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