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