drivers/usb/gadget/function/f_hid.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * f_hid.c -- USB HID function driver
   4  *
   5  * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/hid.h>
  11 #include <linux/idr.h>
  12 #include <linux/cdev.h>
  13 #include <linux/mutex.h>
  14 #include <linux/poll.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/wait.h>
  17 #include <linux/sched.h>
  18 #include <linux/usb/g_hid.h>
  19
  20 #include "u_f.h"
  21 #include "u_hid.h"
  22
  23 #define HIDG_MINORS     4
  24
  25 static int major, minors;
  26 static struct class *hidg_class;
  27 static DEFINE_IDA(hidg_ida);
  28 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
  29
  30 /*-------------------------------------------------------------------------*/
  31 /*                            HID gadget struct                            */
  32
  33 struct f_hidg_req_list {
  34         struct usb_request      *req;
  35         unsigned int            pos;
  36         struct list_head        list;
  37 };
  38
  39 struct f_hidg {
  40         /* configuration */
  41         unsigned char                   bInterfaceSubClass;
  42         unsigned char                   bInterfaceProtocol;
  43         unsigned char                   protocol;
  44         unsigned char                   idle;
  45         unsigned short                  report_desc_length;
  46         char                            *report_desc;
  47         unsigned short                  report_length;
  48
  49         /* recv report */
  50         struct list_head                completed_out_req;
  51         spinlock_t                      read_spinlock;
  52         wait_queue_head_t               read_queue;
  53         unsigned int                    qlen;
  54
  55         /* send report */
  56         spinlock_t                      write_spinlock;
  57         bool                            write_pending;
  58         wait_queue_head_t               write_queue;
  59         struct usb_request              *req;
  60
  61         int                             minor;
  62         struct cdev                     cdev;
  63         struct usb_function             func;
  64
  65         struct usb_ep                   *in_ep;
  66         struct usb_ep                   *out_ep;
  67 };
  68
  69 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
  70 {
  71         return container_of(f, struct f_hidg, func);
  72 }
  73
  74 /*-------------------------------------------------------------------------*/
  75 /*                           Static descriptors                            */
  76
  77 static struct usb_interface_descriptor hidg_interface_desc = {
  78         .bLength                = sizeof hidg_interface_desc,
  79         .bDescriptorType        = USB_DT_INTERFACE,
  80         /* .bInterfaceNumber    = DYNAMIC */
  81         .bAlternateSetting      = 0,
  82         .bNumEndpoints          = 2,
  83         .bInterfaceClass        = USB_CLASS_HID,
  84         /* .bInterfaceSubClass  = DYNAMIC */
  85         /* .bInterfaceProtocol  = DYNAMIC */
  86         /* .iInterface          = DYNAMIC */
  87 };
  88
  89 static struct hid_descriptor hidg_desc = {
  90         .bLength                        = sizeof hidg_desc,
  91         .bDescriptorType                = HID_DT_HID,
  92         .bcdHID                         = cpu_to_le16(0x0101),
  93         .bCountryCode                   = 0x00,
  94         .bNumDescriptors                = 0x1,
  95         /*.desc[0].bDescriptorType      = DYNAMIC */
  96         /*.desc[0].wDescriptorLenght    = DYNAMIC */
  97 };
  98
  99 /* Super-Speed Support */
 100
 101 static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
 102         .bLength                = USB_DT_ENDPOINT_SIZE,
 103         .bDescriptorType        = USB_DT_ENDPOINT,
 104         .bEndpointAddress       = USB_DIR_IN,
 105         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 106         /*.wMaxPacketSize       = DYNAMIC */
 107         .bInterval              = 4, /* FIXME: Add this field in the
 108                                       * HID gadget configuration?
 109                                       * (struct hidg_func_descriptor)
 110                                       */
 111 };
 112
 113 static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
 114         .bLength                = sizeof(hidg_ss_in_comp_desc),
 115         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 116
 117         /* .bMaxBurst           = 0, */
 118         /* .bmAttributes        = 0, */
 119         /* .wBytesPerInterval   = DYNAMIC */
 120 };
 121
 122 static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
 123         .bLength                = USB_DT_ENDPOINT_SIZE,
 124         .bDescriptorType        = USB_DT_ENDPOINT,
 125         .bEndpointAddress       = USB_DIR_OUT,
 126         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 127         /*.wMaxPacketSize       = DYNAMIC */
 128         .bInterval              = 4, /* FIXME: Add this field in the
 129                                       * HID gadget configuration?
 130                                       * (struct hidg_func_descriptor)
 131                                       */
 132 };
 133
 134 static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
 135         .bLength                = sizeof(hidg_ss_out_comp_desc),
 136         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 137
 138         /* .bMaxBurst           = 0, */
 139         /* .bmAttributes        = 0, */
 140         /* .wBytesPerInterval   = DYNAMIC */
 141 };
 142
 143 static struct usb_descriptor_header *hidg_ss_descriptors[] = {
 144         (struct usb_descriptor_header *)&hidg_interface_desc,
 145         (struct usb_descriptor_header *)&hidg_desc,
 146         (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
 147         (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
 148         (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
 149         (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
 150         NULL,
 151 };
 152
 153 /* High-Speed Support */
 154
 155 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 156         .bLength                = USB_DT_ENDPOINT_SIZE,
 157         .bDescriptorType        = USB_DT_ENDPOINT,
 158         .bEndpointAddress       = USB_DIR_IN,
 159         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 160         /*.wMaxPacketSize       = DYNAMIC */
 161         .bInterval              = 4, /* FIXME: Add this field in the
 162                                       * HID gadget configuration?
 163                                       * (struct hidg_func_descriptor)
 164                                       */
 165 };
 166
 167 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 168         .bLength                = USB_DT_ENDPOINT_SIZE,
 169         .bDescriptorType        = USB_DT_ENDPOINT,
 170         .bEndpointAddress       = USB_DIR_OUT,
 171         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 172         /*.wMaxPacketSize       = DYNAMIC */
 173         .bInterval              = 4, /* FIXME: Add this field in the
 174                                       * HID gadget configuration?
 175                                       * (struct hidg_func_descriptor)
 176                                       */
 177 };
 178
 179 static struct usb_descriptor_header *hidg_hs_descriptors[] = {
 180         (struct usb_descriptor_header *)&hidg_interface_desc,
 181         (struct usb_descriptor_header *)&hidg_desc,
 182         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 183         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 184         NULL,
 185 };
 186
 187 /* Full-Speed Support */
 188
 189 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 190         .bLength                = USB_DT_ENDPOINT_SIZE,
 191         .bDescriptorType        = USB_DT_ENDPOINT,
 192         .bEndpointAddress       = USB_DIR_IN,
 193         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 194         /*.wMaxPacketSize       = DYNAMIC */
 195         .bInterval              = 10, /* FIXME: Add this field in the
 196                                        * HID gadget configuration?
 197                                        * (struct hidg_func_descriptor)
 198                                        */
 199 };
 200
 201 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 202         .bLength                = USB_DT_ENDPOINT_SIZE,
 203         .bDescriptorType        = USB_DT_ENDPOINT,
 204         .bEndpointAddress       = USB_DIR_OUT,
 205         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 206         /*.wMaxPacketSize       = DYNAMIC */
 207         .bInterval              = 10, /* FIXME: Add this field in the
 208                                        * HID gadget configuration?
 209                                        * (struct hidg_func_descriptor)
 210                                        */
 211 };
 212
 213 static struct usb_descriptor_header *hidg_fs_descriptors[] = {
 214         (struct usb_descriptor_header *)&hidg_interface_desc,
 215         (struct usb_descriptor_header *)&hidg_desc,
 216         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 217         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 218         NULL,
 219 };
 220
 221 /*-------------------------------------------------------------------------*/
 222 /*                                 Strings                                 */
 223
 224 #define CT_FUNC_HID_IDX 0
 225
 226 static struct usb_string ct_func_string_defs[] = {
 227         [CT_FUNC_HID_IDX].s     = "HID Interface",
 228         {},                     /* end of list */
 229 };
 230
 231 static struct usb_gadget_strings ct_func_string_table = {
 232         .language       = 0x0409,       /* en-US */
 233         .strings        = ct_func_string_defs,
 234 };
 235
 236 static struct usb_gadget_strings *ct_func_strings[] = {
 237         &ct_func_string_table,
 238         NULL,
 239 };
 240
 241 /*-------------------------------------------------------------------------*/
 242 /*                              Char Device                                */
 243
 244 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 245                         size_t count, loff_t *ptr)
 246 {
 247         struct f_hidg *hidg = file->private_data;
 248         struct f_hidg_req_list *list;
 249         struct usb_request *req;
 250         unsigned long flags;
 251         int ret;
 252
 253         if (!count)
 254                 return 0;
 255
 256         spin_lock_irqsave(&hidg->read_spinlock, flags);
 257
 258 #define READ_COND (!list_empty(&hidg->completed_out_req))
 259
 260         /* wait for at least one buffer to complete */
 261         while (!READ_COND) {
 262                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 263                 if (file->f_flags & O_NONBLOCK)
 264                         return -EAGAIN;
 265
 266                 if (wait_event_interruptible(hidg->read_queue, READ_COND))
 267                         return -ERESTARTSYS;
 268
 269                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 270         }
 271
 272         /* pick the first one */
 273         list = list_first_entry(&hidg->completed_out_req,
 274                                 struct f_hidg_req_list, list);
 275
 276         /*
 277          * Remove this from list to protect it from beign free()
 278          * while host disables our function
 279          */
 280         list_del(&list->list);
 281
 282         req = list->req;
 283         count = min_t(unsigned int, count, req->actual - list->pos);
 284         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 285
 286         /* copy to user outside spinlock */
 287         count -= copy_to_user(buffer, req->buf + list->pos, count);
 288         list->pos += count;
 289
 290         /*
 291          * if this request is completely handled and transfered to
 292          * userspace, remove its entry from the list and requeue it
 293          * again. Otherwise, we will revisit it again upon the next
 294          * call, taking into account its current read position.
 295          */
 296         if (list->pos == req->actual) {
 297                 kfree(list);
 298
 299                 req->length = hidg->report_length;
 300                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 301                 if (ret < 0) {
 302                         free_ep_req(hidg->out_ep, req);
 303                         return ret;
 304                 }
 305         } else {
 306                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 307                 list_add(&list->list, &hidg->completed_out_req);
 308                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 309
 310                 wake_up(&hidg->read_queue);
 311         }
 312
 313         return count;
 314 }
 315
 316 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 317 {
 318         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 319         unsigned long flags;
 320
 321         if (req->status != 0) {
 322                 ERROR(hidg->func.config->cdev,
 323                         "End Point Request ERROR: %d\n", req->status);
 324         }
 325
 326         spin_lock_irqsave(&hidg->write_spinlock, flags);
 327         hidg->write_pending = 0;
 328         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 329         wake_up(&hidg->write_queue);
 330 }
 331
 332 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 333                             size_t count, loff_t *offp)
 334 {
 335         struct f_hidg *hidg  = file->private_data;
 336         struct usb_request *req;
 337         unsigned long flags;
 338         ssize_t status = -ENOMEM;
 339
 340         spin_lock_irqsave(&hidg->write_spinlock, flags);
 341
 342         if (!hidg->req) {
 343                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 344                 return -ESHUTDOWN;
 345         }
 346
 347 #define WRITE_COND (!hidg->write_pending)
 348 try_again:
 349         /* write queue */
 350         while (!WRITE_COND) {
 351                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 352                 if (file->f_flags & O_NONBLOCK)
 353                         return -EAGAIN;
 354
 355                 if (wait_event_interruptible_exclusive(
 356                                 hidg->write_queue, WRITE_COND))
 357                         return -ERESTARTSYS;
 358
 359                 spin_lock_irqsave(&hidg->write_spinlock, flags);
 360         }
 361
 362         hidg->write_pending = 1;
 363         req = hidg->req;
 364         count  = min_t(unsigned, count, hidg->report_length);
 365
 366         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 367
 368         if (!req) {
 369                 ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
 370                 status = -ESHUTDOWN;
 371                 goto release_write_pending;
 372         }
 373
 374         status = copy_from_user(req->buf, buffer, count);
 375         if (status != 0) {
 376                 ERROR(hidg->func.config->cdev,
 377                         "copy_from_user error\n");
 378                 status = -EINVAL;
 379                 goto release_write_pending;
 380         }
 381
 382         spin_lock_irqsave(&hidg->write_spinlock, flags);
 383
 384         /* when our function has been disabled by host */
 385         if (!hidg->req) {
 386                 free_ep_req(hidg->in_ep, req);
 387                 /*
 388                  * TODO
 389                  * Should we fail with error here?
 390                  */
 391                 goto try_again;
 392         }
 393
 394         req->status   = 0;
 395         req->zero     = 0;
 396         req->length   = count;
 397         req->complete = f_hidg_req_complete;
 398         req->context  = hidg;
 399
 400         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 401
 402         if (!hidg->in_ep->enabled) {
 403                 ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
 404                 status = -ESHUTDOWN;
 405                 goto release_write_pending;
 406         }
 407
 408         status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
 409         if (status < 0)
 410                 goto release_write_pending;
 411         else
 412                 status = count;
 413
 414         return status;
 415 release_write_pending:
 416         spin_lock_irqsave(&hidg->write_spinlock, flags);
 417         hidg->write_pending = 0;
 418         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 419
 420         wake_up(&hidg->write_queue);
 421
 422         return status;
 423 }
 424
 425 static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
 426 {
 427         struct f_hidg   *hidg  = file->private_data;
 428         __poll_t        ret = 0;
 429
 430         poll_wait(file, &hidg->read_queue, wait);
 431         poll_wait(file, &hidg->write_queue, wait);
 432
 433         if (WRITE_COND)
 434                 ret |= EPOLLOUT | EPOLLWRNORM;
 435
 436         if (READ_COND)
 437                 ret |= EPOLLIN | EPOLLRDNORM;
 438
 439         return ret;
 440 }
 441
 442 #undef WRITE_COND
 443 #undef READ_COND
 444
 445 static int f_hidg_release(struct inode *inode, struct file *fd)
 446 {
 447         fd->private_data = NULL;
 448         return 0;
 449 }
 450
 451 static int f_hidg_open(struct inode *inode, struct file *fd)
 452 {
 453         struct f_hidg *hidg =
 454                 container_of(inode->i_cdev, struct f_hidg, cdev);
 455
 456         fd->private_data = hidg;
 457
 458         return 0;
 459 }
 460
 461 /*-------------------------------------------------------------------------*/
 462 /*                                usb_function                             */
 463
 464 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 465                                                     unsigned length)
 466 {
 467         return alloc_ep_req(ep, length);
 468 }
 469
 470 static void hidg_set_report_complete(struct usb_ep *ep, struct usb_request *req)
 471 {
 472         struct f_hidg *hidg = (struct f_hidg *) req->context;
 473         struct usb_composite_dev *cdev = hidg->func.config->cdev;
 474         struct f_hidg_req_list *req_list;
 475         unsigned long flags;
 476
 477         switch (req->status) {
 478         case 0:
 479                 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 480                 if (!req_list) {
 481                         ERROR(cdev, "Unable to allocate mem for req_list\n");
 482                         goto free_req;
 483                 }
 484
 485                 req_list->req = req;
 486
 487                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 488                 list_add_tail(&req_list->list, &hidg->completed_out_req);
 489                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 490
 491                 wake_up(&hidg->read_queue);
 492                 break;
 493         default:
 494                 ERROR(cdev, "Set report failed %d\n", req->status);
 495                 fallthrough;
 496         case -ECONNABORTED:             /* hardware forced ep reset */
 497         case -ECONNRESET:               /* request dequeued */
 498         case -ESHUTDOWN:                /* disconnect from host */
 499 free_req:
 500                 free_ep_req(ep, req);
 501                 return;
 502         }
 503 }
 504
 505 static int hidg_setup(struct usb_function *f,
 506                 const struct usb_ctrlrequest *ctrl)
 507 {
 508         struct f_hidg                   *hidg = func_to_hidg(f);
 509         struct usb_composite_dev        *cdev = f->config->cdev;
 510         struct usb_request              *req  = cdev->req;
 511         int status = 0;
 512         __u16 value, length;
 513
 514         value   = __le16_to_cpu(ctrl->wValue);
 515         length  = __le16_to_cpu(ctrl->wLength);
 516
 517         VDBG(cdev,
 518              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 519              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 520
 521         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 522         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 523                   | HID_REQ_GET_REPORT):
 524                 VDBG(cdev, "get_report\n");
 525
 526                 /* send an empty report */
 527                 length = min_t(unsigned, length, hidg->report_length);
 528                 memset(req->buf, 0x0, length);
 529
 530                 goto respond;
 531                 break;
 532
 533         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 534                   | HID_REQ_GET_PROTOCOL):
 535                 VDBG(cdev, "get_protocol\n");
 536                 length = min_t(unsigned int, length, 1);
 537                 ((u8 *) req->buf)[0] = hidg->protocol;
 538                 goto respond;
 539                 break;
 540
 541         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 542                   | HID_REQ_GET_IDLE):
 543                 VDBG(cdev, "get_idle\n");
 544                 length = min_t(unsigned int, length, 1);
 545                 ((u8 *) req->buf)[0] = hidg->idle;
 546                 goto respond;
 547                 break;
 548
 549         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 550                   | HID_REQ_SET_REPORT):
 551                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 552                 goto stall;
 553                 break;
 554
 555         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 556                   | HID_REQ_SET_PROTOCOL):
 557                 VDBG(cdev, "set_protocol\n");
 558                 if (value > HID_REPORT_PROTOCOL)
 559                         goto stall;
 560                 length = 0;
 561                 /*
 562                  * We assume that programs implementing the Boot protocol
 563                  * are also compatible with the Report Protocol
 564                  */
 565                 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
 566                         hidg->protocol = value;
 567                         goto respond;
 568                 }
 569                 goto stall;
 570                 break;
 571
 572         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 573                   | HID_REQ_SET_IDLE):
 574                 VDBG(cdev, "set_idle\n");
 575                 length = 0;
 576                 hidg->idle = value >> 8;
 577                 goto respond;
 578                 break;
 579
 580         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 581                   | USB_REQ_GET_DESCRIPTOR):
 582                 switch (value >> 8) {
 583                 case HID_DT_HID:
 584                 {
 585                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 586
 587                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 588                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 589                         hidg_desc_copy.desc[0].wDescriptorLength =
 590                                 cpu_to_le16(hidg->report_desc_length);
 591
 592                         length = min_t(unsigned short, length,
 593                                                    hidg_desc_copy.bLength);
 594                         memcpy(req->buf, &hidg_desc_copy, length);
 595                         goto respond;
 596                         break;
 597                 }
 598                 case HID_DT_REPORT:
 599                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 600                         length = min_t(unsigned short, length,
 601                                                    hidg->report_desc_length);
 602                         memcpy(req->buf, hidg->report_desc, length);
 603                         goto respond;
 604                         break;
 605
 606                 default:
 607                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 608                                  value >> 8);
 609                         goto stall;
 610                         break;
 611                 }
 612                 break;
 613
 614         default:
 615                 VDBG(cdev, "Unknown request 0x%x\n",
 616                          ctrl->bRequest);
 617                 goto stall;
 618                 break;
 619         }
 620
 621 stall:
 622         return -EOPNOTSUPP;
 623
 624 respond:
 625         req->zero = 0;
 626         req->length = length;
 627         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 628         if (status < 0)
 629                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 630         return status;
 631 }
 632
 633 static void hidg_disable(struct usb_function *f)
 634 {
 635         struct f_hidg *hidg = func_to_hidg(f);
 636         struct f_hidg_req_list *list, *next;
 637         unsigned long flags;
 638
 639         usb_ep_disable(hidg->in_ep);
 640         usb_ep_disable(hidg->out_ep);
 641
 642         spin_lock_irqsave(&hidg->read_spinlock, flags);
 643         list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
 644                 free_ep_req(hidg->out_ep, list->req);
 645                 list_del(&list->list);
 646                 kfree(list);
 647         }
 648         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 649
 650         spin_lock_irqsave(&hidg->write_spinlock, flags);
 651         if (!hidg->write_pending) {
 652                 free_ep_req(hidg->in_ep, hidg->req);
 653                 hidg->write_pending = 1;
 654         }
 655
 656         hidg->req = NULL;
 657         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 658 }
 659
 660 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 661 {
 662         struct usb_composite_dev                *cdev = f->config->cdev;
 663         struct f_hidg                           *hidg = func_to_hidg(f);
 664         struct usb_request                      *req_in = NULL;
 665         unsigned long                           flags;
 666         int i, status = 0;
 667
 668         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
 669
 670         if (hidg->in_ep != NULL) {
 671                 /* restart endpoint */
 672                 usb_ep_disable(hidg->in_ep);
 673
 674                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 675                                             hidg->in_ep);
 676                 if (status) {
 677                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 678                         goto fail;
 679                 }
 680                 status = usb_ep_enable(hidg->in_ep);
 681                 if (status < 0) {
 682                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
 683                         goto fail;
 684                 }
 685                 hidg->in_ep->driver_data = hidg;
 686
 687                 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
 688                 if (!req_in) {
 689                         status = -ENOMEM;
 690                         goto disable_ep_in;
 691                 }
 692         }
 693
 694
 695         if (hidg->out_ep != NULL) {
 696                 /* restart endpoint */
 697                 usb_ep_disable(hidg->out_ep);
 698
 699                 status = config_ep_by_speed(f->config->cdev->gadget, f,
 700                                             hidg->out_ep);
 701                 if (status) {
 702                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
 703                         goto free_req_in;
 704                 }
 705                 status = usb_ep_enable(hidg->out_ep);
 706                 if (status < 0) {
 707                         ERROR(cdev, "Enable OUT endpoint FAILED!\n");
 708                         goto free_req_in;
 709                 }
 710                 hidg->out_ep->driver_data = hidg;
 711
 712                 /*
 713                  * allocate a bunch of read buffers and queue them all at once.
 714                  */
 715                 for (i = 0; i < hidg->qlen && status == 0; i++) {
 716                         struct usb_request *req =
 717                                         hidg_alloc_ep_req(hidg->out_ep,
 718                                                           hidg->report_length);
 719                         if (req) {
 720                                 req->complete = hidg_set_report_complete;
 721                                 req->context  = hidg;
 722                                 status = usb_ep_queue(hidg->out_ep, req,
 723                                                       GFP_ATOMIC);
 724                                 if (status) {
 725                                         ERROR(cdev, "%s queue req --> %d\n",
 726                                                 hidg->out_ep->name, status);
 727                                         free_ep_req(hidg->out_ep, req);
 728                                 }
 729                         } else {
 730                                 status = -ENOMEM;
 731                                 goto disable_out_ep;
 732                         }
 733                 }
 734         }
 735
 736         if (hidg->in_ep != NULL) {
 737                 spin_lock_irqsave(&hidg->write_spinlock, flags);
 738                 hidg->req = req_in;
 739                 hidg->write_pending = 0;
 740                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 741
 742                 wake_up(&hidg->write_queue);
 743         }
 744         return 0;
 745 disable_out_ep:
 746         usb_ep_disable(hidg->out_ep);
 747 free_req_in:
 748         if (req_in)
 749                 free_ep_req(hidg->in_ep, req_in);
 750
 751 disable_ep_in:
 752         if (hidg->in_ep)
 753                 usb_ep_disable(hidg->in_ep);
 754
 755 fail:
 756         return status;
 757 }
 758
 759 static const struct file_operations f_hidg_fops = {
 760         .owner          = THIS_MODULE,
 761         .open           = f_hidg_open,
 762         .release        = f_hidg_release,
 763         .write          = f_hidg_write,
 764         .read           = f_hidg_read,
 765         .poll           = f_hidg_poll,
 766         .llseek         = noop_llseek,
 767 };
 768
 769 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 770 {
 771         struct usb_ep           *ep;
 772         struct f_hidg           *hidg = func_to_hidg(f);
 773         struct usb_string       *us;
 774         struct device           *device;
 775         int                     status;
 776         dev_t                   dev;
 777
 778         /* maybe allocate device-global string IDs, and patch descriptors */
 779         us = usb_gstrings_attach(c->cdev, ct_func_strings,
 780                                  ARRAY_SIZE(ct_func_string_defs));
 781         if (IS_ERR(us))
 782                 return PTR_ERR(us);
 783         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
 784
 785         /* allocate instance-specific interface IDs, and patch descriptors */
 786         status = usb_interface_id(c, f);
 787         if (status < 0)
 788                 goto fail;
 789         hidg_interface_desc.bInterfaceNumber = status;
 790
 791         /* allocate instance-specific endpoints */
 792         status = -ENODEV;
 793         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
 794         if (!ep)
 795                 goto fail;
 796         hidg->in_ep = ep;
 797
 798         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
 799         if (!ep)
 800                 goto fail;
 801         hidg->out_ep = ep;
 802
 803         /* set descriptor dynamic values */
 804         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 805         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
 806         hidg->protocol = HID_REPORT_PROTOCOL;
 807         hidg->idle = 1;
 808         hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 809         hidg_ss_in_comp_desc.wBytesPerInterval =
 810                                 cpu_to_le16(hidg->report_length);
 811         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 812         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 813         hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 814         hidg_ss_out_comp_desc.wBytesPerInterval =
 815                                 cpu_to_le16(hidg->report_length);
 816         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 817         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
 818         /*
 819          * We can use hidg_desc struct here but we should not relay
 820          * that its content won't change after returning from this function.
 821          */
 822         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
 823         hidg_desc.desc[0].wDescriptorLength =
 824                 cpu_to_le16(hidg->report_desc_length);
 825
 826         hidg_hs_in_ep_desc.bEndpointAddress =
 827                 hidg_fs_in_ep_desc.bEndpointAddress;
 828         hidg_hs_out_ep_desc.bEndpointAddress =
 829                 hidg_fs_out_ep_desc.bEndpointAddress;
 830
 831         hidg_ss_in_ep_desc.bEndpointAddress =
 832                 hidg_fs_in_ep_desc.bEndpointAddress;
 833         hidg_ss_out_ep_desc.bEndpointAddress =
 834                 hidg_fs_out_ep_desc.bEndpointAddress;
 835
 836         status = usb_assign_descriptors(f, hidg_fs_descriptors,
 837                         hidg_hs_descriptors, hidg_ss_descriptors,
 838                         hidg_ss_descriptors);
 839         if (status)
 840                 goto fail;
 841
 842         spin_lock_init(&hidg->write_spinlock);
 843         hidg->write_pending = 1;
 844         hidg->req = NULL;
 845         spin_lock_init(&hidg->read_spinlock);
 846         init_waitqueue_head(&hidg->write_queue);
 847         init_waitqueue_head(&hidg->read_queue);
 848         INIT_LIST_HEAD(&hidg->completed_out_req);
 849
 850         /* create char device */
 851         cdev_init(&hidg->cdev, &f_hidg_fops);
 852         dev = MKDEV(major, hidg->minor);
 853         status = cdev_add(&hidg->cdev, dev, 1);
 854         if (status)
 855                 goto fail_free_descs;
 856
 857         device = device_create(hidg_class, NULL, dev, NULL,
 858                                "%s%d", "hidg", hidg->minor);
 859         if (IS_ERR(device)) {
 860                 status = PTR_ERR(device);
 861                 goto del;
 862         }
 863
 864         return 0;
 865 del:
 866         cdev_del(&hidg->cdev);
 867 fail_free_descs:
 868         usb_free_all_descriptors(f);
 869 fail:
 870         ERROR(f->config->cdev, "hidg_bind FAILED\n");
 871         if (hidg->req != NULL)
 872                 free_ep_req(hidg->in_ep, hidg->req);
 873
 874         return status;
 875 }
 876
 877 static inline int hidg_get_minor(void)
 878 {
 879         int ret;
 880
 881         ret = ida_simple_get(&hidg_ida, 0, 0, GFP_KERNEL);
 882         if (ret >= HIDG_MINORS) {
 883                 ida_simple_remove(&hidg_ida, ret);
 884                 ret = -ENODEV;
 885         }
 886
 887         return ret;
 888 }
 889
 890 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
 891 {
 892         return container_of(to_config_group(item), struct f_hid_opts,
 893                             func_inst.group);
 894 }
 895
 896 static void hid_attr_release(struct config_item *item)
 897 {
 898         struct f_hid_opts *opts = to_f_hid_opts(item);
 899
 900         usb_put_function_instance(&opts->func_inst);
 901 }
 902
 903 static struct configfs_item_operations hidg_item_ops = {
 904         .release        = hid_attr_release,
 905 };
 906
 907 #define F_HID_OPT(name, prec, limit)                                    \
 908 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
 909 {                                                                       \
 910         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 911         int result;                                                     \
 912                                                                         \
 913         mutex_lock(&opts->lock);                                        \
 914         result = sprintf(page, "%d\n", opts->name);                     \
 915         mutex_unlock(&opts->lock);                                      \
 916                                                                         \
 917         return result;                                                  \
 918 }                                                                       \
 919                                                                         \
 920 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
 921                                          const char *page, size_t len)  \
 922 {                                                                       \
 923         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
 924         int ret;                                                        \
 925         u##prec num;                                                    \
 926                                                                         \
 927         mutex_lock(&opts->lock);                                        \
 928         if (opts->refcnt) {                                             \
 929                 ret = -EBUSY;                                           \
 930                 goto end;                                               \
 931         }                                                               \
 932                                                                         \
 933         ret = kstrtou##prec(page, 0, &num);                             \
 934         if (ret)                                                        \
 935                 goto end;                                               \
 936                                                                         \
 937         if (num > limit) {                                              \
 938                 ret = -EINVAL;                                          \
 939                 goto end;                                               \
 940         }                                                               \
 941         opts->name = num;                                               \
 942         ret = len;                                                      \
 943                                                                         \
 944 end:                                                                    \
 945         mutex_unlock(&opts->lock);                                      \
 946         return ret;                                                     \
 947 }                                                                       \
 948                                                                         \
 949 CONFIGFS_ATTR(f_hid_opts_, name)
 950
 951 F_HID_OPT(subclass, 8, 255);
 952 F_HID_OPT(protocol, 8, 255);
 953 F_HID_OPT(report_length, 16, 65535);
 954
 955 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 956 {
 957         struct f_hid_opts *opts = to_f_hid_opts(item);
 958         int result;
 959
 960         mutex_lock(&opts->lock);
 961         result = opts->report_desc_length;
 962         memcpy(page, opts->report_desc, opts->report_desc_length);
 963         mutex_unlock(&opts->lock);
 964
 965         return result;
 966 }
 967
 968 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
 969                                             const char *page, size_t len)
 970 {
 971         struct f_hid_opts *opts = to_f_hid_opts(item);
 972         int ret = -EBUSY;
 973         char *d;
 974
 975         mutex_lock(&opts->lock);
 976
 977         if (opts->refcnt)
 978                 goto end;
 979         if (len > PAGE_SIZE) {
 980                 ret = -ENOSPC;
 981                 goto end;
 982         }
 983         d = kmemdup(page, len, GFP_KERNEL);
 984         if (!d) {
 985                 ret = -ENOMEM;
 986                 goto end;
 987         }
 988         kfree(opts->report_desc);
 989         opts->report_desc = d;
 990         opts->report_desc_length = len;
 991         opts->report_desc_alloc = true;
 992         ret = len;
 993 end:
 994         mutex_unlock(&opts->lock);
 995         return ret;
 996 }
 997
 998 CONFIGFS_ATTR(f_hid_opts_, report_desc);
 999
1000 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1001 {
1002         struct f_hid_opts *opts = to_f_hid_opts(item);
1003
1004         return sprintf(page, "%d:%d\n", major, opts->minor);
1005 }
1006
1007 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1008
1009 static struct configfs_attribute *hid_attrs[] = {
1010         &f_hid_opts_attr_subclass,
1011         &f_hid_opts_attr_protocol,
1012         &f_hid_opts_attr_report_length,
1013         &f_hid_opts_attr_report_desc,
1014         &f_hid_opts_attr_dev,
1015         NULL,
1016 };
1017
1018 static const struct config_item_type hid_func_type = {
1019         .ct_item_ops    = &hidg_item_ops,
1020         .ct_attrs       = hid_attrs,
1021         .ct_owner       = THIS_MODULE,
1022 };
1023
1024 static inline void hidg_put_minor(int minor)
1025 {
1026         ida_simple_remove(&hidg_ida, minor);
1027 }
1028
1029 static void hidg_free_inst(struct usb_function_instance *f)
1030 {
1031         struct f_hid_opts *opts;
1032
1033         opts = container_of(f, struct f_hid_opts, func_inst);
1034
1035         mutex_lock(&hidg_ida_lock);
1036
1037         hidg_put_minor(opts->minor);
1038         if (ida_is_empty(&hidg_ida))
1039                 ghid_cleanup();
1040
1041         mutex_unlock(&hidg_ida_lock);
1042
1043         if (opts->report_desc_alloc)
1044                 kfree(opts->report_desc);
1045
1046         kfree(opts);
1047 }
1048
1049 static struct usb_function_instance *hidg_alloc_inst(void)
1050 {
1051         struct f_hid_opts *opts;
1052         struct usb_function_instance *ret;
1053         int status = 0;
1054
1055         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1056         if (!opts)
1057                 return ERR_PTR(-ENOMEM);
1058         mutex_init(&opts->lock);
1059         opts->func_inst.free_func_inst = hidg_free_inst;
1060         ret = &opts->func_inst;
1061
1062         mutex_lock(&hidg_ida_lock);
1063
1064         if (ida_is_empty(&hidg_ida)) {
1065                 status = ghid_setup(NULL, HIDG_MINORS);
1066                 if (status)  {
1067                         ret = ERR_PTR(status);
1068                         kfree(opts);
1069                         goto unlock;
1070                 }
1071         }
1072
1073         opts->minor = hidg_get_minor();
1074         if (opts->minor < 0) {
1075                 ret = ERR_PTR(opts->minor);
1076                 kfree(opts);
1077                 if (ida_is_empty(&hidg_ida))
1078                         ghid_cleanup();
1079                 goto unlock;
1080         }
1081         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1082
1083 unlock:
1084         mutex_unlock(&hidg_ida_lock);
1085         return ret;
1086 }
1087
1088 static void hidg_free(struct usb_function *f)
1089 {
1090         struct f_hidg *hidg;
1091         struct f_hid_opts *opts;
1092
1093         hidg = func_to_hidg(f);
1094         opts = container_of(f->fi, struct f_hid_opts, func_inst);
1095         kfree(hidg->report_desc);
1096         kfree(hidg);
1097         mutex_lock(&opts->lock);
1098         --opts->refcnt;
1099         mutex_unlock(&opts->lock);
1100 }
1101
1102 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1103 {
1104         struct f_hidg *hidg = func_to_hidg(f);
1105
1106         device_destroy(hidg_class, MKDEV(major, hidg->minor));
1107         cdev_del(&hidg->cdev);
1108
1109         usb_free_all_descriptors(f);
1110 }
1111
1112 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1113 {
1114         struct f_hidg *hidg;
1115         struct f_hid_opts *opts;
1116
1117         /* allocate and initialize one new instance */
1118         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1119         if (!hidg)
1120                 return ERR_PTR(-ENOMEM);
1121
1122         opts = container_of(fi, struct f_hid_opts, func_inst);
1123
1124         mutex_lock(&opts->lock);
1125         ++opts->refcnt;
1126
1127         hidg->minor = opts->minor;
1128         hidg->bInterfaceSubClass = opts->subclass;
1129         hidg->bInterfaceProtocol = opts->protocol;
1130         hidg->report_length = opts->report_length;
1131         hidg->report_desc_length = opts->report_desc_length;
1132         if (opts->report_desc) {
1133                 hidg->report_desc = kmemdup(opts->report_desc,
1134                                             opts->report_desc_length,
1135                                             GFP_KERNEL);
1136                 if (!hidg->report_desc) {
1137                         kfree(hidg);
1138                         mutex_unlock(&opts->lock);
1139                         return ERR_PTR(-ENOMEM);
1140                 }
1141         }
1142
1143         mutex_unlock(&opts->lock);
1144
1145         hidg->func.name    = "hid";
1146         hidg->func.bind    = hidg_bind;
1147         hidg->func.unbind  = hidg_unbind;
1148         hidg->func.set_alt = hidg_set_alt;
1149         hidg->func.disable = hidg_disable;
1150         hidg->func.setup   = hidg_setup;
1151         hidg->func.free_func = hidg_free;
1152
1153         /* this could be made configurable at some point */
1154         hidg->qlen         = 4;
1155
1156         return &hidg->func;
1157 }
1158
1159 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1160 MODULE_LICENSE("GPL");
1161 MODULE_AUTHOR("Fabien Chouteau");
1162
1163 int ghid_setup(struct usb_gadget *g, int count)
1164 {
1165         int status;
1166         dev_t dev;
1167
1168         hidg_class = class_create(THIS_MODULE, "hidg");
1169         if (IS_ERR(hidg_class)) {
1170                 status = PTR_ERR(hidg_class);
1171                 hidg_class = NULL;
1172                 return status;
1173         }
1174
1175         status = alloc_chrdev_region(&dev, 0, count, "hidg");
1176         if (status) {
1177                 class_destroy(hidg_class);
1178                 hidg_class = NULL;
1179                 return status;
1180         }
1181
1182         major = MAJOR(dev);
1183         minors = count;
1184
1185         return 0;
1186 }
1187
1188 void ghid_cleanup(void)
1189 {
1190         if (major) {
1191                 unregister_chrdev_region(MKDEV(major, 0), minors);
1192                 major = minors = 0;
1193         }
1194
1195         class_destroy(hidg_class);
1196         hidg_class = NULL;
1197 }