/*
 *  HIDPP protocol for Logitech Unifying receivers
 *
 *  Copyright (c) 2011 Logitech (c)
 *  Copyright (c) 2012-2013 Google (c)
 *  Copyright (c) 2013-2014 Red Hat Inc.
 */

/*
 * 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; version 2 of the License.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/hid.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/kfifo.h>
#include <linux/input/mt.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
#include <linux/fixp-arith.h>
#include <asm/unaligned.h>
#include "usbhid/usbhid.h"
#include "hid-ids.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_AUTHOR("Nestor Lopez Casado <nlopezcasad@logitech.com>");

static bool disable_raw_mode;
module_param(disable_raw_mode, bool, 0644);
MODULE_PARM_DESC(disable_raw_mode,
        "Disable Raw mode reporting for touchpads and keep firmware gestures.");

static bool disable_tap_to_click;
module_param(disable_tap_to_click, bool, 0644);
MODULE_PARM_DESC(disable_tap_to_click,
        "Disable Tap-To-Click mode reporting for touchpads (only on the K400 currently).");

#define REPORT_ID_HIDPP_SHORT                   0x10
#define REPORT_ID_HIDPP_LONG                    0x11
#define REPORT_ID_HIDPP_VERY_LONG               0x12

#define HIDPP_REPORT_SHORT_LENGTH               7
#define HIDPP_REPORT_LONG_LENGTH                20
#define HIDPP_REPORT_VERY_LONG_LENGTH           64

#define HIDPP_QUIRK_CLASS_WTP                   BIT(0)
#define HIDPP_QUIRK_CLASS_M560                  BIT(1)
#define HIDPP_QUIRK_CLASS_K400                  BIT(2)
#define HIDPP_QUIRK_CLASS_G920                  BIT(3)
#define HIDPP_QUIRK_CLASS_K750                  BIT(4)

/* bits 2..20 are reserved for classes */
/* #define HIDPP_QUIRK_CONNECT_EVENTS           BIT(21) disabled */
#define HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS        BIT(22)
#define HIDPP_QUIRK_NO_HIDINPUT                 BIT(23)
#define HIDPP_QUIRK_FORCE_OUTPUT_REPORTS        BIT(24)
#define HIDPP_QUIRK_UNIFYING                    BIT(25)

#define HIDPP_QUIRK_DELAYED_INIT                HIDPP_QUIRK_NO_HIDINPUT

#define HIDPP_CAPABILITY_HIDPP10_BATTERY        BIT(0)
#define HIDPP_CAPABILITY_HIDPP20_BATTERY        BIT(1)
#define HIDPP_CAPABILITY_BATTERY_MILEAGE        BIT(2)
#define HIDPP_CAPABILITY_BATTERY_LEVEL_STATUS   BIT(3)

/*
 * There are two hidpp protocols in use, the first version hidpp10 is known
 * as register access protocol or RAP, the second version hidpp20 is known as
 * feature access protocol or FAP
 *
 * Most older devices (including the Unifying usb receiver) use the RAP protocol
 * where as most newer devices use the FAP protocol. Both protocols are
 * compatible with the underlying transport, which could be usb, Unifiying, or
 * bluetooth. The message lengths are defined by the hid vendor specific report
 * descriptor for the HIDPP_SHORT report type (total message lenth 7 bytes) and
 * the HIDPP_LONG report type (total message length 20 bytes)
 *
 * The RAP protocol uses both report types, whereas the FAP only uses HIDPP_LONG
 * messages. The Unifying receiver itself responds to RAP messages (device index
 * is 0xFF for the receiver), and all messages (short or long) with a device
 * index between 1 and 6 are passed untouched to the corresponding paired
 * Unifying device.
 *
 * The paired device can be RAP or FAP, it will receive the message untouched
 * from the Unifiying receiver.
 */

struct fap {
        u8 feature_index;
        u8 funcindex_clientid;
        u8 params[HIDPP_REPORT_VERY_LONG_LENGTH - 4U];
};

struct rap {
        u8 sub_id;
        u8 reg_address;
        u8 params[HIDPP_REPORT_VERY_LONG_LENGTH - 4U];
};

struct hidpp_report {
        u8 report_id;
        u8 device_index;
        union {
                struct fap fap;
                struct rap rap;
                u8 rawbytes[sizeof(struct fap)];
        };
} __packed;

struct hidpp_battery {
        u8 feature_index;
        u8 solar_feature_index;
        struct power_supply_desc desc;
        struct power_supply *ps;
        char name[64];
        int status;
        int capacity;
        int level;
        bool online;
};

struct hidpp_device {
        struct hid_device *hid_dev;
        struct mutex send_mutex;
        void *send_receive_buf;
        char *name;             /* will never be NULL and should not be freed */
        wait_queue_head_t wait;
        bool answer_available;
        u8 protocol_major;
        u8 protocol_minor;

        void *private_data;

        struct work_struct work;
        struct kfifo delayed_work_fifo;
        atomic_t connected;
        struct input_dev *delayed_input;

        unsigned long quirks;
        unsigned long capabilities;

        struct hidpp_battery battery;
};

/* HID++ 1.0 error codes */
#define HIDPP_ERROR                             0x8f
#define HIDPP_ERROR_SUCCESS                     0x00
#define HIDPP_ERROR_INVALID_SUBID               0x01
#define HIDPP_ERROR_INVALID_ADRESS              0x02
#define HIDPP_ERROR_INVALID_VALUE               0x03
#define HIDPP_ERROR_CONNECT_FAIL                0x04
#define HIDPP_ERROR_TOO_MANY_DEVICES            0x05
#define HIDPP_ERROR_ALREADY_EXISTS              0x06
#define HIDPP_ERROR_BUSY                        0x07
#define HIDPP_ERROR_UNKNOWN_DEVICE              0x08
#define HIDPP_ERROR_RESOURCE_ERROR              0x09
#define HIDPP_ERROR_REQUEST_UNAVAILABLE         0x0a
#define HIDPP_ERROR_INVALID_PARAM_VALUE         0x0b
#define HIDPP_ERROR_WRONG_PIN_CODE              0x0c
/* HID++ 2.0 error codes */
#define HIDPP20_ERROR                           0xff

static void hidpp_connect_event(struct hidpp_device *hidpp_dev);

static int __hidpp_send_report(struct hid_device *hdev,
                                struct hidpp_report *hidpp_report)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        int fields_count, ret;

        hidpp = hid_get_drvdata(hdev);

        switch (hidpp_report->report_id) {
        case REPORT_ID_HIDPP_SHORT:
                fields_count = HIDPP_REPORT_SHORT_LENGTH;
                break;
        case REPORT_ID_HIDPP_LONG:
                fields_count = HIDPP_REPORT_LONG_LENGTH;
                break;
        case REPORT_ID_HIDPP_VERY_LONG:
                fields_count = HIDPP_REPORT_VERY_LONG_LENGTH;
                break;
        default:
                return -ENODEV;
        }

        /*
         * set the device_index as the receiver, it will be overwritten by
         * hid_hw_request if needed
         */
        hidpp_report->device_index = 0xff;

        if (hidpp->quirks & HIDPP_QUIRK_FORCE_OUTPUT_REPORTS) {
                ret = hid_hw_output_report(hdev, (u8 *)hidpp_report, fields_count);
        } else {
                ret = hid_hw_raw_request(hdev, hidpp_report->report_id,
                        (u8 *)hidpp_report, fields_count, HID_OUTPUT_REPORT,
                        HID_REQ_SET_REPORT);
        }

        return ret == fields_count ? 0 : -1;
}

/**
 * hidpp_send_message_sync() returns 0 in case of success, and something else
 * in case of a failure.
 * - If ' something else' is positive, that means that an error has been raised
 *   by the protocol itself.
 * - If ' something else' is negative, that means that we had a classic error
 *   (-ENOMEM, -EPIPE, etc...)
 */
static int hidpp_send_message_sync(struct hidpp_device *hidpp,
        struct hidpp_report *message,
        struct hidpp_report *response)
{
        int ret;

        mutex_lock(&hidpp->send_mutex);

        hidpp->send_receive_buf = response;
        hidpp->answer_available = false;

        /*
         * So that we can later validate the answer when it arrives
         * in hidpp_raw_event
         */
        *response = *message;

        ret = __hidpp_send_report(hidpp->hid_dev, message);

        if (ret) {
                dbg_hid("__hidpp_send_report returned err: %d\n", ret);
                memset(response, 0, sizeof(struct hidpp_report));
                goto exit;
        }

        if (!wait_event_timeout(hidpp->wait, hidpp->answer_available,
                                5*HZ)) {
                dbg_hid("%s:timeout waiting for response\n", __func__);
                memset(response, 0, sizeof(struct hidpp_report));
                ret = -ETIMEDOUT;
        }

        if (response->report_id == REPORT_ID_HIDPP_SHORT &&
            response->rap.sub_id == HIDPP_ERROR) {
                ret = response->rap.params[1];
                dbg_hid("%s:got hidpp error %02X\n", __func__, ret);
                goto exit;
        }

        if ((response->report_id == REPORT_ID_HIDPP_LONG ||
                        response->report_id == REPORT_ID_HIDPP_VERY_LONG) &&
                        response->fap.feature_index == HIDPP20_ERROR) {
                ret = response->fap.params[1];
                dbg_hid("%s:got hidpp 2.0 error %02X\n", __func__, ret);
                goto exit;
        }

exit:
        mutex_unlock(&hidpp->send_mutex);
        return ret;

}

static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp,
        u8 feat_index, u8 funcindex_clientid, u8 *params, int param_count,
        struct hidpp_report *response)
{
        struct hidpp_report *message;
        int ret;

        if (param_count > sizeof(message->fap.params))
                return -EINVAL;

        message = kzalloc(sizeof(struct hidpp_report), GFP_KERNEL);
        if (!message)
                return -ENOMEM;

        if (param_count > (HIDPP_REPORT_LONG_LENGTH - 4))
                message->report_id = REPORT_ID_HIDPP_VERY_LONG;
        else
                message->report_id = REPORT_ID_HIDPP_LONG;
        message->fap.feature_index = feat_index;
        message->fap.funcindex_clientid = funcindex_clientid;
        memcpy(&message->fap.params, params, param_count);

        ret = hidpp_send_message_sync(hidpp, message, response);
        kfree(message);
        return ret;
}

static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
        u8 report_id, u8 sub_id, u8 reg_address, u8 *params, int param_count,
        struct hidpp_report *response)
{
        struct hidpp_report *message;
        int ret, max_count;

        switch (report_id) {
        case REPORT_ID_HIDPP_SHORT:
                max_count = HIDPP_REPORT_SHORT_LENGTH - 4;
                break;
        case REPORT_ID_HIDPP_LONG:
                max_count = HIDPP_REPORT_LONG_LENGTH - 4;
                break;
        case REPORT_ID_HIDPP_VERY_LONG:
                max_count = HIDPP_REPORT_VERY_LONG_LENGTH - 4;
                break;
        default:
                return -EINVAL;
        }

        if (param_count > max_count)
                return -EINVAL;

        message = kzalloc(sizeof(struct hidpp_report), GFP_KERNEL);
        if (!message)
                return -ENOMEM;
        message->report_id = report_id;
        message->rap.sub_id = sub_id;
        message->rap.reg_address = reg_address;
        memcpy(&message->rap.params, params, param_count);

        ret = hidpp_send_message_sync(hidpp_dev, message, response);
        kfree(message);
        return ret;
}

static void delayed_work_cb(struct work_struct *work)
{
        struct hidpp_device *hidpp = container_of(work, struct hidpp_device,
                                                        work);
        hidpp_connect_event(hidpp);
}

static inline bool hidpp_match_answer(struct hidpp_report *question,
                struct hidpp_report *answer)
{
        return (answer->fap.feature_index == question->fap.feature_index) &&
           (answer->fap.funcindex_clientid == question->fap.funcindex_clientid);
}

static inline bool hidpp_match_error(struct hidpp_report *question,
                struct hidpp_report *answer)
{
        return ((answer->rap.sub_id == HIDPP_ERROR) ||
            (answer->fap.feature_index == HIDPP20_ERROR)) &&
            (answer->fap.funcindex_clientid == question->fap.feature_index) &&
            (answer->fap.params[0] == question->fap.funcindex_clientid);
}

static inline bool hidpp_report_is_connect_event(struct hidpp_report *report)
{
        return (report->report_id == REPORT_ID_HIDPP_SHORT) &&
                (report->rap.sub_id == 0x41);
}

/**
 * hidpp_prefix_name() prefixes the current given name with "Logitech ".
 */
static void hidpp_prefix_name(char **name, int name_length)
{
#define PREFIX_LENGTH 9 /* "Logitech " */

        int new_length;
        char *new_name;

        if (name_length > PREFIX_LENGTH &&
            strncmp(*name, "Logitech ", PREFIX_LENGTH) == 0)
                /* The prefix has is already in the name */
                return;

        new_length = PREFIX_LENGTH + name_length;
        new_name = kzalloc(new_length, GFP_KERNEL);
        if (!new_name)
                return;

        snprintf(new_name, new_length, "Logitech %s", *name);

        kfree(*name);

        *name = new_name;
}

/* -------------------------------------------------------------------------- */
/* HIDP++ 1.0 commands                                                        */
/* -------------------------------------------------------------------------- */

#define HIDPP_SET_REGISTER                              0x80
#define HIDPP_GET_REGISTER                              0x81
#define HIDPP_SET_LONG_REGISTER                         0x82
#define HIDPP_GET_LONG_REGISTER                         0x83

#define HIDPP_REG_GENERAL                               0x00

static int hidpp10_enable_battery_reporting(struct hidpp_device *hidpp_dev)
{
        struct hidpp_report response;
        int ret;
        u8 params[3] = { 0 };

        ret = hidpp_send_rap_command_sync(hidpp_dev,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_REGISTER,
                                        HIDPP_REG_GENERAL,
                                        NULL, 0, &response);
        if (ret)
                return ret;

        memcpy(params, response.rap.params, 3);

        /* Set the battery bit */
        params[0] |= BIT(4);

        return hidpp_send_rap_command_sync(hidpp_dev,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_SET_REGISTER,
                                        HIDPP_REG_GENERAL,
                                        params, 3, &response);
}

#define HIDPP_REG_BATTERY_STATUS                        0x07

static int hidpp10_battery_status_map_level(u8 param)
{
        int level;

        switch (param) {
        case 1 ... 2:
                level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
                break;
        case 3 ... 4:
                level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
                break;
        case 5 ... 6:
                level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
                break;
        case 7:
                level = POWER_SUPPLY_CAPACITY_LEVEL_HIGH;
                break;
        default:
                level = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
        }

        return level;
}

static int hidpp10_battery_status_map_status(u8 param)
{
        int status;

        switch (param) {
        case 0x00:
                /* discharging (in use) */
                status = POWER_SUPPLY_STATUS_DISCHARGING;
                break;
        case 0x21: /* (standard) charging */
        case 0x24: /* fast charging */
        case 0x25: /* slow charging */
                status = POWER_SUPPLY_STATUS_CHARGING;
                break;
        case 0x26: /* topping charge */
        case 0x22: /* charge complete */
                status = POWER_SUPPLY_STATUS_FULL;
                break;
        case 0x20: /* unknown */
                status = POWER_SUPPLY_STATUS_UNKNOWN;
                break;
        /*
         * 0x01...0x1F = reserved (not charging)
         * 0x23 = charging error
         * 0x27..0xff = reserved
         */
        default:
                status = POWER_SUPPLY_STATUS_NOT_CHARGING;
                break;
        }

        return status;
}

static int hidpp10_query_battery_status(struct hidpp_device *hidpp)
{
        struct hidpp_report response;
        int ret, status;

        ret = hidpp_send_rap_command_sync(hidpp,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_REGISTER,
                                        HIDPP_REG_BATTERY_STATUS,
                                        NULL, 0, &response);
        if (ret)
                return ret;

        hidpp->battery.level =
                hidpp10_battery_status_map_level(response.rap.params[0]);
        status = hidpp10_battery_status_map_status(response.rap.params[1]);
        hidpp->battery.status = status;
        /* the capacity is only available when discharging or full */
        hidpp->battery.online = status == POWER_SUPPLY_STATUS_DISCHARGING ||
                                status == POWER_SUPPLY_STATUS_FULL;

        return 0;
}

#define HIDPP_REG_BATTERY_MILEAGE                       0x0D

static int hidpp10_battery_mileage_map_status(u8 param)
{
        int status;

        switch (param >> 6) {
        case 0x00:
                /* discharging (in use) */
                status = POWER_SUPPLY_STATUS_DISCHARGING;
                break;
        case 0x01: /* charging */
                status = POWER_SUPPLY_STATUS_CHARGING;
                break;
        case 0x02: /* charge complete */
                status = POWER_SUPPLY_STATUS_FULL;
                break;
        /*
         * 0x03 = charging error
         */
        default:
                status = POWER_SUPPLY_STATUS_NOT_CHARGING;
                break;
        }

        return status;
}

static int hidpp10_query_battery_mileage(struct hidpp_device *hidpp)
{
        struct hidpp_report response;
        int ret, status;

        ret = hidpp_send_rap_command_sync(hidpp,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_REGISTER,
                                        HIDPP_REG_BATTERY_MILEAGE,
                                        NULL, 0, &response);
        if (ret)
                return ret;

        hidpp->battery.capacity = response.rap.params[0];
        status = hidpp10_battery_mileage_map_status(response.rap.params[2]);
        hidpp->battery.status = status;
        /* the capacity is only available when discharging or full */
        hidpp->battery.online = status == POWER_SUPPLY_STATUS_DISCHARGING ||
                                status == POWER_SUPPLY_STATUS_FULL;

        return 0;
}

static int hidpp10_battery_event(struct hidpp_device *hidpp, u8 *data, int size)
{
        struct hidpp_report *report = (struct hidpp_report *)data;
        int status, capacity, level;
        bool changed;

        if (report->report_id != REPORT_ID_HIDPP_SHORT)
                return 0;

        switch (report->rap.sub_id) {
        case HIDPP_REG_BATTERY_STATUS:
                capacity = hidpp->battery.capacity;
                level = hidpp10_battery_status_map_level(report->rawbytes[1]);
                status = hidpp10_battery_status_map_status(report->rawbytes[2]);
                break;
        case HIDPP_REG_BATTERY_MILEAGE:
                capacity = report->rap.params[0];
                level = hidpp->battery.level;
                status = hidpp10_battery_mileage_map_status(report->rawbytes[3]);
                break;
        default:
                return 0;
        }

        changed = capacity != hidpp->battery.capacity ||
                  level != hidpp->battery.level ||
                  status != hidpp->battery.status;

        /* the capacity is only available when discharging or full */
        hidpp->battery.online = status == POWER_SUPPLY_STATUS_DISCHARGING ||
                                status == POWER_SUPPLY_STATUS_FULL;

        if (changed) {
                hidpp->battery.level = level;
                hidpp->battery.status = status;
                if (hidpp->battery.ps)
                        power_supply_changed(hidpp->battery.ps);
        }

        return 0;
}

#define HIDPP_REG_PAIRING_INFORMATION                   0xB5
#define HIDPP_EXTENDED_PAIRING                          0x30
#define HIDPP_DEVICE_NAME                               0x40

static char *hidpp_unifying_get_name(struct hidpp_device *hidpp_dev)
{
        struct hidpp_report response;
        int ret;
        u8 params[1] = { HIDPP_DEVICE_NAME };
        char *name;
        int len;

        ret = hidpp_send_rap_command_sync(hidpp_dev,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_LONG_REGISTER,
                                        HIDPP_REG_PAIRING_INFORMATION,
                                        params, 1, &response);
        if (ret)
                return NULL;

        len = response.rap.params[1];

        if (2 + len > sizeof(response.rap.params))
                return NULL;

        name = kzalloc(len + 1, GFP_KERNEL);
        if (!name)
                return NULL;

        memcpy(name, &response.rap.params[2], len);

        /* include the terminating '\0' */
        hidpp_prefix_name(&name, len + 1);

        return name;
}

static int hidpp_unifying_get_serial(struct hidpp_device *hidpp, u32 *serial)
{
        struct hidpp_report response;
        int ret;
        u8 params[1] = { HIDPP_EXTENDED_PAIRING };

        ret = hidpp_send_rap_command_sync(hidpp,
                                        REPORT_ID_HIDPP_SHORT,
                                        HIDPP_GET_LONG_REGISTER,
                                        HIDPP_REG_PAIRING_INFORMATION,
                                        params, 1, &response);
        if (ret)
                return ret;

        /*
         * We don't care about LE or BE, we will output it as a string
         * with %4phD, so we need to keep the order.
         */
        *serial = *((u32 *)&response.rap.params[1]);
        return 0;
}

static int hidpp_unifying_init(struct hidpp_device *hidpp)
{
        struct hid_device *hdev = hidpp->hid_dev;
        const char *name;
        u32 serial;
        int ret;

        ret = hidpp_unifying_get_serial(hidpp, &serial);
        if (ret)
                return ret;

        snprintf(hdev->uniq, sizeof(hdev->uniq), "%04x-%4phD",
                 hdev->product, &serial);
        dbg_hid("HID++ Unifying: Got serial: %s\n", hdev->uniq);

        name = hidpp_unifying_get_name(hidpp);
        if (!name)
                return -EIO;

        snprintf(hdev->name, sizeof(hdev->name), "%s", name);
        dbg_hid("HID++ Unifying: Got name: %s\n", name);

        kfree(name);
        return 0;
}

/* -------------------------------------------------------------------------- */
/* 0x0000: Root                                                               */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_ROOT                                 0x0000
#define HIDPP_PAGE_ROOT_IDX                             0x00

#define CMD_ROOT_GET_FEATURE                            0x01
#define CMD_ROOT_GET_PROTOCOL_VERSION                   0x11

static int hidpp_root_get_feature(struct hidpp_device *hidpp, u16 feature,
        u8 *feature_index, u8 *feature_type)
{
        struct hidpp_report response;
        int ret;
        u8 params[2] = { feature >> 8, feature & 0x00FF };

        ret = hidpp_send_fap_command_sync(hidpp,
                        HIDPP_PAGE_ROOT_IDX,
                        CMD_ROOT_GET_FEATURE,
                        params, 2, &response);
        if (ret)
                return ret;

        if (response.fap.params[0] == 0)
                return -ENOENT;

        *feature_index = response.fap.params[0];
        *feature_type = response.fap.params[1];

        return ret;
}

static int hidpp_root_get_protocol_version(struct hidpp_device *hidpp)
{
        struct hidpp_report response;
        int ret;

        ret = hidpp_send_fap_command_sync(hidpp,
                        HIDPP_PAGE_ROOT_IDX,
                        CMD_ROOT_GET_PROTOCOL_VERSION,
                        NULL, 0, &response);

        if (ret == HIDPP_ERROR_INVALID_SUBID) {
                hidpp->protocol_major = 1;
                hidpp->protocol_minor = 0;
                return 0;
        }

        /* the device might not be connected */
        if (ret == HIDPP_ERROR_RESOURCE_ERROR)
                return -EIO;

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        hidpp->protocol_major = response.fap.params[0];
        hidpp->protocol_minor = response.fap.params[1];

        return ret;
}

static bool hidpp_is_connected(struct hidpp_device *hidpp)
{
        int ret;

        ret = hidpp_root_get_protocol_version(hidpp);
        if (!ret)
                hid_dbg(hidpp->hid_dev, "HID++ %u.%u device connected.\n",
                        hidpp->protocol_major, hidpp->protocol_minor);
        return ret == 0;
}

/* -------------------------------------------------------------------------- */
/* 0x0005: GetDeviceNameType                                                  */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_GET_DEVICE_NAME_TYPE                 0x0005

#define CMD_GET_DEVICE_NAME_TYPE_GET_COUNT              0x01
#define CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME        0x11
#define CMD_GET_DEVICE_NAME_TYPE_GET_TYPE               0x21

static int hidpp_devicenametype_get_count(struct hidpp_device *hidpp,
        u8 feature_index, u8 *nameLength)
{
        struct hidpp_report response;
        int ret;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_GET_DEVICE_NAME_TYPE_GET_COUNT, NULL, 0, &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        *nameLength = response.fap.params[0];

        return ret;
}

static int hidpp_devicenametype_get_device_name(struct hidpp_device *hidpp,
        u8 feature_index, u8 char_index, char *device_name, int len_buf)
{
        struct hidpp_report response;
        int ret, i;
        int count;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_GET_DEVICE_NAME_TYPE_GET_DEVICE_NAME, &char_index, 1,
                &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        switch (response.report_id) {
        case REPORT_ID_HIDPP_VERY_LONG:
                count = HIDPP_REPORT_VERY_LONG_LENGTH - 4;
                break;
        case REPORT_ID_HIDPP_LONG:
                count = HIDPP_REPORT_LONG_LENGTH - 4;
                break;
        case REPORT_ID_HIDPP_SHORT:
                count = HIDPP_REPORT_SHORT_LENGTH - 4;
                break;
        default:
                return -EPROTO;
        }

        if (len_buf < count)
                count = len_buf;

        for (i = 0; i < count; i++)
                device_name[i] = response.fap.params[i];

        return count;
}

static char *hidpp_get_device_name(struct hidpp_device *hidpp)
{
        u8 feature_type;
        u8 feature_index;
        u8 __name_length;
        char *name;
        unsigned index = 0;
        int ret;

        ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_GET_DEVICE_NAME_TYPE,
                &feature_index, &feature_type);
        if (ret)
                return NULL;

        ret = hidpp_devicenametype_get_count(hidpp, feature_index,
                &__name_length);
        if (ret)
                return NULL;

        name = kzalloc(__name_length + 1, GFP_KERNEL);
        if (!name)
                return NULL;

        while (index < __name_length) {
                ret = hidpp_devicenametype_get_device_name(hidpp,
                        feature_index, index, name + index,
                        __name_length - index);
                if (ret <= 0) {
                        kfree(name);
                        return NULL;
                }
                index += ret;
        }

        /* include the terminating '\0' */
        hidpp_prefix_name(&name, __name_length + 1);

        return name;
}

/* -------------------------------------------------------------------------- */
/* 0x1000: Battery level status                                               */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_BATTERY_LEVEL_STATUS                         0x1000

#define CMD_BATTERY_LEVEL_STATUS_GET_BATTERY_LEVEL_STATUS       0x00
#define CMD_BATTERY_LEVEL_STATUS_GET_BATTERY_CAPABILITY         0x10

#define EVENT_BATTERY_LEVEL_STATUS_BROADCAST                    0x00

#define FLAG_BATTERY_LEVEL_DISABLE_OSD                          BIT(0)
#define FLAG_BATTERY_LEVEL_MILEAGE                              BIT(1)
#define FLAG_BATTERY_LEVEL_RECHARGEABLE                         BIT(2)

static int hidpp_map_battery_level(int capacity)
{
        if (capacity < 11)
                return POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
        else if (capacity < 31)
                return POWER_SUPPLY_CAPACITY_LEVEL_LOW;
        else if (capacity < 81)
                return POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
        return POWER_SUPPLY_CAPACITY_LEVEL_FULL;
}

static int hidpp20_batterylevel_map_status_capacity(u8 data[3], int *capacity,
                                                    int *next_capacity,
                                                    int *level)
{
        int status;

        *capacity = data[0];
        *next_capacity = data[1];
        *level = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;

        /* When discharging, we can rely on the device reported capacity.
         * For all other states the device reports 0 (unknown).
         */
        switch (data[2]) {
                case 0: /* discharging (in use) */
                        status = POWER_SUPPLY_STATUS_DISCHARGING;
                        *level = hidpp_map_battery_level(*capacity);
                        break;
                case 1: /* recharging */
                        status = POWER_SUPPLY_STATUS_CHARGING;
                        break;
                case 2: /* charge in final stage */
                        status = POWER_SUPPLY_STATUS_CHARGING;
                        break;
                case 3: /* charge complete */
                        status = POWER_SUPPLY_STATUS_FULL;
                        *level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
                        *capacity = 100;
                        break;
                case 4: /* recharging below optimal speed */
                        status = POWER_SUPPLY_STATUS_CHARGING;
                        break;
                /* 5 = invalid battery type
                   6 = thermal error
                   7 = other charging error */
                default:
                        status = POWER_SUPPLY_STATUS_NOT_CHARGING;
                        break;
        }

        return status;
}

static int hidpp20_batterylevel_get_battery_capacity(struct hidpp_device *hidpp,
                                                     u8 feature_index,
                                                     int *status,
                                                     int *capacity,
                                                     int *next_capacity,
                                                     int *level)
{
        struct hidpp_report response;
        int ret;
        u8 *params = (u8 *)response.fap.params;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                                          CMD_BATTERY_LEVEL_STATUS_GET_BATTERY_LEVEL_STATUS,
                                          NULL, 0, &response);
        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        *status = hidpp20_batterylevel_map_status_capacity(params, capacity,
                                                           next_capacity,
                                                           level);

        return 0;
}

static int hidpp20_batterylevel_get_battery_info(struct hidpp_device *hidpp,
                                                  u8 feature_index)
{
        struct hidpp_report response;
        int ret;
        u8 *params = (u8 *)response.fap.params;
        unsigned int level_count, flags;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                                          CMD_BATTERY_LEVEL_STATUS_GET_BATTERY_CAPABILITY,
                                          NULL, 0, &response);
        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        level_count = params[0];
        flags = params[1];

        if (level_count < 10 || !(flags & FLAG_BATTERY_LEVEL_MILEAGE))
                hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_LEVEL_STATUS;
        else
                hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_MILEAGE;

        return 0;
}

static int hidpp20_query_battery_info(struct hidpp_device *hidpp)
{
        u8 feature_type;
        int ret;
        int status, capacity, next_capacity, level;

        if (hidpp->battery.feature_index == 0xff) {
                ret = hidpp_root_get_feature(hidpp,
                                             HIDPP_PAGE_BATTERY_LEVEL_STATUS,
                                             &hidpp->battery.feature_index,
                                             &feature_type);
                if (ret)
                        return ret;
        }

        ret = hidpp20_batterylevel_get_battery_capacity(hidpp,
                                                hidpp->battery.feature_index,
                                                &status, &capacity,
                                                &next_capacity, &level);
        if (ret)
                return ret;

        ret = hidpp20_batterylevel_get_battery_info(hidpp,
                                                hidpp->battery.feature_index);
        if (ret)
                return ret;

        hidpp->battery.status = status;
        hidpp->battery.capacity = capacity;
        hidpp->battery.level = level;
        /* the capacity is only available when discharging or full */
        hidpp->battery.online = status == POWER_SUPPLY_STATUS_DISCHARGING ||
                                status == POWER_SUPPLY_STATUS_FULL;

        return 0;
}

static int hidpp20_battery_event(struct hidpp_device *hidpp,
                                 u8 *data, int size)
{
        struct hidpp_report *report = (struct hidpp_report *)data;
        int status, capacity, next_capacity, level;
        bool changed;

        if (report->fap.feature_index != hidpp->battery.feature_index ||
            report->fap.funcindex_clientid != EVENT_BATTERY_LEVEL_STATUS_BROADCAST)
                return 0;

        status = hidpp20_batterylevel_map_status_capacity(report->fap.params,
                                                          &capacity,
                                                          &next_capacity,
                                                          &level);

        /* the capacity is only available when discharging or full */
        hidpp->battery.online = status == POWER_SUPPLY_STATUS_DISCHARGING ||
                                status == POWER_SUPPLY_STATUS_FULL;

        changed = capacity != hidpp->battery.capacity ||
                  level != hidpp->battery.level ||
                  status != hidpp->battery.status;

        if (changed) {
                hidpp->battery.level = level;
                hidpp->battery.capacity = capacity;
                hidpp->battery.status = status;
                if (hidpp->battery.ps)
                        power_supply_changed(hidpp->battery.ps);
        }

        return 0;
}

static enum power_supply_property hidpp_battery_props[] = {
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_SCOPE,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_MANUFACTURER,
        POWER_SUPPLY_PROP_SERIAL_NUMBER,
        0, /* placeholder for POWER_SUPPLY_PROP_CAPACITY, */
        0, /* placeholder for POWER_SUPPLY_PROP_CAPACITY_LEVEL, */
};

static int hidpp_battery_get_property(struct power_supply *psy,
                                      enum power_supply_property psp,
                                      union power_supply_propval *val)
{
        struct hidpp_device *hidpp = power_supply_get_drvdata(psy);
        int ret = 0;

        switch(psp) {
                case POWER_SUPPLY_PROP_STATUS:
                        val->intval = hidpp->battery.status;
                        break;
                case POWER_SUPPLY_PROP_CAPACITY:
                        val->intval = hidpp->battery.capacity;
                        break;
                case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
                        val->intval = hidpp->battery.level;
                        break;
                case POWER_SUPPLY_PROP_SCOPE:
                        val->intval = POWER_SUPPLY_SCOPE_DEVICE;
                        break;
                case POWER_SUPPLY_PROP_ONLINE:
                        val->intval = hidpp->battery.online;
                        break;
                case POWER_SUPPLY_PROP_MODEL_NAME:
                        if (!strncmp(hidpp->name, "Logitech ", 9))
                                val->strval = hidpp->name + 9;
                        else
                                val->strval = hidpp->name;
                        break;
                case POWER_SUPPLY_PROP_MANUFACTURER:
                        val->strval = "Logitech";
                        break;
                case POWER_SUPPLY_PROP_SERIAL_NUMBER:
                        val->strval = hidpp->hid_dev->uniq;
                        break;
                default:
                        ret = -EINVAL;
                        break;
        }

        return ret;
}

/* -------------------------------------------------------------------------- */
/* 0x4301: Solar Keyboard                                                     */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_SOLAR_KEYBOARD                       0x4301

#define CMD_SOLAR_SET_LIGHT_MEASURE                     0x00

#define EVENT_SOLAR_BATTERY_BROADCAST                   0x00
#define EVENT_SOLAR_BATTERY_LIGHT_MEASURE               0x10
#define EVENT_SOLAR_CHECK_LIGHT_BUTTON                  0x20

static int hidpp_solar_request_battery_event(struct hidpp_device *hidpp)
{
        struct hidpp_report response;
        u8 params[2] = { 1, 1 };
        u8 feature_type;
        int ret;

        if (hidpp->battery.feature_index == 0xff) {
                ret = hidpp_root_get_feature(hidpp,
                                             HIDPP_PAGE_SOLAR_KEYBOARD,
                                             &hidpp->battery.solar_feature_index,
                                             &feature_type);
                if (ret)
                        return ret;
        }

        ret = hidpp_send_fap_command_sync(hidpp,
                                          hidpp->battery.solar_feature_index,
                                          CMD_SOLAR_SET_LIGHT_MEASURE,
                                          params, 2, &response);
        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_MILEAGE;

        return 0;
}

static int hidpp_solar_battery_event(struct hidpp_device *hidpp,
                                     u8 *data, int size)
{
        struct hidpp_report *report = (struct hidpp_report *)data;
        int capacity, lux, status;
        u8 function;

        function = report->fap.funcindex_clientid;


        if (report->fap.feature_index != hidpp->battery.solar_feature_index ||
            !(function == EVENT_SOLAR_BATTERY_BROADCAST ||
              function == EVENT_SOLAR_BATTERY_LIGHT_MEASURE ||
              function == EVENT_SOLAR_CHECK_LIGHT_BUTTON))
                return 0;

        capacity = report->fap.params[0];

        switch (function) {
        case EVENT_SOLAR_BATTERY_LIGHT_MEASURE:
                lux = (report->fap.params[1] << 8) | report->fap.params[2];
                if (lux > 200)
                        status = POWER_SUPPLY_STATUS_CHARGING;
                else
                        status = POWER_SUPPLY_STATUS_DISCHARGING;
                break;
        case EVENT_SOLAR_CHECK_LIGHT_BUTTON:
        default:
                if (capacity < hidpp->battery.capacity)
                        status = POWER_SUPPLY_STATUS_DISCHARGING;
                else
                        status = POWER_SUPPLY_STATUS_CHARGING;

        }

        if (capacity == 100)
                status = POWER_SUPPLY_STATUS_FULL;

        hidpp->battery.online = true;
        if (capacity != hidpp->battery.capacity ||
            status != hidpp->battery.status) {
                hidpp->battery.capacity = capacity;
                hidpp->battery.status = status;
                if (hidpp->battery.ps)
                        power_supply_changed(hidpp->battery.ps);
        }

        return 0;
}

/* -------------------------------------------------------------------------- */
/* 0x6010: Touchpad FW items                                                  */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_TOUCHPAD_FW_ITEMS                    0x6010

#define CMD_TOUCHPAD_FW_ITEMS_SET                       0x10

struct hidpp_touchpad_fw_items {
        uint8_t presence;
        uint8_t desired_state;
        uint8_t state;
        uint8_t persistent;
};

/**
 * send a set state command to the device by reading the current items->state
 * field. items is then filled with the current state.
 */
static int hidpp_touchpad_fw_items_set(struct hidpp_device *hidpp,
                                       u8 feature_index,
                                       struct hidpp_touchpad_fw_items *items)
{
        struct hidpp_report response;
        int ret;
        u8 *params = (u8 *)response.fap.params;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_TOUCHPAD_FW_ITEMS_SET, &items->state, 1, &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        items->presence = params[0];
        items->desired_state = params[1];
        items->state = params[2];
        items->persistent = params[3];

        return 0;
}

/* -------------------------------------------------------------------------- */
/* 0x6100: TouchPadRawXY                                                      */
/* -------------------------------------------------------------------------- */

#define HIDPP_PAGE_TOUCHPAD_RAW_XY                      0x6100

#define CMD_TOUCHPAD_GET_RAW_INFO                       0x01
#define CMD_TOUCHPAD_SET_RAW_REPORT_STATE               0x21

#define EVENT_TOUCHPAD_RAW_XY                           0x00

#define TOUCHPAD_RAW_XY_ORIGIN_LOWER_LEFT               0x01
#define TOUCHPAD_RAW_XY_ORIGIN_UPPER_LEFT               0x03

struct hidpp_touchpad_raw_info {
        u16 x_size;
        u16 y_size;
        u8 z_range;
        u8 area_range;
        u8 timestamp_unit;
        u8 maxcontacts;
        u8 origin;
        u16 res;
};

struct hidpp_touchpad_raw_xy_finger {
        u8 contact_type;
        u8 contact_status;
        u16 x;
        u16 y;
        u8 z;
        u8 area;
        u8 finger_id;
};

struct hidpp_touchpad_raw_xy {
        u16 timestamp;
        struct hidpp_touchpad_raw_xy_finger fingers[2];
        u8 spurious_flag;
        u8 end_of_frame;
        u8 finger_count;
        u8 button;
};

static int hidpp_touchpad_get_raw_info(struct hidpp_device *hidpp,
        u8 feature_index, struct hidpp_touchpad_raw_info *raw_info)
{
        struct hidpp_report response;
        int ret;
        u8 *params = (u8 *)response.fap.params;

        ret = hidpp_send_fap_command_sync(hidpp, feature_index,
                CMD_TOUCHPAD_GET_RAW_INFO, NULL, 0, &response);

        if (ret > 0) {
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, ret);
                return -EPROTO;
        }
        if (ret)
                return ret;

        raw_info->x_size = get_unaligned_be16(&params[0]);
        raw_info->y_size = get_unaligned_be16(&params[2]);
        raw_info->z_range = params[4];
        raw_info->area_range = params[5];
        raw_info->maxcontacts = params[7];
        raw_info->origin = params[8];
        /* res is given in unit per inch */
        raw_info->res = get_unaligned_be16(&params[13]) * 2 / 51;

        return ret;
}

static int hidpp_touchpad_set_raw_report_state(struct hidpp_device *hidpp_dev,
                u8 feature_index, bool send_raw_reports,
                bool sensor_enhanced_settings)
{
        struct hidpp_report response;

        /*
         * Params:
         *   bit 0 - enable raw
         *   bit 1 - 16bit Z, no area
         *   bit 2 - enhanced sensitivity
         *   bit 3 - width, height (4 bits each) instead of area
         *   bit 4 - send raw + gestures (degrades smoothness)
         *   remaining bits - reserved
         */
        u8 params = send_raw_reports | (sensor_enhanced_settings << 2);

        return hidpp_send_fap_command_sync(hidpp_dev, feature_index,
                CMD_TOUCHPAD_SET_RAW_REPORT_STATE, &params, 1, &response);
}

static void hidpp_touchpad_touch_event(u8 *data,
        struct hidpp_touchpad_raw_xy_finger *finger)
{
        u8 x_m = data[0] << 2;
        u8 y_m = data[2] << 2;

        finger->x = x_m << 6 | data[1];
        finger->y = y_m << 6 | data[3];

        finger->contact_type = data[0] >> 6;
        finger->contact_status = data[2] >> 6;

        finger->z = data[4];
        finger->area = data[5];
        finger->finger_id = data[6] >> 4;
}

static void hidpp_touchpad_raw_xy_event(struct hidpp_device *hidpp_dev,
                u8 *data, struct hidpp_touchpad_raw_xy *raw_xy)
{
        memset(raw_xy, 0, sizeof(struct hidpp_touchpad_raw_xy));
        raw_xy->end_of_frame = data[8] & 0x01;
        raw_xy->spurious_flag = (data[8] >> 1) & 0x01;
        raw_xy->finger_count = data[15] & 0x0f;
        raw_xy->button = (data[8] >> 2) & 0x01;

        if (raw_xy->finger_count) {
                hidpp_touchpad_touch_event(&data[2], &raw_xy->fingers[0]);
                hidpp_touchpad_touch_event(&data[9], &raw_xy->fingers[1]);
        }
}

/* -------------------------------------------------------------------------- */
/* 0x8123: Force feedback support                                             */
/* -------------------------------------------------------------------------- */

#define HIDPP_FF_GET_INFO               0x01
#define HIDPP_FF_RESET_ALL              0x11
#define HIDPP_FF_DOWNLOAD_EFFECT        0x21
#define HIDPP_FF_SET_EFFECT_STATE       0x31
#define HIDPP_FF_DESTROY_EFFECT         0x41
#define HIDPP_FF_GET_APERTURE           0x51
#define HIDPP_FF_SET_APERTURE           0x61
#define HIDPP_FF_GET_GLOBAL_GAINS       0x71
#define HIDPP_FF_SET_GLOBAL_GAINS       0x81

#define HIDPP_FF_EFFECT_STATE_GET       0x00
#define HIDPP_FF_EFFECT_STATE_STOP      0x01
#define HIDPP_FF_EFFECT_STATE_PLAY      0x02
#define HIDPP_FF_EFFECT_STATE_PAUSE     0x03

#define HIDPP_FF_EFFECT_CONSTANT        0x00
#define HIDPP_FF_EFFECT_PERIODIC_SINE           0x01
#define HIDPP_FF_EFFECT_PERIODIC_SQUARE         0x02
#define HIDPP_FF_EFFECT_PERIODIC_TRIANGLE       0x03
#define HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHUP     0x04
#define HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHDOWN   0x05
#define HIDPP_FF_EFFECT_SPRING          0x06
#define HIDPP_FF_EFFECT_DAMPER          0x07
#define HIDPP_FF_EFFECT_FRICTION        0x08
#define HIDPP_FF_EFFECT_INERTIA         0x09
#define HIDPP_FF_EFFECT_RAMP            0x0A

#define HIDPP_FF_EFFECT_AUTOSTART       0x80

#define HIDPP_FF_EFFECTID_NONE          -1
#define HIDPP_FF_EFFECTID_AUTOCENTER    -2

#define HIDPP_FF_MAX_PARAMS     20
#define HIDPP_FF_RESERVED_SLOTS 1

struct hidpp_ff_private_data {
        struct hidpp_device *hidpp;
        u8 feature_index;
        u8 version;
        u16 gain;
        s16 range;
        u8 slot_autocenter;
        u8 num_effects;
        int *effect_ids;
        struct workqueue_struct *wq;
        atomic_t workqueue_size;
};

struct hidpp_ff_work_data {
        struct work_struct work;
        struct hidpp_ff_private_data *data;
        int effect_id;
        u8 command;
        u8 params[HIDPP_FF_MAX_PARAMS];
        u8 size;
};

static const signed short hiddpp_ff_effects[] = {
        FF_CONSTANT,
        FF_PERIODIC,
        FF_SINE,
        FF_SQUARE,
        FF_SAW_UP,
        FF_SAW_DOWN,
        FF_TRIANGLE,
        FF_SPRING,
        FF_DAMPER,
        FF_AUTOCENTER,
        FF_GAIN,
        -1
};

static const signed short hiddpp_ff_effects_v2[] = {
        FF_RAMP,
        FF_FRICTION,
        FF_INERTIA,
        -1
};

static const u8 HIDPP_FF_CONDITION_CMDS[] = {
        HIDPP_FF_EFFECT_SPRING,
        HIDPP_FF_EFFECT_FRICTION,
        HIDPP_FF_EFFECT_DAMPER,
        HIDPP_FF_EFFECT_INERTIA
};

static const char *HIDPP_FF_CONDITION_NAMES[] = {
        "spring",
        "friction",
        "damper",
        "inertia"
};


static u8 hidpp_ff_find_effect(struct hidpp_ff_private_data *data, int effect_id)
{
        int i;

        for (i = 0; i < data->num_effects; i++)
                if (data->effect_ids[i] == effect_id)
                        return i+1;

        return 0;
}

static void hidpp_ff_work_handler(struct work_struct *w)
{
        struct hidpp_ff_work_data *wd = container_of(w, struct hidpp_ff_work_data, work);
        struct hidpp_ff_private_data *data = wd->data;
        struct hidpp_report response;
        u8 slot;
        int ret;

        /* add slot number if needed */
        switch (wd->effect_id) {
        case HIDPP_FF_EFFECTID_AUTOCENTER:
                wd->params[0] = data->slot_autocenter;
                break;
        case HIDPP_FF_EFFECTID_NONE:
                /* leave slot as zero */
                break;
        default:
                /* find current slot for effect */
                wd->params[0] = hidpp_ff_find_effect(data, wd->effect_id);
                break;
        }

        /* send command and wait for reply */
        ret = hidpp_send_fap_command_sync(data->hidpp, data->feature_index,
                wd->command, wd->params, wd->size, &response);

        if (ret) {
                hid_err(data->hidpp->hid_dev, "Failed to send command to device!\n");
                goto out;
        }

        /* parse return data */
        switch (wd->command) {
        case HIDPP_FF_DOWNLOAD_EFFECT:
                slot = response.fap.params[0];
                if (slot > 0 && slot <= data->num_effects) {
                        if (wd->effect_id >= 0)
                                /* regular effect uploaded */
                                data->effect_ids[slot-1] = wd->effect_id;
                        else if (wd->effect_id >= HIDPP_FF_EFFECTID_AUTOCENTER)
                                /* autocenter spring uploaded */
                                data->slot_autocenter = slot;
                }
                break;
        case HIDPP_FF_DESTROY_EFFECT:
                if (wd->effect_id >= 0)
                        /* regular effect destroyed */
                        data->effect_ids[wd->params[0]-1] = -1;
                else if (wd->effect_id >= HIDPP_FF_EFFECTID_AUTOCENTER)
                        /* autocenter spring destoyed */
                        data->slot_autocenter = 0;
                break;
        case HIDPP_FF_SET_GLOBAL_GAINS:
                data->gain = (wd->params[0] << 8) + wd->params[1];
                break;
        case HIDPP_FF_SET_APERTURE:
                data->range = (wd->params[0] << 8) + wd->params[1];
                break;
        default:
                /* no action needed */
                break;
        }

out:
        atomic_dec(&data->workqueue_size);
        kfree(wd);
}

static int hidpp_ff_queue_work(struct hidpp_ff_private_data *data, int effect_id, u8 command, u8 *params, u8 size)
{
        struct hidpp_ff_work_data *wd = kzalloc(sizeof(*wd), GFP_KERNEL);
        int s;

        if (!wd)
                return -ENOMEM;

        INIT_WORK(&wd->work, hidpp_ff_work_handler);

        wd->data = data;
        wd->effect_id = effect_id;
        wd->command = command;
        wd->size = size;
        memcpy(wd->params, params, size);

        atomic_inc(&data->workqueue_size);
        queue_work(data->wq, &wd->work);

        /* warn about excessive queue size */
        s = atomic_read(&data->workqueue_size);
        if (s >= 20 && s % 20 == 0)
                hid_warn(data->hidpp->hid_dev, "Force feedback command queue contains %d commands, causing substantial delays!", s);

        return 0;
}

static int hidpp_ff_upload_effect(struct input_dev *dev, struct ff_effect *effect, struct ff_effect *old)
{
        struct hidpp_ff_private_data *data = dev->ff->private;
        u8 params[20];
        u8 size;
        int force;

        /* set common parameters */
        params[2] = effect->replay.length >> 8;
        params[3] = effect->replay.length & 255;
        params[4] = effect->replay.delay >> 8;
        params[5] = effect->replay.delay & 255;

        switch (effect->type) {
        case FF_CONSTANT:
                force = (effect->u.constant.level * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
                params[1] = HIDPP_FF_EFFECT_CONSTANT;
                params[6] = force >> 8;
                params[7] = force & 255;
                params[8] = effect->u.constant.envelope.attack_level >> 7;
                params[9] = effect->u.constant.envelope.attack_length >> 8;
                params[10] = effect->u.constant.envelope.attack_length & 255;
                params[11] = effect->u.constant.envelope.fade_level >> 7;
                params[12] = effect->u.constant.envelope.fade_length >> 8;
                params[13] = effect->u.constant.envelope.fade_length & 255;
                size = 14;
                dbg_hid("Uploading constant force level=%d in dir %d = %d\n",
                                effect->u.constant.level,
                                effect->direction, force);
                dbg_hid("          envelope attack=(%d, %d ms) fade=(%d, %d ms)\n",
                                effect->u.constant.envelope.attack_level,
                                effect->u.constant.envelope.attack_length,
                                effect->u.constant.envelope.fade_level,
                                effect->u.constant.envelope.fade_length);
                break;
        case FF_PERIODIC:
        {
                switch (effect->u.periodic.waveform) {
                case FF_SINE:
                        params[1] = HIDPP_FF_EFFECT_PERIODIC_SINE;
                        break;
                case FF_SQUARE:
                        params[1] = HIDPP_FF_EFFECT_PERIODIC_SQUARE;
                        break;
                case FF_SAW_UP:
                        params[1] = HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHUP;
                        break;
                case FF_SAW_DOWN:
                        params[1] = HIDPP_FF_EFFECT_PERIODIC_SAWTOOTHDOWN;
                        break;
                case FF_TRIANGLE:
                        params[1] = HIDPP_FF_EFFECT_PERIODIC_TRIANGLE;
                        break;
                default:
                        hid_err(data->hidpp->hid_dev, "Unexpected periodic waveform type %i!\n", effect->u.periodic.waveform);
                        return -EINVAL;
                }
                force = (effect->u.periodic.magnitude * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
                params[6] = effect->u.periodic.magnitude >> 8;
                params[7] = effect->u.periodic.magnitude & 255;
                params[8] = effect->u.periodic.offset >> 8;
                params[9] = effect->u.periodic.offset & 255;
                params[10] = effect->u.periodic.period >> 8;
                params[11] = effect->u.periodic.period & 255;
                params[12] = effect->u.periodic.phase >> 8;
                params[13] = effect->u.periodic.phase & 255;
                params[14] = effect->u.periodic.envelope.attack_level >> 7;
                params[15] = effect->u.periodic.envelope.attack_length >> 8;
                params[16] = effect->u.periodic.envelope.attack_length & 255;
                params[17] = effect->u.periodic.envelope.fade_level >> 7;
                params[18] = effect->u.periodic.envelope.fade_length >> 8;
                params[19] = effect->u.periodic.envelope.fade_length & 255;
                size = 20;
                dbg_hid("Uploading periodic force mag=%d/dir=%d, offset=%d, period=%d ms, phase=%d\n",
                                effect->u.periodic.magnitude, effect->direction,
                                effect->u.periodic.offset,
                                effect->u.periodic.period,
                                effect->u.periodic.phase);
                dbg_hid("          envelope attack=(%d, %d ms) fade=(%d, %d ms)\n",
                                effect->u.periodic.envelope.attack_level,
                                effect->u.periodic.envelope.attack_length,
                                effect->u.periodic.envelope.fade_level,
                                effect->u.periodic.envelope.fade_length);
                break;
        }
        case FF_RAMP:
                params[1] = HIDPP_FF_EFFECT_RAMP;
                force = (effect->u.ramp.start_level * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
                params[6] = force >> 8;
                params[7] = force & 255;
                force = (effect->u.ramp.end_level * fixp_sin16((effect->direction * 360) >> 16)) >> 15;
                params[8] = force >> 8;
                params[9] = force & 255;
                params[10] = effect->u.ramp.envelope.attack_level >> 7;
                params[11] = effect->u.ramp.envelope.attack_length >> 8;
                params[12] = effect->u.ramp.envelope.attack_length & 255;
                params[13] = effect->u.ramp.envelope.fade_level >> 7;
                params[14] = effect->u.ramp.envelope.fade_length >> 8;
                params[15] = effect->u.ramp.envelope.fade_length & 255;
                size = 16;
                dbg_hid("Uploading ramp force level=%d -> %d in dir %d = %d\n",
                                effect->u.ramp.start_level,
                                effect->u.ramp.end_level,
                                effect->direction, force);
                dbg_hid("          envelope attack=(%d, %d ms) fade=(%d, %d ms)\n",
                                effect->u.ramp.envelope.attack_level,
                                effect->u.ramp.envelope.attack_length,
                                effect->u.ramp.envelope.fade_level,
                                effect->u.ramp.envelope.fade_length);
                break;
        case FF_FRICTION:
        case FF_INERTIA:
        case FF_SPRING:
        case FF_DAMPER:
                params[1] = HIDPP_FF_CONDITION_CMDS[effect->type - FF_SPRING];
                params[6] = effect->u.condition[0].left_saturation >> 9;
                params[7] = (effect->u.condition[0].left_saturation >> 1) & 255;
                params[8] = effect->u.condition[0].left_coeff >> 8;
                params[9] = effect->u.condition[0].left_coeff & 255;
                params[10] = effect->u.condition[0].deadband >> 9;
                params[11] = (effect->u.condition[0].deadband >> 1) & 255;
                params[12] = effect->u.condition[0].center >> 8;
                params[13] = effect->u.condition[0].center & 255;
                params[14] = effect->u.condition[0].right_coeff >> 8;
                params[15] = effect->u.condition[0].right_coeff & 255;
                params[16] = effect->u.condition[0].right_saturation >> 9;
                params[17] = (effect->u.condition[0].right_saturation >> 1) & 255;
                size = 18;
                dbg_hid("Uploading %s force left coeff=%d, left sat=%d, right coeff=%d, right sat=%d\n",
                                HIDPP_FF_CONDITION_NAMES[effect->type - FF_SPRING],
                                effect->u.condition[0].left_coeff,
                                effect->u.condition[0].left_saturation,
                                effect->u.condition[0].right_coeff,
                                effect->u.condition[0].right_saturation);
                dbg_hid("          deadband=%d, center=%d\n",
                                effect->u.condition[0].deadband,
                                effect->u.condition[0].center);
                break;
        default:
                hid_err(data->hidpp->hid_dev, "Unexpected force type %i!\n", effect->type);
                return -EINVAL;
        }

        return hidpp_ff_queue_work(data, effect->id, HIDPP_FF_DOWNLOAD_EFFECT, params, size);
}

static int hidpp_ff_playback(struct input_dev *dev, int effect_id, int value)
{
        struct hidpp_ff_private_data *data = dev->ff->private;
        u8 params[2];

        params[1] = value ? HIDPP_FF_EFFECT_STATE_PLAY : HIDPP_FF_EFFECT_STATE_STOP;

        dbg_hid("St%sing playback of effect %d.\n", value?"art":"opp", effect_id);

        return hidpp_ff_queue_work(data, effect_id, HIDPP_FF_SET_EFFECT_STATE, params, ARRAY_SIZE(params));
}

static int hidpp_ff_erase_effect(struct input_dev *dev, int effect_id)
{
        struct hidpp_ff_private_data *data = dev->ff->private;
        u8 slot = 0;

        dbg_hid("Erasing effect %d.\n", effect_id);

        return hidpp_ff_queue_work(data, effect_id, HIDPP_FF_DESTROY_EFFECT, &slot, 1);
}

static void hidpp_ff_set_autocenter(struct input_dev *dev, u16 magnitude)
{
        struct hidpp_ff_private_data *data = dev->ff->private;
        u8 params[18];

        dbg_hid("Setting autocenter to %d.\n", magnitude);

        /* start a standard spring effect */
        params[1] = HIDPP_FF_EFFECT_SPRING | HIDPP_FF_EFFECT_AUTOSTART;
        /* zero delay and duration */
        params[2] = params[3] = params[4] = params[5] = 0;
        /* set coeff to 25% of saturation */
        params[8] = params[14] = magnitude >> 11;
        params[9] = params[15] = (magnitude >> 3) & 255;
        params[6] = params[16] = magnitude >> 9;
        params[7] = params[17] = (magnitude >> 1) & 255;
        /* zero deadband and center */
        params[10] = params[11] = params[12] = params[13] = 0;

        hidpp_ff_queue_work(data, HIDPP_FF_EFFECTID_AUTOCENTER, HIDPP_FF_DOWNLOAD_EFFECT, params, ARRAY_SIZE(params));
}

static void hidpp_ff_set_gain(struct input_dev *dev, u16 gain)
{
        struct hidpp_ff_private_data *data = dev->ff->private;
        u8 params[4];

        dbg_hid("Setting gain to %d.\n", gain);

        params[0] = gain >> 8;
        params[1] = gain & 255;
        params[2] = 0; /* no boost */
        params[3] = 0;

        hidpp_ff_queue_work(data, HIDPP_FF_EFFECTID_NONE, HIDPP_FF_SET_GLOBAL_GAINS, params, ARRAY_SIZE(params));
}

static ssize_t hidpp_ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct hid_device *hid = to_hid_device(dev);
        struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
        struct input_dev *idev = hidinput->input;
        struct hidpp_ff_private_data *data = idev->ff->private;

        return scnprintf(buf, PAGE_SIZE, "%u\n", data->range);
}

static ssize_t hidpp_ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        struct hid_device *hid = to_hid_device(dev);
        struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
        struct input_dev *idev = hidinput->input;
        struct hidpp_ff_private_data *data = idev->ff->private;
        u8 params[2];
        int range = simple_strtoul(buf, NULL, 10);

        range = clamp(range, 180, 900);

        params[0] = range >> 8;
        params[1] = range & 0x00FF;

        hidpp_ff_queue_work(data, -1, HIDPP_FF_SET_APERTURE, params, ARRAY_SIZE(params));

        return count;
}

static DEVICE_ATTR(range, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, hidpp_ff_range_show, hidpp_ff_range_store);

static void hidpp_ff_destroy(struct ff_device *ff)
{
        struct hidpp_ff_private_data *data = ff->private;

        kfree(data->effect_ids);
}

static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
{
        struct hid_device *hid = hidpp->hid_dev;
        struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
        struct input_dev *dev = hidinput->input;
        const struct usb_device_descriptor *udesc = &(hid_to_usb_dev(hid)->descriptor);
        const u16 bcdDevice = le16_to_cpu(udesc->bcdDevice);
        struct ff_device *ff;
        struct hidpp_report response;
        struct hidpp_ff_private_data *data;
        int error, j, num_slots;
        u8 version;

        if (!dev) {
                hid_err(hid, "Struct input_dev not set!\n");
                return -EINVAL;
        }

        /* Get firmware release */
        version = bcdDevice & 255;

        /* Set supported force feedback capabilities */
        for (j = 0; hiddpp_ff_effects[j] >= 0; j++)
                set_bit(hiddpp_ff_effects[j], dev->ffbit);
        if (version > 1)
                for (j = 0; hiddpp_ff_effects_v2[j] >= 0; j++)
                        set_bit(hiddpp_ff_effects_v2[j], dev->ffbit);

        /* Read number of slots available in device */
        error = hidpp_send_fap_command_sync(hidpp, feature_index,
                HIDPP_FF_GET_INFO, NULL, 0, &response);
        if (error) {
                if (error < 0)
                        return error;
                hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
                        __func__, error);
                return -EPROTO;
        }

        num_slots = response.fap.params[0] - HIDPP_FF_RESERVED_SLOTS;

        error = input_ff_create(dev, num_slots);

        if (error) {
                hid_err(dev, "Failed to create FF device!\n");
                return error;
        }

        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
        data->effect_ids = kcalloc(num_slots, sizeof(int), GFP_KERNEL);
        if (!data->effect_ids) {
                kfree(data);
                return -ENOMEM;
        }
        data->hidpp = hidpp;
        data->feature_index = feature_index;
        data->version = version;
        data->slot_autocenter = 0;
        data->num_effects = num_slots;
        for (j = 0; j < num_slots; j++)
                data->effect_ids[j] = -1;

        ff = dev->ff;
        ff->private = data;

        ff->upload = hidpp_ff_upload_effect;
        ff->erase = hidpp_ff_erase_effect;
        ff->playback = hidpp_ff_playback;
        ff->set_gain = hidpp_ff_set_gain;
        ff->set_autocenter = hidpp_ff_set_autocenter;
        ff->destroy = hidpp_ff_destroy;


        /* reset all forces */
        error = hidpp_send_fap_command_sync(hidpp, feature_index,
                HIDPP_FF_RESET_ALL, NULL, 0, &response);

        /* Read current Range */
        error = hidpp_send_fap_command_sync(hidpp, feature_index,
                HIDPP_FF_GET_APERTURE, NULL, 0, &response);
        if (error)
                hid_warn(hidpp->hid_dev, "Failed to read range from device!\n");
        data->range = error ? 900 : get_unaligned_be16(&response.fap.params[0]);

        /* Create sysfs interface */
        error = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
        if (error)
                hid_warn(hidpp->hid_dev, "Unable to create sysfs interface for \"range\", errno %d!\n", error);

        /* Read the current gain values */
        error = hidpp_send_fap_command_sync(hidpp, feature_index,
                HIDPP_FF_GET_GLOBAL_GAINS, NULL, 0, &response);
        if (error)
                hid_warn(hidpp->hid_dev, "Failed to read gain values from device!\n");
        data->gain = error ? 0xffff : get_unaligned_be16(&response.fap.params[0]);
        /* ignore boost value at response.fap.params[2] */

        /* init the hardware command queue */
        data->wq = create_singlethread_workqueue("hidpp-ff-sendqueue");
        atomic_set(&data->workqueue_size, 0);

        /* initialize with zero autocenter to get wheel in usable state */
        hidpp_ff_set_autocenter(dev, 0);

        hid_info(hid, "Force feedback support loaded (firmware release %d).\n",
                 version);

        return 0;
}

static int hidpp_ff_deinit(struct hid_device *hid)
{
        struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
        struct input_dev *dev = hidinput->input;
        struct hidpp_ff_private_data *data;

        if (!dev) {
                hid_err(hid, "Struct input_dev not found!\n");
                return -EINVAL;
        }

        hid_info(hid, "Unloading HID++ force feedback.\n");
        data = dev->ff->private;
        if (!data) {
                hid_err(hid, "Private data not found!\n");
                return -EINVAL;
        }

        destroy_workqueue(data->wq);
        device_remove_file(&hid->dev, &dev_attr_range);

        return 0;
}


/* ************************************************************************** */
/*                                                                            */
/* Device Support                                                             */
/*                                                                            */
/* ************************************************************************** */

/* -------------------------------------------------------------------------- */
/* Touchpad HID++ devices                                                     */
/* -------------------------------------------------------------------------- */

#define WTP_MANUAL_RESOLUTION                           39

struct wtp_data {
        struct input_dev *input;
        u16 x_size, y_size;
        u8 finger_count;
        u8 mt_feature_index;
        u8 button_feature_index;
        u8 maxcontacts;
        bool flip_y;
        unsigned int resolution;
};

static int wtp_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        return -1;
}

static void wtp_populate_input(struct hidpp_device *hidpp,
                struct input_dev *input_dev, bool origin_is_hid_core)
{
        struct wtp_data *wd = hidpp->private_data;

        __set_bit(EV_ABS, input_dev->evbit);
        __set_bit(EV_KEY, input_dev->evbit);
        __clear_bit(EV_REL, input_dev->evbit);
        __clear_bit(EV_LED, input_dev->evbit);

        input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, wd->x_size, 0, 0);
        input_abs_set_res(input_dev, ABS_MT_POSITION_X, wd->resolution);
        input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, wd->y_size, 0, 0);
        input_abs_set_res(input_dev, ABS_MT_POSITION_Y, wd->resolution);

        /* Max pressure is not given by the devices, pick one */
        input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 50, 0, 0);

        input_set_capability(input_dev, EV_KEY, BTN_LEFT);

        if (hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS)
                input_set_capability(input_dev, EV_KEY, BTN_RIGHT);
        else
                __set_bit(INPUT_PROP_BUTTONPAD, input_dev->propbit);

        input_mt_init_slots(input_dev, wd->maxcontacts, INPUT_MT_POINTER |
                INPUT_MT_DROP_UNUSED);

        wd->input = input_dev;
}

static void wtp_touch_event(struct wtp_data *wd,
        struct hidpp_touchpad_raw_xy_finger *touch_report)
{
        int slot;

        if (!touch_report->finger_id || touch_report->contact_type)
                /* no actual data */
                return;

        slot = input_mt_get_slot_by_key(wd->input, touch_report->finger_id);

        input_mt_slot(wd->input, slot);
        input_mt_report_slot_state(wd->input, MT_TOOL_FINGER,
                                        touch_report->contact_status);
        if (touch_report->contact_status) {
                input_event(wd->input, EV_ABS, ABS_MT_POSITION_X,
                                touch_report->x);
                input_event(wd->input, EV_ABS, ABS_MT_POSITION_Y,
                                wd->flip_y ? wd->y_size - touch_report->y :
                                             touch_report->y);
                input_event(wd->input, EV_ABS, ABS_MT_PRESSURE,
                                touch_report->area);
        }
}

static void wtp_send_raw_xy_event(struct hidpp_device *hidpp,
                struct hidpp_touchpad_raw_xy *raw)
{
        struct wtp_data *wd = hidpp->private_data;
        int i;

        for (i = 0; i < 2; i++)
                wtp_touch_event(wd, &(raw->fingers[i]));

        if (raw->end_of_frame &&
            !(hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS))
                input_event(wd->input, EV_KEY, BTN_LEFT, raw->button);

        if (raw->end_of_frame || raw->finger_count <= 2) {
                input_mt_sync_frame(wd->input);
                input_sync(wd->input);
        }
}

static int wtp_mouse_raw_xy_event(struct hidpp_device *hidpp, u8 *data)
{
        struct wtp_data *wd = hidpp->private_data;
        u8 c1_area = ((data[7] & 0xf) * (data[7] & 0xf) +
                      (data[7] >> 4) * (data[7] >> 4)) / 2;
        u8 c2_area = ((data[13] & 0xf) * (data[13] & 0xf) +
                      (data[13] >> 4) * (data[13] >> 4)) / 2;
        struct hidpp_touchpad_raw_xy raw = {
                .timestamp = data[1],
                .fingers = {
                        {
                                .contact_type = 0,
                                .contact_status = !!data[7],
                                .x = get_unaligned_le16(&data[3]),
                                .y = get_unaligned_le16(&data[5]),
                                .z = c1_area,
                                .area = c1_area,
                                .finger_id = data[2],
                        }, {
                                .contact_type = 0,
                                .contact_status = !!data[13],
                                .x = get_unaligned_le16(&data[9]),
                                .y = get_unaligned_le16(&data[11]),
                                .z = c2_area,
                                .area = c2_area,
                                .finger_id = data[8],
                        }
                },
                .finger_count = wd->maxcontacts,
                .spurious_flag = 0,
                .end_of_frame = (data[0] >> 7) == 0,
                .button = data[0] & 0x01,
        };

        wtp_send_raw_xy_event(hidpp, &raw);

        return 1;
}

static int wtp_raw_event(struct hid_device *hdev, u8 *data, int size)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd = hidpp->private_data;
        struct hidpp_report *report = (struct hidpp_report *)data;
        struct hidpp_touchpad_raw_xy raw;

        if (!wd || !wd->input)
                return 1;

        switch (data[0]) {
        case 0x02:
                if (size < 2) {
                        hid_err(hdev, "Received HID report of bad size (%d)",
                                size);
                        return 1;
                }
                if (hidpp->quirks & HIDPP_QUIRK_WTP_PHYSICAL_BUTTONS) {
                        input_event(wd->input, EV_KEY, BTN_LEFT,
                                        !!(data[1] & 0x01));
                        input_event(wd->input, EV_KEY, BTN_RIGHT,
                                        !!(data[1] & 0x02));
                        input_sync(wd->input);
                        return 0;
                } else {
                        if (size < 21)
                                return 1;
                        return wtp_mouse_raw_xy_event(hidpp, &data[7]);
                }
        case REPORT_ID_HIDPP_LONG:
                /* size is already checked in hidpp_raw_event. */
                if ((report->fap.feature_index != wd->mt_feature_index) ||
                    (report->fap.funcindex_clientid != EVENT_TOUCHPAD_RAW_XY))
                        return 1;
                hidpp_touchpad_raw_xy_event(hidpp, data + 4, &raw);

                wtp_send_raw_xy_event(hidpp, &raw);
                return 0;
        }

        return 0;
}

static int wtp_get_config(struct hidpp_device *hidpp)
{
        struct wtp_data *wd = hidpp->private_data;
        struct hidpp_touchpad_raw_info raw_info = {0};
        u8 feature_type;
        int ret;

        ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_TOUCHPAD_RAW_XY,
                &wd->mt_feature_index, &feature_type);
        if (ret)
                /* means that the device is not powered up */
                return ret;

        ret = hidpp_touchpad_get_raw_info(hidpp, wd->mt_feature_index,
                &raw_info);
        if (ret)
                return ret;

        wd->x_size = raw_info.x_size;
        wd->y_size = raw_info.y_size;
        wd->maxcontacts = raw_info.maxcontacts;
        wd->flip_y = raw_info.origin == TOUCHPAD_RAW_XY_ORIGIN_LOWER_LEFT;
        wd->resolution = raw_info.res;
        if (!wd->resolution)
                wd->resolution = WTP_MANUAL_RESOLUTION;

        return 0;
}

static int wtp_allocate(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd;

        wd = devm_kzalloc(&hdev->dev, sizeof(struct wtp_data),
                        GFP_KERNEL);
        if (!wd)
                return -ENOMEM;

        hidpp->private_data = wd;

        return 0;
};

static int wtp_connect(struct hid_device *hdev, bool connected)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct wtp_data *wd = hidpp->private_data;
        int ret;

        if (!wd->x_size) {
                ret = wtp_get_config(hidpp);
                if (ret) {
                        hid_err(hdev, "Can not get wtp config: %d\n", ret);
                        return ret;
                }
        }

        return hidpp_touchpad_set_raw_report_state(hidpp, wd->mt_feature_index,
                        true, true);
}

/* ------------------------------------------------------------------------- */
/* Logitech M560 devices                                                     */
/* ------------------------------------------------------------------------- */

/*
 * Logitech M560 protocol overview
 *
 * The Logitech M560 mouse, is designed for windows 8. When the middle and/or
 * the sides buttons are pressed, it sends some keyboard keys events
 * instead of buttons ones.
 * To complicate things further, the middle button keys sequence
 * is different from the odd press and the even press.
 *
 * forward button -> Super_R
 * backward button -> Super_L+'d' (press only)
 * middle button -> 1st time: Alt_L+SuperL+XF86TouchpadOff (press only)
 *                  2nd time: left-click (press only)
 * NB: press-only means that when the button is pressed, the
 * KeyPress/ButtonPress and KeyRelease/ButtonRelease events are generated
 * together sequentially; instead when the button is released, no event is
 * generated !
 *
 * With the command
 *      10<xx>0a 3500af03 (where <xx> is the mouse id),
 * the mouse reacts differently:
 * - it never sends a keyboard key event
 * - for the three mouse button it sends:
 *      middle button               press   11<xx>0a 3500af00...
 *      side 1 button (forward)     press   11<xx>0a 3500b000...
 *      side 2 button (backward)    press   11<xx>0a 3500ae00...
 *      middle/side1/side2 button   release 11<xx>0a 35000000...
 */

static const u8 m560_config_parameter[] = {0x00, 0xaf, 0x03};

struct m560_private_data {
        struct input_dev *input;
};

/* how buttons are mapped in the report */
#define M560_MOUSE_BTN_LEFT             0x01
#define M560_MOUSE_BTN_RIGHT            0x02
#define M560_MOUSE_BTN_WHEEL_LEFT       0x08
#define M560_MOUSE_BTN_WHEEL_RIGHT      0x10

#define M560_SUB_ID                     0x0a
#define M560_BUTTON_MODE_REGISTER       0x35

static int m560_send_config_command(struct hid_device *hdev, bool connected)
{
        struct hidpp_report response;
        struct hidpp_device *hidpp_dev;

        hidpp_dev = hid_get_drvdata(hdev);

        return hidpp_send_rap_command_sync(
                hidpp_dev,
                REPORT_ID_HIDPP_SHORT,
                M560_SUB_ID,
                M560_BUTTON_MODE_REGISTER,
                (u8 *)m560_config_parameter,
                sizeof(m560_config_parameter),
                &response
        );
}

static int m560_allocate(struct hid_device *hdev)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct m560_private_data *d;

        d = devm_kzalloc(&hdev->dev, sizeof(struct m560_private_data),
                        GFP_KERNEL);
        if (!d)
                return -ENOMEM;

        hidpp->private_data = d;

        return 0;
};

static int m560_raw_event(struct hid_device *hdev, u8 *data, int size)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct m560_private_data *mydata = hidpp->private_data;

        /* sanity check */
        if (!mydata || !mydata->input) {
                hid_err(hdev, "error in parameter\n");
                return -EINVAL;
        }

        if (size < 7) {
                hid_err(hdev, "error in report\n");
                return 0;
        }

        if (data[0] == REPORT_ID_HIDPP_LONG &&
            data[2] == M560_SUB_ID && data[6] == 0x00) {
                /*
                 * m560 mouse report for middle, forward and backward button
                 *
                 * data[0] = 0x11
                 * data[1] = device-id
                 * data[2] = 0x0a
                 * data[5] = 0xaf -> middle
                 *           0xb0 -> forward
                 *           0xae -> backward
                 *           0x00 -> release all
                 * data[6] = 0x00
                 */

                switch (data[5]) {
                case 0xaf:
                        input_report_key(mydata->input, BTN_MIDDLE, 1);
                        break;
                case 0xb0:
                        input_report_key(mydata->input, BTN_FORWARD, 1);
                        break;
                case 0xae:
                        input_report_key(mydata->input, BTN_BACK, 1);
                        break;
                case 0x00:
                        input_report_key(mydata->input, BTN_BACK, 0);
                        input_report_key(mydata->input, BTN_FORWARD, 0);
                        input_report_key(mydata->input, BTN_MIDDLE, 0);
                        break;
                default:
                        hid_err(hdev, "error in report\n");
                        return 0;
                }
                input_sync(mydata->input);

        } else if (data[0] == 0x02) {
                /*
                 * Logitech M560 mouse report
                 *
                 * data[0] = type (0x02)
                 * data[1..2] = buttons
                 * data[3..5] = xy
                 * data[6] = wheel
                 */

                int v;

                input_report_key(mydata->input, BTN_LEFT,
                        !!(data[1] & M560_MOUSE_BTN_LEFT));
                input_report_key(mydata->input, BTN_RIGHT,
                        !!(data[1] & M560_MOUSE_BTN_RIGHT));

                if (data[1] & M560_MOUSE_BTN_WHEEL_LEFT)
                        input_report_rel(mydata->input, REL_HWHEEL, -1);
                else if (data[1] & M560_MOUSE_BTN_WHEEL_RIGHT)
                        input_report_rel(mydata->input, REL_HWHEEL, 1);

                v = hid_snto32(hid_field_extract(hdev, data+3, 0, 12), 12);
                input_report_rel(mydata->input, REL_X, v);

                v = hid_snto32(hid_field_extract(hdev, data+3, 12, 12), 12);
                input_report_rel(mydata->input, REL_Y, v);

                v = hid_snto32(data[6], 8);
                input_report_rel(mydata->input, REL_WHEEL, v);

                input_sync(mydata->input);
        }

        return 1;
}

static void m560_populate_input(struct hidpp_device *hidpp,
                struct input_dev *input_dev, bool origin_is_hid_core)
{
        struct m560_private_data *mydata = hidpp->private_data;

        mydata->input = input_dev;

        __set_bit(EV_KEY, mydata->input->evbit);
        __set_bit(BTN_MIDDLE, mydata->input->keybit);
        __set_bit(BTN_RIGHT, mydata->input->keybit);
        __set_bit(BTN_LEFT, mydata->input->keybit);
        __set_bit(BTN_BACK, mydata->input->keybit);
        __set_bit(BTN_FORWARD, mydata->input->keybit);

        __set_bit(EV_REL, mydata->input->evbit);
        __set_bit(REL_X, mydata->input->relbit);
        __set_bit(REL_Y, mydata->input->relbit);
        __set_bit(REL_WHEEL, mydata->input->relbit);
        __set_bit(REL_HWHEEL, mydata->input->relbit);
}

static int m560_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        return -1;
}

/* ------------------------------------------------------------------------- */
/* Logitech K400 devices                                                     */
/* ------------------------------------------------------------------------- */

/*
 * The Logitech K400 keyboard has an embedded touchpad which is seen
 * as a mouse from the OS point of view. There is a hardware shortcut to disable
 * tap-to-click but the setting is not remembered accross reset, annoying some
 * users.
 *
 * We can toggle this feature from the host by using the feature 0x6010:
 * Touchpad FW items
 */

struct k400_private_data {
        u8 feature_index;
};

static int k400_disable_tap_to_click(struct hidpp_device *hidpp)
{
        struct k400_private_data *k400 = hidpp->private_data;
        struct hidpp_touchpad_fw_items items = {};
        int ret;
        u8 feature_type;

        if (!k400->feature_index) {
                ret = hidpp_root_get_feature(hidpp,
                        HIDPP_PAGE_TOUCHPAD_FW_ITEMS,
                        &k400->feature_index, &feature_type);
                if (ret)
                        /* means that the device is not powered up */
                        return ret;
        }

        ret = hidpp_touchpad_fw_items_set(hidpp, k400->feature_index, &items);
        if (ret)
                return ret;

        return 0;
}

static int k400_allocate(struct hid_device *hdev)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct k400_private_data *k400;

        k400 = devm_kzalloc(&hdev->dev, sizeof(struct k400_private_data),
                            GFP_KERNEL);
        if (!k400)
                return -ENOMEM;

        hidpp->private_data = k400;

        return 0;
};

static int k400_connect(struct hid_device *hdev, bool connected)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if (!disable_tap_to_click)
                return 0;

        return k400_disable_tap_to_click(hidpp);
}

/* ------------------------------------------------------------------------- */
/* Logitech G920 Driving Force Racing Wheel for Xbox One                     */
/* ------------------------------------------------------------------------- */

#define HIDPP_PAGE_G920_FORCE_FEEDBACK                  0x8123

static int g920_get_config(struct hidpp_device *hidpp)
{
        u8 feature_type;
        u8 feature_index;
        int ret;

        /* Find feature and store for later use */
        ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_G920_FORCE_FEEDBACK,
                &feature_index, &feature_type);
        if (ret)
                return ret;

        ret = hidpp_ff_init(hidpp, feature_index);
        if (ret)
                hid_warn(hidpp->hid_dev, "Unable to initialize force feedback support, errno %d\n",
                                ret);

        return 0;
}

/* -------------------------------------------------------------------------- */
/* Generic HID++ devices                                                      */
/* -------------------------------------------------------------------------- */

static int hidpp_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                return wtp_input_mapping(hdev, hi, field, usage, bit, max);
        else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560 &&
                        field->application != HID_GD_MOUSE)
                return m560_input_mapping(hdev, hi, field, usage, bit, max);

        return 0;
}

static int hidpp_input_mapped(struct hid_device *hdev, struct hid_input *hi,
                struct hid_field *field, struct hid_usage *usage,
                unsigned long **bit, int *max)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        /* Ensure that Logitech G920 is not given a default fuzz/flat value */
        if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
                if (usage->type == EV_ABS && (usage->code == ABS_X ||
                                usage->code == ABS_Y || usage->code == ABS_Z ||
                                usage->code == ABS_RZ)) {
                        field->application = HID_GD_MULTIAXIS;
                }
        }

        return 0;
}


static void hidpp_populate_input(struct hidpp_device *hidpp,
                struct input_dev *input, bool origin_is_hid_core)
{
        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                wtp_populate_input(hidpp, input, origin_is_hid_core);
        else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560)
                m560_populate_input(hidpp, input, origin_is_hid_core);
}

static int hidpp_input_configured(struct hid_device *hdev,
                                struct hid_input *hidinput)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        struct input_dev *input = hidinput->input;

        hidpp_populate_input(hidpp, input, true);

        return 0;
}

static int hidpp_raw_hidpp_event(struct hidpp_device *hidpp, u8 *data,
                int size)
{
        struct hidpp_report *question = hidpp->send_receive_buf;
        struct hidpp_report *answer = hidpp->send_receive_buf;
        struct hidpp_report *report = (struct hidpp_report *)data;
        int ret;

        /*
         * If the mutex is locked then we have a pending answer from a
         * previously sent command.
         */
        if (unlikely(mutex_is_locked(&hidpp->send_mutex))) {
                /*
                 * Check for a correct hidpp20 answer or the corresponding
                 * error
                 */
                if (hidpp_match_answer(question, report) ||
                                hidpp_match_error(question, report)) {
                        *answer = *report;
                        hidpp->answer_available = true;
                        wake_up(&hidpp->wait);
                        /*
                         * This was an answer to a command that this driver sent
                         * We return 1 to hid-core to avoid forwarding the
                         * command upstream as it has been treated by the driver
                         */

                        return 1;
                }
        }

        if (unlikely(hidpp_report_is_connect_event(report))) {
                atomic_set(&hidpp->connected,
                                !(report->rap.params[0] & (1 << 6)));
                if (schedule_work(&hidpp->work) == 0)
                        dbg_hid("%s: connect event already queued\n", __func__);
                return 1;
        }

        if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP20_BATTERY) {
                ret = hidpp20_battery_event(hidpp, data, size);
                if (ret != 0)
                        return ret;
                ret = hidpp_solar_battery_event(hidpp, data, size);
                if (ret != 0)
                        return ret;
        }

        if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP10_BATTERY) {
                ret = hidpp10_battery_event(hidpp, data, size);
                if (ret != 0)
                        return ret;
        }

        return 0;
}

static int hidpp_raw_event(struct hid_device *hdev, struct hid_report *report,
                u8 *data, int size)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        int ret = 0;

        /* Generic HID++ processing. */
        switch (data[0]) {
        case REPORT_ID_HIDPP_VERY_LONG:
                if (size != HIDPP_REPORT_VERY_LONG_LENGTH) {
                        hid_err(hdev, "received hid++ report of bad size (%d)",
                                size);
                        return 1;
                }
                ret = hidpp_raw_hidpp_event(hidpp, data, size);
                break;
        case REPORT_ID_HIDPP_LONG:
                if (size != HIDPP_REPORT_LONG_LENGTH) {
                        hid_err(hdev, "received hid++ report of bad size (%d)",
                                size);
                        return 1;
                }
                ret = hidpp_raw_hidpp_event(hidpp, data, size);
                break;
        case REPORT_ID_HIDPP_SHORT:
                if (size != HIDPP_REPORT_SHORT_LENGTH) {
                        hid_err(hdev, "received hid++ report of bad size (%d)",
                                size);
                        return 1;
                }
                ret = hidpp_raw_hidpp_event(hidpp, data, size);
                break;
        }

        /* If no report is available for further processing, skip calling
         * raw_event of subclasses. */
        if (ret != 0)
                return ret;

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)
                return wtp_raw_event(hdev, data, size);
        else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560)
                return m560_raw_event(hdev, data, size);

        return 0;
}

static int hidpp_initialize_battery(struct hidpp_device *hidpp)
{
        static atomic_t battery_no = ATOMIC_INIT(0);
        struct power_supply_config cfg = { .drv_data = hidpp };
        struct power_supply_desc *desc = &hidpp->battery.desc;
        enum power_supply_property *battery_props;
        struct hidpp_battery *battery;
        unsigned int num_battery_props;
        unsigned long n;
        int ret;

        if (hidpp->battery.ps)
                return 0;

        hidpp->battery.feature_index = 0xff;
        hidpp->battery.solar_feature_index = 0xff;

        if (hidpp->protocol_major >= 2) {
                if (hidpp->quirks & HIDPP_QUIRK_CLASS_K750)
                        ret = hidpp_solar_request_battery_event(hidpp);
                else
                        ret = hidpp20_query_battery_info(hidpp);

                if (ret)
                        return ret;
                hidpp->capabilities |= HIDPP_CAPABILITY_HIDPP20_BATTERY;
        } else {
                ret = hidpp10_query_battery_status(hidpp);
                if (ret) {
                        ret = hidpp10_query_battery_mileage(hidpp);
                        if (ret)
                                return -ENOENT;
                        hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_MILEAGE;
                } else {
                        hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_LEVEL_STATUS;
                }
                hidpp->capabilities |= HIDPP_CAPABILITY_HIDPP10_BATTERY;
        }

        battery_props = devm_kmemdup(&hidpp->hid_dev->dev,
                                     hidpp_battery_props,
                                     sizeof(hidpp_battery_props),
                                     GFP_KERNEL);
        if (!battery_props)
                return -ENOMEM;

        num_battery_props = ARRAY_SIZE(hidpp_battery_props) - 2;

        if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_MILEAGE)
                battery_props[num_battery_props++] =
                                POWER_SUPPLY_PROP_CAPACITY;

        if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_LEVEL_STATUS)
                battery_props[num_battery_props++] =
                                POWER_SUPPLY_PROP_CAPACITY_LEVEL;

        battery = &hidpp->battery;

        n = atomic_inc_return(&battery_no) - 1;
        desc->properties = battery_props;
        desc->num_properties = num_battery_props;
        desc->get_property = hidpp_battery_get_property;
        sprintf(battery->name, "hidpp_battery_%ld", n);
        desc->name = battery->name;
        desc->type = POWER_SUPPLY_TYPE_BATTERY;
        desc->use_for_apm = 0;

        battery->ps = devm_power_supply_register(&hidpp->hid_dev->dev,
                                                 &battery->desc,
                                                 &cfg);
        if (IS_ERR(battery->ps))
                return PTR_ERR(battery->ps);

        power_supply_powers(battery->ps, &hidpp->hid_dev->dev);

        return ret;
}

static void hidpp_overwrite_name(struct hid_device *hdev)
{
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);
        char *name;

        if (hidpp->protocol_major < 2)
                return;

        name = hidpp_get_device_name(hidpp);

        if (!name) {
                hid_err(hdev, "unable to retrieve the name of the device");
        } else {
                dbg_hid("HID++: Got name: %s\n", name);
                snprintf(hdev->name, sizeof(hdev->name), "%s", name);
        }

        kfree(name);
}

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

        return hid_hw_open(hid);
}

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

        hid_hw_close(hid);
}

static struct input_dev *hidpp_allocate_input(struct hid_device *hdev)
{
        struct input_dev *input_dev = devm_input_allocate_device(&hdev->dev);
        struct hidpp_device *hidpp = hid_get_drvdata(hdev);

        if (!input_dev)
                return NULL;

        input_set_drvdata(input_dev, hdev);
        input_dev->open = hidpp_input_open;
        input_dev->close = hidpp_input_close;

        input_dev->name = hidpp->name;
        input_dev->phys = hdev->phys;
        input_dev->uniq = hdev->uniq;
        input_dev->id.bustype = hdev->bus;
        input_dev->id.vendor  = hdev->vendor;
        input_dev->id.product = hdev->product;
        input_dev->id.version = hdev->version;
        input_dev->dev.parent = &hdev->dev;

        return input_dev;
}

static void hidpp_connect_event(struct hidpp_device *hidpp)
{
        struct hid_device *hdev = hidpp->hid_dev;
        int ret = 0;
        bool connected = atomic_read(&hidpp->connected);
        struct input_dev *input;
        char *name, *devm_name;

        if (!connected) {
                if (hidpp->battery.ps) {
                        hidpp->battery.online = false;
                        hidpp->battery.status = POWER_SUPPLY_STATUS_UNKNOWN;
                        hidpp->battery.level = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
                        power_supply_changed(hidpp->battery.ps);
                }
                return;
        }

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) {
                ret = wtp_connect(hdev, connected);
                if (ret)
                        return;
        } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560) {
                ret = m560_send_config_command(hdev, connected);
                if (ret)
                        return;
        } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_K400) {
                ret = k400_connect(hdev, connected);
                if (ret)
                        return;
        }

        /* the device is already connected, we can ask for its name and
         * protocol */
        if (!hidpp->protocol_major) {
                ret = !hidpp_is_connected(hidpp);
                if (ret) {
                        hid_err(hdev, "Can not get the protocol version.\n");
                        return;
                }
                hid_info(hdev, "HID++ %u.%u device connected.\n",
                         hidpp->protocol_major, hidpp->protocol_minor);
        }

        if (hidpp->name == hdev->name && hidpp->protocol_major >= 2) {
                name = hidpp_get_device_name(hidpp);
                if (!name) {
                        hid_err(hdev,
                                "unable to retrieve the name of the device");
                        return;
                }

                devm_name = devm_kasprintf(&hdev->dev, GFP_KERNEL, "%s", name);
                kfree(name);
                if (!devm_name)
                        return;

                hidpp->name = devm_name;
        }

        hidpp_initialize_battery(hidpp);

        /* forward current battery state */
        if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP10_BATTERY) {
                hidpp10_enable_battery_reporting(hidpp);
                if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_MILEAGE)
                        hidpp10_query_battery_mileage(hidpp);
                else
                        hidpp10_query_battery_status(hidpp);
        } else if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP20_BATTERY) {
                hidpp20_query_battery_info(hidpp);
        }
        if (hidpp->battery.ps)
                power_supply_changed(hidpp->battery.ps);

        if (!(hidpp->quirks & HIDPP_QUIRK_NO_HIDINPUT) || hidpp->delayed_input)
                /* if the input nodes are already created, we can stop now */
                return;

        input = hidpp_allocate_input(hdev);
        if (!input) {
                hid_err(hdev, "cannot allocate new input device: %d\n", ret);
                return;
        }

        hidpp_populate_input(hidpp, input, false);

        ret = input_register_device(input);
        if (ret)
                input_free_device(input);

        hidpp->delayed_input = input;
}

static DEVICE_ATTR(builtin_power_supply, 0000, NULL, NULL);

static struct attribute *sysfs_attrs[] = {
        &dev_attr_builtin_power_supply.attr,
        NULL
};

static const struct attribute_group ps_attribute_group = {
        .attrs = sysfs_attrs
};

static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
        struct hidpp_device *hidpp;
        int ret;
        bool connected;
        unsigned int connect_mask = HID_CONNECT_DEFAULT;

        hidpp = devm_kzalloc(&hdev->dev, sizeof(struct hidpp_device),
                        GFP_KERNEL);
        if (!hidpp)
                return -ENOMEM;

        hidpp->hid_dev = hdev;
        hidpp->name = hdev->name;
        hid_set_drvdata(hdev, hidpp);

        hidpp->quirks = id->driver_data;

        if (id->group == HID_GROUP_LOGITECH_DJ_DEVICE)
                hidpp->quirks |= HIDPP_QUIRK_UNIFYING;

        if (disable_raw_mode) {
                hidpp->quirks &= ~HIDPP_QUIRK_CLASS_WTP;
                hidpp->quirks &= ~HIDPP_QUIRK_NO_HIDINPUT;
        }

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP) {
                ret = wtp_allocate(hdev, id);
                if (ret)
                        goto allocate_fail;
        } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_M560) {
                ret = m560_allocate(hdev);
                if (ret)
                        goto allocate_fail;
        } else if (hidpp->quirks & HIDPP_QUIRK_CLASS_K400) {
                ret = k400_allocate(hdev);
                if (ret)
                        goto allocate_fail;
        }

        INIT_WORK(&hidpp->work, delayed_work_cb);
        mutex_init(&hidpp->send_mutex);
        init_waitqueue_head(&hidpp->wait);

        /* indicates we are handling the battery properties in the kernel */
        ret = sysfs_create_group(&hdev->dev.kobj, &ps_attribute_group);
        if (ret)
                hid_warn(hdev, "Cannot allocate sysfs group for %s\n",
                         hdev->name);

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "%s:parse failed\n", __func__);
                goto hid_parse_fail;
        }

        if (hidpp->quirks & HIDPP_QUIRK_NO_HIDINPUT)
                connect_mask &= ~HID_CONNECT_HIDINPUT;

        if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
                ret = hid_hw_start(hdev, connect_mask);
                if (ret) {
                        hid_err(hdev, "hw start failed\n");
                        goto hid_hw_start_fail;
                }
                ret = hid_hw_open(hdev);
                if (ret < 0) {