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 <[email protected]>
   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/workqueue.h>
  19 #include <linux/usb/func_utils.h>
  20 #include <linux/usb/g_hid.h>
  21 #include <uapi/linux/usb/g_hid.h>
  22
  23 #include "u_hid.h"
  24
  25 #define HIDG_MINORS     4
  26
  27 /*
  28  * Most operating systems seem to allow for 5000ms timeout, we will allow
  29  * userspace half that time to respond before we return an empty report.
  30  */
  31 #define GET_REPORT_TIMEOUT_MS 2500
  32
  33 static int major, minors;
  34
  35 static const struct class hidg_class = {
  36         .name = "hidg",
  37 };
  38
  39 static DEFINE_IDA(hidg_ida);
  40 static DEFINE_MUTEX(hidg_ida_lock); /* protects access to hidg_ida */
  41
  42 struct report_entry {
  43         struct usb_hidg_report report_data;
  44         struct list_head node;
  45 };
  46
  47 /*-------------------------------------------------------------------------*/
  48 /*                            HID gadget struct                            */
  49
  50 struct f_hidg_req_list {
  51         struct usb_request      *req;
  52         unsigned int            pos;
  53         struct list_head        list;
  54 };
  55
  56 struct f_hidg {
  57         /* configuration */
  58         unsigned char                   bInterfaceSubClass;
  59         unsigned char                   bInterfaceProtocol;
  60         unsigned char                   protocol;
  61         unsigned char                   idle;
  62         unsigned short                  report_desc_length;
  63         char                            *report_desc;
  64         unsigned short                  report_length;
  65         /*
  66          * use_out_ep - if true, the OUT Endpoint (interrupt out method)
  67          *              will be used to receive reports from the host
  68          *              using functions with the "intout" suffix.
  69          *              Otherwise, the OUT Endpoint will not be configured
  70          *              and the SETUP/SET_REPORT method ("ssreport" suffix)
  71          *              will be used to receive reports.
  72          */
  73         bool                            use_out_ep;
  74
  75         /* recv report */
  76         spinlock_t                      read_spinlock;
  77         wait_queue_head_t               read_queue;
  78         /* recv report - interrupt out only (use_out_ep == 1) */
  79         struct list_head                completed_out_req;
  80         unsigned int                    qlen;
  81         /* recv report - setup set_report only (use_out_ep == 0) */
  82         char                            *set_report_buf;
  83         unsigned int                    set_report_length;
  84
  85         /* send report */
  86         spinlock_t                      write_spinlock;
  87         bool                            write_pending;
  88         wait_queue_head_t               write_queue;
  89         struct usb_request              *req;
  90
  91         /* get report */
  92         struct usb_request              *get_req;
  93         struct usb_hidg_report          get_report;
  94         bool                            get_report_returned;
  95         int                             get_report_req_report_id;
  96         int                             get_report_req_report_length;
  97         spinlock_t                      get_report_spinlock;
  98         wait_queue_head_t               get_queue;    /* Waiting for userspace response */
  99         wait_queue_head_t               get_id_queue; /* Get ID came in */
 100         struct work_struct              work;
 101         struct workqueue_struct         *workqueue;
 102         struct list_head                report_list;
 103
 104         struct device                   dev;
 105         struct cdev                     cdev;
 106         struct usb_function             func;
 107
 108         struct usb_ep                   *in_ep;
 109         struct usb_ep                   *out_ep;
 110 };
 111
 112 static inline struct f_hidg *func_to_hidg(struct usb_function *f)
 113 {
 114         return container_of(f, struct f_hidg, func);
 115 }
 116
 117 static void hidg_release(struct device *dev)
 118 {
 119         struct f_hidg *hidg = container_of(dev, struct f_hidg, dev);
 120
 121         kfree(hidg->report_desc);
 122         kfree(hidg->set_report_buf);
 123         kfree(hidg);
 124 }
 125
 126 /*-------------------------------------------------------------------------*/
 127 /*                           Static descriptors                            */
 128
 129 static struct usb_interface_descriptor hidg_interface_desc = {
 130         .bLength                = sizeof hidg_interface_desc,
 131         .bDescriptorType        = USB_DT_INTERFACE,
 132         /* .bInterfaceNumber    = DYNAMIC */
 133         .bAlternateSetting      = 0,
 134         /* .bNumEndpoints       = DYNAMIC (depends on use_out_ep) */
 135         .bInterfaceClass        = USB_CLASS_HID,
 136         /* .bInterfaceSubClass  = DYNAMIC */
 137         /* .bInterfaceProtocol  = DYNAMIC */
 138         /* .iInterface          = DYNAMIC */
 139 };
 140
 141 static struct hid_descriptor hidg_desc = {
 142         .bLength                        = sizeof hidg_desc,
 143         .bDescriptorType                = HID_DT_HID,
 144         .bcdHID                         = cpu_to_le16(0x0101),
 145         .bCountryCode                   = 0x00,
 146         .bNumDescriptors                = 0x1,
 147         /*.desc[0].bDescriptorType      = DYNAMIC */
 148         /*.desc[0].wDescriptorLenght    = DYNAMIC */
 149 };
 150
 151 /* Super-Speed Support */
 152
 153 static struct usb_endpoint_descriptor hidg_ss_in_ep_desc = {
 154         .bLength                = USB_DT_ENDPOINT_SIZE,
 155         .bDescriptorType        = USB_DT_ENDPOINT,
 156         .bEndpointAddress       = USB_DIR_IN,
 157         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 158         /*.wMaxPacketSize       = DYNAMIC */
 159         .bInterval              = 4, /* FIXME: Add this field in the
 160                                       * HID gadget configuration?
 161                                       * (struct hidg_func_descriptor)
 162                                       */
 163 };
 164
 165 static struct usb_ss_ep_comp_descriptor hidg_ss_in_comp_desc = {
 166         .bLength                = sizeof(hidg_ss_in_comp_desc),
 167         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 168
 169         /* .bMaxBurst           = 0, */
 170         /* .bmAttributes        = 0, */
 171         /* .wBytesPerInterval   = DYNAMIC */
 172 };
 173
 174 static struct usb_endpoint_descriptor hidg_ss_out_ep_desc = {
 175         .bLength                = USB_DT_ENDPOINT_SIZE,
 176         .bDescriptorType        = USB_DT_ENDPOINT,
 177         .bEndpointAddress       = USB_DIR_OUT,
 178         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 179         /*.wMaxPacketSize       = DYNAMIC */
 180         .bInterval              = 4, /* FIXME: Add this field in the
 181                                       * HID gadget configuration?
 182                                       * (struct hidg_func_descriptor)
 183                                       */
 184 };
 185
 186 static struct usb_ss_ep_comp_descriptor hidg_ss_out_comp_desc = {
 187         .bLength                = sizeof(hidg_ss_out_comp_desc),
 188         .bDescriptorType        = USB_DT_SS_ENDPOINT_COMP,
 189
 190         /* .bMaxBurst           = 0, */
 191         /* .bmAttributes        = 0, */
 192         /* .wBytesPerInterval   = DYNAMIC */
 193 };
 194
 195 static struct usb_descriptor_header *hidg_ss_descriptors_intout[] = {
 196         (struct usb_descriptor_header *)&hidg_interface_desc,
 197         (struct usb_descriptor_header *)&hidg_desc,
 198         (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
 199         (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
 200         (struct usb_descriptor_header *)&hidg_ss_out_ep_desc,
 201         (struct usb_descriptor_header *)&hidg_ss_out_comp_desc,
 202         NULL,
 203 };
 204
 205 static struct usb_descriptor_header *hidg_ss_descriptors_ssreport[] = {
 206         (struct usb_descriptor_header *)&hidg_interface_desc,
 207         (struct usb_descriptor_header *)&hidg_desc,
 208         (struct usb_descriptor_header *)&hidg_ss_in_ep_desc,
 209         (struct usb_descriptor_header *)&hidg_ss_in_comp_desc,
 210         NULL,
 211 };
 212
 213 /* High-Speed Support */
 214
 215 static struct usb_endpoint_descriptor hidg_hs_in_ep_desc = {
 216         .bLength                = USB_DT_ENDPOINT_SIZE,
 217         .bDescriptorType        = USB_DT_ENDPOINT,
 218         .bEndpointAddress       = USB_DIR_IN,
 219         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 220         /*.wMaxPacketSize       = DYNAMIC */
 221         .bInterval              = 4, /* FIXME: Add this field in the
 222                                       * HID gadget configuration?
 223                                       * (struct hidg_func_descriptor)
 224                                       */
 225 };
 226
 227 static struct usb_endpoint_descriptor hidg_hs_out_ep_desc = {
 228         .bLength                = USB_DT_ENDPOINT_SIZE,
 229         .bDescriptorType        = USB_DT_ENDPOINT,
 230         .bEndpointAddress       = USB_DIR_OUT,
 231         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 232         /*.wMaxPacketSize       = DYNAMIC */
 233         .bInterval              = 4, /* FIXME: Add this field in the
 234                                       * HID gadget configuration?
 235                                       * (struct hidg_func_descriptor)
 236                                       */
 237 };
 238
 239 static struct usb_descriptor_header *hidg_hs_descriptors_intout[] = {
 240         (struct usb_descriptor_header *)&hidg_interface_desc,
 241         (struct usb_descriptor_header *)&hidg_desc,
 242         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 243         (struct usb_descriptor_header *)&hidg_hs_out_ep_desc,
 244         NULL,
 245 };
 246
 247 static struct usb_descriptor_header *hidg_hs_descriptors_ssreport[] = {
 248         (struct usb_descriptor_header *)&hidg_interface_desc,
 249         (struct usb_descriptor_header *)&hidg_desc,
 250         (struct usb_descriptor_header *)&hidg_hs_in_ep_desc,
 251         NULL,
 252 };
 253
 254 /* Full-Speed Support */
 255
 256 static struct usb_endpoint_descriptor hidg_fs_in_ep_desc = {
 257         .bLength                = USB_DT_ENDPOINT_SIZE,
 258         .bDescriptorType        = USB_DT_ENDPOINT,
 259         .bEndpointAddress       = USB_DIR_IN,
 260         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 261         /*.wMaxPacketSize       = DYNAMIC */
 262         .bInterval              = 10, /* FIXME: Add this field in the
 263                                        * HID gadget configuration?
 264                                        * (struct hidg_func_descriptor)
 265                                        */
 266 };
 267
 268 static struct usb_endpoint_descriptor hidg_fs_out_ep_desc = {
 269         .bLength                = USB_DT_ENDPOINT_SIZE,
 270         .bDescriptorType        = USB_DT_ENDPOINT,
 271         .bEndpointAddress       = USB_DIR_OUT,
 272         .bmAttributes           = USB_ENDPOINT_XFER_INT,
 273         /*.wMaxPacketSize       = DYNAMIC */
 274         .bInterval              = 10, /* FIXME: Add this field in the
 275                                        * HID gadget configuration?
 276                                        * (struct hidg_func_descriptor)
 277                                        */
 278 };
 279
 280 static struct usb_descriptor_header *hidg_fs_descriptors_intout[] = {
 281         (struct usb_descriptor_header *)&hidg_interface_desc,
 282         (struct usb_descriptor_header *)&hidg_desc,
 283         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 284         (struct usb_descriptor_header *)&hidg_fs_out_ep_desc,
 285         NULL,
 286 };
 287
 288 static struct usb_descriptor_header *hidg_fs_descriptors_ssreport[] = {
 289         (struct usb_descriptor_header *)&hidg_interface_desc,
 290         (struct usb_descriptor_header *)&hidg_desc,
 291         (struct usb_descriptor_header *)&hidg_fs_in_ep_desc,
 292         NULL,
 293 };
 294
 295 /*-------------------------------------------------------------------------*/
 296 /*                                 Strings                                 */
 297
 298 #define CT_FUNC_HID_IDX 0
 299
 300 static struct usb_string ct_func_string_defs[] = {
 301         [CT_FUNC_HID_IDX].s     = "HID Interface",
 302         {},                     /* end of list */
 303 };
 304
 305 static struct usb_gadget_strings ct_func_string_table = {
 306         .language       = 0x0409,       /* en-US */
 307         .strings        = ct_func_string_defs,
 308 };
 309
 310 static struct usb_gadget_strings *ct_func_strings[] = {
 311         &ct_func_string_table,
 312         NULL,
 313 };
 314
 315 /*-------------------------------------------------------------------------*/
 316 /*                              Char Device                                */
 317
 318 static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer,
 319                                   size_t count, loff_t *ptr)
 320 {
 321         struct f_hidg *hidg = file->private_data;
 322         struct f_hidg_req_list *list;
 323         struct usb_request *req;
 324         unsigned long flags;
 325         int ret;
 326
 327         if (!count)
 328                 return 0;
 329
 330         spin_lock_irqsave(&hidg->read_spinlock, flags);
 331
 332 #define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req))
 333
 334         /* wait for at least one buffer to complete */
 335         while (!READ_COND_INTOUT) {
 336                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 337                 if (file->f_flags & O_NONBLOCK)
 338                         return -EAGAIN;
 339
 340                 if (wait_event_interruptible(hidg->read_queue, READ_COND_INTOUT))
 341                         return -ERESTARTSYS;
 342
 343                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 344         }
 345
 346         /* pick the first one */
 347         list = list_first_entry(&hidg->completed_out_req,
 348                                 struct f_hidg_req_list, list);
 349
 350         /*
 351          * Remove this from list to protect it from beign free()
 352          * while host disables our function
 353          */
 354         list_del(&list->list);
 355
 356         req = list->req;
 357         count = min_t(unsigned int, count, req->actual - list->pos);
 358         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 359
 360         /* copy to user outside spinlock */
 361         count -= copy_to_user(buffer, req->buf + list->pos, count);
 362         list->pos += count;
 363
 364         /*
 365          * if this request is completely handled and transfered to
 366          * userspace, remove its entry from the list and requeue it
 367          * again. Otherwise, we will revisit it again upon the next
 368          * call, taking into account its current read position.
 369          */
 370         if (list->pos == req->actual) {
 371                 kfree(list);
 372
 373                 req->length = hidg->report_length;
 374                 ret = usb_ep_queue(hidg->out_ep, req, GFP_KERNEL);
 375                 if (ret < 0) {
 376                         free_ep_req(hidg->out_ep, req);
 377                         return ret;
 378                 }
 379         } else {
 380                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 381                 list_add(&list->list, &hidg->completed_out_req);
 382                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 383
 384                 wake_up(&hidg->read_queue);
 385         }
 386
 387         return count;
 388 }
 389
 390 #define READ_COND_SSREPORT (hidg->set_report_buf != NULL)
 391
 392 static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer,
 393                                     size_t count, loff_t *ptr)
 394 {
 395         struct f_hidg *hidg = file->private_data;
 396         char *tmp_buf = NULL;
 397         unsigned long flags;
 398
 399         if (!count)
 400                 return 0;
 401
 402         spin_lock_irqsave(&hidg->read_spinlock, flags);
 403
 404         while (!READ_COND_SSREPORT) {
 405                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 406                 if (file->f_flags & O_NONBLOCK)
 407                         return -EAGAIN;
 408
 409                 if (wait_event_interruptible(hidg->read_queue, READ_COND_SSREPORT))
 410                         return -ERESTARTSYS;
 411
 412                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 413         }
 414
 415         count = min_t(unsigned int, count, hidg->set_report_length);
 416         tmp_buf = hidg->set_report_buf;
 417         hidg->set_report_buf = NULL;
 418
 419         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 420
 421         if (tmp_buf != NULL) {
 422                 count -= copy_to_user(buffer, tmp_buf, count);
 423                 kfree(tmp_buf);
 424         } else {
 425                 count = -ENOMEM;
 426         }
 427
 428         wake_up(&hidg->read_queue);
 429
 430         return count;
 431 }
 432
 433 static ssize_t f_hidg_read(struct file *file, char __user *buffer,
 434                            size_t count, loff_t *ptr)
 435 {
 436         struct f_hidg *hidg = file->private_data;
 437
 438         if (hidg->use_out_ep)
 439                 return f_hidg_intout_read(file, buffer, count, ptr);
 440         else
 441                 return f_hidg_ssreport_read(file, buffer, count, ptr);
 442 }
 443
 444 static void f_hidg_req_complete(struct usb_ep *ep, struct usb_request *req)
 445 {
 446         struct f_hidg *hidg = (struct f_hidg *)ep->driver_data;
 447         unsigned long flags;
 448
 449         if (req->status != 0) {
 450                 ERROR(hidg->func.config->cdev,
 451                         "End Point Request ERROR: %d\n", req->status);
 452         }
 453
 454         spin_lock_irqsave(&hidg->write_spinlock, flags);
 455         hidg->write_pending = 0;
 456         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 457         wake_up(&hidg->write_queue);
 458 }
 459
 460 static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 461                             size_t count, loff_t *offp)
 462 {
 463         struct f_hidg *hidg  = file->private_data;
 464         struct usb_request *req;
 465         unsigned long flags;
 466         ssize_t status = -ENOMEM;
 467
 468         spin_lock_irqsave(&hidg->write_spinlock, flags);
 469
 470         if (!hidg->req) {
 471                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 472                 return -ESHUTDOWN;
 473         }
 474
 475 #define WRITE_COND (!hidg->write_pending)
 476 try_again:
 477         /* write queue */
 478         while (!WRITE_COND) {
 479                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 480                 if (file->f_flags & O_NONBLOCK)
 481                         return -EAGAIN;
 482
 483                 if (wait_event_interruptible_exclusive(
 484                                 hidg->write_queue, WRITE_COND))
 485                         return -ERESTARTSYS;
 486
 487                 spin_lock_irqsave(&hidg->write_spinlock, flags);
 488         }
 489
 490         hidg->write_pending = 1;
 491         req = hidg->req;
 492         count  = min_t(unsigned, count, hidg->report_length);
 493
 494         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 495
 496         if (!req) {
 497                 ERROR(hidg->func.config->cdev, "hidg->req is NULL\n");
 498                 status = -ESHUTDOWN;
 499                 goto release_write_pending;
 500         }
 501
 502         status = copy_from_user(req->buf, buffer, count);
 503         if (status != 0) {
 504                 ERROR(hidg->func.config->cdev,
 505                         "copy_from_user error\n");
 506                 status = -EINVAL;
 507                 goto release_write_pending;
 508         }
 509
 510         spin_lock_irqsave(&hidg->write_spinlock, flags);
 511
 512         /* when our function has been disabled by host */
 513         if (!hidg->req) {
 514                 free_ep_req(hidg->in_ep, req);
 515                 /*
 516                  * TODO
 517                  * Should we fail with error here?
 518                  */
 519                 goto try_again;
 520         }
 521
 522         req->status   = 0;
 523         req->zero     = 0;
 524         req->length   = count;
 525         req->complete = f_hidg_req_complete;
 526         req->context  = hidg;
 527
 528         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 529
 530         if (!hidg->in_ep->enabled) {
 531                 ERROR(hidg->func.config->cdev, "in_ep is disabled\n");
 532                 status = -ESHUTDOWN;
 533                 goto release_write_pending;
 534         }
 535
 536         status = usb_ep_queue(hidg->in_ep, req, GFP_ATOMIC);
 537         if (status < 0)
 538                 goto release_write_pending;
 539         else
 540                 status = count;
 541
 542         return status;
 543 release_write_pending:
 544         spin_lock_irqsave(&hidg->write_spinlock, flags);
 545         hidg->write_pending = 0;
 546         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
 547
 548         wake_up(&hidg->write_queue);
 549
 550         return status;
 551 }
 552
 553 static struct report_entry *f_hidg_search_for_report(struct f_hidg *hidg, u8 report_id)
 554 {
 555         struct list_head        *ptr;
 556         struct report_entry     *entry;
 557
 558         list_for_each(ptr, &hidg->report_list) {
 559                 entry = list_entry(ptr, struct report_entry, node);
 560                 if (entry->report_data.report_id == report_id)
 561                         return entry;
 562         }
 563
 564         return NULL;
 565 }
 566
 567 static void get_report_workqueue_handler(struct work_struct *work)
 568 {
 569         struct f_hidg *hidg = container_of(work, struct f_hidg, work);
 570         struct usb_composite_dev *cdev = hidg->func.config->cdev;
 571         struct usb_request              *req;
 572         struct report_entry *ptr;
 573         unsigned long   flags;
 574
 575         int status = 0;
 576
 577         spin_lock_irqsave(&hidg->get_report_spinlock, flags);
 578         req = hidg->get_req;
 579         if (!req) {
 580                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 581                 return;
 582         }
 583
 584         req->zero = 0;
 585         req->length = min_t(unsigned int, min_t(unsigned int, hidg->get_report_req_report_length,
 586                                                               hidg->report_length),
 587                                           MAX_REPORT_LENGTH);
 588
 589         /* Check if there is a response available for immediate response */
 590         ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
 591         if (ptr && !ptr->report_data.userspace_req) {
 592                 /* Report exists in list and it is to be used for immediate response */
 593                 req->buf = ptr->report_data.data;
 594                 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 595                 hidg->get_report_returned = true;
 596                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 597         } else {
 598                 /*
 599                  * Report does not exist in list or should not be immediately sent
 600                  * i.e. give userspace time to respond
 601                  */
 602                 hidg->get_report_returned = false;
 603                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 604                 wake_up(&hidg->get_id_queue);
 605 #define GET_REPORT_COND (!hidg->get_report_returned)
 606                 /* Wait until userspace has responded or timeout */
 607                 status = wait_event_interruptible_timeout(hidg->get_queue, !GET_REPORT_COND,
 608                                         msecs_to_jiffies(GET_REPORT_TIMEOUT_MS));
 609                 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
 610                 req = hidg->get_req;
 611                 if (!req) {
 612                         spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 613                         return;
 614                 }
 615                 if (status == 0 && !hidg->get_report_returned) {
 616                         /* GET_REPORT request was not serviced by userspace within timeout period */
 617                         VDBG(cdev, "get_report : userspace timeout.\n");
 618                         hidg->get_report_returned = true;
 619                 }
 620
 621                 /* Search again for report ID in list and respond to GET_REPORT request */
 622                 ptr = f_hidg_search_for_report(hidg, hidg->get_report_req_report_id);
 623                 if (ptr) {
 624                         /*
 625                          * Either get an updated response just serviced by userspace
 626                          * or send the latest response in the list
 627                          */
 628                         req->buf = ptr->report_data.data;
 629                 } else {
 630                         /* If there are no prevoiusly sent reports send empty report */
 631                         req->buf = hidg->get_report.data;
 632                         memset(req->buf, 0x0, req->length);
 633                 }
 634
 635                 status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 636                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 637         }
 638
 639         if (status < 0)
 640                 VDBG(cdev, "usb_ep_queue error on ep0 responding to GET_REPORT\n");
 641 }
 642
 643 static int f_hidg_get_report_id(struct file *file, __u8 __user *buffer)
 644 {
 645         struct f_hidg                   *hidg = file->private_data;
 646         int ret = 0;
 647
 648         ret = put_user(hidg->get_report_req_report_id, buffer);
 649
 650         return ret;
 651 }
 652
 653 static int f_hidg_get_report(struct file *file, struct usb_hidg_report __user *buffer)
 654 {
 655         struct f_hidg                   *hidg = file->private_data;
 656         struct usb_composite_dev        *cdev = hidg->func.config->cdev;
 657         unsigned long   flags;
 658         struct report_entry *entry;
 659         struct report_entry *ptr;
 660         __u8 report_id;
 661
 662         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 663         if (!entry)
 664                 return -ENOMEM;
 665
 666         if (copy_from_user(&entry->report_data, buffer,
 667                                 sizeof(struct usb_hidg_report))) {
 668                 ERROR(cdev, "copy_from_user error\n");
 669                 kfree(entry);
 670                 return -EINVAL;
 671         }
 672
 673         report_id = entry->report_data.report_id;
 674
 675         spin_lock_irqsave(&hidg->get_report_spinlock, flags);
 676         ptr = f_hidg_search_for_report(hidg, report_id);
 677
 678         if (ptr) {
 679                 /* Report already exists in list - update it */
 680                 if (copy_from_user(&ptr->report_data, buffer,
 681                                 sizeof(struct usb_hidg_report))) {
 682                         spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 683                         ERROR(cdev, "copy_from_user error\n");
 684                         kfree(entry);
 685                         return -EINVAL;
 686                 }
 687                 kfree(entry);
 688         } else {
 689                 /* Report does not exist in list - add it */
 690                 list_add_tail(&entry->node, &hidg->report_list);
 691         }
 692
 693         /* If there is no response pending then do nothing further */
 694         if (hidg->get_report_returned) {
 695                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 696                 return 0;
 697         }
 698
 699         /* If this userspace response serves the current pending report */
 700         if (hidg->get_report_req_report_id == report_id) {
 701                 hidg->get_report_returned = true;
 702                 wake_up(&hidg->get_queue);
 703         }
 704
 705         spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 706         return 0;
 707 }
 708
 709 static long f_hidg_ioctl(struct file *file, unsigned int code, unsigned long arg)
 710 {
 711         switch (code) {
 712         case GADGET_HID_READ_GET_REPORT_ID:
 713                 return f_hidg_get_report_id(file, (__u8 __user *)arg);
 714         case GADGET_HID_WRITE_GET_REPORT:
 715                 return f_hidg_get_report(file, (struct usb_hidg_report __user *)arg);
 716         default:
 717                 return -ENOTTY;
 718         }
 719 }
 720
 721 static __poll_t f_hidg_poll(struct file *file, poll_table *wait)
 722 {
 723         struct f_hidg   *hidg  = file->private_data;
 724         __poll_t        ret = 0;
 725
 726         poll_wait(file, &hidg->read_queue, wait);
 727         poll_wait(file, &hidg->write_queue, wait);
 728         poll_wait(file, &hidg->get_queue, wait);
 729         poll_wait(file, &hidg->get_id_queue, wait);
 730
 731         if (WRITE_COND)
 732                 ret |= EPOLLOUT | EPOLLWRNORM;
 733
 734         if (hidg->use_out_ep) {
 735                 if (READ_COND_INTOUT)
 736                         ret |= EPOLLIN | EPOLLRDNORM;
 737         } else {
 738                 if (READ_COND_SSREPORT)
 739                         ret |= EPOLLIN | EPOLLRDNORM;
 740         }
 741
 742         if (GET_REPORT_COND)
 743                 ret |= EPOLLPRI;
 744
 745         return ret;
 746 }
 747
 748 #undef WRITE_COND
 749 #undef READ_COND_SSREPORT
 750 #undef READ_COND_INTOUT
 751 #undef GET_REPORT_COND
 752
 753 static int f_hidg_release(struct inode *inode, struct file *fd)
 754 {
 755         fd->private_data = NULL;
 756         return 0;
 757 }
 758
 759 static int f_hidg_open(struct inode *inode, struct file *fd)
 760 {
 761         struct f_hidg *hidg =
 762                 container_of(inode->i_cdev, struct f_hidg, cdev);
 763
 764         fd->private_data = hidg;
 765
 766         return 0;
 767 }
 768
 769 /*-------------------------------------------------------------------------*/
 770 /*                                usb_function                             */
 771
 772 static inline struct usb_request *hidg_alloc_ep_req(struct usb_ep *ep,
 773                                                     unsigned length)
 774 {
 775         return alloc_ep_req(ep, length);
 776 }
 777
 778 static void hidg_intout_complete(struct usb_ep *ep, struct usb_request *req)
 779 {
 780         struct f_hidg *hidg = (struct f_hidg *) req->context;
 781         struct usb_composite_dev *cdev = hidg->func.config->cdev;
 782         struct f_hidg_req_list *req_list;
 783         unsigned long flags;
 784
 785         switch (req->status) {
 786         case 0:
 787                 req_list = kzalloc(sizeof(*req_list), GFP_ATOMIC);
 788                 if (!req_list) {
 789                         ERROR(cdev, "Unable to allocate mem for req_list\n");
 790                         goto free_req;
 791                 }
 792
 793                 req_list->req = req;
 794
 795                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 796                 list_add_tail(&req_list->list, &hidg->completed_out_req);
 797                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 798
 799                 wake_up(&hidg->read_queue);
 800                 break;
 801         default:
 802                 ERROR(cdev, "Set report failed %d\n", req->status);
 803                 fallthrough;
 804         case -ECONNABORTED:             /* hardware forced ep reset */
 805         case -ECONNRESET:               /* request dequeued */
 806         case -ESHUTDOWN:                /* disconnect from host */
 807 free_req:
 808                 free_ep_req(ep, req);
 809                 return;
 810         }
 811 }
 812
 813 static void hidg_ssreport_complete(struct usb_ep *ep, struct usb_request *req)
 814 {
 815         struct f_hidg *hidg = (struct f_hidg *)req->context;
 816         struct usb_composite_dev *cdev = hidg->func.config->cdev;
 817         char *new_buf = NULL;
 818         unsigned long flags;
 819
 820         if (req->status != 0 || req->buf == NULL || req->actual == 0) {
 821                 ERROR(cdev,
 822                       "%s FAILED: status=%d, buf=%p, actual=%d\n",
 823                       __func__, req->status, req->buf, req->actual);
 824                 return;
 825         }
 826
 827         spin_lock_irqsave(&hidg->read_spinlock, flags);
 828
 829         new_buf = krealloc(hidg->set_report_buf, req->actual, GFP_ATOMIC);
 830         if (new_buf == NULL) {
 831                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 832                 return;
 833         }
 834         hidg->set_report_buf = new_buf;
 835
 836         hidg->set_report_length = req->actual;
 837         memcpy(hidg->set_report_buf, req->buf, req->actual);
 838
 839         spin_unlock_irqrestore(&hidg->read_spinlock, flags);
 840
 841         wake_up(&hidg->read_queue);
 842 }
 843
 844 static void hidg_get_report_complete(struct usb_ep *ep, struct usb_request *req)
 845 {
 846 }
 847
 848 static int hidg_setup(struct usb_function *f,
 849                 const struct usb_ctrlrequest *ctrl)
 850 {
 851         struct f_hidg                   *hidg = func_to_hidg(f);
 852         struct usb_composite_dev        *cdev = f->config->cdev;
 853         struct usb_request              *req  = cdev->req;
 854         int status = 0;
 855         __u16 value, length;
 856         unsigned long   flags;
 857
 858         value   = __le16_to_cpu(ctrl->wValue);
 859         length  = __le16_to_cpu(ctrl->wLength);
 860
 861         VDBG(cdev,
 862              "%s crtl_request : bRequestType:0x%x bRequest:0x%x Value:0x%x\n",
 863              __func__, ctrl->bRequestType, ctrl->bRequest, value);
 864
 865         switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 866         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 867                   | HID_REQ_GET_REPORT):
 868                 VDBG(cdev, "get_report | wLength=%d\n", ctrl->wLength);
 869
 870                 /*
 871                  * Update GET_REPORT ID so that an ioctl can be used to determine what
 872                  * GET_REPORT the request was actually for.
 873                  */
 874                 spin_lock_irqsave(&hidg->get_report_spinlock, flags);
 875                 hidg->get_report_req_report_id = value & 0xff;
 876                 hidg->get_report_req_report_length = length;
 877                 spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
 878
 879                 queue_work(hidg->workqueue, &hidg->work);
 880
 881                 return status;
 882
 883         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 884                   | HID_REQ_GET_PROTOCOL):
 885                 VDBG(cdev, "get_protocol\n");
 886                 length = min_t(unsigned int, length, 1);
 887                 ((u8 *) req->buf)[0] = hidg->protocol;
 888                 goto respond;
 889                 break;
 890
 891         case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 892                   | HID_REQ_GET_IDLE):
 893                 VDBG(cdev, "get_idle\n");
 894                 length = min_t(unsigned int, length, 1);
 895                 ((u8 *) req->buf)[0] = hidg->idle;
 896                 goto respond;
 897                 break;
 898
 899         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 900                   | HID_REQ_SET_REPORT):
 901                 VDBG(cdev, "set_report | wLength=%d\n", ctrl->wLength);
 902                 if (hidg->use_out_ep)
 903                         goto stall;
 904                 req->complete = hidg_ssreport_complete;
 905                 req->context  = hidg;
 906                 goto respond;
 907                 break;
 908
 909         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 910                   | HID_REQ_SET_PROTOCOL):
 911                 VDBG(cdev, "set_protocol\n");
 912                 if (value > HID_REPORT_PROTOCOL)
 913                         goto stall;
 914                 length = 0;
 915                 /*
 916                  * We assume that programs implementing the Boot protocol
 917                  * are also compatible with the Report Protocol
 918                  */
 919                 if (hidg->bInterfaceSubClass == USB_INTERFACE_SUBCLASS_BOOT) {
 920                         hidg->protocol = value;
 921                         goto respond;
 922                 }
 923                 goto stall;
 924                 break;
 925
 926         case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8
 927                   | HID_REQ_SET_IDLE):
 928                 VDBG(cdev, "set_idle\n");
 929                 length = 0;
 930                 hidg->idle = value >> 8;
 931                 goto respond;
 932                 break;
 933
 934         case ((USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE) << 8
 935                   | USB_REQ_GET_DESCRIPTOR):
 936                 switch (value >> 8) {
 937                 case HID_DT_HID:
 938                 {
 939                         struct hid_descriptor hidg_desc_copy = hidg_desc;
 940
 941                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n");
 942                         hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT;
 943                         hidg_desc_copy.desc[0].wDescriptorLength =
 944                                 cpu_to_le16(hidg->report_desc_length);
 945
 946                         length = min_t(unsigned short, length,
 947                                                    hidg_desc_copy.bLength);
 948                         memcpy(req->buf, &hidg_desc_copy, length);
 949                         goto respond;
 950                         break;
 951                 }
 952                 case HID_DT_REPORT:
 953                         VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: REPORT\n");
 954                         length = min_t(unsigned short, length,
 955                                                    hidg->report_desc_length);
 956                         memcpy(req->buf, hidg->report_desc, length);
 957                         goto respond;
 958                         break;
 959
 960                 default:
 961                         VDBG(cdev, "Unknown descriptor request 0x%x\n",
 962                                  value >> 8);
 963                         goto stall;
 964                         break;
 965                 }
 966                 break;
 967
 968         default:
 969                 VDBG(cdev, "Unknown request 0x%x\n",
 970                          ctrl->bRequest);
 971                 goto stall;
 972                 break;
 973         }
 974
 975 stall:
 976         return -EOPNOTSUPP;
 977
 978 respond:
 979         req->zero = 0;
 980         req->length = length;
 981         status = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 982         if (status < 0)
 983                 ERROR(cdev, "usb_ep_queue error on ep0 %d\n", value);
 984         return status;
 985 }
 986
 987 static void hidg_disable(struct usb_function *f)
 988 {
 989         struct f_hidg *hidg = func_to_hidg(f);
 990         struct f_hidg_req_list *list, *next;
 991         unsigned long flags;
 992
 993         usb_ep_disable(hidg->in_ep);
 994
 995         if (hidg->out_ep) {
 996                 usb_ep_disable(hidg->out_ep);
 997
 998                 spin_lock_irqsave(&hidg->read_spinlock, flags);
 999                 list_for_each_entry_safe(list, next, &hidg->completed_out_req, list) {
1000                         free_ep_req(hidg->out_ep, list->req);
1001                         list_del(&list->list);
1002                         kfree(list);
1003                 }
1004                 spin_unlock_irqrestore(&hidg->read_spinlock, flags);
1005         }
1006
1007         spin_lock_irqsave(&hidg->get_report_spinlock, flags);
1008         if (!hidg->get_report_returned) {
1009                 usb_ep_free_request(f->config->cdev->gadget->ep0, hidg->get_req);
1010                 hidg->get_req = NULL;
1011                 hidg->get_report_returned = true;
1012         }
1013         spin_unlock_irqrestore(&hidg->get_report_spinlock, flags);
1014
1015         spin_lock_irqsave(&hidg->write_spinlock, flags);
1016         if (!hidg->write_pending) {
1017                 free_ep_req(hidg->in_ep, hidg->req);
1018                 hidg->write_pending = 1;
1019         }
1020
1021         hidg->req = NULL;
1022         spin_unlock_irqrestore(&hidg->write_spinlock, flags);
1023 }
1024
1025 static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
1026 {
1027         struct usb_composite_dev                *cdev = f->config->cdev;
1028         struct f_hidg                           *hidg = func_to_hidg(f);
1029         struct usb_request                      *req_in = NULL;
1030         unsigned long                           flags;
1031         int i, status = 0;
1032
1033         VDBG(cdev, "hidg_set_alt intf:%d alt:%d\n", intf, alt);
1034
1035         if (hidg->in_ep != NULL) {
1036                 /* restart endpoint */
1037                 usb_ep_disable(hidg->in_ep);
1038
1039                 status = config_ep_by_speed(f->config->cdev->gadget, f,
1040                                             hidg->in_ep);
1041                 if (status) {
1042                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
1043                         goto fail;
1044                 }
1045                 status = usb_ep_enable(hidg->in_ep);
1046                 if (status < 0) {
1047                         ERROR(cdev, "Enable IN endpoint FAILED!\n");
1048                         goto fail;
1049                 }
1050                 hidg->in_ep->driver_data = hidg;
1051
1052                 req_in = hidg_alloc_ep_req(hidg->in_ep, hidg->report_length);
1053                 if (!req_in) {
1054                         status = -ENOMEM;
1055                         goto disable_ep_in;
1056                 }
1057         }
1058
1059         if (hidg->use_out_ep && hidg->out_ep != NULL) {
1060                 /* restart endpoint */
1061                 usb_ep_disable(hidg->out_ep);
1062
1063                 status = config_ep_by_speed(f->config->cdev->gadget, f,
1064                                             hidg->out_ep);
1065                 if (status) {
1066                         ERROR(cdev, "config_ep_by_speed FAILED!\n");
1067                         goto free_req_in;
1068                 }
1069                 status = usb_ep_enable(hidg->out_ep);
1070                 if (status < 0) {
1071                         ERROR(cdev, "Enable OUT endpoint FAILED!\n");
1072                         goto free_req_in;
1073                 }
1074                 hidg->out_ep->driver_data = hidg;
1075
1076                 /*
1077                  * allocate a bunch of read buffers and queue them all at once.
1078                  */
1079                 for (i = 0; i < hidg->qlen && status == 0; i++) {
1080                         struct usb_request *req =
1081                                         hidg_alloc_ep_req(hidg->out_ep,
1082                                                           hidg->report_length);
1083                         if (req) {
1084                                 req->complete = hidg_intout_complete;
1085                                 req->context  = hidg;
1086                                 status = usb_ep_queue(hidg->out_ep, req,
1087                                                       GFP_ATOMIC);
1088                                 if (status) {
1089                                         ERROR(cdev, "%s queue req --> %d\n",
1090                                                 hidg->out_ep->name, status);
1091                                         free_ep_req(hidg->out_ep, req);
1092                                 }
1093                         } else {
1094                                 status = -ENOMEM;
1095                                 goto disable_out_ep;
1096                         }
1097                 }
1098         }
1099
1100         if (hidg->in_ep != NULL) {
1101                 spin_lock_irqsave(&hidg->write_spinlock, flags);
1102                 hidg->req = req_in;
1103                 hidg->write_pending = 0;
1104                 spin_unlock_irqrestore(&hidg->write_spinlock, flags);
1105
1106                 wake_up(&hidg->write_queue);
1107         }
1108         return 0;
1109 disable_out_ep:
1110         if (hidg->out_ep)
1111                 usb_ep_disable(hidg->out_ep);
1112 free_req_in:
1113         if (req_in)
1114                 free_ep_req(hidg->in_ep, req_in);
1115
1116 disable_ep_in:
1117         if (hidg->in_ep)
1118                 usb_ep_disable(hidg->in_ep);
1119
1120 fail:
1121         return status;
1122 }
1123
1124 #ifdef CONFIG_COMPAT
1125 static long f_hidg_compat_ioctl(struct file *file, unsigned int code,
1126                 unsigned long value)
1127 {
1128         return f_hidg_ioctl(file, code, value);
1129 }
1130 #endif
1131
1132 static const struct file_operations f_hidg_fops = {
1133         .owner          = THIS_MODULE,
1134         .open           = f_hidg_open,
1135         .release        = f_hidg_release,
1136         .write          = f_hidg_write,
1137         .read           = f_hidg_read,
1138         .poll           = f_hidg_poll,
1139         .unlocked_ioctl = f_hidg_ioctl,
1140 #ifdef CONFIG_COMPAT
1141         .compat_ioctl = f_hidg_compat_ioctl,
1142 #endif
1143         .llseek         = noop_llseek,
1144 };
1145
1146 static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
1147 {
1148         struct usb_ep           *ep;
1149         struct f_hidg           *hidg = func_to_hidg(f);
1150         struct usb_string       *us;
1151         int                     status;
1152
1153         hidg->get_req = usb_ep_alloc_request(c->cdev->gadget->ep0, GFP_ATOMIC);
1154         if (!hidg->get_req)
1155                 return -ENOMEM;
1156
1157         hidg->get_req->zero = 0;
1158         hidg->get_req->complete = hidg_get_report_complete;
1159         hidg->get_req->context = hidg;
1160         hidg->get_report_returned = true;
1161
1162         /* maybe allocate device-global string IDs, and patch descriptors */
1163         us = usb_gstrings_attach(c->cdev, ct_func_strings,
1164                                  ARRAY_SIZE(ct_func_string_defs));
1165         if (IS_ERR(us))
1166                 return PTR_ERR(us);
1167         hidg_interface_desc.iInterface = us[CT_FUNC_HID_IDX].id;
1168
1169         /* allocate instance-specific interface IDs, and patch descriptors */
1170         status = usb_interface_id(c, f);
1171         if (status < 0)
1172                 goto fail;
1173         hidg_interface_desc.bInterfaceNumber = status;
1174
1175         /* allocate instance-specific endpoints */
1176         status = -ENODEV;
1177         ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_in_ep_desc);
1178         if (!ep)
1179                 goto fail;
1180         hidg->in_ep = ep;
1181
1182         hidg->out_ep = NULL;
1183         if (hidg->use_out_ep) {
1184                 ep = usb_ep_autoconfig(c->cdev->gadget, &hidg_fs_out_ep_desc);
1185                 if (!ep)
1186                         goto fail;
1187                 hidg->out_ep = ep;
1188         }
1189
1190         /* used only if use_out_ep == 1 */
1191         hidg->set_report_buf = NULL;
1192
1193         /* set descriptor dynamic values */
1194         hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
1195         hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;
1196         hidg_interface_desc.bNumEndpoints = hidg->use_out_ep ? 2 : 1;
1197         hidg->protocol = HID_REPORT_PROTOCOL;
1198         hidg->idle = 1;
1199         hidg_ss_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1200         hidg_ss_in_comp_desc.wBytesPerInterval =
1201                                 cpu_to_le16(hidg->report_length);
1202         hidg_hs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1203         hidg_fs_in_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1204         hidg_ss_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1205         hidg_ss_out_comp_desc.wBytesPerInterval =
1206                                 cpu_to_le16(hidg->report_length);
1207         hidg_hs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1208         hidg_fs_out_ep_desc.wMaxPacketSize = cpu_to_le16(hidg->report_length);
1209         /*
1210          * We can use hidg_desc struct here but we should not relay
1211          * that its content won't change after returning from this function.
1212          */
1213         hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT;
1214         hidg_desc.desc[0].wDescriptorLength =
1215                 cpu_to_le16(hidg->report_desc_length);
1216
1217         hidg_hs_in_ep_desc.bEndpointAddress =
1218                 hidg_fs_in_ep_desc.bEndpointAddress;
1219         hidg_hs_out_ep_desc.bEndpointAddress =
1220                 hidg_fs_out_ep_desc.bEndpointAddress;
1221
1222         hidg_ss_in_ep_desc.bEndpointAddress =
1223                 hidg_fs_in_ep_desc.bEndpointAddress;
1224         hidg_ss_out_ep_desc.bEndpointAddress =
1225                 hidg_fs_out_ep_desc.bEndpointAddress;
1226
1227         if (hidg->use_out_ep)
1228                 status = usb_assign_descriptors(f,
1229                         hidg_fs_descriptors_intout,
1230                         hidg_hs_descriptors_intout,
1231                         hidg_ss_descriptors_intout,
1232                         hidg_ss_descriptors_intout);
1233         else
1234                 status = usb_assign_descriptors(f,
1235                         hidg_fs_descriptors_ssreport,
1236                         hidg_hs_descriptors_ssreport,
1237                         hidg_ss_descriptors_ssreport,
1238                         hidg_ss_descriptors_ssreport);
1239
1240         if (status)
1241                 goto fail;
1242
1243         spin_lock_init(&hidg->write_spinlock);
1244         hidg->write_pending = 1;
1245         hidg->req = NULL;
1246         spin_lock_init(&hidg->read_spinlock);
1247         spin_lock_init(&hidg->get_report_spinlock);
1248         init_waitqueue_head(&hidg->write_queue);
1249         init_waitqueue_head(&hidg->read_queue);
1250         init_waitqueue_head(&hidg->get_queue);
1251         init_waitqueue_head(&hidg->get_id_queue);
1252         INIT_LIST_HEAD(&hidg->completed_out_req);
1253         INIT_LIST_HEAD(&hidg->report_list);
1254
1255         INIT_WORK(&hidg->work, get_report_workqueue_handler);
1256         hidg->workqueue = alloc_workqueue("report_work",
1257                                           WQ_FREEZABLE |
1258                                           WQ_MEM_RECLAIM,
1259                                           1);
1260
1261         if (!hidg->workqueue) {
1262                 status = -ENOMEM;
1263                 goto fail;
1264         }
1265
1266         /* create char device */
1267         cdev_init(&hidg->cdev, &f_hidg_fops);
1268         status = cdev_device_add(&hidg->cdev, &hidg->dev);
1269         if (status)
1270                 goto fail_free_descs;
1271
1272         return 0;
1273 fail_free_descs:
1274         destroy_workqueue(hidg->workqueue);
1275         usb_free_all_descriptors(f);
1276 fail:
1277         ERROR(f->config->cdev, "hidg_bind FAILED\n");
1278         if (hidg->req != NULL)
1279                 free_ep_req(hidg->in_ep, hidg->req);
1280
1281         usb_ep_free_request(c->cdev->gadget->ep0, hidg->get_req);
1282         hidg->get_req = NULL;
1283
1284         return status;
1285 }
1286
1287 static inline int hidg_get_minor(void)
1288 {
1289         int ret;
1290
1291         ret = ida_alloc(&hidg_ida, GFP_KERNEL);
1292         if (ret >= HIDG_MINORS) {
1293                 ida_free(&hidg_ida, ret);
1294                 ret = -ENODEV;
1295         }
1296
1297         return ret;
1298 }
1299
1300 static inline struct f_hid_opts *to_f_hid_opts(struct config_item *item)
1301 {
1302         return container_of(to_config_group(item), struct f_hid_opts,
1303                             func_inst.group);
1304 }
1305
1306 static void hid_attr_release(struct config_item *item)
1307 {
1308         struct f_hid_opts *opts = to_f_hid_opts(item);
1309
1310         usb_put_function_instance(&opts->func_inst);
1311 }
1312
1313 static struct configfs_item_operations hidg_item_ops = {
1314         .release        = hid_attr_release,
1315 };
1316
1317 #define F_HID_OPT(name, prec, limit)                                    \
1318 static ssize_t f_hid_opts_##name##_show(struct config_item *item, char *page)\
1319 {                                                                       \
1320         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
1321         int result;                                                     \
1322                                                                         \
1323         mutex_lock(&opts->lock);                                        \
1324         result = sprintf(page, "%d\n", opts->name);                     \
1325         mutex_unlock(&opts->lock);                                      \
1326                                                                         \
1327         return result;                                                  \
1328 }                                                                       \
1329                                                                         \
1330 static ssize_t f_hid_opts_##name##_store(struct config_item *item,      \
1331                                          const char *page, size_t len)  \
1332 {                                                                       \
1333         struct f_hid_opts *opts = to_f_hid_opts(item);                  \
1334         int ret;                                                        \
1335         u##prec num;                                                    \
1336                                                                         \
1337         mutex_lock(&opts->lock);                                        \
1338         if (opts->refcnt) {                                             \
1339                 ret = -EBUSY;                                           \
1340                 goto end;                                               \
1341         }                                                               \
1342                                                                         \
1343         ret = kstrtou##prec(page, 0, &num);                             \
1344         if (ret)                                                        \
1345                 goto end;                                               \
1346                                                                         \
1347         if (num > limit) {                                              \
1348                 ret = -EINVAL;                                          \
1349                 goto end;                                               \
1350         }                                                               \
1351         opts->name = num;                                               \
1352         ret = len;                                                      \
1353                                                                         \
1354 end:                                                                    \
1355         mutex_unlock(&opts->lock);                                      \
1356         return ret;                                                     \
1357 }                                                                       \
1358                                                                         \
1359 CONFIGFS_ATTR(f_hid_opts_, name)
1360
1361 F_HID_OPT(subclass, 8, 255);
1362 F_HID_OPT(protocol, 8, 255);
1363 F_HID_OPT(no_out_endpoint, 8, 1);
1364 F_HID_OPT(report_length, 16, 65535);
1365
1366 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
1367 {
1368         struct f_hid_opts *opts = to_f_hid_opts(item);
1369         int result;
1370
1371         mutex_lock(&opts->lock);
1372         result = opts->report_desc_length;
1373         memcpy(page, opts->report_desc, opts->report_desc_length);
1374         mutex_unlock(&opts->lock);
1375
1376         return result;
1377 }
1378
1379 static ssize_t f_hid_opts_report_desc_store(struct config_item *item,
1380                                             const char *page, size_t len)
1381 {
1382         struct f_hid_opts *opts = to_f_hid_opts(item);
1383         int ret = -EBUSY;
1384         char *d;
1385
1386         mutex_lock(&opts->lock);
1387
1388         if (opts->refcnt)
1389                 goto end;
1390         if (len > PAGE_SIZE) {
1391                 ret = -ENOSPC;
1392                 goto end;
1393         }
1394         d = kmemdup(page, len, GFP_KERNEL);
1395         if (!d) {
1396                 ret = -ENOMEM;
1397                 goto end;
1398         }
1399         kfree(opts->report_desc);
1400         opts->report_desc = d;
1401         opts->report_desc_length = len;
1402         opts->report_desc_alloc = true;
1403         ret = len;
1404 end:
1405         mutex_unlock(&opts->lock);
1406         return ret;
1407 }
1408
1409 CONFIGFS_ATTR(f_hid_opts_, report_desc);
1410
1411 static ssize_t f_hid_opts_dev_show(struct config_item *item, char *page)
1412 {
1413         struct f_hid_opts *opts = to_f_hid_opts(item);
1414
1415         return sprintf(page, "%d:%d\n", major, opts->minor);
1416 }
1417
1418 CONFIGFS_ATTR_RO(f_hid_opts_, dev);
1419
1420 static struct configfs_attribute *hid_attrs[] = {
1421         &f_hid_opts_attr_subclass,
1422         &f_hid_opts_attr_protocol,
1423         &f_hid_opts_attr_no_out_endpoint,
1424         &f_hid_opts_attr_report_length,
1425         &f_hid_opts_attr_report_desc,
1426         &f_hid_opts_attr_dev,
1427         NULL,
1428 };
1429
1430 static const struct config_item_type hid_func_type = {
1431         .ct_item_ops    = &hidg_item_ops,
1432         .ct_attrs       = hid_attrs,
1433         .ct_owner       = THIS_MODULE,
1434 };
1435
1436 static inline void hidg_put_minor(int minor)
1437 {
1438         ida_free(&hidg_ida, minor);
1439 }
1440
1441 static void hidg_free_inst(struct usb_function_instance *f)
1442 {
1443         struct f_hid_opts *opts;
1444
1445         opts = container_of(f, struct f_hid_opts, func_inst);
1446
1447         mutex_lock(&hidg_ida_lock);
1448
1449         hidg_put_minor(opts->minor);
1450         if (ida_is_empty(&hidg_ida))
1451                 ghid_cleanup();
1452
1453         mutex_unlock(&hidg_ida_lock);
1454
1455         if (opts->report_desc_alloc)
1456                 kfree(opts->report_desc);
1457
1458         kfree(opts);
1459 }
1460
1461 static struct usb_function_instance *hidg_alloc_inst(void)
1462 {
1463         struct f_hid_opts *opts;
1464         struct usb_function_instance *ret;
1465         int status = 0;
1466
1467         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1468         if (!opts)
1469                 return ERR_PTR(-ENOMEM);
1470         mutex_init(&opts->lock);
1471         opts->func_inst.free_func_inst = hidg_free_inst;
1472         ret = &opts->func_inst;
1473
1474         mutex_lock(&hidg_ida_lock);
1475
1476         if (ida_is_empty(&hidg_ida)) {
1477                 status = ghid_setup(NULL, HIDG_MINORS);
1478                 if (status)  {
1479                         ret = ERR_PTR(status);
1480                         kfree(opts);
1481                         goto unlock;
1482                 }
1483         }
1484
1485         opts->minor = hidg_get_minor();
1486         if (opts->minor < 0) {
1487                 ret = ERR_PTR(opts->minor);
1488                 kfree(opts);
1489                 if (ida_is_empty(&hidg_ida))
1490                         ghid_cleanup();
1491                 goto unlock;
1492         }
1493         config_group_init_type_name(&opts->func_inst.group, "", &hid_func_type);
1494
1495 unlock:
1496         mutex_unlock(&hidg_ida_lock);
1497         return ret;
1498 }
1499
1500 static void hidg_free(struct usb_function *f)
1501 {
1502         struct f_hidg *hidg;
1503         struct f_hid_opts *opts;
1504
1505         hidg = func_to_hidg(f);
1506         opts = container_of(f->fi, struct f_hid_opts, func_inst);
1507         put_device(&hidg->dev);
1508         mutex_lock(&opts->lock);
1509         --opts->refcnt;
1510         mutex_unlock(&opts->lock);
1511 }
1512
1513 static void hidg_unbind(struct usb_configuration *c, struct usb_function *f)
1514 {
1515         struct f_hidg *hidg = func_to_hidg(f);
1516
1517         cdev_device_del(&hidg->cdev, &hidg->dev);
1518         destroy_workqueue(hidg->workqueue);
1519         usb_free_all_descriptors(f);
1520 }
1521
1522 static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
1523 {
1524         struct f_hidg *hidg;
1525         struct f_hid_opts *opts;
1526         int ret;
1527
1528         /* allocate and initialize one new instance */
1529         hidg = kzalloc(sizeof(*hidg), GFP_KERNEL);
1530         if (!hidg)
1531                 return ERR_PTR(-ENOMEM);
1532
1533         opts = container_of(fi, struct f_hid_opts, func_inst);
1534
1535         mutex_lock(&opts->lock);
1536
1537         device_initialize(&hidg->dev);
1538         hidg->dev.release = hidg_release;
1539         hidg->dev.class = &hidg_class;
1540         hidg->dev.devt = MKDEV(major, opts->minor);
1541         ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor);
1542         if (ret)
1543                 goto err_unlock;
1544
1545         hidg->bInterfaceSubClass = opts->subclass;
1546         hidg->bInterfaceProtocol = opts->protocol;
1547         hidg->report_length = opts->report_length;
1548         hidg->report_desc_length = opts->report_desc_length;
1549         if (opts->report_desc) {
1550                 hidg->report_desc = kmemdup(opts->report_desc,
1551                                             opts->report_desc_length,
1552                                             GFP_KERNEL);
1553                 if (!hidg->report_desc) {
1554                         ret = -ENOMEM;
1555                         goto err_put_device;
1556                 }
1557         }
1558         hidg->use_out_ep = !opts->no_out_endpoint;
1559
1560         ++opts->refcnt;
1561         mutex_unlock(&opts->lock);
1562
1563         hidg->func.name    = "hid";
1564         hidg->func.bind    = hidg_bind;
1565         hidg->func.unbind  = hidg_unbind;
1566         hidg->func.set_alt = hidg_set_alt;
1567         hidg->func.disable = hidg_disable;
1568         hidg->func.setup   = hidg_setup;
1569         hidg->func.free_func = hidg_free;
1570
1571         /* this could be made configurable at some point */
1572         hidg->qlen         = 4;
1573
1574         return &hidg->func;
1575
1576 err_put_device:
1577         put_device(&hidg->dev);
1578 err_unlock:
1579         mutex_unlock(&opts->lock);
1580         return ERR_PTR(ret);
1581 }
1582
1583 DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);
1584 MODULE_DESCRIPTION("USB HID function driver");
1585 MODULE_LICENSE("GPL");
1586 MODULE_AUTHOR("Fabien Chouteau");
1587
1588 int ghid_setup(struct usb_gadget *g, int count)
1589 {
1590         int status;
1591         dev_t dev;
1592
1593         status = class_register(&hidg_class);
1594         if (status)
1595                 return status;
1596
1597         status = alloc_chrdev_region(&dev, 0, count, "hidg");
1598         if (status) {
1599                 class_unregister(&hidg_class);
1600                 return status;
1601         }
1602
1603         major = MAJOR(dev);
1604         minors = count;
1605
1606         return 0;
1607 }
1608
1609 void ghid_cleanup(void)
1610 {
1611         if (major) {
1612                 unregister_chrdev_region(MKDEV(major, 0), minors);
1613                 major = minors = 0;
1614         }
1615
1616         class_unregister(&hidg_class);
1617 }