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 char                   protocol;
  48         unsigned char                   idle;
  49         unsigned short                  report_desc_length;
  50         char                            *report_desc;
  51         unsigned short                  report_length;
  52
  53         /* recv report */
  54         struct list_head                completed_out_req;
  55         spinlock_t                      read_spinlock;
  56         wait_queue_head_t               read_queue;
  57         unsigned int                    qlen;
  58
  59         /* send report */
  60         spinlock_t                      write_spinlock;
  61         bool                            write_pending;
  62         wait_queue_head_t               write_queue;
  63         struct usb_request              *req;
  64
  65         int                             minor;
  66         struct cdev                     cdev;
  67         struct usb_function             func;
  68
  69         struct usb_ep                   *in_ep;
  70         struct usb_ep                   *out_ep;
  71 };
  72
  73 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  74 {
  75         return container_of(f, struct f_hidg, func);
  76 }
  77
  78 /*-------------------------------------------------------------------------*/
  79 /*                           Static descriptors                            */
  80
  81 static struct usb_interface_descriptor hidg_interface_desc = {
  82         .bLength                = sizeof hidg_interface_desc,
  83         .bDescriptorType        = USB_DT_INTERFACE,
  84         /* .bInterfaceNumber    = DYNAMIC */
  85         .bAlternateSetting      = 0,
  86         .bNumEndpoints          = 2,
  87         .bInterfaceClass        = USB_CLASS_HID,
  88         /* .bInterfaceSubClass  = DYNAMIC */
  89         /* .bInterfaceProtocol  = DYNAMIC */
  90         /* .iInterface          = DYNAMIC */
  91 };
  92
  93 static struct hid_descriptor hidg_desc = {
  94         .bLength                        = sizeof hidg_desc,
  95         .bDescriptorType                = HID_DT_HID,
  96         .bcdHID                         = cpu_to_le16(0x0101),
  97         .bCountryCode                   = 0x00,
  98         .bNumDescriptors                = 0x1,
  99         /*.desc[0].bDescriptorType      = DYNAMIC */
 100         /*.desc[0].wDescriptorLenght    = DYNAMIC */
 101 };
 102
 103 /* Super-Speed Support */
 104
 105 static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
 106         .bLength                = USB_DT_ENDPOINT_SIZE,
 107         .bDescriptorType        = USB_DT_ENDPOINT,
 108         .bEndpointAddress       = USB_DIR_IN,
 109         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 110         /*.wMaxPacketSize       = DYNAMIC */
 111         .bInterval              = 4, /* FIXME: Add this field in the
 112                                       * HID gadget configuration?
 113                                       * (struct hidg_func_descriptor)
 114                                       */
 115 };
 116
 117 static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
 118         .bLength                = sizeof(hidg_ss_in_comp_desc),
 119         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 120
 121         /* .bMaxBurst           = 0, */
 122         /* .bmAttributes        = 0, */
 123         /* .wBytesPerInterval   = DYNAMIC */
 124 };
 125
 126 static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
 127         .bLength                = USB_DT_ENDPOINT_SIZE,
 128         .bDescriptorType        = USB_DT_ENDPOINT,
 129         .bEndpointAddress       = USB_DIR_OUT,
 130         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 131         /*.wMaxPacketSize       = DYNAMIC */
 132         .bInterval              = 4, /* FIXME: Add this field in the
 133                                       * HID gadget configuration?
 134                                       * (struct hidg_func_descriptor)
 135                                       */
 136 };
 137
 138 static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
 139         .bLength                = sizeof(hidg_ss_out_comp_desc),
 140         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 141
 142         /* .bMaxBurst           = 0, */
 143         /* .bmAttributes        = 0, */
 144         /* .wBytesPerInterval   = DYNAMIC */
 145 };
 146
 147 static struct usb_descriptor_header *hidg_ss_descriptors[] = {
 148         (struct usb_descriptor_header *)&hidg_interface_desc,
 149         (struct usb_descriptor_header *)&hidg_desc,
 150         (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
 151         (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
 152         (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
 153         (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
 154         NULL,
 155 };
 156
 157 /* High-Speed Support */
 158
 159 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 160         .bLength                = USB_DT_ENDPOINT_SIZE,
 161         .bDescriptorType        = USB_DT_ENDPOINT,
 162         .bEndpointAddress       = USB_DIR_IN,
 163         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 164         /*.wMaxPacketSize       = DYNAMIC */
 165         .bInterval              = 4, /* FIXME: Add this field in the
 166                                       * HID gadget configuration?
 167                                       * (struct hidg_func_descriptor)
 168                                       */
 169 };
 170
 171 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 172         .bLength                = USB_DT_ENDPOINT_SIZE,
 173         .bDescriptorType        = USB_DT_ENDPOINT,
 174         .bEndpointAddress       = USB_DIR_OUT,
 175         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 176         /*.wMaxPacketSize       = DYNAMIC */
 177         .bInterval              = 4, /* FIXME: Add this field in the
 178                                       * HID gadget configuration?
 179                                       * (struct hidg_func_descriptor)
 180                                       */
 181 };
 182
 183 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 184         (struct usb_descriptor_header *)&hidg_interface_desc,
 185         (struct usb_descriptor_header *)&hidg_desc,
 186         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 187         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 188         NULL,
 189 };
 190
 191 /* Full-Speed Support */
 192
 193 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 194         .bLength                = USB_DT_ENDPOINT_SIZE,
 195         .bDescriptorType        = USB_DT_ENDPOINT,
 196         .bEndpointAddress       = USB_DIR_IN,
 197         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 198         /*.wMaxPacketSize       = DYNAMIC */
 199         .bInterval              = 10, /* FIXME: Add this field in the
 200                                        * HID gadget configuration?
 201                                        * (struct hidg_func_descriptor)
 202                                        */
 203 };
 204
 205 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 206         .bLength                = USB_DT_ENDPOINT_SIZE,
 207         .bDescriptorType        = USB_DT_ENDPOINT,
 208         .bEndpointAddress       = USB_DIR_OUT,
 209         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 210         /*.wMaxPacketSize       = DYNAMIC */
 211         .bInterval              = 10, /* FIXME: Add this field in the
 212                                        * HID gadget configuration?
 213                                        * (struct hidg_func_descriptor)
 214                                        */
 215 };
 216
 217 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 218         (struct usb_descriptor_header *)&hidg_interface_desc,
 219         (struct usb_descriptor_header *)&hidg_desc,
 220         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 221         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 222         NULL,
 223 };
 224
 225 /*-------------------------------------------------------------------------*/
 226 /*                                 Strings                                 */
 227
 228 #define CT_FUNC_HID_IDX 0
 229
 230 static struct usb_string ct_func_string_defs[] = {
 231         [CT_FUNC_HID_IDX].s     = "HID Interface",
 232         {},                     /* end of list */
 233 };
 234
 235 static struct usb_gadget_strings ct_func_string_table = {
 236         .language       = 0x0409,       /* en-US */
 237         .strings        = ct_func_string_defs,
 238 };
 239
 240 static struct usb_gadget_strings *ct_func_strings[] = {
 241         &ct_func_string_table,
 242         NULL,
 243 };
 244
 245 /*-------------------------------------------------------------------------*/
 246 /*                              Char Device                                */
 247
 248 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 249                         size_t count, loff_t *ptr)
 250 {
 251         struct f_hidg *hidg = file->private_data;
 252         struct f_hidg_req_list *list;
 253         struct usb_request *req;
 254         unsigned long flags;
 255         int ret;
 256
 257         if (!count)
 258                 return 0;
 259
 260         if (!access_ok(VERIFY_WRITE, buffer, count))
 261                 return -EFAULT;
 262
 263         spin_lock_irqsave(&hidg->read_spinlock, flags);
 264
 265 #define READ_COND (!list_empty(&hidg->completed_out_req))
 266
 267         /* wait for at least one buffer to complete */
 268         while (!READ_COND) {
 269                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 270                 if (file->f_flags & O_NONBLOCK)
 271                         return -EAGAIN;
 272
 273                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 274                         return -ERESTARTSYS;
 275
 276                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 277         }
 278
 279         /* pick the first one */
 280         list = list_first_entry(&hidg->completed_out_req,
 281                                 struct f_hidg_req_list, list);
 282
 283         /*
 284          * Remove this from list to protect it from beign free()
 285          * while host disables our function
 286          */
 287         list_del(&list->list);
 288
 289         req = list->req;
 290         count = min_t(unsigned int, count, req->actual - list->pos);
 291         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 292
 293         /* copy to user outside spinlock */
 294         count -= copy_to_user(buffer, req->buf + list->pos, count);
 295         list->pos += count;
 296
 297         /*
 298          * if this request is completely handled and transfered to
 299          * userspace, remove its entry from the list and requeue it
 300          * again. Otherwise, we will revisit it again upon the next
 301          * call, taking into account its current read position.
 302          */
 303         if (list->pos == req->actual) {
 304                 kfree(list);
 305
 306                 req->length = hidg->report_length;
 307                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 308                 if (ret < 0) {
 309                         free_ep_req(hidg->out_ep, req);
 310                         return ret;
 311                 }
 312         } else {
 313                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 314                 list_add(&list->list, &hidg->completed_out_req);
 315                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 316
 317                 wake_up(&hidg->read_queue);
 318         }
 319
 320         return count;
 321 }
 322
 323 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 324 {
 325         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 326         unsigned long flags;
 327
 328         if (req->status != 0) {
 329                 ERROR(hidg->func.config->cdev,
 330                         "End Point Request ERROR: %d\n", req->status);
 331         }
 332
 333         spin_lock_irqsave(&hidg->write_spinlock, flags);
 334         hidg->write_pending = 0;
 335         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 336         wake_up(&hidg->write_queue);
 337 }
 338
 339 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 340                             size_t count, loff_t *offp)
 341 {
 342         struct f_hidg *hidg  = file->private_data;
 343         struct usb_request *req;
 344         unsigned long flags;
 345         ssize_t status = -ENOMEM;
 346
 347         if (!access_ok(VERIFY_READ, buffer, count))
 348                 return -EFAULT;
 349
 350         spin_lock_irqsave(&hidg->write_spinlock, flags);
 351
 352         if (!hidg->req) {
 353                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 354                 return -ESHUTDOWN;
 355         }
 356
 357 #define WRITE_COND (!hidg->write_pending)
 358 try_again:
 359         /* write queue */
 360         while (!WRITE_COND) {
 361                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 362                 if (file->f_flags & O_NONBLOCK)
 363                         return -EAGAIN;
 364
 365                 if (wait_event_interruptible_exclusive(
 366                                 hidg->write_queue, WRITE_COND))
 367                         return -ERESTARTSYS;
 368
 369                 spin_lock_irqsave(&hidg->write_spinlock, flags);
 370         }
 371
 372         hidg->write_pending = 1;
 373         req = hidg->req;
 374         count  = min_t(unsigned, count, hidg->report_length);
 375
 376         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 377
 378         if (!req) {
 379                 ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
 380                 status = -ESHUTDOWN;
 381                 goto release_write_pending;
 382         }
 383
 384         status = copy_from_user(req->buf, buffer, count);
 385         if (status != 0) {
 386                 ERROR(hidg->func.config->cdev,
 387                         "copy_from_user error\n");
 388                 status = -EINVAL;
 389                 goto release_write_pending;
 390         }
 391
 392         spin_lock_irqsave(&hidg->write_spinlock, flags);
 393
 394         /* when our function has been disabled by host */
 395         if (!hidg->req) {
 396                 free_ep_req(hidg->in_ep, req);
 397                 /*
 398                  * TODO
 399                  * Should we fail with error here?
 400                  */
 401                 goto try_again;
 402         }
 403
 404         req->status   = 0;
 405         req->zero     = 0;
 406         req->length   = count;
 407         req->complete = f_hidg_req_complete;
 408         req->context  = hidg;
 409
 410         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 411
 412         if (!hidg->in_ep->enabled) {
 413                 ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
 414                 status = -ESHUTDOWN;
 415                 goto release_write_pending;
 416         }
 417
 418         status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
 419         if (status < 0)
 420                 goto release_write_pending;
 421         else
 422                 status = count;
 423
 424         return status;
 425 release_write_pending:
 426         spin_lock_irqsave(&hidg->write_spinlock, flags);
 427         hidg->write_pending = 0;
 428         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 429
 430         wake_up(&hidg->write_queue);
 431
 432         return status;
 433 }
 434
 435 static unsigned int f_hidg_poll(struct file *file, poll_table *wait)
 436 {
 437         struct f_hidg   *hidg  = file->private_data;
 438         unsigned int    ret = 0;
 439
 440         poll_wait(file, &hidg->read_queue, wait);
 441         poll_wait(file, &hidg->write_queue, wait);
 442
 443         if (WRITE_COND)
 444                 ret |= POLLOUT | POLLWRNORM;
 445
 446         if (READ_COND)
 447                 ret |= POLLIN | POLLRDNORM;
 448
 449         return ret;
 450 }
 451
 452 #undef WRITE_COND
 453 #undef READ_COND
 454
 455 static int f_hidg_release(struct inode *inode, struct file *fd)
 456 {
 457         fd->private_data = NULL;
 458         return 0;
 459 }
 460
 461 static int f_hidg_open(struct inode *inode, struct file *fd)
 462 {
 463         struct f_hidg *hidg =
 464                 container_of(inode->i_cdev, struct f_hidg, cdev);
 465
 466         fd->private_data = hidg;
 467
 468         return 0;
 469 }
 470
 471 /*-------------------------------------------------------------------------*/
 472 /*                                usb_function                             */
 473
 474 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 475                                                     unsigned length)
 476 {
 477         return alloc_ep_req(ep, length);
 478 }
 479
 480 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 481 {
 482         struct f_hidg *hidg = (struct f_hidg *) req->context;
 483         struct usb_composite_dev *cdev = hidg->func.config->cdev;
 484         struct f_hidg_req_list *req_list;
 485         unsigned long flags;
 486
 487         switch (req->status) {
 488         case 0:
 489                 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 490                 if (!req_list) {
 491                         ERROR(cdev, "Unable to allocate mem for req_list\n");
 492                         goto free_req;
 493                 }
 494
 495                 req_list->req = req;
 496
 497                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 498                 list_add_tail(&req_list->list, &hidg->completed_out_req);
 499                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 500
 501                 wake_up(&hidg->read_queue);
 502                 break;
 503         default:
 504                 ERROR(cdev, "Set report failed %d\n", req->status);
 505                 /* FALLTHROUGH */
 506         case -ECONNABORTED:             /* hardware forced ep reset */
 507         case -ECONNRESET:               /* request dequeued */
 508         case -ESHUTDOWN:                /* disconnect from host */
 509 free_req:
 510                 free_ep_req(ep, req);
 511                 return;
 512         }
 513 }
 514
 515 static int hidg_setup(struct usb_function *f,
 516                 const struct usb_ctrlrequest *ctrl)
 517 {
 518         struct f_hidg                   *hidg = func_to_hidg(f);
 519         struct usb_composite_dev        *cdev = f->config->cdev;
 520         struct usb_request              *req  = cdev->req;
 521         int status = 0;
 522         __u16 value, length;
 523
 524         value   = __le16_to_cpu(ctrl->wValue);
 525         length  = __le16_to_cpu(ctrl->wLength);
 526
 527         VDBG(cdev,
 528              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 529              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 530
 531         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 532         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 533                   | HID_REQ_GET_REPORT):
 534                 VDBG(cdev, "get_report\n");
 535
 536                 /* send an empty report */
 537                 length = min_t(unsigned, length, hidg->report_length);
 538                 memset(req->buf, 0x0, length);
 539
 540                 goto respond;
 541                 break;
 542
 543         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 544                   | HID_REQ_GET_PROTOCOL):
 545                 VDBG(cdev, "get_protocol\n");
 546                 length = min_t(unsigned int, length, 1);
 547                 ((u8 *) req->buf)[0] = hidg->protocol;
 548                 goto respond;
 549                 break;
 550
 551         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 552                   | HID_REQ_GET_IDLE):
 553                 VDBG(cdev, "get_idle\n");
 554                 length = min_t(unsigned int, length, 1);
 555                 ((u8 *) req->buf)[0] = hidg->idle;
 556                 goto respond;
 557                 break;
 558
 559         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 560                   | HID_REQ_SET_REPORT):
 561                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 562                 goto stall;
 563                 break;
 564
 565         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 566                   | HID_REQ_SET_PROTOCOL):
 567                 VDBG(cdev, "set_protocol\n");
 568                 if (value > HID_REPORT_PROTOCOL)
 569                         goto stall;
 570                 length = 0;
 571                 /*
 572                  * We assume that programs implementing the Boot protocol
 573                  * are also compatible with the Report Protocol
 574                  */
 575                 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
 576                         hidg->protocol = value;
 577                         goto respond;
 578                 }
 579                 goto stall;
 580                 break;
 581
 582         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 583                   | HID_REQ_SET_IDLE):
 584                 VDBG(cdev, "set_idle\n");
 585                 length = 0;
 586                 hidg->idle = value >> 8;
 587                 goto respond;
 588                 break;
 589
 590         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 591                   | USB_REQ_GET_DESCRIPTOR):
 592                 switch (value >> 8) {
 593                 case HID_DT_HID:
 594                 {
 595                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 596
 597                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 598                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 599                         hidg_desc_copy.desc[0].wDescriptorLength =
 600                                 cpu_to_le16(hidg->report_desc_length);
 601
 602                         length = min_t(unsigned short, length,
 603                                                    hidg_desc_copy.bLength);
 604                         memcpy(req->buf, &hidg_desc_copy, length);
 605                         goto respond;
 606                         break;
 607                 }
 608                 case HID_DT_REPORT:
 609                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 610                         length = min_t(unsigned short, length,
 611                                                    hidg->report_desc_length);
 612                         memcpy(req->buf, hidg->report_desc, length);
 613                         goto respond;
 614                         break;
 615
 616                 default:
 617                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 618                                  value >> 8);
 619                         goto stall;
 620                         break;
 621                 }
 622                 break;
 623
 624         default:
 625                 VDBG(cdev, "Unknown request 0x%x\n",
 626                          ctrl->bRequest);
 627                 goto stall;
 628                 break;
 629         }
 630
 631 stall:
 632         return -EOPNOTSUPP;
 633
 634 respond:
 635         req->zero = 0;
 636         req->length = length;
 637         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 638         if (status < 0)
 639                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 640         return status;
 641 }
 642
 643 static void hidg_disable(struct usb_function *f)
 644 {
 645         struct f_hidg *hidg = func_to_hidg(f);
 646         struct f_hidg_req_list *list, *next;
 647         unsigned long flags;
 648
 649         usb_ep_disable(hidg->in_ep);
 650         usb_ep_disable(hidg->out_ep);
 651
 652         spin_lock_irqsave(&hidg->read_spinlock, flags);
 653         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 654                 free_ep_req(hidg->out_ep, list->req);
 655                 list_del(&list->list);
 656                 kfree(list);
 657         }
 658         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 659
 660         spin_lock_irqsave(&hidg->write_spinlock, flags);
 661         if (!hidg->write_pending) {
 662                 free_ep_req(hidg->in_ep, hidg->req);
 663                 hidg->write_pending = 1;
 664         }
 665
 666         hidg->req = NULL;
 667         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 668 }
 669
 670 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 671 {
 672         struct usb_composite_dev                *cdev = f->config->cdev;
 673         struct f_hidg                           *hidg = func_to_hidg(f);
 674         struct usb_request                      *req_in = NULL;
 675         unsigned long                           flags;
 676         int i, status = 0;
 677
 678         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 679
 680         if (hidg->in_ep != NULL) {
 681                 /* restart endpoint */
 682                 usb_ep_disable(hidg->in_ep);
 683
 684                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 685                                             hidg->in_ep);
 686                 if (status) {
 687                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 688                         goto fail;
 689                 }
 690                 status = usb_ep_enable(hidg->in_ep);
 691                 if (status < 0) {
 692                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 693                         goto fail;
 694                 }
 695                 hidg->in_ep->driver_data = hidg;
 696
 697                 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
 698                 if (!req_in) {
 699                         status = -ENOMEM;
 700                         goto disable_ep_in;
 701                 }
 702         }
 703
 704
 705         if (hidg->out_ep != NULL) {
 706                 /* restart endpoint */
 707                 usb_ep_disable(hidg->out_ep);
 708
 709                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 710                                             hidg->out_ep);
 711                 if (status) {
 712                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 713                         goto free_req_in;
 714                 }
 715                 status = usb_ep_enable(hidg->out_ep);
 716                 if (status < 0) {
 717                         ERROR(cdev, "Enable OUT endpoint FAILED!\n");
 718                         goto free_req_in;
 719                 }
 720                 hidg->out_ep->driver_data = hidg;
 721
 722                 /*
 723                  * allocate a bunch of read buffers and queue them all at once.
 724                  */
 725                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 726                         struct usb_request *req =
 727                                         hidg_alloc_ep_req(hidg->out_ep,
 728                                                           hidg->report_length);
 729                         if (req) {
 730                                 req->complete = hidg_set_report_complete;
 731                                 req->context  = hidg;
 732                                 status = usb_ep_queue(hidg->out_ep, req,
 733                                                       GFP_ATOMIC);
 734                                 if (status) {
 735                                         ERROR(cdev, "%s queue req --> %d\n",
 736                                                 hidg->out_ep->name, status);
 737                                         free_ep_req(hidg->out_ep, req);
 738                                 }
 739                         } else {
 740                                 status = -ENOMEM;
 741                                 goto disable_out_ep;
 742                         }
 743                 }
 744         }
 745
 746         if (hidg->in_ep != NULL) {
 747                 spin_lock_irqsave(&hidg->write_spinlock, flags);
 748                 hidg->req = req_in;
 749                 hidg->write_pending = 0;
 750                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 751
 752                 wake_up(&hidg->write_queue);
 753         }
 754         return 0;
 755 disable_out_ep:
 756         usb_ep_disable(hidg->out_ep);
 757 free_req_in:
 758         if (req_in)
 759                 free_ep_req(hidg->in_ep, req_in);
 760
 761 disable_ep_in:
 762         if (hidg->in_ep)
 763                 usb_ep_disable(hidg->in_ep);
 764
 765 fail:
 766         return status;
 767 }
 768
 769 static const struct file_operations f_hidg_fops = {
 770         .owner          = THIS_MODULE,
 771         .open           = f_hidg_open,
 772         .release        = f_hidg_release,
 773         .write          = f_hidg_write,
 774         .read           = f_hidg_read,
 775         .poll           = f_hidg_poll,
 776         .llseek         = noop_llseek,
 777 };
 778
 779 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 780 {
 781         struct usb_ep           *ep;
 782         struct f_hidg           *hidg = func_to_hidg(f);
 783         struct usb_string       *us;
 784         struct device           *device;
 785         int                     status;
 786         dev_t                   dev;
 787
 788         /* maybe allocate device-global string IDs, and patch descriptors */
 789         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 790                                  ARRAY_SIZE(ct_func_string_defs));
 791         if (IS_ERR(us))
 792                 return PTR_ERR(us);
 793         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 794
 795         /* allocate instance-specific interface IDs, and patch descriptors */
 796         status = usb_interface_id(c, f);
 797         if (status < 0)
 798                 goto fail;
 799         hidg_interface_desc.bInterfaceNumber = status;
 800
 801         /* allocate instance-specific endpoints */
 802         status = -ENODEV;
 803         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 804         if (!ep)
 805                 goto fail;
 806         hidg->in_ep = ep;
 807
 808         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 809         if (!ep)
 810                 goto fail;
 811         hidg->out_ep = ep;
 812
 813         /* set descriptor dynamic values */
 814         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 815         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 816         hidg->protocol = HID_REPORT_PROTOCOL;
 817         hidg->idle = 1;
 818         hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 819         hidg_ss_in_comp_desc.wBytesPerInterval =
 820                                 cpu_to_le16(hidg->report_length);
 821         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 822         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 823         hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 824         hidg_ss_out_comp_desc.wBytesPerInterval =
 825                                 cpu_to_le16(hidg->report_length);
 826         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 827         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 828         /*
 829          * We can use hidg_desc struct here but we should not relay
 830          * that its content won't change after returning from this function.
 831          */
 832         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 833         hidg_desc.desc[0].wDescriptorLength =
 834                 cpu_to_le16(hidg->report_desc_length);
 835
 836         hidg_hs_in_ep_desc.bEndpointAddress =
 837                 hidg_fs_in_ep_desc.bEndpointAddress;
 838         hidg_hs_out_ep_desc.bEndpointAddress =
 839                 hidg_fs_out_ep_desc.bEndpointAddress;
 840
 841         hidg_ss_in_ep_desc.bEndpointAddress =
 842                 hidg_fs_in_ep_desc.bEndpointAddress;
 843         hidg_ss_out_ep_desc.bEndpointAddress =
 844                 hidg_fs_out_ep_desc.bEndpointAddress;
 845
 846         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 847                         hidg_hs_descriptors, hidg_ss_descriptors,
 848                         hidg_ss_descriptors);
 849         if (status)
 850                 goto fail;
 851
 852         spin_lock_init(&hidg->write_spinlock);
 853         hidg->write_pending = 1;
 854         hidg->req = NULL;
 855         spin_lock_init(&hidg->read_spinlock);
 856         init_waitqueue_head(&hidg->write_queue);
 857         init_waitqueue_head(&hidg->read_queue);
 858         INIT_LIST_HEAD(&hidg->completed_out_req);
 859
 860         /* create char device */
 861         cdev_init(&hidg->cdev, &f_hidg_fops);
 862         dev = MKDEV(major, hidg->minor);
 863         status = cdev_add(&hidg->cdev, dev, 1);
 864         if (status)
 865                 goto fail_free_descs;
 866
 867         device = device_create(hidg_class, NULL, dev, NULL,
 868                                "%s%d", "hidg", hidg->minor);
 869         if (IS_ERR(device)) {
 870                 status = PTR_ERR(device);
 871                 goto del;
 872         }
 873
 874         return 0;
 875 del:
 876         cdev_del(&hidg->cdev);
 877 fail_free_descs:
 878         usb_free_all_descriptors(f);
 879 fail:
 880         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 881         if (hidg->req != NULL)
 882                 free_ep_req(hidg->in_ep, hidg->req);
 883
 884         return status;
 885 }
 886
 887 static inline int hidg_get_minor(void)
 888 {
 889         int ret;
 890
 891         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 892         if (ret >= HIDG_MINORS) {
 893                 ida_simple_remove(&hidg_ida, ret);
 894                 ret = -ENODEV;
 895         }
 896
 897         return ret;
 898 }
 899
 900 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 901 {
 902         return container_of(to_config_group(item), struct f_hid_opts,
 903                             func_inst.group);
 904 }
 905
 906 static void hid_attr_release(struct config_item *item)
 907 {
 908         struct f_hid_opts *opts = to_f_hid_opts(item);
 909
 910         usb_put_function_instance(&opts->func_inst);
 911 }
 912
 913 static struct configfs_item_operations hidg_item_ops = {
 914         .release        = hid_attr_release,
 915 };
 916
 917 #define F_HID_OPT(name, prec, limit)                                    \
 918 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 919 {                                                                       \
 920         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 921         int result;                                                     \
 922                                                                         \
 923         mutex_lock(&opts->lock);                                        \
 924         result = sprintf(page, "%d\n", opts->name);                     \
 925         mutex_unlock(&opts->lock);                                      \
 926                                                                         \
 927         return result;                                                  \
 928 }                                                                       \
 929                                                                         \
 930 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 931                                          const char *page, size_t len)  \
 932 {                                                                       \
 933         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 934         int ret;                                                        \
 935         u##prec num;                                                    \
 936                                                                         \
 937         mutex_lock(&opts->lock);                                        \
 938         if (opts->refcnt) {                                             \
 939                 ret = -EBUSY;                                           \
 940                 goto end;                                               \
 941         }                                                               \
 942                                                                         \
 943         ret = kstrtou##prec(page, 0, &num);                             \
 944         if (ret)                                                        \
 945                 goto end;                                               \
 946                                                                         \
 947         if (num > limit) {                                              \
 948                 ret = -EINVAL;                                          \
 949                 goto end;                                               \
 950         }                                                               \
 951         opts->name = num;                                               \
 952         ret = len;                                                      \
 953                                                                         \
 954 end:                                                                    \
 955         mutex_unlock(&opts->lock);                                      \
 956         return ret;                                                     \
 957 }                                                                       \
 958                                                                         \
 959 CONFIGFS_ATTR(f_hid_opts_, name)
 960
 961 F_HID_OPT(subclass, 8, 255);
 962 F_HID_OPT(protocol, 8, 255);
 963 F_HID_OPT(report_length, 16, 65535);
 964
 965 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 966 {
 967         struct f_hid_opts *opts = to_f_hid_opts(item);
 968         int result;
 969
 970         mutex_lock(&opts->lock);
 971         result = opts->report_desc_length;
 972         memcpy(page, opts->report_desc, opts->report_desc_length);
 973         mutex_unlock(&opts->lock);
 974
 975         return result;
 976 }
 977
 978 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 979                                             const char *page, size_t len)
 980 {
 981         struct f_hid_opts *opts = to_f_hid_opts(item);
 982         int ret = -EBUSY;
 983         char *d;
 984
 985         mutex_lock(&opts->lock);
 986
 987         if (opts->refcnt)
 988                 goto end;
 989         if (len > PAGE_SIZE) {
 990                 ret = -ENOSPC;
 991                 goto end;
 992         }
 993         d = kmemdup(page, len, GFP_KERNEL);
 994         if (!d) {
 995                 ret = -ENOMEM;
 996                 goto end;
 997         }
 998         kfree(opts->report_desc);
 999         opts->report_desc = d;
1000         opts->report_desc_length = len;
1001         opts->report_desc_alloc = true;
1002         ret = len;
1003 end:
1004         mutex_unlock(&opts->lock);
1005         return ret;
1006 }
1007
1008 CONFIGFS_ATTR(f_hid_opts_, report_desc);
1009
1010 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1011 {
1012         struct f_hid_opts *opts = to_f_hid_opts(item);
1013
1014         return sprintf(page, "%d:%d\n", major, opts->minor);
1015 }
1016
1017 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1018
1019 static struct configfs_attribute *hid_attrs[] = {
1020         &f_hid_opts_attr_subclass,
1021         &f_hid_opts_attr_protocol,
1022         &f_hid_opts_attr_report_length,
1023         &f_hid_opts_attr_report_desc,
1024         &f_hid_opts_attr_dev,
1025         NULL,
1026 };
1027
1028 static struct config_item_type hid_func_type = {
1029         .ct_item_ops    = &hidg_item_ops,
1030         .ct_attrs       = hid_attrs,
1031         .ct_owner       = THIS_MODULE,
1032 };
1033
1034 static inline void hidg_put_minor(int minor)
1035 {
1036         ida_simple_remove(&hidg_ida, minor);
1037 }
1038
1039 static void hidg_free_inst(struct usb_function_instance *f)
1040 {
1041         struct f_hid_opts *opts;
1042
1043         opts = container_of(f, struct f_hid_opts, func_inst);
1044
1045         mutex_lock(&hidg_ida_lock);
1046
1047         hidg_put_minor(opts->minor);
1048         if (ida_is_empty(&hidg_ida))
1049                 ghid_cleanup();
1050
1051         mutex_unlock(&hidg_ida_lock);
1052
1053         if (opts->report_desc_alloc)
1054                 kfree(opts->report_desc);
1055
1056         kfree(opts);
1057 }
1058
1059 static struct usb_function_instance *hidg_alloc_inst(void)
1060 {
1061         struct f_hid_opts *opts;
1062         struct usb_function_instance *ret;
1063         int status = 0;
1064
1065         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1066         if (!opts)
1067                 return ERR_PTR(-ENOMEM);
1068         mutex_init(&opts->lock);
1069         opts->func_inst.free_func_inst = hidg_free_inst;
1070         ret = &opts->func_inst;
1071
1072         mutex_lock(&hidg_ida_lock);
1073
1074         if (ida_is_empty(&hidg_ida)) {
1075                 status = ghid_setup(NULL, HIDG_MINORS);
1076                 if (status)  {
1077                         ret = ERR_PTR(status);
1078                         kfree(opts);
1079                         goto unlock;
1080                 }
1081         }
1082
1083         opts->minor = hidg_get_minor();
1084         if (opts->minor < 0) {
1085                 ret = ERR_PTR(opts->minor);
1086                 kfree(opts);
1087                 if (ida_is_empty(&hidg_ida))
1088                         ghid_cleanup();
1089                 goto unlock;
1090         }
1091         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1092
1093 unlock:
1094         mutex_unlock(&hidg_ida_lock);
1095         return ret;
1096 }
1097
1098 static void hidg_free(struct usb_function *f)
1099 {
1100         struct f_hidg *hidg;
1101         struct f_hid_opts *opts;
1102
1103         hidg = func_to_hidg(f);
1104         opts = container_of(f->fi, struct f_hid_opts, func_inst);
1105         kfree(hidg->report_desc);
1106         kfree(hidg);
1107         mutex_lock(&opts->lock);
1108         --opts->refcnt;
1109         mutex_unlock(&opts->lock);
1110 }
1111
1112 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1113 {
1114         struct f_hidg *hidg = func_to_hidg(f);
1115
1116         device_destroy(hidg_class, MKDEV(major, hidg->minor));
1117         cdev_del(&hidg->cdev);
1118
1119         usb_free_all_descriptors(f);
1120 }
1121
1122 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1123 {
1124         struct f_hidg *hidg;
1125         struct f_hid_opts *opts;
1126
1127         /* allocate and initialize one new instance */
1128         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1129         if (!hidg)
1130                 return ERR_PTR(-ENOMEM);
1131
1132         opts = container_of(fi, struct f_hid_opts, func_inst);
1133
1134         mutex_lock(&opts->lock);
1135         ++opts->refcnt;
1136
1137         hidg->minor = opts->minor;
1138         hidg->bInterfaceSubClass = opts->subclass;
1139         hidg->bInterfaceProtocol = opts->protocol;
1140         hidg->report_length = opts->report_length;
1141         hidg->report_desc_length = opts->report_desc_length;
1142         if (opts->report_desc) {
1143                 hidg->report_desc = kmemdup(opts->report_desc,
1144                                             opts->report_desc_length,
1145                                             GFP_KERNEL);
1146                 if (!hidg->report_desc) {
1147                         kfree(hidg);
1148                         mutex_unlock(&opts->lock);
1149                         return ERR_PTR(-ENOMEM);
1150                 }
1151         }
1152
1153         mutex_unlock(&opts->lock);
1154
1155         hidg->func.name    = "hid";
1156         hidg->func.bind    = hidg_bind;
1157         hidg->func.unbind  = hidg_unbind;
1158         hidg->func.set_alt = hidg_set_alt;
1159         hidg->func.disable = hidg_disable;
1160         hidg->func.setup   = hidg_setup;
1161         hidg->func.free_func = hidg_free;
1162
1163         /* this could me made configurable at some point */
1164         hidg->qlen         = 4;
1165
1166         return &hidg->func;
1167 }
1168
1169 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1170 MODULE_LICENSE("GPL");
1171 MODULE_AUTHOR("Fabien Chouteau");
1172
1173 int ghid_setup(struct usb_gadget *g, int count)
1174 {
1175         int status;
1176         dev_t dev;
1177
1178         hidg_class = class_create(THIS_MODULE, "hidg");
1179         if (IS_ERR(hidg_class)) {
1180                 status = PTR_ERR(hidg_class);
1181                 hidg_class = NULL;
1182                 return status;
1183         }
1184
1185         status = alloc_chrdev_region(&dev, 0, count, "hidg");
1186         if (status) {
1187                 class_destroy(hidg_class);
1188                 hidg_class = NULL;
1189                 return status;
1190         }
1191
1192         major = MAJOR(dev);
1193         minors = count;
1194
1195         return 0;
1196 }
1197
1198 void ghid_cleanup(void)
1199 {
1200         if (major) {
1201                 unregister_chrdev_region(MKDEV(major, 0), minors);
1202                 major = minors = 0;
1203         }
1204
1205         class_destroy(hidg_class);
1206         hidg_class = NULL;
1207 }