// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 2000-2001 Vojtech Pavlik
 *  Copyright (c) 2006-2010 Jiri Kosina
 *
 *  HID to Linux Input mapping
 */

/*
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kernel.h>

#include <linux/hid.h>
#include <linux/hid-debug.h>

#include "hid-ids.h"

#define unk     KEY_UNKNOWN

static const unsigned char hid_keyboard[256] = {
          0,  0,  0,  0, 30, 48, 46, 32, 18, 33, 34, 35, 23, 36, 37, 38,
         50, 49, 24, 25, 16, 19, 31, 20, 22, 47, 17, 45, 21, 44,  2,  3,
          4,  5,  6,  7,  8,  9, 10, 11, 28,  1, 14, 15, 57, 12, 13, 26,
         27, 43, 43, 39, 40, 41, 51, 52, 53, 58, 59, 60, 61, 62, 63, 64,
         65, 66, 67, 68, 87, 88, 99, 70,119,110,102,104,111,107,109,106,
        105,108,103, 69, 98, 55, 74, 78, 96, 79, 80, 81, 75, 76, 77, 71,
         72, 73, 82, 83, 86,127,116,117,183,184,185,186,187,188,189,190,
        191,192,193,194,134,138,130,132,128,129,131,137,133,135,136,113,
        115,114,unk,unk,unk,121,unk, 89, 93,124, 92, 94, 95,unk,unk,unk,
        122,123, 90, 91, 85,unk,unk,unk,unk,unk,unk,unk,111,unk,unk,unk,
        unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,
        unk,unk,unk,unk,unk,unk,179,180,unk,unk,unk,unk,unk,unk,unk,unk,
        unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,unk,
        unk,unk,unk,unk,unk,unk,unk,unk,111,unk,unk,unk,unk,unk,unk,unk,
         29, 42, 56,125, 97, 54,100,126,164,166,165,163,161,115,114,113,
        150,158,159,128,136,177,178,176,142,152,173,140,unk,unk,unk,unk
};

static const struct {
        __s32 x;
        __s32 y;
}  hid_hat_to_axis[] = {{ 0, 0}, { 0,-1}, { 1,-1}, { 1, 0}, { 1, 1}, { 0, 1}, {-1, 1}, {-1, 0}, {-1,-1}};

#define map_abs(c)      hid_map_usage(hidinput, usage, &bit, &max, EV_ABS, (c))
#define map_rel(c)      hid_map_usage(hidinput, usage, &bit, &max, EV_REL, (c))
#define map_key(c)      hid_map_usage(hidinput, usage, &bit, &max, EV_KEY, (c))
#define map_led(c)      hid_map_usage(hidinput, usage, &bit, &max, EV_LED, (c))

#define map_abs_clear(c)        hid_map_usage_clear(hidinput, usage, &bit, \
                &max, EV_ABS, (c))
#define map_key_clear(c)        hid_map_usage_clear(hidinput, usage, &bit, \
                &max, EV_KEY, (c))

static bool match_scancode(struct hid_usage *usage,
                           unsigned int cur_idx, unsigned int scancode)
{
        return (usage->hid & (HID_USAGE_PAGE | HID_USAGE)) == scancode;
}

static bool match_keycode(struct hid_usage *usage,
                          unsigned int cur_idx, unsigned int keycode)
{
        /*
         * We should exclude unmapped usages when doing lookup by keycode.
         */
        return (usage->type == EV_KEY && usage->code == keycode);
}

static bool match_index(struct hid_usage *usage,
                        unsigned int cur_idx, unsigned int idx)
{
        return cur_idx == idx;
}

typedef bool (*hid_usage_cmp_t)(struct hid_usage *usage,
                                unsigned int cur_idx, unsigned int val);

static struct hid_usage *hidinput_find_key(struct hid_device *hid,
                                           hid_usage_cmp_t match,
                                           unsigned int value,
                                           unsigned int *usage_idx)
{
        unsigned int i, j, k, cur_idx = 0;
        struct hid_report *report;
        struct hid_usage *usage;

        for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {
                list_for_each_entry(report, &hid->report_enum[k].report_list, list) {
                        for (i = 0; i < report->maxfield; i++) {
                                for (j = 0; j < report->field[i]->maxusage; j++) {
                                        usage = report->field[i]->usage + j;
                                        if (usage->type == EV_KEY || usage->type == 0) {
                                                if (match(usage, cur_idx, value)) {
                                                        if (usage_idx)
                                                                *usage_idx = cur_idx;
                                                        return usage;
                                                }
                                                cur_idx++;
                                        }
                                }
                        }
                }
        }
        return NULL;
}

static struct hid_usage *hidinput_locate_usage(struct hid_device *hid,
                                        const struct input_keymap_entry *ke,
                                        unsigned int *index)
{
        struct hid_usage *usage;
        unsigned int scancode;

        if (ke->flags & INPUT_KEYMAP_BY_INDEX)
                usage = hidinput_find_key(hid, match_index, ke->index, index);
        else if (input_scancode_to_scalar(ke, &scancode) == 0)
                usage = hidinput_find_key(hid, match_scancode, scancode, index);
        else
                usage = NULL;

        return usage;
}

static int hidinput_getkeycode(struct input_dev *dev,
                               struct input_keymap_entry *ke)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct hid_usage *usage;
        unsigned int scancode, index;

        usage = hidinput_locate_usage(hid, ke, &index);
        if (usage) {
                ke->keycode = usage->type == EV_KEY ?
                                usage->code : KEY_RESERVED;
                ke->index = index;
                scancode = usage->hid & (HID_USAGE_PAGE | HID_USAGE);
                ke->len = sizeof(scancode);
                memcpy(ke->scancode, &scancode, sizeof(scancode));
                return 0;
        }

        return -EINVAL;
}

static int hidinput_setkeycode(struct input_dev *dev,
                               const struct input_keymap_entry *ke,
                               unsigned int *old_keycode)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct hid_usage *usage;

        usage = hidinput_locate_usage(hid, ke, NULL);
        if (usage) {
                *old_keycode = usage->type == EV_KEY ?
                                usage->code : KEY_RESERVED;
                usage->code = ke->keycode;

                clear_bit(*old_keycode, dev->keybit);
                set_bit(usage->code, dev->keybit);
                dbg_hid("Assigned keycode %d to HID usage code %x\n",
                        usage->code, usage->hid);

                /*
                 * Set the keybit for the old keycode if the old keycode is used
                 * by another key
                 */
                if (hidinput_find_key(hid, match_keycode, *old_keycode, NULL))
                        set_bit(*old_keycode, dev->keybit);

                return 0;
        }

        return -EINVAL;
}


/**
 * hidinput_calc_abs_res - calculate an absolute axis resolution
 * @field: the HID report field to calculate resolution for
 * @code: axis code
 *
 * The formula is:
 *                         (logical_maximum - logical_minimum)
 * resolution = ----------------------------------------------------------
 *              (physical_maximum - physical_minimum) * 10 ^ unit_exponent
 *
 * as seen in the HID specification v1.11 6.2.2.7 Global Items.
 *
 * Only exponent 1 length units are processed. Centimeters and inches are
 * converted to millimeters. Degrees are converted to radians.
 */
__s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
{
        __s32 unit_exponent = field->unit_exponent;
        __s32 logical_extents = field->logical_maximum -
                                        field->logical_minimum;
        __s32 physical_extents = field->physical_maximum -
                                        field->physical_minimum;
        __s32 prev;

        /* Check if the extents are sane */
        if (logical_extents <= 0 || physical_extents <= 0)
                return 0;

        /*
         * Verify and convert units.
         * See HID specification v1.11 6.2.2.7 Global Items for unit decoding
         */
        switch (code) {
        case ABS_X:
        case ABS_Y:
        case ABS_Z:
        case ABS_MT_POSITION_X:
        case ABS_MT_POSITION_Y:
        case ABS_MT_TOOL_X:
        case ABS_MT_TOOL_Y:
        case ABS_MT_TOUCH_MAJOR:
        case ABS_MT_TOUCH_MINOR:
                if (field->unit == 0x11) {              /* If centimeters */
                        /* Convert to millimeters */
                        unit_exponent += 1;
                } else if (field->unit == 0x13) {       /* If inches */
                        /* Convert to millimeters */
                        prev = physical_extents;
                        physical_extents *= 254;
                        if (physical_extents < prev)
                                return 0;
                        unit_exponent -= 1;
                } else {
                        return 0;
                }
                break;

        case ABS_RX:
        case ABS_RY:
        case ABS_RZ:
        case ABS_WHEEL:
        case ABS_TILT_X:
        case ABS_TILT_Y:
                if (field->unit == 0x14) {              /* If degrees */
                        /* Convert to radians */
                        prev = logical_extents;
                        logical_extents *= 573;
                        if (logical_extents < prev)
                                return 0;
                        unit_exponent += 1;
                } else if (field->unit != 0x12) {       /* If not radians */
                        return 0;
                }
                break;

        default:
                return 0;
        }

        /* Apply negative unit exponent */
        for (; unit_exponent < 0; unit_exponent++) {
                prev = logical_extents;
                logical_extents *= 10;
                if (logical_extents < prev)
                        return 0;
        }
        /* Apply positive unit exponent */
        for (; unit_exponent > 0; unit_exponent--) {
                prev = physical_extents;
                physical_extents *= 10;
                if (physical_extents < prev)
                        return 0;
        }

        /* Calculate resolution */
        return DIV_ROUND_CLOSEST(logical_extents, physical_extents);
}
EXPORT_SYMBOL_GPL(hidinput_calc_abs_res);

#ifdef CONFIG_HID_BATTERY_STRENGTH
static enum power_supply_property hidinput_battery_props[] = {
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_SCOPE,
};

#define HID_BATTERY_QUIRK_PERCENT       (1 << 0) /* always reports percent */
#define HID_BATTERY_QUIRK_FEATURE       (1 << 1) /* ask for feature report */
#define HID_BATTERY_QUIRK_IGNORE        (1 << 2) /* completely ignore the battery */

static const struct hid_device_id hid_battery_quirks[] = {
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_ALU_WIRELESS_2009_ISO),
          HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_ALU_WIRELESS_2009_ANSI),
          HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_ALU_WIRELESS_2011_ANSI),
          HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                               USB_DEVICE_ID_APPLE_ALU_WIRELESS_2011_ISO),
          HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_ALU_WIRELESS_ANSI),
          HID_BATTERY_QUIRK_PERCENT | HID_BATTERY_QUIRK_FEATURE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM,
                USB_DEVICE_ID_ELECOM_BM084),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_USB_DEVICE(USB_VENDOR_ID_SYMBOL,
                USB_DEVICE_ID_SYMBOL_SCANNER_3),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ASUSTEK,
                USB_DEVICE_ID_ASUSTEK_T100CHI_KEYBOARD),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LOGITECH,
                USB_DEVICE_ID_LOGITECH_DINOVO_EDGE_KBD),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_ASUS_UX550_TOUCHSCREEN),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, I2C_DEVICE_ID_HP_SPECTRE_X360_15),
          HID_BATTERY_QUIRK_IGNORE },
        { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, I2C_DEVICE_ID_SURFACE_GO_TOUCHSCREEN),
          HID_BATTERY_QUIRK_IGNORE },
        {}
};

static unsigned find_battery_quirk(struct hid_device *hdev)
{
        unsigned quirks = 0;
        const struct hid_device_id *match;

        match = hid_match_id(hdev, hid_battery_quirks);
        if (match != NULL)
                quirks = match->driver_data;

        return quirks;
}

static int hidinput_scale_battery_capacity(struct hid_device *dev,
                                           int value)
{
        if (dev->battery_min < dev->battery_max &&
            value >= dev->battery_min && value <= dev->battery_max)
                value = ((value - dev->battery_min) * 100) /
                        (dev->battery_max - dev->battery_min);

        return value;
}

static int hidinput_query_battery_capacity(struct hid_device *dev)
{
        u8 *buf;
        int ret;

        buf = kmalloc(4, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        ret = hid_hw_raw_request(dev, dev->battery_report_id, buf, 4,
                                 dev->battery_report_type, HID_REQ_GET_REPORT);
        if (ret < 2) {
                kfree(buf);
                return -ENODATA;
        }

        ret = hidinput_scale_battery_capacity(dev, buf[1]);
        kfree(buf);
        return ret;
}

static int hidinput_get_battery_property(struct power_supply *psy,
                                         enum power_supply_property prop,
                                         union power_supply_propval *val)
{
        struct hid_device *dev = power_supply_get_drvdata(psy);
        int value;
        int ret = 0;

        switch (prop) {
        case POWER_SUPPLY_PROP_PRESENT:
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = 1;
                break;

        case POWER_SUPPLY_PROP_CAPACITY:
                if (dev->battery_status != HID_BATTERY_REPORTED &&
                    !dev->battery_avoid_query) {
                        value = hidinput_query_battery_capacity(dev);
                        if (value < 0)
                                return value;
                } else  {
                        value = dev->battery_capacity;
                }

                val->intval = value;
                break;

        case POWER_SUPPLY_PROP_MODEL_NAME:
                val->strval = dev->name;
                break;

        case POWER_SUPPLY_PROP_STATUS:
                if (dev->battery_status != HID_BATTERY_REPORTED &&
                    !dev->battery_avoid_query) {
                        value = hidinput_query_battery_capacity(dev);
                        if (value < 0)
                                return value;

                        dev->battery_capacity = value;
                        dev->battery_status = HID_BATTERY_QUERIED;
                }

                if (dev->battery_status == HID_BATTERY_UNKNOWN)
                        val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
                else
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                break;

        case POWER_SUPPLY_PROP_SCOPE:
                val->intval = POWER_SUPPLY_SCOPE_DEVICE;
                break;

        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
                                  struct hid_field *field, bool is_percentage)
{
        struct power_supply_desc *psy_desc;
        struct power_supply_config psy_cfg = { .drv_data = dev, };
        unsigned quirks;
        s32 min, max;
        int error;

        if (dev->battery)
                return 0;       /* already initialized? */

        quirks = find_battery_quirk(dev);

        hid_dbg(dev, "device %x:%x:%x %d quirks %d\n",
                dev->bus, dev->vendor, dev->product, dev->version, quirks);

        if (quirks & HID_BATTERY_QUIRK_IGNORE)
                return 0;

        psy_desc = kzalloc(sizeof(*psy_desc), GFP_KERNEL);
        if (!psy_desc)
                return -ENOMEM;

        psy_desc->name = kasprintf(GFP_KERNEL, "hid-%s-battery",
                                   strlen(dev->uniq) ?
                                        dev->uniq : dev_name(&dev->dev));
        if (!psy_desc->name) {
                error = -ENOMEM;
                goto err_free_mem;
        }

        psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
        psy_desc->properties = hidinput_battery_props;
        psy_desc->num_properties = ARRAY_SIZE(hidinput_battery_props);
        psy_desc->use_for_apm = 0;
        psy_desc->get_property = hidinput_get_battery_property;

        min = field->logical_minimum;
        max = field->logical_maximum;

        if (is_percentage || (quirks & HID_BATTERY_QUIRK_PERCENT)) {
                min = 0;
                max = 100;
        }

        if (quirks & HID_BATTERY_QUIRK_FEATURE)
                report_type = HID_FEATURE_REPORT;

        dev->battery_min = min;
        dev->battery_max = max;
        dev->battery_report_type = report_type;
        dev->battery_report_id = field->report->id;

        /*
         * Stylus is normally not connected to the device and thus we
         * can't query the device and get meaningful battery strength.
         * We have to wait for the device to report it on its own.
         */
        dev->battery_avoid_query = report_type == HID_INPUT_REPORT &&
                                   field->physical == HID_DG_STYLUS;

        dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg);
        if (IS_ERR(dev->battery)) {
                error = PTR_ERR(dev->battery);
                hid_warn(dev, "can't register power supply: %d\n", error);
                goto err_free_name;
        }

        power_supply_powers(dev->battery, &dev->dev);
        return 0;

err_free_name:
        kfree(psy_desc->name);
err_free_mem:
        kfree(psy_desc);
        dev->battery = NULL;
        return error;
}

static void hidinput_cleanup_battery(struct hid_device *dev)
{
        const struct power_supply_desc *psy_desc;

        if (!dev->battery)
                return;

        psy_desc = dev->battery->desc;
        power_supply_unregister(dev->battery);
        kfree(psy_desc->name);
        kfree(psy_desc);
        dev->battery = NULL;
}

static void hidinput_update_battery(struct hid_device *dev, int value)
{
        int capacity;

        if (!dev->battery)
                return;

        if (value == 0 || value < dev->battery_min || value > dev->battery_max)
                return;

        capacity = hidinput_scale_battery_capacity(dev, value);

        if (dev->battery_status != HID_BATTERY_REPORTED ||
            capacity != dev->battery_capacity ||
            ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) {
                dev->battery_capacity = capacity;
                dev->battery_status = HID_BATTERY_REPORTED;
                dev->battery_ratelimit_time =
                        ktime_add_ms(ktime_get_coarse(), 30 * 1000);
                power_supply_changed(dev->battery);
        }
}
#else  /* !CONFIG_HID_BATTERY_STRENGTH */
static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type,
                                  struct hid_field *field, bool is_percentage)
{
        return 0;
}

static void hidinput_cleanup_battery(struct hid_device *dev)
{
}

static void hidinput_update_battery(struct hid_device *dev, int value)
{
}
#endif  /* CONFIG_HID_BATTERY_STRENGTH */

static bool hidinput_field_in_collection(struct hid_device *device, struct hid_field *field,
                                         unsigned int type, unsigned int usage)
{
        struct hid_collection *collection;

        collection = &device->collection[field->usage->collection_index];

        return collection->type == type && collection->usage == usage;
}

static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_field *field,
                                     struct hid_usage *usage)
{
        struct input_dev *input = hidinput->input;
        struct hid_device *device = input_get_drvdata(input);
        int max = 0, code;
        unsigned long *bit = NULL;

        field->hidinput = hidinput;

        if (field->flags & HID_MAIN_ITEM_CONSTANT)
                goto ignore;

        /* Ignore if report count is out of bounds. */
        if (field->report_count < 1)
                goto ignore;

        /* only LED usages are supported in output fields */
        if (field->report_type == HID_OUTPUT_REPORT &&
                        (usage->hid & HID_USAGE_PAGE) != HID_UP_LED) {
                goto ignore;
        }

        if (device->driver->input_mapping) {
                int ret = device->driver->input_mapping(device, hidinput, field,
                                usage, &bit, &max);
                if (ret > 0)
                        goto mapped;
                if (ret < 0)
                        goto ignore;
        }

        switch (usage->hid & HID_USAGE_PAGE) {
        case HID_UP_UNDEFINED:
                goto ignore;

        case HID_UP_KEYBOARD:
                set_bit(EV_REP, input->evbit);

                if ((usage->hid & HID_USAGE) < 256) {
                        if (!hid_keyboard[usage->hid & HID_USAGE]) goto ignore;
                        map_key_clear(hid_keyboard[usage->hid & HID_USAGE]);
                } else
                        map_key(KEY_UNKNOWN);

                break;

        case HID_UP_BUTTON:
                code = ((usage->hid - 1) & HID_USAGE);

                switch (field->application) {
                case HID_GD_MOUSE:
                case HID_GD_POINTER:  code += BTN_MOUSE; break;
                case HID_GD_JOYSTICK:
                                if (code <= 0xf)
                                        code += BTN_JOYSTICK;
                                else
                                        code += BTN_TRIGGER_HAPPY - 0x10;
                                break;
                case HID_GD_GAMEPAD:
                                if (code <= 0xf)
                                        code += BTN_GAMEPAD;
                                else
                                        code += BTN_TRIGGER_HAPPY - 0x10;
                                break;
                case HID_CP_CONSUMER_CONTROL:
                                if (hidinput_field_in_collection(device, field,
                                                                 HID_COLLECTION_NAMED_ARRAY,
                                                                 HID_CP_PROGRAMMABLEBUTTONS)) {
                                        if (code <= 0x1d)
                                                code += KEY_MACRO1;
                                        else
                                                code += BTN_TRIGGER_HAPPY - 0x1e;
                                } else {
                                        goto ignore;
                                }
                                break;
                default:
                        switch (field->physical) {
                        case HID_GD_MOUSE:
                        case HID_GD_POINTER:  code += BTN_MOUSE; break;
                        case HID_GD_JOYSTICK: code += BTN_JOYSTICK; break;
                        case HID_GD_GAMEPAD:  code += BTN_GAMEPAD; break;
                        default:              code += BTN_MISC;
                        }
                }

                map_key(code);
                break;

        case HID_UP_SIMULATION:
                switch (usage->hid & 0xffff) {
                case 0xba: map_abs(ABS_RUDDER);   break;
                case 0xbb: map_abs(ABS_THROTTLE); break;
                case 0xc4: map_abs(ABS_GAS);      break;
                case 0xc5: map_abs(ABS_BRAKE);    break;
                case 0xc8: map_abs(ABS_WHEEL);    break;
                default:   goto ignore;
                }
                break;

        case HID_UP_GENDESK:
                if ((usage->hid & 0xf0) == 0x80) {      /* SystemControl */
                        switch (usage->hid & 0xf) {
                        case 0x1: map_key_clear(KEY_POWER);  break;
                        case 0x2: map_key_clear(KEY_SLEEP);  break;
                        case 0x3: map_key_clear(KEY_WAKEUP); break;
                        case 0x4: map_key_clear(KEY_CONTEXT_MENU); break;
                        case 0x5: map_key_clear(KEY_MENU); break;
                        case 0x6: map_key_clear(KEY_PROG1); break;
                        case 0x7: map_key_clear(KEY_HELP); break;
                        case 0x8: map_key_clear(KEY_EXIT); break;
                        case 0x9: map_key_clear(KEY_SELECT); break;
                        case 0xa: map_key_clear(KEY_RIGHT); break;
                        case 0xb: map_key_clear(KEY_LEFT); break;
                        case 0xc: map_key_clear(KEY_UP); break;
                        case 0xd: map_key_clear(KEY_DOWN); break;
                        case 0xe: map_key_clear(KEY_POWER2); break;
                        case 0xf: map_key_clear(KEY_RESTART); break;
                        default: goto unknown;
                        }
                        break;
                }

                if ((usage->hid & 0xf0) == 0xb0) {      /* SC - Display */
                        switch (usage->hid & 0xf) {
                        case 0x05: map_key_clear(KEY_SWITCHVIDEOMODE); break;
                        default: goto ignore;
                        }
                        break;
                }

                /*
                 * Some lazy vendors declare 255 usages for System Control,
                 * leading to the creation of ABS_X|Y axis and too many others.
                 * It wouldn't be a problem if joydev doesn't consider the
                 * device as a joystick then.
                 */
                if (field->application == HID_GD_SYSTEM_CONTROL)
                        goto ignore;

                if ((usage->hid & 0xf0) == 0x90) {      /* D-pad */
                        switch (usage->hid) {
                        case HID_GD_UP:    usage->hat_dir = 1; break;
                        case HID_GD_DOWN:  usage->hat_dir = 5; break;
                        case HID_GD_RIGHT: usage->hat_dir = 3; break;
                        case HID_GD_LEFT:  usage->hat_dir = 7; break;
                        default: goto unknown;
                        }
                        if (field->dpad) {
                                map_abs(field->dpad);
                                goto ignore;
                        }
                        map_abs(ABS_HAT0X);
                        break;
                }

                switch (usage->hid) {
                /* These usage IDs map directly to the usage codes. */
                case HID_GD_X: case HID_GD_Y: case HID_GD_Z:
                case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ:
                        if (field->flags & HID_MAIN_ITEM_RELATIVE)
                                map_rel(usage->hid & 0xf);
                        else
                                map_abs_clear(usage->hid & 0xf);
                        break;

                case HID_GD_WHEEL:
                        if (field->flags & HID_MAIN_ITEM_RELATIVE) {
                                set_bit(REL_WHEEL, input->relbit);
                                map_rel(REL_WHEEL_HI_RES);
                        } else {
                                map_abs(usage->hid & 0xf);
                        }
                        break;
                case HID_GD_SLIDER: case HID_GD_DIAL:
                        if (field->flags & HID_MAIN_ITEM_RELATIVE)
                                map_rel(usage->hid & 0xf);
                        else
                                map_abs(usage->hid & 0xf);
                        break;

                case HID_GD_HATSWITCH:
                        usage->hat_min = field->logical_minimum;
                        usage->hat_max = field->logical_maximum;
                        map_abs(ABS_HAT0X);
                        break;

                case HID_GD_START:      map_key_clear(BTN_START);       break;
                case HID_GD_SELECT:     map_key_clear(BTN_SELECT);      break;

                case HID_GD_RFKILL_BTN:
                        /* MS wireless radio ctl extension, also check CA */
                        if (field->application == HID_GD_WIRELESS_RADIO_CTLS) {
                                map_key_clear(KEY_RFKILL);
                                /* We need to simulate the btn release */
                                field->flags |= HID_MAIN_ITEM_RELATIVE;
                                break;
                        }
                        goto unknown;

                default: goto unknown;
                }

                break;

        case HID_UP_LED:
                switch (usage->hid & 0xffff) {                /* HID-Value:                   */
                case 0x01:  map_led (LED_NUML);     break;    /*   "Num Lock"                 */
                case 0x02:  map_led (LED_CAPSL);    break;    /*   "Caps Lock"                */
                case 0x03:  map_led (LED_SCROLLL);  break;    /*   "Scroll Lock"              */
                case 0x04:  map_led (LED_COMPOSE);  break;    /*   "Compose"                  */
                case 0x05:  map_led (LED_KANA);     break;    /*   "Kana"                     */
                case 0x27:  map_led (LED_SLEEP);    break;    /*   "Stand-By"                 */
                case 0x4c:  map_led (LED_SUSPEND);  break;    /*   "System Suspend"           */
                case 0x09:  map_led (LED_MUTE);     break;    /*   "Mute"                     */
                case 0x4b:  map_led (LED_MISC);     break;    /*   "Generic Indicator"        */
                case 0x19:  map_led (LED_MAIL);     break;    /*   "Message Waiting"          */
                case 0x4d:  map_led (LED_CHARGING); break;    /*   "External Power Connected" */

                default: goto ignore;
                }
                break;

        case HID_UP_DIGITIZER:
                if ((field->application & 0xff) == 0x01) /* Digitizer */
                        __set_bit(INPUT_PROP_POINTER, input->propbit);
                else if ((field->application & 0xff) == 0x02) /* Pen */
                        __set_bit(INPUT_PROP_DIRECT, input->propbit);

                switch (usage->hid & 0xff) {
                case 0x00: /* Undefined */
                        goto ignore;

                case 0x30: /* TipPressure */
                        if (!test_bit(BTN_TOUCH, input->keybit)) {
                                device->quirks |= HID_QUIRK_NOTOUCH;
                                set_bit(EV_KEY, input->evbit);
                                set_bit(BTN_TOUCH, input->keybit);
                        }
                        map_abs_clear(ABS_PRESSURE);
                        break;

                case 0x32: /* InRange */
                        switch (field->physical & 0xff) {
                        case 0x21: map_key(BTN_TOOL_MOUSE); break;
                        case 0x22: map_key(BTN_TOOL_FINGER); break;
                        default: map_key(BTN_TOOL_PEN); break;
                        }
                        break;

                case 0x3b: /* Battery Strength */
                        hidinput_setup_battery(device, HID_INPUT_REPORT, field, false);
                        usage->type = EV_PWR;
                        return;

                case 0x3c: /* Invert */
                        map_key_clear(BTN_TOOL_RUBBER);
                        break;

                case 0x3d: /* X Tilt */
                        map_abs_clear(ABS_TILT_X);
                        break;

                case 0x3e: /* Y Tilt */
                        map_abs_clear(ABS_TILT_Y);
                        break;

                case 0x33: /* Touch */
                case 0x42: /* TipSwitch */
                case 0x43: /* TipSwitch2 */
                        device->quirks &= ~HID_QUIRK_NOTOUCH;
                        map_key_clear(BTN_TOUCH);
                        break;

                case 0x44: /* BarrelSwitch */
                        map_key_clear(BTN_STYLUS);
                        break;

                case 0x45: /* ERASER */
                        /*
                         * This event is reported when eraser tip touches the surface.
                         * Actual eraser (BTN_TOOL_RUBBER) is set by Invert usage when
                         * tool gets in proximity.
                         */
                        map_key_clear(BTN_TOUCH);
                        break;

                case 0x46: /* TabletPick */
                case 0x5a: /* SecondaryBarrelSwitch */
                        map_key_clear(BTN_STYLUS2);
                        break;

                case 0x5b: /* TransducerSerialNumber */
                        usage->type = EV_MSC;
                        usage->code = MSC_SERIAL;
                        bit = input->mscbit;
                        max = MSC_MAX;
                        break;

                default:  goto unknown;
                }
                break;

        case HID_UP_TELEPHONY:
                switch (usage->hid & HID_USAGE) {
                case 0x2f: map_key_clear(KEY_MICMUTE);          break;
                case 0xb0: map_key_clear(KEY_NUMERIC_0);        break;
                case 0xb1: map_key_clear(KEY_NUMERIC_1);        break;
                case 0xb2: map_key_clear(KEY_NUMERIC_2);        break;
                case 0xb3: map_key_clear(KEY_NUMERIC_3);        break;
                case 0xb4: map_key_clear(KEY_NUMERIC_4);        break;
                case 0xb5: map_key_clear(KEY_NUMERIC_5);        break;
                case 0xb6: map_key_clear(KEY_NUMERIC_6);        break;
                case 0xb7: map_key_clear(KEY_NUMERIC_7);        break;
                case 0xb8: map_key_clear(KEY_NUMERIC_8);        break;
                case 0xb9: map_key_clear(KEY_NUMERIC_9);        break;
                case 0xba: map_key_clear(KEY_NUMERIC_STAR);     break;
                case 0xbb: map_key_clear(KEY_NUMERIC_POUND);    break;
                case 0xbc: map_key_clear(KEY_NUMERIC_A);        break;
                case 0xbd: map_key_clear(KEY_NUMERIC_B);        break;
                case 0xbe: map_key_clear(KEY_NUMERIC_C);        break;
                case 0xbf: map_key_clear(KEY_NUMERIC_D);        break;
                default: goto ignore;
                }
                break;

        case HID_UP_CONSUMER:   /* USB HUT v1.12, pages 75-84 */
                switch (usage->hid & HID_USAGE) {
                case 0x000: goto ignore;
                case 0x030: map_key_clear(KEY_POWER);           break;
                case 0x031: map_key_clear(KEY_RESTART);         break;
                case 0x032: map_key_clear(KEY_SLEEP);           break;
                case 0x034: map_key_clear(KEY_SLEEP);           break;
                case 0x035: map_key_clear(KEY_KBDILLUMTOGGLE);  break;
                case 0x036: map_key_clear(BTN_MISC);            break;

                case 0x040: map_key_clear(KEY_MENU);            break; /* Menu */
                case 0x041: map_key_clear(KEY_SELECT);          break; /* Menu Pick */
                case 0x042: map_key_clear(KEY_UP);              break; /* Menu Up */
                case 0x043: map_key_clear(KEY_DOWN);            break; /* Menu Down */
                case 0x044: map_key_clear(KEY_LEFT);            break; /* Menu Left */
                case 0x045: map_key_clear(KEY_RIGHT);           break; /* Menu Right */
                case 0x046: map_key_clear(KEY_ESC);             break; /* Menu Escape */
                case 0x047: map_key_clear(KEY_KPPLUS);          break; /* Menu Value Increase */
                case 0x048: map_key_clear(KEY_KPMINUS);         break; /* Menu Value Decrease */

                case 0x060: map_key_clear(KEY_INFO);            break; /* Data On Screen */
                case 0x061: map_key_clear(KEY_SUBTITLE);        break; /* Closed Caption */
                case 0x063: map_key_clear(KEY_VCR);             break; /* VCR/TV */
                case 0x065: map_key_clear(KEY_CAMERA);          break; /* Snapshot */
                case 0x069: map_key_clear(KEY_RED);             break;
                case 0x06a: map_key_clear(KEY_GREEN);           break;
                case 0x06b: map_key_clear(KEY_BLUE);            break;
                case 0x06c: map_key_clear(KEY_YELLOW);          break;
                case 0x06d: map_key_clear(KEY_ASPECT_RATIO);    break;

                case 0x06f: map_key_clear(KEY_BRIGHTNESSUP);            break;
                case 0x070: map_key_clear(KEY_BRIGHTNESSDOWN);          break;
                case 0x072: map_key_clear(KEY_BRIGHTNESS_TOGGLE);       break;
                case 0x073: map_key_clear(KEY_BRIGHTNESS_MIN);          break;
                case 0x074: map_key_clear(KEY_BRIGHTNESS_MAX);          break;
                case 0x075: map_key_clear(KEY_BRIGHTNESS_AUTO);         break;

                case 0x079: map_key_clear(KEY_KBDILLUMUP);      break;
                case 0x07a: map_key_clear(KEY_KBDILLUMDOWN);    break;
                case 0x07c: map_key_clear(KEY_KBDILLUMTOGGLE);  break;

                case 0x082: map_key_clear(KEY_VIDEO_NEXT);      break;
                case 0x083: map_key_clear(KEY_LAST);            break;
                case 0x084: map_key_clear(KEY_ENTER);           break;
                case 0x088: map_key_clear(KEY_PC);              break;
                case 0x089: map_key_clear(KEY_TV);              break;
                case 0x08a: map_key_clear(KEY_WWW);             break;
                case 0x08b: map_key_clear(KEY_DVD);             break;
                case 0x08c: map_key_clear(KEY_PHONE);           break;
                case 0x08d: map_key_clear(KEY_PROGRAM);         break;
                case 0x08e: map_key_clear(KEY_VIDEOPHONE);      break;
                case 0x08f: map_key_clear(KEY_GAMES);           break;
                case 0x090: map_key_clear(KEY_MEMO);            break;
                case 0x091: map_key_clear(KEY_CD);              break;
                case 0x092: map_key_clear(KEY_VCR);             break;
                case 0x093: map_key_clear(KEY_TUNER);           break;
                case 0x094: map_key_clear(KEY_EXIT);            break;
                case 0x095: map_key_clear(KEY_HELP);            break;
                case 0x096: map_key_clear(KEY_TAPE);            break;
                case 0x097: map_key_clear(KEY_TV2);             break;
                case 0x098: map_key_clear(KEY_SAT);             break;
                case 0x09a: map_key_clear(KEY_PVR);             break;

                case 0x09c: map_key_clear(KEY_CHANNELUP);       break;
                case 0x09d: map_key_clear(KEY_CHANNELDOWN);     break;
                case 0x0a0: map_key_clear(KEY_VCR2);            break;

                case 0x0b0: map_key_clear(KEY_PLAY);            break;
                case 0x0b1: map_key_clear(KEY_PAUSE);           break;
                case 0x0b2: map_key_clear(KEY_RECORD);          break;
                case 0x0b3: map_key_clear(KEY_FASTFORWARD);     break;
                case 0x0b4: map_key_clear(KEY_REWIND);          break;
                case 0x0b5: map_key_clear(KEY_NEXTSONG);        break;
                case 0x0b6: map_key_clear(KEY_PREVIOUSSONG);    break;
                case 0x0b7: map_key_clear(KEY_STOPCD);          break;
                case 0x0b8: map_key_clear(KEY_EJECTCD);         break;
                case 0x0bc: map_key_clear(KEY_MEDIA_REPEAT);    break;
                case 0x0b9: map_key_clear(KEY_SHUFFLE);         break;
                case 0x0bf: map_key_clear(KEY_SLOW);            break;

                case 0x0cd: map_key_clear(KEY_PLAYPAUSE);       break;
                case 0x0cf: map_key_clear(KEY_VOICECOMMAND);    break;

                case 0x0d9: map_key_clear(KEY_EMOJI_PICKER);    break;

                case 0x0e0: map_abs_clear(ABS_VOLUME);          break;
                case 0x0e2: map_key_clear(KEY_MUTE);            break;
                case 0x0e5: map_key_clear(KEY_BASSBOOST);       break;
                case 0x0e9: map_key_clear(KEY_VOLUMEUP);        break;
                case 0x0ea: map_key_clear(KEY_VOLUMEDOWN);      break;
                case 0x0f5: map_key_clear(KEY_SLOW);            break;

                case 0x181: map_key_clear(KEY_BUTTONCONFIG);    break;
                case 0x182: map_key_clear(KEY_BOOKMARKS);       break;

                case 0x183: map_key_clear(KEY_CONFIG);          break;
                case 0x184: map_key_clear(KEY_WORDPROCESSOR);   break;
                case 0x185: map_key_clear(KEY_EDITOR);          break;
                case 0x186: map_key_clear(KEY_SPREADSHEET);     break;
                case 0x187: map_key_clear(KEY_GRAPHICSEDITOR);  break;
                case 0x188: map_key_clear(KEY_PRESENTATION);    break;
                case 0x189: map_key_clear(KEY_DATABASE);        break;
                case 0x18a: map_key_clear(KEY_MAIL);            break;
                case 0x18b: map_key_clear(KEY_NEWS);            break;
                case 0x18c: map_key_clear(KEY_VOICEMAIL);       break;
                case 0x18d: map_key_clear(KEY_ADDRESSBOOK);     break;
                case 0x18e: map_key_clear(KEY_CALENDAR);        break;
                case 0x18f: map_key_clear(KEY_TASKMANAGER);     break;
                case 0x190: map_key_clear(KEY_JOURNAL);         break;
                case 0x191: map_key_clear(KEY_FINANCE);         break;
                case 0x192: map_key_clear(KEY_CALC);            break;
                case 0x193: map_key_clear(KEY_PLAYER);          break;
                case 0x194: map_key_clear(KEY_FILE);            break;
                case 0x196: map_key_clear(KEY_WWW);             break;
                case 0x199: map_key_clear(KEY_CHAT);            break;
                case 0x19c: map_key_clear(KEY_LOGOFF);          break;
                case 0x19e: map_key_clear(KEY_COFFEE);          break;
                case 0x19f: map_key_clear(KEY_CONTROLPANEL);            break;
                case 0x1a2: map_key_clear(KEY_APPSELECT);               break;
                case 0x1a3: map_key_clear(KEY_NEXT);            break;
                case 0x1a4: map_key_clear(KEY_PREVIOUS);        break;
                case 0x1a6: map_key_clear(KEY_HELP);            break;
                case 0x1a7: map_key_clear(KEY_DOCUMENTS);       break;
                case 0x1ab: map_key_clear(KEY_SPELLCHECK);      break;
                case 0x1ae: map_key_clear(KEY_KEYBOARD);        break;
                case 0x1b1: map_key_clear(KEY_SCREENSAVER);             break;
                case 0x1b4: map_key_clear(KEY_FILE);            break;
                case 0x1b6: map_key_clear(KEY_IMAGES);          break;
                case 0x1b7: map_key_clear(KEY_AUDIO);           break;
                case 0x1b8: map_key_clear(KEY_VIDEO);           break;
                case 0x1bc: map_key_clear(KEY_MESSENGER);       break;
                case 0x1bd: map_key_clear(KEY_INFO);            break;
                case 0x1cb: map_key_clear(KEY_ASSISTANT);       break;
                case 0x201: map_key_clear(KEY_NEW);             break;
                case 0x202: map_key_clear(KEY_OPEN);            break;
                case 0x203: map_key_clear(KEY_CLOSE);           break;
                case 0x204: map_key_clear(KEY_EXIT);            break;
                case 0x207: map_key_clear(KEY_SAVE);            break;
                case 0x208: map_key_clear(KEY_PRINT);           break;
                case 0x209: map_key_clear(KEY_PROPS);           break;
                case 0x21a: map_key_clear(KEY_UNDO);            break;
                case 0x21b: map_key_clear(KEY_COPY);            break;
                case 0x21c: map_key_clear(KEY_CUT);             break;
                case 0x21d: map_key_clear(KEY_PASTE);           break;
                case 0x21f: map_key_clear(KEY_FIND);            break;
                case 0x221: map_key_clear(KEY_SEARCH);          break;
                case 0x222: map_key_clear(KEY_GOTO);            break;
                case 0x223: map_key_clear(KEY_HOMEPAGE);        break;
                case 0x224: map_key_clear(KEY_BACK);            break;
                case 0x225: map_key_clear(KEY_FORWARD);         break;
                case 0x226: map_key_clear(KEY_STOP);            break;
                case 0x227: map_key_clear(KEY_REFRESH);         break;
                case 0x22a: map_key_clear(KEY_BOOKMARKS);       break;
                case 0x22d: map_key_clear(KEY_ZOOMIN);          break;
                case 0x22e: map_key_clear(KEY_ZOOMOUT);         break;
                case 0x22f: map_key_clear(KEY_ZOOMRESET);       break;
                case 0x232: map_key_clear(KEY_FULL_SCREEN);     break;
                case 0x233: map_key_clear(KEY_SCROLLUP);        break;
                case 0x234: map_key_clear(KEY_SCROLLDOWN);      break;
                case 0x238: /* AC Pan */
                        set_bit(REL_HWHEEL, input->relbit);
                        map_rel(REL_HWHEEL_HI_RES);
                        break;
                case 0x23d: map_key_clear(KEY_EDIT);            break;
                case 0x25f: map_key_clear(KEY_CANCEL);          break;
                case 0x269: map_key_clear(KEY_INSERT);          break;
                case 0x26a: map_key_clear(KEY_DELETE);          break;
                case 0x279: map_key_clear(KEY_REDO);            break;

                case 0x289: map_key_clear(KEY_REPLY);           break;
                case 0x28b: map_key_clear(KEY_FORWARDMAIL);     break;
                case 0x28c: map_key_clear(KEY_SEND);            break;

                case 0x29d: map_key_clear(KEY_KBD_LAYOUT_NEXT); break;

                case 0x2c7: map_key_clear(KEY_KBDINPUTASSIST_PREV);             break;
                case 0x2c8: map_key_clear(KEY_KBDINPUTASSIST_NEXT);             break;
                case 0x2c9: map_key_clear(KEY_KBDINPUTASSIST_PREVGROUP);                break;
                case 0x2ca: map_key_clear(KEY_KBDINPUTASSIST_NEXTGROUP);                break;
                case 0x2cb: map_key_clear(KEY_KBDINPUTASSIST_ACCEPT);   break;
                case 0x2cc: map_key_clear(KEY_KBDINPUTASSIST_CANCEL);   break;

                case 0x29f: map_key_clear(KEY_SCALE);           break;

                default: map_key_clear(KEY_UNKNOWN);
                }
                break;

        case HID_UP_GENDEVCTRLS:
                switch (usage->hid) {
                case HID_DC_BATTERYSTRENGTH:
                        hidinput_setup_battery(device, HID_INPUT_REPORT, field, false);
                        usage->type = EV_PWR;
                        return;
                }
                goto unknown;

        case HID_UP_BATTERY:
                switch (usage->hid) {
                case HID_BAT_ABSOLUTESTATEOFCHARGE:
                        hidinput_setup_battery(device, HID_INPUT_REPORT, field, true);
                        usage->type = EV_PWR;
                        return;
                }
                goto unknown;

        case HID_UP_HPVENDOR:   /* Reported on a Dutch layout HP5308 */
                set_bit(EV_REP, input->evbit);
                switch (usage->hid & HID_USAGE) {
                case 0x021: map_key_clear(KEY_PRINT);           break;
                case 0x070: map_key_clear(KEY_HP);              break;
                case 0x071: map_key_clear(KEY_CAMERA);          break;
                case 0x072: map_key_clear(KEY_SOUND);           break;
                case 0x073: map_key_clear(KEY_QUESTION);        break;
                case 0x080: map_key_clear(KEY_EMAIL);           break;
                case 0x081: map_key_clear(KEY_CHAT);            break;
                case 0x082: map_key_clear(KEY_SEARCH);          break;
                case 0x083: map_key_clear(KEY_CONNECT);         break;
                case 0x084: map_key_clear(KEY_FINANCE);         break;
                case 0x085: map_key_clear(KEY_SPORT);           break;
                case 0x086: map_key_clear(KEY_SHOP);            break;
                default:    goto ignore;
                }
                break;

        case HID_UP_HPVENDOR2:
                set_bit(EV_REP, input->evbit);
                switch (usage->hid & HID_USAGE) {
                case 0x001: map_key_clear(KEY_MICMUTE);         break;
                case 0x003: map_key_clear(KEY_BRIGHTNESSDOWN);  break;
                case 0x004: map_key_clear(KEY_BRIGHTNESSUP);    break;
                default:    goto ignore;
                }
                break;

        case HID_UP_MSVENDOR:
                goto ignore;

        case HID_UP_CUSTOM: /* Reported on Logitech and Apple USB keyboards */
                set_bit(EV_REP, input->evbit);
                goto ignore;

        case HID_UP_LOGIVENDOR:
                /* intentional fallback */
        case HID_UP_LOGIVENDOR2:
                /* intentional fallback */
        case HID_UP_LOGIVENDOR3:
                goto ignore;

        case HID_UP_PID:
                switch (usage->hid & HID_USAGE) {
                case 0xa4: map_key_clear(BTN_DEAD);     break;
                default: goto ignore;
                }
                break;

        default:
        unknown:
                if (field->report_size == 1) {
                        if (field->report->type == HID_OUTPUT_REPORT) {
                                map_led(LED_MISC);
                                break;
                        }
                        map_key(BTN_MISC);
                        break;
                }
                if (field->flags & HID_MAIN_ITEM_RELATIVE) {
                        map_rel(REL_MISC);
                        break;
                }
                map_abs(ABS_MISC);
                break;
        }

mapped:
        /* Mapping failed, bail out */
        if (!bit)
                return;

        if (device->driver->input_mapped &&
            device->driver->input_mapped(device, hidinput, field, usage,
                                         &bit, &max) < 0) {
                /*
                 * The driver indicated that no further generic handling
                 * of the usage is desired.
                 */
                return;
        }

        set_bit(usage->type, input->evbit);

        /*
         * This part is *really* controversial:
         * - HID aims at being generic so we should do our best to export
         *   all incoming events
         * - HID describes what events are, so there is no reason for ABS_X
         *   to be mapped to ABS_Y
         * - HID is using *_MISC+N as a default value, but nothing prevents
         *   *_MISC+N to overwrite a legitimate even, which confuses userspace
         *   (for instance ABS_MISC + 7 is ABS_MT_SLOT, which has a different
         *   processing)
         *
         * If devices still want to use this (at their own risk), they will
         * have to use the quirk HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE, but
         * the default should be a reliable mapping.
         */
        while (usage->code <= max && test_and_set_bit(usage->code, bit)) {
                if (device->quirks & HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE) {
                        usage->code = find_next_zero_bit(bit,
                                                         max + 1,
                                                         usage->code);
                } else {
                        device->status |= HID_STAT_DUP_DETECTED;
                        goto ignore;
                }
        }

        if (usage->code > max)
                goto ignore;

        if (usage->type == EV_ABS) {

                int a = field->logical_minimum;
                int b = field->logical_maximum;

                if ((device->quirks & HID_QUIRK_BADPAD) && (usage->code == ABS_X || usage->code == ABS_Y)) {
                        a = field->logical_minimum = 0;
                        b = field->logical_maximum = 255;
                }

                if (field->application == HID_GD_GAMEPAD || field->application == HID_GD_JOYSTICK)
                        input_set_abs_params(input, usage->code, a, b, (b - a) >> 8, (b - a) >> 4);
                else    input_set_abs_params(input, usage->code, a, b, 0, 0);

                input_abs_set_res(input, usage->code,
                                  hidinput_calc_abs_res(field, usage->code));

                /* use a larger default input buffer for MT devices */
                if (usage->code == ABS_MT_POSITION_X && input->hint_events_per_packet == 0)
                        input_set_events_per_packet(input, 60);
        }

        if (usage->type == EV_ABS &&
            (usage->hat_min < usage->hat_max || usage->hat_dir)) {
                int i;
                for (i = usage->code; i < usage->code + 2 && i <= max; i++) {
                        input_set_abs_params(input, i, -1, 1, 0, 0);
                        set_bit(i, input->absbit);
                }
                if (usage->hat_dir && !field->dpad)
                        field->dpad = usage->code;
        }

        /* for those devices which produce Consumer volume usage as relative,
         * we emulate pressing volumeup/volumedown appropriate number of times
         * in hidinput_hid_event()
         */
        if ((usage->type == EV_ABS) && (field->flags & HID_MAIN_ITEM_RELATIVE) &&
                        (usage->code == ABS_VOLUME)) {
                set_bit(KEY_VOLUMEUP, input->keybit);
                set_bit(KEY_VOLUMEDOWN, input->keybit);
        }

        if (usage->type == EV_KEY) {
                set_bit(EV_MSC, input->evbit);
                set_bit(MSC_SCAN, input->mscbit);
        }

        return;

ignore:
        usage->type = 0;
        usage->code = 0;
}

static void hidinput_handle_scroll(struct hid_usage *usage,
                                   struct input_dev *input,
                                   __s32 value)
{
        int code;
        int hi_res, lo_res;

        if (value == 0)
                return;

        if (usage->code == REL_WHEEL_HI_RES)
                code = REL_WHEEL;
        else
                code = REL_HWHEEL;

        /*
         * Windows reports one wheel click as value 120. Where a high-res
         * scroll wheel is present, a fraction of 120 is reported instead.
         * Our REL_WHEEL_HI_RES axis does the same because all HW must
         * adhere to the 120 expectation.
         */
        hi_res = value * 120/usage->resolution_multiplier;

        usage->wheel_accumulated += hi_res;
        lo_res = usage->wheel_accumulated/120;
        if (lo_res)
                usage->wheel_accumulated -= lo_res * 120;

        input_event(input, EV_REL, code, lo_res);
        input_event(input, EV_REL, usage->code, hi_res);
}

void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value)
{
        struct input_dev *input;
        unsigned *quirks = &hid->quirks;

        if (!usage->type)
                return;

        if (usage->type == EV_PWR) {
                hidinput_update_battery(hid, value);
                return;
        }

        if (!field->hidinput)
                return;

        input = field->hidinput->input;

        if (usage->hat_min < usage->hat_max || usage->hat_dir) {
                int hat_dir = usage->hat_dir;
                if (!hat_dir)
                        hat_dir = (value - usage->hat_min) * 8 / (usage->hat_max - usage->hat_min + 1) + 1;
                if (hat_dir < 0 || hat_dir > 8) hat_dir = 0;
                input_event(input, usage->type, usage->code    , hid_hat_to_axis[hat_dir].x);
                input_event(input, usage->type, usage->code + 1, hid_hat_to_axis[hat_dir].y);
                return;
        }

        if (usage->hid == HID_DG_INVERT) {
                *quirks = value ? (*quirks | HID_QUIRK_INVERT) : (*quirks & ~HID_QUIRK_INVERT);
                return;
        }

        if (usage->hid == HID_DG_INRANGE) {
                if (value) {
                        input_event(input, usage->type, (*quirks & HID_QUIRK_INVERT) ? BTN_TOOL_RUBBER : usage->code, 1);
                        return;
                }
                input_event(input, usage->type, usage->code, 0);
                input_event(input, usage->type, BTN_TOOL_RUBBER, 0);
                return;
        }

        if (usage->hid == HID_DG_TIPPRESSURE && (*quirks & HID_QUIRK_NOTOUCH)) {
                int a = field->logical_minimum;
                int b = field->logical_maximum;
                input_event(input, EV_KEY, BTN_TOUCH, value > a + ((b - a) >> 3));
        }

        if (usage->hid == (HID_UP_PID | 0x83UL)) { /* Simultaneous Effects Max */
                dbg_hid("Maximum Effects - %d\n",value);
                return;
        }

        if (usage->hid == (HID_UP_PID | 0x7fUL)) {
                dbg_hid("PID Pool Report\n");
                return;
        }

        if ((usage->type == EV_KEY) && (usage->code == 0)) /* Key 0 is "unassigned", not KEY_UNKNOWN */
                return;

        if ((usage->type == EV_REL) && (usage->code == REL_WHEEL_HI_RES ||
                                        usage->code == REL_HWHEEL_HI_RES)) {
                hidinput_handle_scroll(usage, input, value);
                return;
        }

        if ((usage->type == EV_ABS) && (field->flags & HID_MAIN_ITEM_RELATIVE) &&
                        (usage->code == ABS_VOLUME)) {
                int count = abs(value);
                int direction = value > 0 ? KEY_VOLUMEUP : KEY_VOLUMEDOWN;
                int i;

                for (i = 0; i < count; i++) {
                        input_event(input, EV_KEY, direction, 1);
                        input_sync(input);
                        input_event(input, EV_KEY, direction, 0);
                        input_sync(input);
                }
                return;
        }

        /*
         * Ignore out-of-range values as per HID specification,
         * section 5.10 and 6.2.25, when NULL state bit is present.
         * When it's not, clamp the value to match Microsoft's input
         * driver as mentioned in "Required HID usages for digitizers":
         * https://msdn.microsoft.com/en-us/library/windows/hardware/dn672278(v=vs.85).asp
         *
         * The logical_minimum < logical_maximum check is done so that we
         * don't unintentionally discard values sent by devices which
         * don't specify logical min and max.
         */
        if ((field->flags & HID_MAIN_ITEM_VARIABLE) &&
            (field->logical_minimum < field->logical_maximum)) {
                if (field->flags & HID_MAIN_ITEM_NULL_STATE &&
                    (value < field->logical_minimum ||
                     value > field->logical_maximum)) {
                        dbg_hid("Ignoring out-of-range value %x\n", value);
                        return;
                }
                value = clamp(value,
                              field->logical_minimum,
                              field->logical_maximum);
        }

        /*
         * Ignore reports for absolute data if the data didn't change. This is
         * not only an optimization but also fixes 'dead' key reports. Some
         * RollOver implementations for localized keys (like BACKSLASH/PIPE; HID
         * 0x31 and 0x32) report multiple keys, even though a localized keyboard
         * can only have one of them physically available. The 'dead' keys
         * report constant 0. As all map to the same keycode, they'd confuse
         * the input layer. If we filter the 'dead' keys on the HID level, we
         * skip the keycode translation and only forward real events.
         */
        if (!(field->flags & (HID_MAIN_ITEM_RELATIVE |
                              HID_MAIN_ITEM_BUFFERED_BYTE)) &&
                              (field->flags & HID_MAIN_ITEM_VARIABLE) &&
            usage->usage_index < field->maxusage &&
            value == field->value[usage->usage_index])
                return;

        /* report the usage code as scancode if the key status has changed */
        if (usage->type == EV_KEY &&
            (!test_bit(usage->code, input->key)) == value)
                input_event(input, EV_MSC, MSC_SCAN, usage->hid);

        input_event(input, usage->type, usage->code, value);

        if ((field->flags & HID_MAIN_ITEM_RELATIVE) &&
            usage->type == EV_KEY && value) {
                input_sync(input);
                input_event(input, usage->type, usage->code, 0);
        }
}

void hidinput_report_event(struct hid_device *hid, struct hid_report *report)
{
        struct hid_input *hidinput;

        if (hid->quirks & HID_QUIRK_NO_INPUT_SYNC)
                return;

        list_for_each_entry(hidinput, &hid->inputs, list)
                input_sync(hidinput->input);
}
EXPORT_SYMBOL_GPL(hidinput_report_event);

int hidinput_find_field(struct hid_device *hid, unsigned int type, unsigned int code, struct hid_field **field)
{
        struct hid_report *report;
        int i, j;

        list_for_each_entry(report, &hid->report_enum[HID_OUTPUT_REPORT].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].type == type && (*field)->usage[j].code == code)
                                        return j;
                }
        }
        return -1;
}
EXPORT_SYMBOL_GPL(hidinput_find_field);

struct hid_field *hidinput_get_led_field(struct hid_device *hid)
{
        struct hid_report *report;
        struct hid_field *field;
        int i, j;

        list_for_each_entry(report,
                            &hid->report_enum[HID_OUTPUT_REPORT].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].type == EV_LED)
                                        return field;
                }
        }
        return NULL;
}
EXPORT_SYMBOL_GPL(hidinput_get_led_field);

unsigned int hidinput_count_leds(struct hid_device *hid)
{
        struct hid_report *report;
        struct hid_field *field;
        int i, j;
        unsigned int count = 0;

        list_for_each_entry(report,
                            &hid->report_enum[HID_OUTPUT_REPORT].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].type == EV_LED &&
                                    field->value[j])
                                        count += 1;
                }
        }
        return count;
}
EXPORT_SYMBOL_GPL(hidinput_count_leds);

static void hidinput_led_worker(struct work_struct *work)
{
        struct hid_device *hid = container_of(work, struct hid_device,
                                              led_work);
        struct hid_field *field;
        struct hid_report *report;
        int ret;
        u32 len;
        __u8 *buf;

        field = hidinput_get_led_field(hid);
        if (!field)
                return;

        /*
         * field->report is accessed unlocked regarding HID core. So there might
         * be another incoming SET-LED request from user-space, which changes
         * the LED state while we assemble our outgoing buffer. However, this
         * doesn't matter as hid_output_report() correctly converts it into a
         * boolean value no matter what information is currently set on the LED
         * field (even garbage). So the remote device will always get a valid
         * request.
         * And in case we send a wrong value, a next led worker is spawned
         * for every SET-LED request so the following worker will send the
         * correct value, guaranteed!
         */

        report = field->report;

        /* use custom SET_REPORT request if possible (asynchronous) */
        if (hid->ll_driver->request)
                return hid->ll_driver->request(hid, report, HID_REQ_SET_REPORT);

        /* fall back to generic raw-output-report */
        len = hid_report_len(report);
        buf = hid_alloc_report_buf(report, GFP_KERNEL);
        if (!buf)
                return;

        hid_output_report(report, buf);
        /* synchronous output report */
        ret = hid_hw_output_report(hid, buf, len);
        if (ret == -ENOSYS)
                hid_hw_raw_request(hid, report->id, buf, len, HID_OUTPUT_REPORT,
                                HID_REQ_SET_REPORT);
        kfree(buf);
}

static int hidinput_input_event(struct input_dev *dev, unsigned int type,
                                unsigned int code, int value)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct hid_field *field;
        int offset;

        if (type == EV_FF)
                return input_ff_event(dev, type, code, value);

        if (type != EV_LED)
                return -1;

        if ((offset = hidinput_find_field(hid, type, code, &field)) == -1) {
                hid_warn(dev, "event field not found\n");
                return -1;
        }

        hid_set_field(field, offset, value);

        schedule_work(&hid->led_work);
        return 0;
}

static int hidinput_open(struct input_dev *dev)
{
        struct hid_device *hid = input_get_drvdata(dev);

        return hid_hw_open(hid);
}

static void hidinput_close(struct input_dev *dev)
{
        struct hid_device *hid = input_get_drvdata(dev);

        hid_hw_close(hid);
}

static bool __hidinput_change_resolution_multipliers(struct hid_device *hid,
                struct hid_report *report, bool use_logical_max)
{
        struct hid_usage *usage;
        bool update_needed = false;
        bool get_report_completed = false;
        int i, j;

        if (report->maxfield == 0)
                return false;

        for (i = 0; i < report->maxfield; i++) {
                __s32 value = use_logical_max ?
                              report->field[i]->logical_maximum :
                              report->field[i]->logical_minimum;

                /* There is no good reason for a Resolution
                 * Multiplier to have a count other than 1.
                 * Ignore that case.
                 */
                if (report->field[i]->report_count != 1)
                        continue;

                for (j = 0; j < report->field[i]->maxusage; j++) {
                        usage = &report->field[i]->usage[j];

                        if (usage->hid != HID_GD_RESOLUTION_MULTIPLIER)
                                continue;

                        /*
                         * If we have more than one feature within this
                         * report we need to fill in the bits from the
                         * others before we can overwrite the ones for the
                         * Resolution Multiplier.
                         *
                         * But if we're not allowed to read from the device,
                         * we just bail. Such a device should not exist
                         * anyway.
                         */
                        if (!get_report_completed && report->maxfield > 1) {
                                if (hid->quirks & HID_QUIRK_NO_INIT_REPORTS)
                                        return update_needed;

                                hid_hw_request(hid, report, HID_REQ_GET_REPORT);
                                hid_hw_wait(hid);
                                get_report_completed = true;
                        }

                        report->field[i]->value[j] = value;
                        update_needed = true;
                }
        }

        return update_needed;
}

static void hidinput_change_resolution_multipliers(struct hid_device *hid)
{
        struct hid_report_enum *rep_enum;
        struct hid_report *rep;
        int ret;

        rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
        list_for_each_entry(rep, &rep_enum->report_list, list) {
                bool update_needed = __hidinput_change_resolution_multipliers(hid,
                                                                     rep, true);

                if (update_needed) {
                        ret = __hid_request(hid, rep, HID_REQ_SET_REPORT);
                        if (ret) {
                                __hidinput_change_resolution_multipliers(hid,
                                                                    rep, false);
                                return;
                        }
                }
        }

        /* refresh our structs */
        hid_setup_resolution_multiplier(hid);
}

static void report_features(struct hid_device *hid)
{
        struct hid_driver *drv = hid->driver;
        struct hid_report_enum *rep_enum;
        struct hid_report *rep;
        struct hid_usage *usage;
        int i, j;

        rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
        list_for_each_entry(rep, &rep_enum->report_list, list)
                for (i = 0; i < rep->maxfield; i++) {
                        /* Ignore if report count is out of bounds. */
                        if (rep->field[i]->report_count < 1)
                                continue;

                        for (j = 0; j < rep->field[i]->maxusage; j++) {
                                usage = &rep->field[i]->usage[j];

                                /* Verify if Battery Strength feature is available */
                                if (usage->hid == HID_DC_BATTERYSTRENGTH)
                                        hidinput_setup_battery(hid, HID_FEATURE_REPORT,
                                                               rep->field[i], false);

                                if (drv->feature_mapping)
                                        drv->feature_mapping(hid, rep->field[i], usage);
                        }
                }
}

static struct hid_input *hidinput_allocate(struct hid_device *hid,
                                           unsigned int application)
{
        struct hid_input *hidinput = kzalloc(sizeof(*hidinput), GFP_KERNEL);
        struct input_dev *input_dev = input_allocate_device();
        const char *suffix = NULL;
        size_t suffix_len, name_len;

        if (!hidinput || !input_dev)
                goto fail;

        if ((hid->quirks & HID_QUIRK_INPUT_PER_APP) &&
            hid->maxapplication > 1) {
                switch (application) {
                case HID_GD_KEYBOARD:
                        suffix = "Keyboard";
                        break;
                case HID_GD_KEYPAD:
                        suffix = "Keypad";
                        break;
                case HID_GD_MOUSE:
                        suffix = "Mouse";
                        break;
                case HID_DG_STYLUS:
                        suffix = "Pen";
                        break;
                case HID_DG_TOUCHSCREEN:
                        suffix = "Touchscreen";
                        break;
                case HID_DG_TOUCHPAD:
                        suffix = "Touchpad";
                        break;
                case HID_GD_SYSTEM_CONTROL:
                        suffix = "System Control";
                        break;
                case HID_CP_CONSUMER_CONTROL:
                        suffix = "Consumer Control";
                        break;
                case HID_GD_WIRELESS_RADIO_CTLS:
                        suffix = "Wireless Radio Control";
                        break;
                case HID_GD_SYSTEM_MULTIAXIS:
                        suffix = "System Multi Axis";
                        break;
                default:
                        break;
                }
        }

        if (suffix) {
                name_len = strlen(hid->name);
                suffix_len = strlen(suffix);
                if ((name_len < suffix_len) ||
                    strcmp(hid->name + name_len - suffix_len, suffix)) {
                        hidinput->name = kasprintf(GFP_KERNEL, "%s %s",
                                                   hid->name, suffix);
                        if (!hidinput->name)
                                goto fail;
                }
        }

        input_set_drvdata(input_dev, hid);
        input_dev->event = hidinput_input_event;
        input_dev->open = hidinput_open;
        input_dev->close = hidinput_close;
        input_dev->setkeycode = hidinput_setkeycode;
        input_dev->getkeycode = hidinput_getkeycode;

        input_dev->name = hidinput->name ? hidinput->name : hid->name;
        input_dev->phys = hid->phys;
        input_dev->uniq = hid->uniq;
        input_dev->id.bustype = hid->bus;
        input_dev->id.vendor  = hid->vendor;
        input_dev->id.product = hid->product;
        input_dev->id.version = hid->version;
        input_dev->dev.parent = &hid->dev;

        hidinput->input = input_dev;
        hidinput->application = application;
        list_add_tail(&hidinput->list, &hid->inputs);

        INIT_LIST_HEAD(&hidinput->reports);

        return hidinput;

fail:
        kfree(hidinput);
        input_free_device(input_dev);
        hid_err(hid, "Out of memory during hid input probe\n");
        return NULL;
}

static bool hidinput_has_been_populated(struct hid_input *hidinput)
{
        int i;
        unsigned long r = 0;

        for (i = 0; i < BITS_TO_LONGS(EV_CNT); i++)
                r |= hidinput->input->evbit[i];

        for (i = 0; i < BITS_TO_LONGS(KEY_CNT); i++)
                r |= hidinput->input->keybit[i];

        for (i = 0; i < BITS_TO_LONGS(REL_CNT); i++)
                r |= hidinput->input->relbit[i];

        for (i = 0; i < BITS_TO_LONGS(ABS_CNT); i++)
                r |= hidinput->input->absbit[i];

        for (i = 0; i < BITS_TO_LONGS(MSC_CNT); i++)
                r |= hidinput->input->mscbit[i];

        for (i = 0; i < BITS_TO_LONGS(LED_CNT); i++)
                r |= hidinput->input->ledbit[i];

        for (i = 0; i < BITS_TO_LONGS(SND_CNT); i++)
                r |= hidinput->input->sndbit[i];

        for (i = 0; i < BITS_TO_LONGS(FF_CNT); i++)
                r |= hidinput->input->ffbit[i];

        for (i = 0; i < BITS_TO_LONGS(SW_CNT); i++)
                r |= hidinput->input->swbit[i];

        return !!r;
}

static void hidinput_cleanup_hidinput(struct hid_device *hid,
                struct hid_input *hidinput)
{
        struct hid_report *report;
        int i, k;

        list_del(&hidinput->list);
        input_free_device(hidinput->input);
        kfree(hidinput->name);

        for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {
                if (k == HID_OUTPUT_REPORT &&
                        hid->quirks & HID_QUIRK_SKIP_OUTPUT_REPORTS)
                        continue;

                list_for_each_entry(report, &hid->report_enum[k].report_list,
                                    list) {

                        for (i = 0; i < report->maxfield; i++)
                                if (report->field[i]->hidinput == hidinput)
                                        report->field[i]->hidinput = NULL;
                }
        }

        kfree(hidinput);
}

static struct hid_input *hidinput_match(struct hid_report *report)
{
        struct hid_device *hid = report->device;
        struct hid_input *hidinput;

        list_for_each_entry(hidinput, &hid->inputs, list) {
                if (hidinput->report &&
                    hidinput->report->id == report->id)
                        return hidinput;
        }

        return NULL;
}

static struct hid_input *hidinput_match_application(struct hid_report *report)
{
        struct hid_device *hid = report->device;
        struct hid_input *hidinput;

        list_for_each_entry(hidinput, &hid->inputs, list) {
                if (hidinput->application == report->application)
                        return hidinput;

                /*
                 * Keep SystemControl and ConsumerControl applications together
                 * with the main keyboard, if present.
                 */
                if ((report->application == HID_GD_SYSTEM_CONTROL ||
                     report->application == HID_CP_CONSUMER_CONTROL) &&
                    hidinput->application == HID_GD_KEYBOARD) {
                        return hidinput;
                }
        }

        return NULL;
}

static inline void hidinput_configure_usages(struct hid_input *hidinput,
                                             struct hid_report *report)
{
        int i, j;

        for (i = 0; i < report->maxfield; i++)
                for (j = 0; j < report->field[i]->maxusage; j++)
                        hidinput_configure_usage(hidinput, report->field[i],
                                                 report->field[i]->usage + j);
}

/*
 * Register the input device; print a message.
 * Configure the input layer interface
 * Read all reports and initialize the absolute field values.
 */

int hidinput_connect(struct hid_device *hid, unsigned int force)
{
        struct hid_driver *drv = hid->driver;
        struct hid_report *report;
        struct hid_input *next, *hidinput = NULL;
        unsigned int application;
        int i, k;

        INIT_LIST_HEAD(&hid->inputs);
        INIT_WORK(&hid->led_work, hidinput_led_worker);

        hid->status &= ~HID_STAT_DUP_DETECTED;

        if (!force) {
                for (i = 0; i < hid->maxcollection; i++) {
                        struct hid_collection *col = &hid->collection[i];
                        if (col->type == HID_COLLECTION_APPLICATION ||
                                        col->type == HID_COLLECTION_PHYSICAL)
                                if (IS_INPUT_APPLICATION(col->usage))
                                        break;
                }

                if (i == hid->maxcollection)
                        return -1;
        }

        report_features(hid);

        for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {
                if (k == HID_OUTPUT_REPORT &&
                        hid->quirks & HID_QUIRK_SKIP_OUTPUT_REPORTS)
                        continue;

                list_for_each_entry(report, &hid->report_enum[k].report_list, list) {

                        if (!report->maxfield)
                                continue;

                        application = report->application;

                        /*
                         * Find the previous hidinput report attached
                         * to this report id.
                         */
                        if (hid->quirks & HID_QUIRK_MULTI_INPUT)
                                hidinput = hidinput_match(report);
                        else if (hid->maxapplication > 1 &&
                                 (hid->quirks & HID_QUIRK_INPUT_PER_APP))
                                hidinput = hidinput_match_application(report);

                        if (!hidinput) {
                                hidinput = hidinput_allocate(hid, application);
                                if (!hidinput)
                                        goto out_unwind;
                        }

                        hidinput_configure_usages(hidinput, report);

                        if (hid->quirks & HID_QUIRK_MULTI_INPUT)
                                hidinput->report = report;

                        list_add_tail(&report->hidinput_list,
                                      &hidinput->reports);
                }
        }

        hidinput_change_resolution_multipliers(hid);

        list_for_each_entry_safe(hidinput, next, &hid->inputs, list) {
                if (drv->input_configured &&
                    drv->input_configured(hid, hidinput))
                        goto out_unwind;

                if (!hidinput_has_been_populated(hidinput)) {
                        /* no need to register an input device not populated */

                        hidinput_cleanup_hidinput(hid, hidinput);
                        continue;
                }

                if (input_register_device(hidinput->input))
                        goto out_unwind;
                hidinput->registered = true;
        }

        if (list_empty(&hid->inputs)) {
                hid_err(hid, "No inputs registered, leaving\n");
                goto out_unwind;
        }

        if (hid->status & HID_STAT_DUP_DETECTED)
                hid_dbg(hid,
                        "Some usages could not be mapped, please use HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE if this is legitimate.\n");

        return 0;

out_unwind:
        /* unwind the ones we already registered */
        hidinput_disconnect(hid);

        return -1;
}
EXPORT_SYMBOL_GPL(hidinput_connect);

void hidinput_disconnect(struct hid_device *hid)
{
        struct hid_input *hidinput, *next;

        hidinput_cleanup_battery(hid);

        list_for_each_entry_safe(hidinput, next, &hid->inputs, list) {
                list_del(&hidinput->list);
                if (hidinput->registered)
                        input_unregister_device(hidinput->input);
                else
                        input_free_device(hidinput->input);
                kfree(hidinput->name);
                kfree(hidinput);
        }

        /* led_work is spawned by input_dev callbacks, but doesn't access the
         * parent input_dev at all. Once all input devices are removed, we
         * know that led_work will never get restarted, so we can cancel it
         * synchronously and are safe. */
        cancel_work_sync(&hid->led_work);
}
EXPORT_SYMBOL_GPL(hidinput_disconnect);