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