Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / hid / usbhid / hiddev.c
diff --git a/kernel/drivers/hid/usbhid/hiddev.c b/kernel/drivers/hid/usbhid/hiddev.c
new file mode 100644 (file)
index 0000000..2f1ddca
--- /dev/null
@@ -0,0 +1,939 @@
+/*
+ *  Copyright (c) 2001 Paul Stewart
+ *  Copyright (c) 2001 Vojtech Pavlik
+ *
+ *  HID char devices, giving access to raw HID device events.
+ *
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Should you need to contact me, the author, you can do so either by
+ * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
+ */
+
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/hid.h>
+#include <linux/hiddev.h>
+#include <linux/compat.h>
+#include <linux/vmalloc.h>
+#include "usbhid.h"
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+#define HIDDEV_MINOR_BASE      0
+#define HIDDEV_MINORS          256
+#else
+#define HIDDEV_MINOR_BASE      96
+#define HIDDEV_MINORS          16
+#endif
+#define HIDDEV_BUFFER_SIZE     2048
+
+struct hiddev {
+       int exist;
+       int open;
+       struct mutex existancelock;
+       wait_queue_head_t wait;
+       struct hid_device *hid;
+       struct list_head list;
+       spinlock_t list_lock;
+};
+
+struct hiddev_list {
+       struct hiddev_usage_ref buffer[HIDDEV_BUFFER_SIZE];
+       int head;
+       int tail;
+       unsigned flags;
+       struct fasync_struct *fasync;
+       struct hiddev *hiddev;
+       struct list_head node;
+       struct mutex thread_lock;
+};
+
+/*
+ * Find a report, given the report's type and ID.  The ID can be specified
+ * indirectly by REPORT_ID_FIRST (which returns the first report of the given
+ * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
+ * given type which follows old_id.
+ */
+static struct hid_report *
+hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
+{
+       unsigned int flags = rinfo->report_id & ~HID_REPORT_ID_MASK;
+       unsigned int rid = rinfo->report_id & HID_REPORT_ID_MASK;
+       struct hid_report_enum *report_enum;
+       struct hid_report *report;
+       struct list_head *list;
+
+       if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
+           rinfo->report_type > HID_REPORT_TYPE_MAX)
+               return NULL;
+
+       report_enum = hid->report_enum +
+               (rinfo->report_type - HID_REPORT_TYPE_MIN);
+
+       switch (flags) {
+       case 0: /* Nothing to do -- report_id is already set correctly */
+               break;
+
+       case HID_REPORT_ID_FIRST:
+               if (list_empty(&report_enum->report_list))
+                       return NULL;
+
+               list = report_enum->report_list.next;
+               report = list_entry(list, struct hid_report, list);
+               rinfo->report_id = report->id;
+               break;
+
+       case HID_REPORT_ID_NEXT:
+               report = report_enum->report_id_hash[rid];
+               if (!report)
+                       return NULL;
+
+               list = report->list.next;
+               if (list == &report_enum->report_list)
+                       return NULL;
+
+               report = list_entry(list, struct hid_report, list);
+               rinfo->report_id = report->id;
+               break;
+
+       default:
+               return NULL;
+       }
+
+       return report_enum->report_id_hash[rinfo->report_id];
+}
+
+/*
+ * Perform an exhaustive search of the report table for a usage, given its
+ * type and usage id.
+ */
+static struct hid_field *
+hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
+{
+       int i, j;
+       struct hid_report *report;
+       struct hid_report_enum *report_enum;
+       struct hid_field *field;
+
+       if (uref->report_type < HID_REPORT_TYPE_MIN ||
+           uref->report_type > HID_REPORT_TYPE_MAX)
+               return NULL;
+
+       report_enum = hid->report_enum +
+               (uref->report_type - HID_REPORT_TYPE_MIN);
+
+       list_for_each_entry(report, &report_enum->report_list, list) {
+               for (i = 0; i < report->maxfield; i++) {
+                       field = report->field[i];
+                       for (j = 0; j < field->maxusage; j++) {
+                               if (field->usage[j].hid == uref->usage_code) {
+                                       uref->report_id = report->id;
+                                       uref->field_index = i;
+                                       uref->usage_index = j;
+                                       return field;
+                               }
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+static void hiddev_send_event(struct hid_device *hid,
+                             struct hiddev_usage_ref *uref)
+{
+       struct hiddev *hiddev = hid->hiddev;
+       struct hiddev_list *list;
+       unsigned long flags;
+
+       spin_lock_irqsave(&hiddev->list_lock, flags);
+       list_for_each_entry(list, &hiddev->list, node) {
+               if (uref->field_index != HID_FIELD_INDEX_NONE ||
+                   (list->flags & HIDDEV_FLAG_REPORT) != 0) {
+                       list->buffer[list->head] = *uref;
+                       list->head = (list->head + 1) &
+                               (HIDDEV_BUFFER_SIZE - 1);
+                       kill_fasync(&list->fasync, SIGIO, POLL_IN);
+               }
+       }
+       spin_unlock_irqrestore(&hiddev->list_lock, flags);
+
+       wake_up_interruptible(&hiddev->wait);
+}
+
+/*
+ * This is where hid.c calls into hiddev to pass an event that occurred over
+ * the interrupt pipe
+ */
+void hiddev_hid_event(struct hid_device *hid, struct hid_field *field,
+                     struct hid_usage *usage, __s32 value)
+{
+       unsigned type = field->report_type;
+       struct hiddev_usage_ref uref;
+
+       uref.report_type =
+         (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
+         ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
+          ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
+       uref.report_id = field->report->id;
+       uref.field_index = field->index;
+       uref.usage_index = (usage - field->usage);
+       uref.usage_code = usage->hid;
+       uref.value = value;
+
+       hiddev_send_event(hid, &uref);
+}
+EXPORT_SYMBOL_GPL(hiddev_hid_event);
+
+void hiddev_report_event(struct hid_device *hid, struct hid_report *report)
+{
+       unsigned type = report->type;
+       struct hiddev_usage_ref uref;
+
+       memset(&uref, 0, sizeof(uref));
+       uref.report_type =
+         (type == HID_INPUT_REPORT) ? HID_REPORT_TYPE_INPUT :
+         ((type == HID_OUTPUT_REPORT) ? HID_REPORT_TYPE_OUTPUT :
+          ((type == HID_FEATURE_REPORT) ? HID_REPORT_TYPE_FEATURE : 0));
+       uref.report_id = report->id;
+       uref.field_index = HID_FIELD_INDEX_NONE;
+
+       hiddev_send_event(hid, &uref);
+}
+
+/*
+ * fasync file op
+ */
+static int hiddev_fasync(int fd, struct file *file, int on)
+{
+       struct hiddev_list *list = file->private_data;
+
+       return fasync_helper(fd, file, on, &list->fasync);
+}
+
+
+/*
+ * release file op
+ */
+static int hiddev_release(struct inode * inode, struct file * file)
+{
+       struct hiddev_list *list = file->private_data;
+       unsigned long flags;
+
+       spin_lock_irqsave(&list->hiddev->list_lock, flags);
+       list_del(&list->node);
+       spin_unlock_irqrestore(&list->hiddev->list_lock, flags);
+
+       mutex_lock(&list->hiddev->existancelock);
+       if (!--list->hiddev->open) {
+               if (list->hiddev->exist) {
+                       usbhid_close(list->hiddev->hid);
+                       usbhid_put_power(list->hiddev->hid);
+               } else {
+                       mutex_unlock(&list->hiddev->existancelock);
+                       kfree(list->hiddev);
+                       vfree(list);
+                       return 0;
+               }
+       }
+
+       mutex_unlock(&list->hiddev->existancelock);
+       vfree(list);
+
+       return 0;
+}
+
+/*
+ * open file op
+ */
+static int hiddev_open(struct inode *inode, struct file *file)
+{
+       struct hiddev_list *list;
+       struct usb_interface *intf;
+       struct hid_device *hid;
+       struct hiddev *hiddev;
+       int res;
+
+       intf = usbhid_find_interface(iminor(inode));
+       if (!intf)
+               return -ENODEV;
+       hid = usb_get_intfdata(intf);
+       hiddev = hid->hiddev;
+
+       if (!(list = vzalloc(sizeof(struct hiddev_list))))
+               return -ENOMEM;
+       mutex_init(&list->thread_lock);
+       list->hiddev = hiddev;
+       file->private_data = list;
+
+       /*
+        * no need for locking because the USB major number
+        * is shared which usbcore guards against disconnect
+        */
+       if (list->hiddev->exist) {
+               if (!list->hiddev->open++) {
+                       res = usbhid_open(hiddev->hid);
+                       if (res < 0) {
+                               res = -EIO;
+                               goto bail;
+                       }
+               }
+       } else {
+               res = -ENODEV;
+               goto bail;
+       }
+
+       spin_lock_irq(&list->hiddev->list_lock);
+       list_add_tail(&list->node, &hiddev->list);
+       spin_unlock_irq(&list->hiddev->list_lock);
+
+       mutex_lock(&hiddev->existancelock);
+       if (!list->hiddev->open++)
+               if (list->hiddev->exist) {
+                       struct hid_device *hid = hiddev->hid;
+                       res = usbhid_get_power(hid);
+                       if (res < 0) {
+                               res = -EIO;
+                               goto bail_unlock;
+                       }
+                       usbhid_open(hid);
+               }
+       mutex_unlock(&hiddev->existancelock);
+       return 0;
+bail_unlock:
+       mutex_unlock(&hiddev->existancelock);
+bail:
+       file->private_data = NULL;
+       vfree(list);
+       return res;
+}
+
+/*
+ * "write" file op
+ */
+static ssize_t hiddev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
+{
+       return -EINVAL;
+}
+
+/*
+ * "read" file op
+ */
+static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
+{
+       DEFINE_WAIT(wait);
+       struct hiddev_list *list = file->private_data;
+       int event_size;
+       int retval;
+
+       event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
+               sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
+
+       if (count < event_size)
+               return 0;
+
+       /* lock against other threads */
+       retval = mutex_lock_interruptible(&list->thread_lock);
+       if (retval)
+               return -ERESTARTSYS;
+
+       while (retval == 0) {
+               if (list->head == list->tail) {
+                       prepare_to_wait(&list->hiddev->wait, &wait, TASK_INTERRUPTIBLE);
+
+                       while (list->head == list->tail) {
+                               if (signal_pending(current)) {
+                                       retval = -ERESTARTSYS;
+                                       break;
+                               }
+                               if (!list->hiddev->exist) {
+                                       retval = -EIO;
+                                       break;
+                               }
+                               if (file->f_flags & O_NONBLOCK) {
+                                       retval = -EAGAIN;
+                                       break;
+                               }
+
+                               /* let O_NONBLOCK tasks run */
+                               mutex_unlock(&list->thread_lock);
+                               schedule();
+                               if (mutex_lock_interruptible(&list->thread_lock)) {
+                                       finish_wait(&list->hiddev->wait, &wait);
+                                       return -EINTR;
+                               }
+                               set_current_state(TASK_INTERRUPTIBLE);
+                       }
+                       finish_wait(&list->hiddev->wait, &wait);
+
+               }
+
+               if (retval) {
+                       mutex_unlock(&list->thread_lock);
+                       return retval;
+               }
+
+
+               while (list->head != list->tail &&
+                      retval + event_size <= count) {
+                       if ((list->flags & HIDDEV_FLAG_UREF) == 0) {
+                               if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE) {
+                                       struct hiddev_event event;
+
+                                       event.hid = list->buffer[list->tail].usage_code;
+                                       event.value = list->buffer[list->tail].value;
+                                       if (copy_to_user(buffer + retval, &event, sizeof(struct hiddev_event))) {
+                                               mutex_unlock(&list->thread_lock);
+                                               return -EFAULT;
+                                       }
+                                       retval += sizeof(struct hiddev_event);
+                               }
+                       } else {
+                               if (list->buffer[list->tail].field_index != HID_FIELD_INDEX_NONE ||
+                                   (list->flags & HIDDEV_FLAG_REPORT) != 0) {
+
+                                       if (copy_to_user(buffer + retval, list->buffer + list->tail, sizeof(struct hiddev_usage_ref))) {
+                                               mutex_unlock(&list->thread_lock);
+                                               return -EFAULT;
+                                       }
+                                       retval += sizeof(struct hiddev_usage_ref);
+                               }
+                       }
+                       list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
+               }
+
+       }
+       mutex_unlock(&list->thread_lock);
+
+       return retval;
+}
+
+/*
+ * "poll" file op
+ * No kernel lock - fine
+ */
+static unsigned int hiddev_poll(struct file *file, poll_table *wait)
+{
+       struct hiddev_list *list = file->private_data;
+
+       poll_wait(file, &list->hiddev->wait, wait);
+       if (list->head != list->tail)
+               return POLLIN | POLLRDNORM;
+       if (!list->hiddev->exist)
+               return POLLERR | POLLHUP;
+       return 0;
+}
+
+/*
+ * "ioctl" file op
+ */
+static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
+{
+       struct hid_device *hid = hiddev->hid;
+       struct hiddev_report_info rinfo;
+       struct hiddev_usage_ref_multi *uref_multi = NULL;
+       struct hiddev_usage_ref *uref;
+       struct hid_report *report;
+       struct hid_field *field;
+       int i;
+
+       uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
+       if (!uref_multi)
+               return -ENOMEM;
+       uref = &uref_multi->uref;
+       if (cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) {
+               if (copy_from_user(uref_multi, user_arg,
+                                  sizeof(*uref_multi)))
+                       goto fault;
+       } else {
+               if (copy_from_user(uref, user_arg, sizeof(*uref)))
+                       goto fault;
+       }
+
+       switch (cmd) {
+       case HIDIOCGUCODE:
+               rinfo.report_type = uref->report_type;
+               rinfo.report_id = uref->report_id;
+               if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                       goto inval;
+
+               if (uref->field_index >= report->maxfield)
+                       goto inval;
+
+               field = report->field[uref->field_index];
+               if (uref->usage_index >= field->maxusage)
+                       goto inval;
+
+               uref->usage_code = field->usage[uref->usage_index].hid;
+
+               if (copy_to_user(user_arg, uref, sizeof(*uref)))
+                       goto fault;
+
+               goto goodreturn;
+
+       default:
+               if (cmd != HIDIOCGUSAGE &&
+                   cmd != HIDIOCGUSAGES &&
+                   uref->report_type == HID_REPORT_TYPE_INPUT)
+                       goto inval;
+
+               if (uref->report_id == HID_REPORT_ID_UNKNOWN) {
+                       field = hiddev_lookup_usage(hid, uref);
+                       if (field == NULL)
+                               goto inval;
+               } else {
+                       rinfo.report_type = uref->report_type;
+                       rinfo.report_id = uref->report_id;
+                       if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                               goto inval;
+
+                       if (uref->field_index >= report->maxfield)
+                               goto inval;
+
+                       field = report->field[uref->field_index];
+
+                       if (cmd == HIDIOCGCOLLECTIONINDEX) {
+                               if (uref->usage_index >= field->maxusage)
+                                       goto inval;
+                       } else if (uref->usage_index >= field->report_count)
+                               goto inval;
+
+                       else if ((cmd == HIDIOCGUSAGES || cmd == HIDIOCSUSAGES) &&
+                                (uref_multi->num_values > HID_MAX_MULTI_USAGES ||
+                                 uref->usage_index + uref_multi->num_values > field->report_count))
+                               goto inval;
+               }
+
+               switch (cmd) {
+               case HIDIOCGUSAGE:
+                       uref->value = field->value[uref->usage_index];
+                       if (copy_to_user(user_arg, uref, sizeof(*uref)))
+                               goto fault;
+                       goto goodreturn;
+
+               case HIDIOCSUSAGE:
+                       field->value[uref->usage_index] = uref->value;
+                       goto goodreturn;
+
+               case HIDIOCGCOLLECTIONINDEX:
+                       i = field->usage[uref->usage_index].collection_index;
+                       kfree(uref_multi);
+                       return i;
+               case HIDIOCGUSAGES:
+                       for (i = 0; i < uref_multi->num_values; i++)
+                               uref_multi->values[i] =
+                                   field->value[uref->usage_index + i];
+                       if (copy_to_user(user_arg, uref_multi,
+                                        sizeof(*uref_multi)))
+                               goto fault;
+                       goto goodreturn;
+               case HIDIOCSUSAGES:
+                       for (i = 0; i < uref_multi->num_values; i++)
+                               field->value[uref->usage_index + i] =
+                                   uref_multi->values[i];
+                       goto goodreturn;
+               }
+
+goodreturn:
+               kfree(uref_multi);
+               return 0;
+fault:
+               kfree(uref_multi);
+               return -EFAULT;
+inval:
+               kfree(uref_multi);
+               return -EINVAL;
+       }
+}
+
+static noinline int hiddev_ioctl_string(struct hiddev *hiddev, unsigned int cmd, void __user *user_arg)
+{
+       struct hid_device *hid = hiddev->hid;
+       struct usb_device *dev = hid_to_usb_dev(hid);
+       int idx, len;
+       char *buf;
+
+       if (get_user(idx, (int __user *)user_arg))
+               return -EFAULT;
+
+       if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
+               return -ENOMEM;
+
+       if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
+               kfree(buf);
+               return -EINVAL;
+       }
+
+       if (copy_to_user(user_arg+sizeof(int), buf, len+1)) {
+               kfree(buf);
+               return -EFAULT;
+       }
+
+       kfree(buf);
+
+       return len;
+}
+
+static long hiddev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       struct hiddev_list *list = file->private_data;
+       struct hiddev *hiddev = list->hiddev;
+       struct hid_device *hid;
+       struct hiddev_collection_info cinfo;
+       struct hiddev_report_info rinfo;
+       struct hiddev_field_info finfo;
+       struct hiddev_devinfo dinfo;
+       struct hid_report *report;
+       struct hid_field *field;
+       void __user *user_arg = (void __user *)arg;
+       int i, r = -EINVAL;
+
+       /* Called without BKL by compat methods so no BKL taken */
+
+       mutex_lock(&hiddev->existancelock);
+       if (!hiddev->exist) {
+               r = -ENODEV;
+               goto ret_unlock;
+       }
+
+       hid = hiddev->hid;
+
+       switch (cmd) {
+
+       case HIDIOCGVERSION:
+               r = put_user(HID_VERSION, (int __user *)arg) ?
+                       -EFAULT : 0;
+               break;
+
+       case HIDIOCAPPLICATION:
+               if (arg >= hid->maxapplication)
+                       break;
+
+               for (i = 0; i < hid->maxcollection; i++)
+                       if (hid->collection[i].type ==
+                           HID_COLLECTION_APPLICATION && arg-- == 0)
+                               break;
+
+               if (i < hid->maxcollection)
+                       r = hid->collection[i].usage;
+               break;
+
+       case HIDIOCGDEVINFO:
+               {
+                       struct usb_device *dev = hid_to_usb_dev(hid);
+                       struct usbhid_device *usbhid = hid->driver_data;
+
+                       memset(&dinfo, 0, sizeof(dinfo));
+
+                       dinfo.bustype = BUS_USB;
+                       dinfo.busnum = dev->bus->busnum;
+                       dinfo.devnum = dev->devnum;
+                       dinfo.ifnum = usbhid->ifnum;
+                       dinfo.vendor = le16_to_cpu(dev->descriptor.idVendor);
+                       dinfo.product = le16_to_cpu(dev->descriptor.idProduct);
+                       dinfo.version = le16_to_cpu(dev->descriptor.bcdDevice);
+                       dinfo.num_applications = hid->maxapplication;
+
+                       r = copy_to_user(user_arg, &dinfo, sizeof(dinfo)) ?
+                               -EFAULT : 0;
+                       break;
+               }
+
+       case HIDIOCGFLAG:
+               r = put_user(list->flags, (int __user *)arg) ?
+                       -EFAULT : 0;
+               break;
+
+       case HIDIOCSFLAG:
+               {
+                       int newflags;
+
+                       if (get_user(newflags, (int __user *)arg)) {
+                               r = -EFAULT;
+                               break;
+                       }
+
+                       if ((newflags & ~HIDDEV_FLAGS) != 0 ||
+                           ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
+                            (newflags & HIDDEV_FLAG_UREF) == 0))
+                               break;
+
+                       list->flags = newflags;
+
+                       r = 0;
+                       break;
+               }
+
+       case HIDIOCGSTRING:
+               r = hiddev_ioctl_string(hiddev, cmd, user_arg);
+               break;
+
+       case HIDIOCINITREPORT:
+               usbhid_init_reports(hid);
+               r = 0;
+               break;
+
+       case HIDIOCGREPORT:
+               if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
+                       r = -EFAULT;
+                       break;
+               }
+
+               if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
+                       break;
+
+               report = hiddev_lookup_report(hid, &rinfo);
+               if (report == NULL)
+                       break;
+
+               hid_hw_request(hid, report, HID_REQ_GET_REPORT);
+               hid_hw_wait(hid);
+
+               r = 0;
+               break;
+
+       case HIDIOCSREPORT:
+               if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
+                       r = -EFAULT;
+                       break;
+               }
+
+               if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
+                       break;
+
+               report = hiddev_lookup_report(hid, &rinfo);
+               if (report == NULL)
+                       break;
+
+               hid_hw_request(hid, report, HID_REQ_SET_REPORT);
+               hid_hw_wait(hid);
+
+               r = 0;
+               break;
+
+       case HIDIOCGREPORTINFO:
+               if (copy_from_user(&rinfo, user_arg, sizeof(rinfo))) {
+                       r = -EFAULT;
+                       break;
+               }
+
+               report = hiddev_lookup_report(hid, &rinfo);
+               if (report == NULL)
+                       break;
+
+               rinfo.num_fields = report->maxfield;
+
+               r = copy_to_user(user_arg, &rinfo, sizeof(rinfo)) ?
+                       -EFAULT : 0;
+               break;
+
+       case HIDIOCGFIELDINFO:
+               if (copy_from_user(&finfo, user_arg, sizeof(finfo))) {
+                       r = -EFAULT;
+                       break;
+               }
+
+               rinfo.report_type = finfo.report_type;
+               rinfo.report_id = finfo.report_id;
+
+               report = hiddev_lookup_report(hid, &rinfo);
+               if (report == NULL)
+                       break;
+
+               if (finfo.field_index >= report->maxfield)
+                       break;
+
+               field = report->field[finfo.field_index];
+               memset(&finfo, 0, sizeof(finfo));
+               finfo.report_type = rinfo.report_type;
+               finfo.report_id = rinfo.report_id;
+               finfo.field_index = field->report_count - 1;
+               finfo.maxusage = field->maxusage;
+               finfo.flags = field->flags;
+               finfo.physical = field->physical;
+               finfo.logical = field->logical;
+               finfo.application = field->application;
+               finfo.logical_minimum = field->logical_minimum;
+               finfo.logical_maximum = field->logical_maximum;
+               finfo.physical_minimum = field->physical_minimum;
+               finfo.physical_maximum = field->physical_maximum;
+               finfo.unit_exponent = field->unit_exponent;
+               finfo.unit = field->unit;
+
+               r = copy_to_user(user_arg, &finfo, sizeof(finfo)) ?
+                       -EFAULT : 0;
+               break;
+
+       case HIDIOCGUCODE:
+               /* fall through */
+       case HIDIOCGUSAGE:
+       case HIDIOCSUSAGE:
+       case HIDIOCGUSAGES:
+       case HIDIOCSUSAGES:
+       case HIDIOCGCOLLECTIONINDEX:
+               r = hiddev_ioctl_usage(hiddev, cmd, user_arg);
+               break;
+
+       case HIDIOCGCOLLECTIONINFO:
+               if (copy_from_user(&cinfo, user_arg, sizeof(cinfo))) {
+                       r = -EFAULT;
+                       break;
+               }
+
+               if (cinfo.index >= hid->maxcollection)
+                       break;
+
+               cinfo.type = hid->collection[cinfo.index].type;
+               cinfo.usage = hid->collection[cinfo.index].usage;
+               cinfo.level = hid->collection[cinfo.index].level;
+
+               r = copy_to_user(user_arg, &cinfo, sizeof(cinfo)) ?
+                       -EFAULT : 0;
+               break;
+
+       default:
+               if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
+                       break;
+
+               if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
+                       int len = strlen(hid->name) + 1;
+                       if (len > _IOC_SIZE(cmd))
+                                len = _IOC_SIZE(cmd);
+                       r = copy_to_user(user_arg, hid->name, len) ?
+                               -EFAULT : len;
+                       break;
+               }
+
+               if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
+                       int len = strlen(hid->phys) + 1;
+                       if (len > _IOC_SIZE(cmd))
+                               len = _IOC_SIZE(cmd);
+                       r = copy_to_user(user_arg, hid->phys, len) ?
+                               -EFAULT : len;
+                       break;
+               }
+       }
+
+ret_unlock:
+       mutex_unlock(&hiddev->existancelock);
+       return r;
+}
+
+#ifdef CONFIG_COMPAT
+static long hiddev_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       return hiddev_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations hiddev_fops = {
+       .owner =        THIS_MODULE,
+       .read =         hiddev_read,
+       .write =        hiddev_write,
+       .poll =         hiddev_poll,
+       .open =         hiddev_open,
+       .release =      hiddev_release,
+       .unlocked_ioctl =       hiddev_ioctl,
+       .fasync =       hiddev_fasync,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = hiddev_compat_ioctl,
+#endif
+       .llseek         = noop_llseek,
+};
+
+static char *hiddev_devnode(struct device *dev, umode_t *mode)
+{
+       return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
+}
+
+static struct usb_class_driver hiddev_class = {
+       .name =         "hiddev%d",
+       .devnode =      hiddev_devnode,
+       .fops =         &hiddev_fops,
+       .minor_base =   HIDDEV_MINOR_BASE,
+};
+
+/*
+ * This is where hid.c calls us to connect a hid device to the hiddev driver
+ */
+int hiddev_connect(struct hid_device *hid, unsigned int force)
+{
+       struct hiddev *hiddev;
+       struct usbhid_device *usbhid = hid->driver_data;
+       int retval;
+
+       if (!force) {
+               unsigned int i;
+               for (i = 0; i < hid->maxcollection; i++)
+                       if (hid->collection[i].type ==
+                           HID_COLLECTION_APPLICATION &&
+                           !IS_INPUT_APPLICATION(hid->collection[i].usage))
+                               break;
+
+               if (i == hid->maxcollection)
+                       return -1;
+       }
+
+       if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
+               return -1;
+
+       init_waitqueue_head(&hiddev->wait);
+       INIT_LIST_HEAD(&hiddev->list);
+       spin_lock_init(&hiddev->list_lock);
+       mutex_init(&hiddev->existancelock);
+       hid->hiddev = hiddev;
+       hiddev->hid = hid;
+       hiddev->exist = 1;
+       retval = usb_register_dev(usbhid->intf, &hiddev_class);
+       if (retval) {
+               hid_err(hid, "Not able to get a minor for this device\n");
+               hid->hiddev = NULL;
+               kfree(hiddev);
+               return -1;
+       }
+       return 0;
+}
+
+/*
+ * This is where hid.c calls us to disconnect a hiddev device from the
+ * corresponding hid device (usually because the usb device has disconnected)
+ */
+static struct usb_class_driver hiddev_class;
+void hiddev_disconnect(struct hid_device *hid)
+{
+       struct hiddev *hiddev = hid->hiddev;
+       struct usbhid_device *usbhid = hid->driver_data;
+
+       usb_deregister_dev(usbhid->intf, &hiddev_class);
+
+       mutex_lock(&hiddev->existancelock);
+       hiddev->exist = 0;
+
+       if (hiddev->open) {
+               mutex_unlock(&hiddev->existancelock);
+               usbhid_close(hiddev->hid);
+               wake_up_interruptible(&hiddev->wait);
+       } else {
+               mutex_unlock(&hiddev->existancelock);
+               kfree(hiddev);
+       }
+}