USB HID: move usbhid code from drivers/usb/input to drivers/hid/usbhid

Separate usbhid code into dedicated drivers/hid/usbhid directory as
discussed previously with Greg, so that it eases maintaineance process.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 847 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
new file mode 100644
index 000000000000..a8b3d66cd498
--- /dev/null
+++ b/drivers/hid/usbhid/hiddev.c
@@ -0,0 +1,847 @@
+/*
+ *  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/smp_lock.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/hid.h>
+#include <linux/hiddev.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      64
+
+struct hiddev {
+        int exist;
+        int open;
+        wait_queue_head_t wait;
+        struct hid_device *hid;
+        struct list_head list;
+};
+
+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;
+};
+
+static struct hiddev *hiddev_table[HIDDEV_MINORS];
+
+/*
+ * 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;
+
+        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);
+                }
+        }
+
+        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)
+{
+        int retval;
+        struct hiddev_list *list = file->private_data;
+
+        retval = fasync_helper(fd, file, on, &list->fasync);
+
+        return retval < 0 ? retval : 0;
+}
+
+
+/*
+ * release file op
+ */
+static int hiddev_release(struct inode * inode, struct file * file)
+{
+        struct hiddev_list *list = file->private_data;
+
+        hiddev_fasync(-1, file, 0);
+        list_del(&list->node);
+
+        if (!--list->hiddev->open) {
+                if (list->hiddev->exist)
+                        usbhid_close(list->hiddev->hid);
+                else
+                        kfree(list->hiddev);
+        }
+
+        kfree(list);
+
+        return 0;
+}
+
+/*
+ * open file op
+ */
+static int hiddev_open(struct inode *inode, struct file *file)
+{
+        struct hiddev_list *list;
+
+        int i = iminor(inode) - HIDDEV_MINOR_BASE;
+
+        if (i >= HIDDEV_MINORS || !hiddev_table[i])
+                return -ENODEV;
+
+        if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
+                return -ENOMEM;
+
+        list->hiddev = hiddev_table[i];
+        list_add_tail(&list->node, &hiddev_table[i]->list);
+        file->private_data = list;
+
+        if (!list->hiddev->open++)
+                if (list->hiddev->exist)
+                        usbhid_open(hiddev_table[i]->hid);
+
+        return 0;
+}
+
+/*
+ * "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)
+{
+        DECLARE_WAITQUEUE(wait, current);
+        struct hiddev_list *list = file->private_data;
+        int event_size;
+        int retval = 0;
+
+        event_size = ((list->flags & HIDDEV_FLAG_UREF) != 0) ?
+                sizeof(struct hiddev_usage_ref) : sizeof(struct hiddev_event);
+
+        if (count < event_size)
+                return 0;
+
+        while (retval == 0) {
+                if (list->head == list->tail) {
+                        add_wait_queue(&list->hiddev->wait, &wait);
+                        set_current_state(TASK_INTERRUPTIBLE);
+
+                        while (list->head == list->tail) {
+                                if (file->f_flags & O_NONBLOCK) {
+                                        retval = -EAGAIN;
+                                        break;
+                                }
+                                if (signal_pending(current)) {
+                                        retval = -ERESTARTSYS;
+                                        break;
+                                }
+                                if (!list->hiddev->exist) {
+                                        retval = -EIO;
+                                        break;
+                                }
+
+                                schedule();
+                                set_current_state(TASK_INTERRUPTIBLE);
+                        }
+
+                        set_current_state(TASK_RUNNING);
+                        remove_wait_queue(&list->hiddev->wait, &wait);
+                }
+
+                if (retval)
+                        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)))
+                                                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)))
+                                                return -EFAULT;
+                                        retval += sizeof(struct hiddev_usage_ref);
+                                }
+                        }
+                        list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
+                }
+
+        }
+
+        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 int hiddev_ioctl(struct inode *inode, 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 = hiddev->hid;
+        struct usb_device *dev = hid_to_usb_dev(hid);
+        struct hiddev_collection_info cinfo;
+        struct hiddev_report_info rinfo;
+        struct hiddev_field_info finfo;
+        struct hiddev_usage_ref_multi *uref_multi = NULL;
+        struct hiddev_usage_ref *uref;
+        struct hiddev_devinfo dinfo;
+        struct hid_report *report;
+        struct hid_field *field;
+        struct usbhid_device *usbhid = hid->driver_data;
+        void __user *user_arg = (void __user *)arg;
+        int i;
+
+        if (!hiddev->exist)
+                return -EIO;
+
+        switch (cmd) {
+
+        case HIDIOCGVERSION:
+                return put_user(HID_VERSION, (int __user *)arg);
+
+        case HIDIOCAPPLICATION:
+                if (arg < 0 || arg >= hid->maxapplication)
+                        return -EINVAL;
+
+                for (i = 0; i < hid->maxcollection; i++)
+                        if (hid->collection[i].type ==
+                            HID_COLLECTION_APPLICATION && arg-- == 0)
+                                break;
+
+                if (i == hid->maxcollection)
+                        return -EINVAL;
+
+                return hid->collection[i].usage;
+
+        case HIDIOCGDEVINFO:
+                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;
+                if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
+                        return -EFAULT;
+
+                return 0;
+
+        case HIDIOCGFLAG:
+                if (put_user(list->flags, (int __user *)arg))
+                        return -EFAULT;
+
+                return 0;
+
+        case HIDIOCSFLAG:
+                {
+                        int newflags;
+                        if (get_user(newflags, (int __user *)arg))
+                                return -EFAULT;
+
+                        if ((newflags & ~HIDDEV_FLAGS) != 0 ||
+                            ((newflags & HIDDEV_FLAG_REPORT) != 0 &&
+                             (newflags & HIDDEV_FLAG_UREF) == 0))
+                                return -EINVAL;
+
+                        list->flags = newflags;
+
+                        return 0;
+                }
+
+        case HIDIOCGSTRING:
+                {
+                        int idx, len;
+                        char *buf;
+
+                        if (get_user(idx, (int __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;
+                }
+
+        case HIDIOCINITREPORT:
+                usbhid_init_reports(hid);
+
+                return 0;
+
+        case HIDIOCGREPORT:
+                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
+                        return -EFAULT;
+
+                if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
+                        return -EINVAL;
+
+                if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                        return -EINVAL;
+
+                usbhid_submit_report(hid, report, USB_DIR_IN);
+                usbhid_wait_io(hid);
+
+                return 0;
+
+        case HIDIOCSREPORT:
+                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
+                        return -EFAULT;
+
+                if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
+                        return -EINVAL;
+
+                if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                        return -EINVAL;
+
+                usbhid_submit_report(hid, report, USB_DIR_OUT);
+                usbhid_wait_io(hid);
+
+                return 0;
+
+        case HIDIOCGREPORTINFO:
+                if (copy_from_user(&rinfo, user_arg, sizeof(rinfo)))
+                        return -EFAULT;
+
+                if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                        return -EINVAL;
+
+                rinfo.num_fields = report->maxfield;
+
+                if (copy_to_user(user_arg, &rinfo, sizeof(rinfo)))
+                        return -EFAULT;
+
+                return 0;
+
+        case HIDIOCGFIELDINFO:
+                if (copy_from_user(&finfo, user_arg, sizeof(finfo)))
+                        return -EFAULT;
+                rinfo.report_type = finfo.report_type;
+                rinfo.report_id = finfo.report_id;
+                if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
+                        return -EINVAL;
+
+                if (finfo.field_index >= report->maxfield)
+                        return -EINVAL;
+
+                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;
+
+                if (copy_to_user(user_arg, &finfo, sizeof(finfo)))
+                        return -EFAULT;
+
+                return 0;
+
+        case HIDIOCGUCODE:
+                uref_multi = kmalloc(sizeof(struct hiddev_usage_ref_multi), GFP_KERNEL);
+                if (!uref_multi)
+                        return -ENOMEM;
+                uref = &uref_multi->uref;
+                if (copy_from_user(uref, user_arg, sizeof(*uref)))
+                        goto fault;
+
+                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;
+
+                kfree(uref_multi);
+                return 0;
+
+        case HIDIOCGUSAGE:
+        case HIDIOCSUSAGE:
+        case HIDIOCGUSAGES:
+        case HIDIOCSUSAGES:
+        case HIDIOCGCOLLECTIONINDEX:
+                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;
+                }
+
+                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:
+                                kfree(uref_multi);
+                                return field->usage[uref->usage_index].collection_index;
+                        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;
+
+        case HIDIOCGCOLLECTIONINFO:
+                if (copy_from_user(&cinfo, user_arg, sizeof(cinfo)))
+                        return -EFAULT;
+
+                if (cinfo.index >= hid->maxcollection)
+                        return -EINVAL;
+
+                cinfo.type = hid->collection[cinfo.index].type;
+                cinfo.usage = hid->collection[cinfo.index].usage;
+                cinfo.level = hid->collection[cinfo.index].level;
+
+                if (copy_to_user(user_arg, &cinfo, sizeof(cinfo)))
+                        return -EFAULT;
+                return 0;
+
+        default:
+
+                if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
+                        return -EINVAL;
+
+                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
+                        int len;
+                        if (!hid->name)
+                                return 0;
+                        len = strlen(hid->name) + 1;
+                        if (len > _IOC_SIZE(cmd))
+                                 len = _IOC_SIZE(cmd);
+                        return copy_to_user(user_arg, hid->name, len) ?
+                                -EFAULT : len;
+                }
+
+                if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGPHYS(0))) {
+                        int len;
+                        if (!hid->phys)
+                                return 0;
+                        len = strlen(hid->phys) + 1;
+                        if (len > _IOC_SIZE(cmd))
+                                len = _IOC_SIZE(cmd);
+                        return copy_to_user(user_arg, hid->phys, len) ?
+                                -EFAULT : len;
+                }
+        }
+        return -EINVAL;
+}
+
+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,
+        .ioctl =        hiddev_ioctl,
+        .fasync =       hiddev_fasync,
+};
+
+static struct usb_class_driver hiddev_class = {
+        .name =         "hiddev%d",
+        .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)
+{
+        struct hiddev *hiddev;
+        struct usbhid_device *usbhid = hid->driver_data;
+        int i;
+        int retval;
+
+        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 && (hid->quirks & HID_QUIRK_HIDDEV) == 0)
+                return -1;
+
+        if (!(hiddev = kzalloc(sizeof(struct hiddev), GFP_KERNEL)))
+                return -1;
+
+        retval = usb_register_dev(usbhid->intf, &hiddev_class);
+        if (retval) {
+                err("Not able to get a minor for this device.");
+                kfree(hiddev);
+                return -1;
+        }
+
+        init_waitqueue_head(&hiddev->wait);
+        INIT_LIST_HEAD(&hiddev->list);
+        hiddev->hid = hid;
+        hiddev->exist = 1;
+
+        hid->minor = usbhid->intf->minor;
+        hid->hiddev = hiddev;
+
+        hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
+
+        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;
+
+        hiddev->exist = 0;
+
+        hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
+        usb_deregister_dev(usbhid->intf, &hiddev_class);
+
+        if (hiddev->open) {
+                usbhid_close(hiddev->hid);
+                wake_up_interruptible(&hiddev->wait);
+        } else {
+                kfree(hiddev);
+        }
+}
+
+/* Currently this driver is a USB driver.  It's not a conventional one in
+ * the sense that it doesn't probe at the USB level.  Instead it waits to
+ * be connected by HID through the hiddev_connect / hiddev_disconnect
+ * routines.  The reason to register as a USB device is to gain part of the
+ * minor number space from the USB major.
+ *
+ * In theory, should the HID code be generalized to more than one physical
+ * medium (say, IEEE 1384), this driver will probably need to register its
+ * own major number, and in doing so, no longer need to register with USB.
+ * At that point the probe routine and hiddev_driver struct below will no
+ * longer be useful.
+ */
+
+
+/* We never attach in this manner, and rely on HID to connect us.  This
+ * is why there is no disconnect routine defined in the usb_driver either.
+ */
+static int hiddev_usbd_probe(struct usb_interface *intf,
+                             const struct usb_device_id *hiddev_info)
+{
+        return -ENODEV;
+}
+
+
+static /* const */ struct usb_driver hiddev_driver = {
+        .name =         "hiddev",
+        .probe =        hiddev_usbd_probe,
+};
+
+int __init hiddev_init(void)
+{
+        return usb_register(&hiddev_driver);
+}
+
+void hiddev_exit(void)
+{
+        usb_deregister(&hiddev_driver);
+}