156
 157 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 158         .bLength                = USB_DT_ENDPOINT_SIZE,
 159         .bDescriptorType        = USB_DT_ENDPOINT,
 160         .bEndpointAddress       = USB_DIR_IN,
 161         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 162         /*.wMaxPacketSize       = DYNAMIC */
 163         .bInterval              = 4, /* FIXME: Add this field in the
 164                                       * HID gadget configuration?
 165                                       * (struct hidg_func_descriptor)
 166                                       */
 167 };
 168
 169 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 170         .bLength                = USB_DT_ENDPOINT_SIZE,
 171         .bDescriptorType        = USB_DT_ENDPOINT,
 172         .bEndpointAddress       = USB_DIR_OUT,
 173         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 174         /*.wMaxPacketSize       = DYNAMIC */
 175         .bInterval              = 4, /* FIXME: Add this field in the
 176                                       * HID gadget configuration?
 177                                       * (struct hidg_func_descriptor)
 178                                       */
 179 };
 180
 181 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 182         (struct usb_descriptor_header *)&hidg_interface_desc,
 183         (struct usb_descriptor_header *)&hidg_desc,
 184         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 185         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 186         NULL,
 187 };
 188
 189 /* Full-Speed Support */
 190
 191 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 192         .bLength                = USB_DT_ENDPOINT_SIZE,
 193         .bDescriptorType        = USB_DT_ENDPOINT,
 194         .bEndpointAddress       = USB_DIR_IN,
 195         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 196         /*.wMaxPacketSize       = DYNAMIC */
 197         .bInterval              = 10, /* FIXME: Add this field in the
 198                                        * HID gadget configuration?
 199                                        * (struct hidg_func_descriptor)
 200                                        */
 201 };
 202
 203 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 204         .bLength                = USB_DT_ENDPOINT_SIZE,
 205         .bDescriptorType        = USB_DT_ENDPOINT,
 206         .bEndpointAddress       = USB_DIR_OUT,
 207         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 208         /*.wMaxPacketSize       = DYNAMIC */
 209         .bInterval              = 10, /* FIXME: Add this field in the
 210                                        * HID gadget configuration?
 211                                        * (struct hidg_func_descriptor)
 212                                        */
 213 };
 214
 215 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 216         (struct usb_descriptor_header *)&hidg_interface_desc,
 217         (struct usb_descriptor_header *)&hidg_desc,
 218         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 219         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 220         NULL,
 221 };
 222
 223 /*-------------------------------------------------------------------------*/
 224 /*                                 Strings                                 */
 225
 226 #define CT_FUNC_HID_IDX 0
 227
 228 static struct usb_string ct_func_string_defs[] = {
 229         [CT_FUNC_HID_IDX].s     = "HID Interface",
 230         {},                     /* end of list */
 231 };
 232
 233 static struct usb_gadget_strings ct_func_string_table = {
 234         .language       = 0x0409,       /* en-US */
 235         .strings        = ct_func_string_defs,
 236 };
 237
 238 static struct usb_gadget_strings *ct_func_strings[] = {
 239         &ct_func_string_table,
 240         NULL,
 241 };
 242
 243 /*-------------------------------------------------------------------------*/
 244 /*                              Char Device                                */
 245
 246 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 247                         size_t count, loff_t *ptr)
 248 {
 249         struct f_hidg *hidg = file->private_data;
 250         struct f_hidg_req_list *list;
 251         struct usb_request *req;
 252         unsigned long flags;
 253         int ret;
 254
 255         if (!count)
 256                 return 0;
 257
 258         if (!access_ok(VERIFY_WRITE, buffer, count))
 259                 return -EFAULT;
 260
 261         spin_lock_irqsave(&hidg->spinlock, flags);
 262
 263 #define READ_COND (!list_empty(&hidg->completed_out_req))
 264
 265         /* wait for at least one buffer to complete */
 266         while (!READ_COND) {
 267                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 268                 if (file->f_flags & O_NONBLOCK)
 269                         return -EAGAIN;
 270
 271                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 272                         return -ERESTARTSYS;
 273
 274                 spin_lock_irqsave(&hidg->spinlock, flags);
 275         }
 276
 277         /* pick the first one */
 278         list = list_first_entry(&hidg->completed_out_req,
 279                                 struct f_hidg_req_list, list);
 280         req = list->req;
 281         count = min_t(unsigned int, count, req->actual - list->pos);
 282         spin_unlock_irqrestore(&hidg->spinlock, flags);
 283
 284         /* copy to user outside spinlock */
 285         count -= copy_to_user(buffer, req->buf + list->pos, count);
 286         list->pos += count;
 287
 288         /*
 289          * if this request is completely handled and transfered to
 290          * userspace, remove its entry from the list and requeue it
 291          * again. Otherwise, we will revisit it again upon the next
 292          * call, taking into account its current read position.
 293          */
 294         if (list->pos == req->actual) {
 295                 spin_lock_irqsave(&hidg->spinlock, flags);
 296                 list_del(&list->list);
 297                 kfree(list);
 298                 spin_unlock_irqrestore(&hidg->spinlock, flags);
 299
 300                 req->length = hidg->report_length;
 301                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 302                 if (ret < 0)
 303                         return ret;
 304         }
 305
 306         return count;
 307 }
 308
 309 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 310 {
 311         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 312
 313         if (req->status != 0) {
 314                 ERROR(hidg->func.config->cdev,
 315                         "End Point Request ERROR: %d\n", req->status);
 316         }
 317
 318         hidg->write_pending = 0;
 319         wake_up(&hidg->write_queue);
 320 }
 321
 322 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 323                             size_t count, loff_t *offp)
 324 {
 325         struct f_hidg *hidg  = file->private_data;
 326         ssize_t status = -ENOMEM;
 327
 328         if (!access_ok(VERIFY_READ, buffer, count))
 329                 return -EFAULT;
 330
 331         mutex_lock(&hidg->lock);
 332
 333 #define WRITE_COND (!hidg->write_pending)
 334
 335         /* write queue */
 336         while (!WRITE_COND) {
 337                 mutex_unlock(&hidg->lock);
 338                 if (file->f_flags & O_NONBLOCK)
 339                         return -EAGAIN;
 340
 341                 if (wait_event_interruptible_exclusive(
 342                                 hidg->write_queue, WRITE_COND))
 343                         return -ERESTARTSYS;
 344
 345                 mutex_lock(&hidg->lock);
 346         }
 347
 348         count  = min_t(unsigned, count, hidg->report_length);
 349         status = copy_from_user(hidg->req->buf, buffer, count);
 350
 351         if (status != 0) {
 352                 ERROR(hidg->func.config->cdev,
 353                         "copy_from_user error\n");
 354                 mutex_unlock(&hidg->lock);
 355                 return -EINVAL;
 356         }
 357
 358         hidg->req->status   = 0;
 359         hidg->req->zero     = 0;
 360         hidg->req->length   = count;
 361         hidg->req->complete = f_hidg_req_complete;
 362         hidg->req->context  = hidg;
 363         hidg->write_pending = 1;
 364
 365         status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
 366         if (status < 0) {
 367                 ERROR(hidg->func.config->cdev,
 368                         "usb_ep_queue error on int endpoint %zd\n", status);
 369                 hidg->write_pending = 0;
 370                 wake_up(&hidg->write_queue);
 371         } else {
 372                 status = count;
 373         }
 374
 375         mutex_unlock(&hidg->lock);
 376
 377         return status;
 378 }
 379
 380 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 381 {
 382         struct f_hidg   *hidg  = file->private_data;
 383         unsigned int    ret = 0;
 384
 385         poll_wait(file, &hidg->read_queue, wait);
 386         poll_wait(file, &hidg->write_queue, wait);
 387
 388         if (WRITE_COND)
 389                 ret |= POLLOUT | POLLWRNORM;
 390
 391         if (READ_COND)
 392                 ret |= POLLIN | POLLRDNORM;
 393
 394         return ret;
 395 }
 396
 397 #undef WRITE_COND
 398 #undef READ_COND
 399
 400 static int f_hidg_release(struct inode *inode, struct file *fd)
 401 {
 402         fd->private_data = NULL;
 403         return 0;
 404 }
 405
 406 static int f_hidg_open(struct inode *inode, struct file *fd)
 407 {
 408         struct f_hidg *hidg =
 409                 container_of(inode->i_cdev, struct f_hidg, cdev);
 410
 411         fd->private_data = hidg;
 412
 413         return 0;
 414 }
 415
 416 /*-------------------------------------------------------------------------*/
 417 /*                                usb_function                             */
 418
 419 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 420                                                     unsigned length)
 421 {
 422         return alloc_ep_req(ep, length);
 423 }
 424
 425 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 426 {
 427         struct f_hidg *hidg = (struct f_hidg *) req->context;
 428         struct f_hidg_req_list *req_list;
 429         unsigned long flags;
 430
 431         req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 432         if (!req_list)
 433                 return;
 434
 435         req_list->req = req;
 436
 437         spin_lock_irqsave(&hidg->spinlock, flags);
 438         list_add_tail(&req_list->list, &hidg->completed_out_req);
 439         spin_unlock_irqrestore(&hidg->spinlock, flags);
 440
 441         wake_up(&hidg->read_queue);
 442 }
 443
 444 static int hidg_setup(struct usb_function *f,
 445                 const struct usb_ctrlrequest *ctrl)
 446 {
 447         struct f_hidg                   *hidg = func_to_hidg(f);
 448         struct usb_composite_dev        *cdev = f->config->cdev;
 449         struct usb_request              *req  = cdev->req;
 450         int status = 0;
 451         __u16 value, length;
 452
 453         value   = __le16_to_cpu(ctrl->wValue);
 454         length  = __le16_to_cpu(ctrl->wLength);
 455
 456         VDBG(cdev,
 457              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 458              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 459
 460         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 461         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 462                   | HID_REQ_GET_REPORT):
 463                 VDBG(cdev, "get_report\n");
 464
 465                 /* send an empty report */
 466                 length = min_t(unsigned, length, hidg->report_length);
 467                 memset(req->buf, 0x0, length);
 468
 469                 goto respond;
 470                 break;
 471
 472         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 473                   | HID_REQ_GET_PROTOCOL):
 474                 VDBG(cdev, "get_protocol\n");
 475                 goto stall;
 476                 break;
 477
 478         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 479                   | HID_REQ_SET_REPORT):
 480                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 481                 goto stall;
 482                 break;
 483
 484         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 485                   | HID_REQ_SET_PROTOCOL):
 486                 VDBG(cdev, "set_protocol\n");
 487                 goto stall;
 488                 break;
 489
 490         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 491                   | USB_REQ_GET_DESCRIPTOR):
 492                 switch (value >> 8) {
 493                 case HID_DT_HID:
 494                 {
 495                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 496
 497                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 498                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 499                         hidg_desc_copy.desc[0].wDescriptorLength =
 500                                 cpu_to_le16(hidg->report_desc_length);
 501
 502                         length = min_t(unsigned short, length,
 503                                                    hidg_desc_copy.bLength);
 504                         memcpy(req->buf, &hidg_desc_copy, length);
 505                         goto respond;
 506                         break;
 507                 }
 508                 case HID_DT_REPORT:
 509                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 510                         length = min_t(unsigned short, length,
 511                                                    hidg->report_desc_length);
 512                         memcpy(req->buf, hidg->report_desc, length);
 513                         goto respond;
 514                         break;
 515
 516                 default:
 517                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 518                                  value >> 8);
 519                         goto stall;
 520                         break;
 521                 }
 522                 break;
 523
 524         default:
 525                 VDBG(cdev, "Unknown request 0x%x\n",
 526                          ctrl->bRequest);
 527                 goto stall;
 528                 break;
 529         }
 530
 531 stall:
 532         return -EOPNOTSUPP;
 533
 534 respond:
 535         req->zero = 0;
 536         req->length = length;
 537         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 538         if (status < 0)
 539                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 540         return status;
 541 }
 542
 543 static void hidg_disable(struct usb_function *f)
 544 {
 545         struct f_hidg *hidg = func_to_hidg(f);
 546         struct f_hidg_req_list *list, *next;
 547
 548         usb_ep_disable(hidg->in_ep);
 549         usb_ep_disable(hidg->out_ep);
 550
 551         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 552                 list_del(&list->list);
 553                 kfree(list);
 554         }
 555 }
 556
 557 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 558 {
 559         struct usb_composite_dev                *cdev = f->config->cdev;
 560         struct f_hidg                           *hidg = func_to_hidg(f);
 561         int i, status = 0;
 562
 563         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 564
 565         if (hidg->in_ep != NULL) {
 566                 /* restart endpoint */
 567                 usb_ep_disable(hidg->in_ep);
 568
 569                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 570                                             hidg->in_ep);
 571                 if (status) {
 572                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 573                         goto fail;
 574                 }
 575                 status = usb_ep_enable(hidg->in_ep);
 576                 if (status < 0) {
 577                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 578                         goto fail;
 579                 }
 580                 hidg->in_ep->driver_data = hidg;
 581         }
 582
 583
 584         if (hidg->out_ep != NULL) {
 585                 /* restart endpoint */
 586                 usb_ep_disable(hidg->out_ep);
 587
 588                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 589                                             hidg->out_ep);
 590                 if (status) {
 591                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 592                         goto fail;
 593                 }
 594                 status = usb_ep_enable(hidg->out_ep);
 595                 if (status < 0) {
 596                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 597                         goto fail;
 598                 }
 599                 hidg->out_ep->driver_data = hidg;
 600
 601                 /*
 602                  * allocate a bunch of read buffers and queue them all at once.
 603                  */
 604                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 605                         struct usb_request *req =
 606                                         hidg_alloc_ep_req(hidg->out_ep,
 607                                                           hidg->report_length);
 608                         if (req) {
 609                                 req->complete = hidg_set_report_complete;
 610                                 req->context  = hidg;
 611                                 status = usb_ep_queue(hidg->out_ep, req,
 612                                                       GFP_ATOMIC);
 613                                 if (status)
 614                                         ERROR(cdev, "%s queue req --> %d\n",
 615                                                 hidg->out_ep->name, status);
 616                         } else {
 617                                 usb_ep_disable(hidg->out_ep);
 618                                 status = -ENOMEM;
 619                                 goto fail;
 620                         }
 621                 }
 622         }
 623
 624 fail:
 625         return status;
 626 }
 627
 628 static const struct file_operations f_hidg_fops = {
 629         .owner          = THIS_MODULE,
 630         .open           = f_hidg_open,
 631         .release        = f_hidg_release,
 632         .write          = f_hidg_write,
 633         .read           = f_hidg_read,
 634         .poll           = f_hidg_poll,
 635         .llseek         = noop_llseek,
 636 };
 637
 638 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 639 {
 640         struct usb_ep           *ep;
 641         struct f_hidg           *hidg = func_to_hidg(f);
 642         struct usb_string       *us;
 643         struct device           *device;
 644         int                     status;
 645         dev_t                   dev;
 646
 647         /* maybe allocate device-global string IDs, and patch descriptors */
 648         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 649                                  ARRAY_SIZE(ct_func_string_defs));
 650         if (IS_ERR(us))
 651                 return PTR_ERR(us);
 652         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 653
 654         /* allocate instance-specific interface IDs, and patch descriptors */
 655         status = usb_interface_id(c, f);
 656         if (status < 0)
 657                 goto fail;
 658         hidg_interface_desc.bInterfaceNumber = status;
 659
 660         /* allocate instance-specific endpoints */
 661         status = -ENODEV;
 662         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 663         if (!ep)
 664                 goto fail;
 665         hidg->in_ep = ep;
 666
 667         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 668         if (!ep)
 669                 goto fail;
 670         hidg->out_ep = ep;
 671
 672         /* preallocate request and buffer */
 673         status = -ENOMEM;
 674         hidg->req = alloc_ep_req(hidg->in_ep, hidg->report_length);
 675         if (!hidg->req)
 676                 goto fail;
 677
 678         /* set descriptor dynamic values */
 679         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 680         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 681         hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 682         hidg_ss_in_comp_desc.wBytesPerInterval =
 683                                 cpu_to_le16(hidg->report_length);
 684         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 685         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 686         hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 687         hidg_ss_out_comp_desc.wBytesPerInterval =
 688                                 cpu_to_le16(hidg->report_length);
 689         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 690         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 691         /*
 692          * We can use hidg_desc struct here but we should not relay
 693          * that its content won't change after returning from this function.
 694          */
 695         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 696         hidg_desc.desc[0].wDescriptorLength =
 697                 cpu_to_le16(hidg->report_desc_length);
 698
 699         hidg_hs_in_ep_desc.bEndpointAddress =
 700                 hidg_fs_in_ep_desc.bEndpointAddress;
 701         hidg_hs_out_ep_desc.bEndpointAddress =
 702                 hidg_fs_out_ep_desc.bEndpointAddress;
 703
 704         hidg_ss_in_ep_desc.bEndpointAddress =
 705                 hidg_fs_in_ep_desc.bEndpointAddress;
 706         hidg_ss_out_ep_desc.bEndpointAddress =
 707                 hidg_fs_out_ep_desc.bEndpointAddress;
 708
 709         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 710                         hidg_hs_descriptors, hidg_ss_descriptors, NULL);
 711         if (status)
 712                 goto fail;
 713
 714         mutex_init(&hidg->lock);
 715         spin_lock_init(&hidg->spinlock);
 716         init_waitqueue_head(&hidg->write_queue);
 717         init_waitqueue_head(&hidg->read_queue);
 718         INIT_LIST_HEAD(&hidg->completed_out_req);
 719
 720         /* create char device */
 721         cdev_init(&hidg->cdev, &f_hidg_fops);
 722         dev = MKDEV(major, hidg->minor);
 723         status = cdev_add(&hidg->cdev, dev, 1);
 724         if (status)
 725                 goto fail_free_descs;
 726
 727         device = device_create(hidg_class, NULL, dev, NULL,
 728                                "%s%d", "hidg", hidg->minor);
 729         if (IS_ERR(device)) {
 730                 status = PTR_ERR(device);
 731                 goto del;
 732         }
 733
 734         return 0;
 735 del:
 736         cdev_del(&hidg->cdev);
 737 fail_free_descs:
 738         usb_free_all_descriptors(f);
 739 fail:
 740         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 741         if (hidg->req != NULL)
 742                 free_ep_req(hidg->in_ep, hidg->req);
 743
 744         return status;
 745 }
 746
 747 static inline int hidg_get_minor(void)
 748 {
 749         int ret;
 750
 751         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 752         if (ret >= HIDG_MINORS) {
 753                 ida_simple_remove(&hidg_ida, ret);
 754                 ret = -ENODEV;
 755         }
 756
 757         return ret;
 758 }
 759
 760 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 761 {
 762         return container_of(to_config_group(item), struct f_hid_opts,
 763                             func_inst.group);
 764 }
 765
 766 static void hid_attr_release(struct config_item *item)
 767 {
 768         struct f_hid_opts *opts = to_f_hid_opts(item);
 769
 770         usb_put_function_instance(&opts->func_inst);
 771 }
 772
 773 static struct configfs_item_operations hidg_item_ops = {
 774         .release        = hid_attr_release,
 775 };
 776
 777 #define F_HID_OPT(name, prec, limit)                                    \
 778 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 779 {                                                                       \
 780         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 781         int result;                                                     \
 782                                                                         \
 783         mutex_lock(&opts->lock);                                        \
 784         result = sprintf(page, "%d\n", opts->name);                     \
 785         mutex_unlock(&opts->lock);                                      \
 786                                                                         \
 787         return result;                                                  \
 788 }                                                                       \
 789                                                                         \
 790 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 791                                          const char *page, size_t len)  \
 792 {                                                                       \
 793         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 794         int ret;                                                        \
 795         u##prec num;                                                    \
 796                                                                         \
 797         mutex_lock(&opts->lock);                                        \
 798         if (opts->refcnt) {                                             \
 799                 ret = -EBUSY;                                           \
 800                 goto end;                                               \
 801         }                                                               \
 802                                                                         \
 803         ret = kstrtou##prec(page, 0, &num);                             \
 804         if (ret)                                                        \
 805                 goto end;                                               \
 806                                                                         \
 807         if (num > limit) {                                              \
 808                 ret = -EINVAL;                                          \
 809                 goto end;                                               \
 810         }                                                               \
 811         opts->name = num;                                               \
 812         ret = len;                                                      \
 813                                                                         \
 814 end:                                                                    \
 815         mutex_unlock(&opts->lock);                                      \
 816         return ret;                                                     \
 817 }                                                                       \
 818                                                                         \
 819 CONFIGFS_ATTR(f_hid_opts_, name)
 820
 821 F_HID_OPT(subclass, 8, 255);
 822 F_HID_OPT(protocol, 8, 255);
 823 F_HID_OPT(report_length, 16, 65535);
 824
 825 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 826 {
 827         struct f_hid_opts *opts = to_f_hid_opts(item);
 828         int result;
 829
 830         mutex_lock(&opts->lock);
 831         result = opts->report_desc_length;
 832         memcpy(page, opts->report_desc, opts->report_desc_length);
 833         mutex_unlock(&opts->lock);
 834
 835         return result;
 836 }
 837
 838 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 839                                             const char *page, size_t len)
 840 {
 841         struct f_hid_opts *opts = to_f_hid_opts(item);
 842         int ret = -EBUSY;
 843         char *d;
 844
 845         mutex_lock(&opts->lock);
 846
 847         if (opts->refcnt)
 848                 goto end;
 849         if (len > PAGE_SIZE) {
 850                 ret = -ENOSPC;
 851                 goto end;
 852         }
 853         d = kmemdup(page, len, GFP_KERNEL);
 854         if (!d) {
 855                 ret = -ENOMEM;
 856                 goto end;
 857         }
 858         kfree(opts->report_desc);
 859         opts->report_desc = d;
 860         opts->report_desc_length = len;
 861         opts->report_desc_alloc = true;
 862         ret = len;
 863 end:
 864         mutex_unlock(&opts->lock);
 865         return ret;
 866 }
 867
 868 CONFIGFS_ATTR(f_hid_opts_, report_desc);
 869
 870 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
 871 {
 872         struct f_hid_opts *opts = to_f_hid_opts(item);
 873
 874         return sprintf(page, "%d:%d\n", major, opts->minor);
 875 }
 876
 877 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
 878
 879 static struct configfs_attribute *hid_attrs[] = {
 880         &f_hid_opts_attr_subclass,
 881         &f_hid_opts_attr_protocol,
 882         &f_hid_opts_attr_report_length,
 883         &f_hid_opts_attr_report_desc,
 884         &f_hid_opts_attr_dev,
 885         NULL,
 886 };
 887
 888 static struct config_item_type hid_func_type = {
 889         .ct_item_ops    = &hidg_item_ops,
 890         .ct_attrs       = hid_attrs,
 891         .ct_owner       = THIS_MODULE,
 892 };
 893
 894 static inline void hidg_put_minor(int minor)
 895 {
 896         ida_simple_remove(&hidg_ida, minor);
 897 }
 898
 899 static void hidg_free_inst(struct usb_function_instance *f)
 900 {
 901         struct f_hid_opts *opts;
 902
 903         opts = container_of(f, struct f_hid_opts, func_inst);
 904
 905         mutex_lock(&hidg_ida_lock);
 906
 907         hidg_put_minor(opts->minor);
 908         if (ida_is_empty(&hidg_ida))
 909                 ghid_cleanup();
 910
 911         mutex_unlock(&hidg_ida_lock);
 912
 913         if (opts->report_desc_alloc)
 914                 kfree(opts->report_desc);
 915
 916         kfree(opts);
 917 }
 918
 919 static struct usb_function_instance *hidg_alloc_inst(void)
 920 {
 921         struct f_hid_opts *opts;
 922         struct usb_function_instance *ret;
 923         int status = 0;
 924
 925         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 926         if (!opts)
 927                 return ERR_PTR(-ENOMEM);
 928         mutex_init(&opts->lock);
 929         opts->func_inst.free_func_inst = hidg_free_inst;
 930         ret = &opts->func_inst;
 931
 932         mutex_lock(&hidg_ida_lock);
 933
 934         if (ida_is_empty(&hidg_ida)) {
 935                 status = ghid_setup(NULL, HIDG_MINORS);
 936                 if (status)  {
 937                         ret = ERR_PTR(status);
 938                         kfree(opts);
 939                         goto unlock;
 940                 }
 941         }
 942
 943         opts->minor = hidg_get_minor();
 944         if (opts->minor < 0) {
 945                 ret = ERR_PTR(opts->minor);
 946                 kfree(opts);
 947                 if (ida_is_empty(&hidg_ida))
 948                         ghid_cleanup();
 949                 goto unlock;
 950         }
 951         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
 952
 953 unlock:
 954         mutex_unlock(&hidg_ida_lock);
 955         return ret;
 956 }
 957
 958 static void hidg_free(struct usb_function *f)
 959 {
 960         struct f_hidg *hidg;
 961         struct f_hid_opts *opts;
 962
 963         hidg = func_to_hidg(f);
 964         opts = container_of(f->fi, struct f_hid_opts, func_inst);
 965         kfree(hidg->report_desc);
 966         kfree(hidg);
 967         mutex_lock(&opts->lock);
 968         --opts->refcnt;
 969         mutex_unlock(&opts->lock);
 970 }
 971
 972 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
 973 {
 974         struct f_hidg *hidg = func_to_hidg(f);
 975
 976         device_destroy(hidg_class, MKDEV(major, hidg->minor));
 977         cdev_del(&hidg->cdev);
 978
 979         /* disable/free request and end point */
 980         usb_ep_disable(hidg->in_ep);
 981         free_ep_req(hidg->in_ep, hidg->req);
 982
 983         usb_free_all_descriptors(f);
 984 }
 985
 986 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 987 {
 988         struct f_hidg *hidg;
 989         struct f_hid_opts *opts;
 990
 991         /* allocate and initialize one new instance */
 992         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
 993         if (!hidg)
 994                 return ERR_PTR(-ENOMEM);
 995
 996         opts = container_of(fi, struct f_hid_opts, func_inst);
 997
 998         mutex_lock(&opts->lock);
 999         ++opts->refcnt;
1000
1001         hidg->minor = opts->minor;
1002         hidg->bInterfaceSubClass = opts->subclass;
1003         hidg->bInterfaceProtocol = opts->protocol;
1004         hidg->report_length = opts->report_length;
1005         hidg->report_desc_length = opts->report_desc_length;
1006         if (opts->report_desc) {
1007                 hidg->report_desc = kmemdup(opts->report_desc,
1008                                             opts->report_desc_length,
1009                                             GFP_KERNEL);
1010                 if (!hidg->report_desc) {
1011                         kfree(hidg);
1012                         mutex_unlock(&opts->lock);
1013                         return ERR_PTR(-ENOMEM);
1014                 }
1015         }
1016
1017         mutex_unlock(&opts->lock);
1018
1019         hidg->func.name    = "hid";
1020         hidg->func.bind    = hidg_bind;
1021         hidg->func.unbind  = hidg_unbind;
1022         hidg->func.set_alt = hidg_set_alt;
1023         hidg->func.disable = hidg_disable;
1024         hidg->func.setup   = hidg_setup;
1025         hidg->func.free_func = hidg_free;
1026
1027         /* this could me made configurable at some point */
1028         hidg->qlen         = 4;
1029
1030         return &hidg->func;
1031 }
1032
1033 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1034 MODULE_LICENSE("GPL");
1035 MODULE_AUTHOR("Fabien Chouteau");
1036
1037 int ghid_setup(struct usb_gadget *g, int count)
1038 {
1039         int status;
1040         dev_t dev;
1041
1042         hidg_class = class_create(THIS_MODULE, "hidg");
1043         if (IS_ERR(hidg_class)) {
1044                 status = PTR_ERR(hidg_class);
1045                 hidg_class = NULL;
1046                 return status;
1047         }
1048
1049         status = alloc_chrdev_region(&dev, 0, count, "hidg");
1050         if (status) {
1051                 class_destroy(hidg_class);
1052                 hidg_class = NULL;
1053                 return status;
1054         }
1055
1056         major = MAJOR(dev);
1057         minors = count;
1058
1059         return 0;
1060 }
1061
1062 void ghid_cleanup(void)
1063 {
1064         if (major) {
1065                 unregister_chrdev_region(MKDEV(major, 0), minors);
1066                 major = minors = 0;
1067         }
1068
1069         class_destroy(hidg_class);
1070         hidg_class = NULL;
1071 }