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