// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Apple "Magic" Wireless Mouse driver
 *
 *   Copyright (c) 2010 Michael Poole <mdpoole@troilus.org>
 *   Copyright (c) 2010 Chase Douglas <chase.douglas@canonical.com>
 */

/*
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/input/mt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "hid-ids.h"

static bool emulate_3button = true;
module_param(emulate_3button, bool, 0644);
MODULE_PARM_DESC(emulate_3button, "Emulate a middle button");

static int middle_button_start = -350;
static int middle_button_stop = +350;

static bool emulate_scroll_wheel = true;
module_param(emulate_scroll_wheel, bool, 0644);
MODULE_PARM_DESC(emulate_scroll_wheel, "Emulate a scroll wheel");

static unsigned int scroll_speed = 32;
static int param_set_scroll_speed(const char *val,
                                  const struct kernel_param *kp) {
        unsigned long speed;
        if (!val || kstrtoul(val, 0, &speed) || speed > 63)
                return -EINVAL;
        scroll_speed = speed;
        return 0;
}
module_param_call(scroll_speed, param_set_scroll_speed, param_get_uint, &scroll_speed, 0644);
MODULE_PARM_DESC(scroll_speed, "Scroll speed, value from 0 (slow) to 63 (fast)");

static bool scroll_acceleration = false;
module_param(scroll_acceleration, bool, 0644);
MODULE_PARM_DESC(scroll_acceleration, "Accelerate sequential scroll events");

static bool report_undeciphered;
module_param(report_undeciphered, bool, 0644);
MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state field using a MSC_RAW event");

#define TRACKPAD2_2021_BT_VERSION 0x110
#define TRACKPAD_2024_BT_VERSION 0x314

#define TRACKPAD_REPORT_ID 0x28
#define TRACKPAD2_USB_REPORT_ID 0x02
#define TRACKPAD2_BT_REPORT_ID 0x31
#define MOUSE_REPORT_ID    0x29
#define MOUSE2_REPORT_ID   0x12
#define DOUBLE_REPORT_ID   0xf7
#define USB_BATTERY_TIMEOUT_SEC 60

/* These definitions are not precise, but they're close enough.  (Bits
 * 0x03 seem to indicate the aspect ratio of the touch, bits 0x70 seem
 * to be some kind of bit mask -- 0x20 may be a near-field reading,
 * and 0x40 is actual contact, and 0x10 may be a start/stop or change
 * indication.)
 */
#define TOUCH_STATE_MASK  0xf0
#define TOUCH_STATE_NONE  0x00
#define TOUCH_STATE_START 0x30
#define TOUCH_STATE_DRAG  0x40

/* Number of high-resolution events for each low-resolution detent. */
#define SCROLL_HR_STEPS 10
#define SCROLL_HR_MULT (120 / SCROLL_HR_STEPS)
#define SCROLL_HR_THRESHOLD 90 /* units */
#define SCROLL_ACCEL_DEFAULT 7

/* Touch surface information. Dimension is in hundredths of a mm, min and max
 * are in units. */
#define MOUSE_DIMENSION_X (float)9056
#define MOUSE_MIN_X -1100
#define MOUSE_MAX_X 1258
#define MOUSE_RES_X ((MOUSE_MAX_X - MOUSE_MIN_X) / (MOUSE_DIMENSION_X / 100))
#define MOUSE_DIMENSION_Y (float)5152
#define MOUSE_MIN_Y -1589
#define MOUSE_MAX_Y 2047
#define MOUSE_RES_Y ((MOUSE_MAX_Y - MOUSE_MIN_Y) / (MOUSE_DIMENSION_Y / 100))

#define TRACKPAD_DIMENSION_X (float)13000
#define TRACKPAD_MIN_X -2909
#define TRACKPAD_MAX_X 3167
#define TRACKPAD_RES_X \
        ((TRACKPAD_MAX_X - TRACKPAD_MIN_X) / (TRACKPAD_DIMENSION_X / 100))
#define TRACKPAD_DIMENSION_Y (float)11000
#define TRACKPAD_MIN_Y -2456
#define TRACKPAD_MAX_Y 2565
#define TRACKPAD_RES_Y \
        ((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))

#define TRACKPAD2_DIMENSION_X (float)16000
#define TRACKPAD2_MIN_X -3678
#define TRACKPAD2_MAX_X 3934
#define TRACKPAD2_RES_X \
        ((TRACKPAD2_MAX_X - TRACKPAD2_MIN_X) / (TRACKPAD2_DIMENSION_X / 100))
#define TRACKPAD2_DIMENSION_Y (float)11490
#define TRACKPAD2_MIN_Y -2478
#define TRACKPAD2_MAX_Y 2587
#define TRACKPAD2_RES_Y \
        ((TRACKPAD2_MAX_Y - TRACKPAD2_MIN_Y) / (TRACKPAD2_DIMENSION_Y / 100))

/**
 * struct magicmouse_sc - Tracks Magic Mouse-specific data.
 * @input: Input device through which we report events.
 * @quirks: Currently unused.
 * @ntouches: Number of touches in most recent touch report.
 * @scroll_accel: Number of consecutive scroll motions.
 * @scroll_jiffies: Time of last scroll motion.
 * @touches: Most recent data for a touch, indexed by tracking ID.
 * @tracking_ids: Mapping of current touch input data to @touches.
 * @hdev: Pointer to the underlying HID device.
 * @work: Workqueue to handle initialization retry for quirky devices.
 * @battery_timer: Timer for obtaining battery level information.
 */
struct magicmouse_sc {
        struct input_dev *input;
        unsigned long quirks;

        int ntouches;
        int scroll_accel;
        unsigned long scroll_jiffies;

        struct {
                short x;
                short y;
                short scroll_x;
                short scroll_y;
                short scroll_x_hr;
                short scroll_y_hr;
                u8 size;
                bool scroll_x_active;
                bool scroll_y_active;
        } touches[16];
        int tracking_ids[16];

        struct hid_device *hdev;
        struct delayed_work work;
        struct timer_list battery_timer;
};

static int magicmouse_firm_touch(struct magicmouse_sc *msc)
{
        int touch = -1;
        int ii;

        /* If there is only one "firm" touch, set touch to its
         * tracking ID.
         */
        for (ii = 0; ii < msc->ntouches; ii++) {
                int idx = msc->tracking_ids[ii];
                if (msc->touches[idx].size < 8) {
                        /* Ignore this touch. */
                } else if (touch >= 0) {
                        touch = -1;
                        break;
                } else {
                        touch = idx;
                }
        }

        return touch;
}

static void magicmouse_emit_buttons(struct magicmouse_sc *msc, int state)
{
        int last_state = test_bit(BTN_LEFT, msc->input->key) << 0 |
                test_bit(BTN_RIGHT, msc->input->key) << 1 |
                test_bit(BTN_MIDDLE, msc->input->key) << 2;

        if (emulate_3button) {
                int id;

                /* If some button was pressed before, keep it held
                 * down.  Otherwise, if there's exactly one firm
                 * touch, use that to override the mouse's guess.
                 */
                if (state == 0) {
                        /* The button was released. */
                } else if (last_state != 0) {
                        state = last_state;
                } else if ((id = magicmouse_firm_touch(msc)) >= 0) {
                        int x = msc->touches[id].x;
                        if (x < middle_button_start)
                                state = 1;
                        else if (x > middle_button_stop)
                                state = 2;
                        else
                                state = 4;
                } /* else: we keep the mouse's guess */

                input_report_key(msc->input, BTN_MIDDLE, state & 4);
        }

        input_report_key(msc->input, BTN_LEFT, state & 1);
        input_report_key(msc->input, BTN_RIGHT, state & 2);

        if (state != last_state)
                msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
}

static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tdata)
{
        struct input_dev *input = msc->input;
        int id, x, y, size, orientation, touch_major, touch_minor, state, down;
        int pressure = 0;

        if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC) {
                id = (tdata[6] << 2 | tdata[5] >> 6) & 0xf;
                x = (tdata[1] << 28 | tdata[0] << 20) >> 20;
                y = -((tdata[2] << 24 | tdata[1] << 16) >> 20);
                size = tdata[5] & 0x3f;
                orientation = (tdata[6] >> 2) - 32;
                touch_major = tdata[3];
                touch_minor = tdata[4];
                state = tdata[7] & TOUCH_STATE_MASK;
                down = state != TOUCH_STATE_NONE;
        } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
                   input->id.product ==
                           USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                id = tdata[8] & 0xf;
                x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
                y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
                size = tdata[6];
                orientation = (tdata[8] >> 5) - 4;
                touch_major = tdata[4];
                touch_minor = tdata[5];
                pressure = tdata[7];
                state = tdata[3] & 0xC0;
                down = state == 0x80;
        } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                id = (tdata[7] << 2 | tdata[6] >> 6) & 0xf;
                x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
                y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
                size = tdata[6] & 0x3f;
                orientation = (tdata[7] >> 2) - 32;
                touch_major = tdata[4];
                touch_minor = tdata[5];
                state = tdata[8] & TOUCH_STATE_MASK;
                down = state != TOUCH_STATE_NONE;
        }

        /* Store tracking ID and other fields. */
        msc->tracking_ids[raw_id] = id;
        msc->touches[id].x = x;
        msc->touches[id].y = y;
        msc->touches[id].size = size;

        /* If requested, emulate a scroll wheel by detecting small
         * vertical touch motions.
         */
        if (emulate_scroll_wheel &&
            input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
            input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                unsigned long now = jiffies;
                int step_x = msc->touches[id].scroll_x - x;
                int step_y = msc->touches[id].scroll_y - y;
                int step_hr =
                        max_t(int,
                              ((64 - (int)scroll_speed) * msc->scroll_accel) /
                                        SCROLL_HR_STEPS,
                              1);
                int step_x_hr = msc->touches[id].scroll_x_hr - x;
                int step_y_hr = msc->touches[id].scroll_y_hr - y;

                /* Calculate and apply the scroll motion. */
                switch (state) {
                case TOUCH_STATE_START:
                        msc->touches[id].scroll_x = x;
                        msc->touches[id].scroll_y = y;
                        msc->touches[id].scroll_x_hr = x;
                        msc->touches[id].scroll_y_hr = y;
                        msc->touches[id].scroll_x_active = false;
                        msc->touches[id].scroll_y_active = false;

                        /* Reset acceleration after half a second. */
                        if (scroll_acceleration && time_before(now,
                                                msc->scroll_jiffies + HZ / 2))
                                msc->scroll_accel = max_t(int,
                                                msc->scroll_accel - 1, 1);
                        else
                                msc->scroll_accel = SCROLL_ACCEL_DEFAULT;

                        break;
                case TOUCH_STATE_DRAG:
                        step_x /= (64 - (int)scroll_speed) * msc->scroll_accel;
                        if (step_x != 0) {
                                msc->touches[id].scroll_x -= step_x *
                                        (64 - scroll_speed) * msc->scroll_accel;
                                msc->scroll_jiffies = now;
                                input_report_rel(input, REL_HWHEEL, -step_x);
                        }

                        step_y /= (64 - (int)scroll_speed) * msc->scroll_accel;
                        if (step_y != 0) {
                                msc->touches[id].scroll_y -= step_y *
                                        (64 - scroll_speed) * msc->scroll_accel;
                                msc->scroll_jiffies = now;
                                input_report_rel(input, REL_WHEEL, step_y);
                        }

                        if (!msc->touches[id].scroll_x_active &&
                            abs(step_x_hr) > SCROLL_HR_THRESHOLD) {
                                msc->touches[id].scroll_x_active = true;
                                msc->touches[id].scroll_x_hr = x;
                                step_x_hr = 0;
                        }

                        step_x_hr /= step_hr;
                        if (step_x_hr != 0 &&
                            msc->touches[id].scroll_x_active) {
                                msc->touches[id].scroll_x_hr -= step_x_hr *
                                        step_hr;
                                input_report_rel(input,
                                                 REL_HWHEEL_HI_RES,
                                                 -step_x_hr * SCROLL_HR_MULT);
                        }

                        if (!msc->touches[id].scroll_y_active &&
                            abs(step_y_hr) > SCROLL_HR_THRESHOLD) {
                                msc->touches[id].scroll_y_active = true;
                                msc->touches[id].scroll_y_hr = y;
                                step_y_hr = 0;
                        }

                        step_y_hr /= step_hr;
                        if (step_y_hr != 0 &&
                            msc->touches[id].scroll_y_active) {
                                msc->touches[id].scroll_y_hr -= step_y_hr *
                                        step_hr;
                                input_report_rel(input,
                                                 REL_WHEEL_HI_RES,
                                                 step_y_hr * SCROLL_HR_MULT);
                        }
                        break;
                }
        }

        if (down)
                msc->ntouches++;

        input_mt_slot(input, id);
        input_mt_report_slot_state(input, MT_TOOL_FINGER, down);

        /* Generate the input events for this touch. */
        if (down) {
                input_report_abs(input, ABS_MT_TOUCH_MAJOR, touch_major << 2);
                input_report_abs(input, ABS_MT_TOUCH_MINOR, touch_minor << 2);
                input_report_abs(input, ABS_MT_ORIENTATION, -orientation);
                input_report_abs(input, ABS_MT_POSITION_X, x);
                input_report_abs(input, ABS_MT_POSITION_Y, y);

                if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
                    input->id.product ==
                            USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC)
                        input_report_abs(input, ABS_MT_PRESSURE, pressure);

                if (report_undeciphered) {
                        if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE ||
                            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
                            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC)
                                input_event(input, EV_MSC, MSC_RAW, tdata[7]);
                        else if (input->id.product !=
                                         USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
                                 input->id.product !=
                                         USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC)
                                input_event(input, EV_MSC, MSC_RAW, tdata[8]);
                }
        }
}

static int magicmouse_raw_event(struct hid_device *hdev,
                struct hid_report *report, u8 *data, int size)
{
        struct magicmouse_sc *msc = hid_get_drvdata(hdev);
        struct input_dev *input = msc->input;
        int x = 0, y = 0, ii, clicks = 0, npoints;

        switch (data[0]) {
        case TRACKPAD_REPORT_ID:
        case TRACKPAD2_BT_REPORT_ID:
                /* Expect four bytes of prefix, and N*9 bytes of touch data. */
                if (size < 4 || ((size - 4) % 9) != 0)
                        return 0;
                npoints = (size - 4) / 9;
                if (npoints > 15) {
                        hid_warn(hdev, "invalid size value (%d) for TRACKPAD_REPORT_ID\n",
                                        size);
                        return 0;
                }
                msc->ntouches = 0;
                for (ii = 0; ii < npoints; ii++)
                        magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);

                clicks = data[1];

                /* The following bits provide a device specific timestamp. They
                 * are unused here.
                 *
                 * ts = data[1] >> 6 | data[2] << 2 | data[3] << 10;
                 */
                break;
        case TRACKPAD2_USB_REPORT_ID:
                /* Expect twelve bytes of prefix and N*9 bytes of touch data. */
                if (size < 12 || ((size - 12) % 9) != 0)
                        return 0;
                npoints = (size - 12) / 9;
                if (npoints > 15) {
                        hid_warn(hdev, "invalid size value (%d) for TRACKPAD2_USB_REPORT_ID\n",
                                        size);
                        return 0;
                }
                msc->ntouches = 0;
                for (ii = 0; ii < npoints; ii++)
                        magicmouse_emit_touch(msc, ii, data + ii * 9 + 12);

                clicks = data[1];
                break;
        case MOUSE_REPORT_ID:
                /* Expect six bytes of prefix, and N*8 bytes of touch data. */
                if (size < 6 || ((size - 6) % 8) != 0)
                        return 0;
                npoints = (size - 6) / 8;
                if (npoints > 15) {
                        hid_warn(hdev, "invalid size value (%d) for MOUSE_REPORT_ID\n",
                                        size);
                        return 0;
                }
                msc->ntouches = 0;
                for (ii = 0; ii < npoints; ii++)
                        magicmouse_emit_touch(msc, ii, data + ii * 8 + 6);

                /* When emulating three-button mode, it is important
                 * to have the current touch information before
                 * generating a click event.
                 */
                x = (int)(((data[3] & 0x0c) << 28) | (data[1] << 22)) >> 22;
                y = (int)(((data[3] & 0x30) << 26) | (data[2] << 22)) >> 22;
                clicks = data[3];

                /* The following bits provide a device specific timestamp. They
                 * are unused here.
                 *
                 * ts = data[3] >> 6 | data[4] << 2 | data[5] << 10;
                 */
                break;
        case MOUSE2_REPORT_ID:
                /* Size is either 8 or (14 + 8 * N) */
                if (size != 8 && (size < 14 || (size - 14) % 8 != 0))
                        return 0;
                npoints = (size - 14) / 8;
                if (npoints > 15) {
                        hid_warn(hdev, "invalid size value (%d) for MOUSE2_REPORT_ID\n",
                                        size);
                        return 0;
                }
                msc->ntouches = 0;
                for (ii = 0; ii < npoints; ii++)
                        magicmouse_emit_touch(msc, ii, data + ii * 8 + 14);

                /* When emulating three-button mode, it is important
                 * to have the current touch information before
                 * generating a click event.
                 */
                x = (int)((data[3] << 24) | (data[2] << 16)) >> 16;
                y = (int)((data[5] << 24) | (data[4] << 16)) >> 16;
                clicks = data[1];

                /* The following bits provide a device specific timestamp. They
                 * are unused here.
                 *
                 * ts = data[11] >> 6 | data[12] << 2 | data[13] << 10;
                 */
                break;
        case DOUBLE_REPORT_ID:
                /* Sometimes the trackpad sends two touch reports in one
                 * packet.
                 */
                magicmouse_raw_event(hdev, report, data + 2, data[1]);
                magicmouse_raw_event(hdev, report, data + 2 + data[1],
                        size - 2 - data[1]);
                return 0;
        default:
                return 0;
        }

        if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC) {
                magicmouse_emit_buttons(msc, clicks & 3);
                input_report_rel(input, REL_X, x);
                input_report_rel(input, REL_Y, y);
        } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
                   input->id.product ==
                           USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                input_mt_sync_frame(input);
                input_report_key(input, BTN_MOUSE, clicks & 1);
        } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                input_report_key(input, BTN_MOUSE, clicks & 1);
                input_mt_report_pointer_emulation(input, true);
        }

        input_sync(input);
        return 1;
}

static int magicmouse_event(struct hid_device *hdev, struct hid_field *field,
                struct hid_usage *usage, __s32 value)
{
        struct magicmouse_sc *msc = hid_get_drvdata(hdev);
        if ((msc->input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
             msc->input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC) &&
            field->report->id == MOUSE2_REPORT_ID) {
                /*
                 * magic_mouse_raw_event has done all the work. Skip hidinput.
                 *
                 * Specifically, hidinput may modify BTN_LEFT and BTN_RIGHT,
                 * breaking emulate_3button.
                 */
                return 1;
        }
        return 0;
}

static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hdev)
{
        int error;
        int mt_flags = 0;

        __set_bit(EV_KEY, input->evbit);

        if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC) {
                __set_bit(BTN_LEFT, input->keybit);
                __set_bit(BTN_RIGHT, input->keybit);
                if (emulate_3button)
                        __set_bit(BTN_MIDDLE, input->keybit);

                __set_bit(EV_REL, input->evbit);
                __set_bit(REL_X, input->relbit);
                __set_bit(REL_Y, input->relbit);
                if (emulate_scroll_wheel) {
                        __set_bit(REL_WHEEL, input->relbit);
                        __set_bit(REL_HWHEEL, input->relbit);
                        __set_bit(REL_WHEEL_HI_RES, input->relbit);
                        __set_bit(REL_HWHEEL_HI_RES, input->relbit);
                }
        } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
                   input->id.product ==
                           USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                /* If the trackpad has been connected to a Mac, the name is
                 * automatically personalized, e.g., "José Expósito's Trackpad".
                 * When connected through Bluetooth, the personalized name is
                 * reported, however, when connected through USB the generic
                 * name is reported.
                 * Set the device name to ensure the same driver settings get
                 * loaded, whether connected through bluetooth or USB.
                 */
                if (hdev->vendor == BT_VENDOR_ID_APPLE) {
                        if (input->id.version == TRACKPAD2_2021_BT_VERSION)
                                input->name = "Apple Inc. Magic Trackpad 2021";
                        else if (input->id.version == TRACKPAD_2024_BT_VERSION) {
                                input->name = "Apple Inc. Magic Trackpad USB-C";
                        } else {
                                input->name = "Apple Inc. Magic Trackpad";
                        }
                } else { /* USB_VENDOR_ID_APPLE */
                        input->name = hdev->name;
                }

                __clear_bit(EV_MSC, input->evbit);
                __clear_bit(BTN_0, input->keybit);
                __clear_bit(BTN_RIGHT, input->keybit);
                __clear_bit(BTN_MIDDLE, input->keybit);
                __set_bit(BTN_MOUSE, input->keybit);
                __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
                __set_bit(BTN_TOOL_FINGER, input->keybit);

                mt_flags = INPUT_MT_POINTER | INPUT_MT_DROP_UNUSED |
                                INPUT_MT_TRACK;
        } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                /* input->keybit is initialized with incorrect button info
                 * for Magic Trackpad. There really is only one physical
                 * button (BTN_LEFT == BTN_MOUSE). Make sure we don't
                 * advertise buttons that don't exist...
                 */
                __clear_bit(BTN_RIGHT, input->keybit);
                __clear_bit(BTN_MIDDLE, input->keybit);
                __set_bit(BTN_MOUSE, input->keybit);
                __set_bit(BTN_TOOL_FINGER, input->keybit);
                __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
                __set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
                __set_bit(BTN_TOOL_QUADTAP, input->keybit);
                __set_bit(BTN_TOOL_QUINTTAP, input->keybit);
                __set_bit(BTN_TOUCH, input->keybit);
                __set_bit(INPUT_PROP_POINTER, input->propbit);
                __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
        }


        __set_bit(EV_ABS, input->evbit);

        error = input_mt_init_slots(input, 16, mt_flags);
        if (error)
                return error;
        input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255 << 2,
                             4, 0);
        input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 255 << 2,
                             4, 0);

        /* Note: Touch Y position from the device is inverted relative
         * to how pointer motion is reported (and relative to how USB
         * HID recommends the coordinates work).  This driver keeps
         * the origin at the same position, and just uses the additive
         * inverse of the reported Y.
         */
        if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
            input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC) {
                input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
                input_set_abs_params(input, ABS_MT_POSITION_X,
                                     MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
                input_set_abs_params(input, ABS_MT_POSITION_Y,
                                     MOUSE_MIN_Y, MOUSE_MAX_Y, 4, 0);

                input_abs_set_res(input, ABS_MT_POSITION_X,
                                  MOUSE_RES_X);
                input_abs_set_res(input, ABS_MT_POSITION_Y,
                                  MOUSE_RES_Y);
        } else if (input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
                   input->id.product ==
                           USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                input_set_abs_params(input, ABS_MT_PRESSURE, 0, 253, 0, 0);
                input_set_abs_params(input, ABS_PRESSURE, 0, 253, 0, 0);
                input_set_abs_params(input, ABS_MT_ORIENTATION, -3, 4, 0, 0);
                input_set_abs_params(input, ABS_X, TRACKPAD2_MIN_X,
                                     TRACKPAD2_MAX_X, 0, 0);
                input_set_abs_params(input, ABS_Y, TRACKPAD2_MIN_Y,
                                     TRACKPAD2_MAX_Y, 0, 0);
                input_set_abs_params(input, ABS_MT_POSITION_X,
                                     TRACKPAD2_MIN_X, TRACKPAD2_MAX_X, 0, 0);
                input_set_abs_params(input, ABS_MT_POSITION_Y,
                                     TRACKPAD2_MIN_Y, TRACKPAD2_MAX_Y, 0, 0);

                input_abs_set_res(input, ABS_X, TRACKPAD2_RES_X);
                input_abs_set_res(input, ABS_Y, TRACKPAD2_RES_Y);
                input_abs_set_res(input, ABS_MT_POSITION_X, TRACKPAD2_RES_X);
                input_abs_set_res(input, ABS_MT_POSITION_Y, TRACKPAD2_RES_Y);
        } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
                input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
                                     TRACKPAD_MAX_X, 4, 0);
                input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
                                     TRACKPAD_MAX_Y, 4, 0);
                input_set_abs_params(input, ABS_MT_POSITION_X,
                                     TRACKPAD_MIN_X, TRACKPAD_MAX_X, 4, 0);
                input_set_abs_params(input, ABS_MT_POSITION_Y,
                                     TRACKPAD_MIN_Y, TRACKPAD_MAX_Y, 4, 0);

                input_abs_set_res(input, ABS_X, TRACKPAD_RES_X);
                input_abs_set_res(input, ABS_Y, TRACKPAD_RES_Y);
                input_abs_set_res(input, ABS_MT_POSITION_X,
                                  TRACKPAD_RES_X);
                input_abs_set_res(input, ABS_MT_POSITION_Y,
                                  TRACKPAD_RES_Y);
        }

        input_set_events_per_packet(input, 60);

        if (report_undeciphered &&
            input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 &&
            input->id.product != USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) {
                __set_bit(EV_MSC, input->evbit);
                __set_bit(MSC_RAW, input->mscbit);
        }

        /*
         * hid-input may mark device as using autorepeat, but neither
         * the trackpad, nor the mouse actually want it.
         */
        __clear_bit(EV_REP, input->evbit);

        return 0;
}

static int magicmouse_input_mapping(struct hid_device *hdev,
                struct hid_input *hi, struct hid_field *field,
                struct hid_usage *usage, unsigned long **bit, int *max)
{
        struct magicmouse_sc *msc = hid_get_drvdata(hdev);

        if (!msc->input)
                msc->input = hi->input;

        /* Magic Trackpad does not give relative data after switching to MT */
        if ((hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD ||
             hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
             hi->input->id.product ==
                     USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC) &&
            field->flags & HID_MAIN_ITEM_RELATIVE)
                return -1;

        return 0;
}

static int magicmouse_input_configured(struct hid_device *hdev,
                struct hid_input *hi)

{
        struct magicmouse_sc *msc = hid_get_drvdata(hdev);
        int ret;

        if (!msc->input) {
                hid_err(hdev, "magicmouse setup input failed (no input)");
                return -EINVAL;
        }

        ret = magicmouse_setup_input(msc->input, hdev);
        if (ret) {
                hid_err(hdev, "magicmouse setup input failed (%d)\n", ret);
                /* clean msc->input to notify probe() of the failure */
                msc->input = NULL;
                return ret;
        }

        return 0;
}

static int magicmouse_enable_multitouch(struct hid_device *hdev)
{
        const u8 *feature;
        const u8 feature_mt[] = { 0xD7, 0x01 };
        const u8 feature_mt_mouse2[] = { 0xF1, 0x02, 0x01 };
        const u8 feature_mt_trackpad2_usb[] = { 0x02, 0x01 };
        const u8 feature_mt_trackpad2_bt[] = { 0xF1, 0x02, 0x01 };
        u8 *buf;
        int ret;
        int feature_size;

        switch (hdev->product) {
        case USB_DEVICE_ID_APPLE_MAGICTRACKPAD2:
        case USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC:
                switch (hdev->vendor) {
                case BT_VENDOR_ID_APPLE:
                        feature_size = sizeof(feature_mt_trackpad2_bt);
                        feature = feature_mt_trackpad2_bt;
                        break;
                default: /* USB_VENDOR_ID_APPLE */
                        feature_size = sizeof(feature_mt_trackpad2_usb);
                        feature = feature_mt_trackpad2_usb;
                }
                break;
        case USB_DEVICE_ID_APPLE_MAGICMOUSE2:
        case USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC:
                feature_size = sizeof(feature_mt_mouse2);
                feature = feature_mt_mouse2;
                break;
        default:
                feature_size = sizeof(feature_mt);
                feature = feature_mt;
        }

        buf = kmemdup(feature, feature_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        ret = hid_hw_raw_request(hdev, buf[0], buf, feature_size,
                                HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
        kfree(buf);
        return ret;
}

static void magicmouse_enable_mt_work(struct work_struct *work)
{
        struct magicmouse_sc *msc =
                container_of(work, struct magicmouse_sc, work.work);
        int ret;

        ret = magicmouse_enable_multitouch(msc->hdev);
        if (ret < 0)
                hid_err(msc->hdev, "unable to request touch data (%d)\n", ret);
}

static bool is_usb_magicmouse2(__u32 vendor, __u32 product)
{
        if (vendor != USB_VENDOR_ID_APPLE)
                return false;
        return product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
               product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC;
}

static bool is_usb_magictrackpad2(__u32 vendor, __u32 product)
{
        if (vendor != USB_VENDOR_ID_APPLE)
                return false;
        return product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2 ||
               product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC;
}

static int magicmouse_fetch_battery(struct hid_device *hdev)
{
#ifdef CONFIG_HID_BATTERY_STRENGTH
        struct hid_report_enum *report_enum;
        struct hid_report *report;

        if (!hdev->battery ||
            (!is_usb_magicmouse2(hdev->vendor, hdev->product) &&
             !is_usb_magictrackpad2(hdev->vendor, hdev->product)))
                return -1;

        report_enum = &hdev->report_enum[hdev->battery_report_type];
        report = report_enum->report_id_hash[hdev->battery_report_id];

        if (!report || report->maxfield < 1)
                return -1;

        if (hdev->battery_capacity == hdev->battery_max)
                return -1;

        hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
        return 0;
#else
        return -1;
#endif
}

static void magicmouse_battery_timer_tick(struct timer_list *t)
{
        struct magicmouse_sc *msc = timer_container_of(msc, t, battery_timer);
        struct hid_device *hdev = msc->hdev;

        if (magicmouse_fetch_battery(hdev) == 0) {
                mod_timer(&msc->battery_timer,
                          jiffies + secs_to_jiffies(USB_BATTERY_TIMEOUT_SEC));
        }
}

static int magicmouse_probe(struct hid_device *hdev,
        const struct hid_device_id *id)
{
        struct magicmouse_sc *msc;
        struct hid_report *report;
        int ret;

        msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
        if (msc == NULL) {
                hid_err(hdev, "can't alloc magicmouse descriptor\n");
                return -ENOMEM;
        }

        msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
        msc->hdev = hdev;
        INIT_DEFERRABLE_WORK(&msc->work, magicmouse_enable_mt_work);

        msc->quirks = id->driver_data;
        hid_set_drvdata(hdev, msc);

        ret = hid_parse(hdev);
        if (ret) {
                hid_err(hdev, "magicmouse hid parse failed\n");
                return ret;
        }

        ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
        if (ret) {
                hid_err(hdev, "magicmouse hw start failed\n");
                return ret;
        }

        if (is_usb_magicmouse2(id->vendor, id->product) ||
            is_usb_magictrackpad2(id->vendor, id->product)) {
                timer_setup(&msc->battery_timer, magicmouse_battery_timer_tick, 0);
                mod_timer(&msc->battery_timer,
                          jiffies + secs_to_jiffies(USB_BATTERY_TIMEOUT_SEC));
                magicmouse_fetch_battery(hdev);
        }

        if (is_usb_magicmouse2(id->vendor, id->product) ||
            (is_usb_magictrackpad2(id->vendor, id->product) &&
             hdev->type != HID_TYPE_USBMOUSE))
                return 0;

        if (!msc->input) {
                hid_err(hdev, "magicmouse input not registered\n");
                ret = -ENOMEM;
                goto err_stop_hw;
        }

        switch (id->product) {
        case USB_DEVICE_ID_APPLE_MAGICMOUSE:
                report = hid_register_report(hdev, HID_INPUT_REPORT, MOUSE_REPORT_ID, 0);
                break;
        case USB_DEVICE_ID_APPLE_MAGICMOUSE2:
        case USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC:
                report = hid_register_report(hdev, HID_INPUT_REPORT, MOUSE2_REPORT_ID, 0);
                break;
        case USB_DEVICE_ID_APPLE_MAGICTRACKPAD2:
        case USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC:
                switch (id->vendor) {
                case BT_VENDOR_ID_APPLE:
                        report = hid_register_report(hdev, HID_INPUT_REPORT,
                                TRACKPAD2_BT_REPORT_ID, 0);
                        break;
                default:
                        report = hid_register_report(hdev, HID_INPUT_REPORT,
                                TRACKPAD2_USB_REPORT_ID, 0);
                }
                break;
        default: /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                report = hid_register_report(hdev, HID_INPUT_REPORT,
                        TRACKPAD_REPORT_ID, 0);
                report = hid_register_report(hdev, HID_INPUT_REPORT,
                        DOUBLE_REPORT_ID, 0);
        }

        if (!report) {
                hid_err(hdev, "unable to register touch report\n");
                ret = -ENOMEM;
                goto err_stop_hw;
        }
        report->size = 6;

        /*
         * Some devices repond with 'invalid report id' when feature
         * report switching it into multitouch mode is sent to it.
         *
         * This results in -EIO from the _raw low-level transport callback,
         * but there seems to be no other way of switching the mode.
         * Thus the super-ugly hacky success check below.
         */
        ret = magicmouse_enable_multitouch(hdev);
        if (ret != -EIO && ret < 0) {
                hid_err(hdev, "unable to request touch data (%d)\n", ret);
                goto err_stop_hw;
        }
        if (ret == -EIO && (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE2 ||
                            id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC)) {
                schedule_delayed_work(&msc->work, msecs_to_jiffies(500));
        }

        return 0;
err_stop_hw:
        if (is_usb_magicmouse2(id->vendor, id->product) ||
            is_usb_magictrackpad2(id->vendor, id->product))
                timer_delete_sync(&msc->battery_timer);

        hid_hw_stop(hdev);
        return ret;
}

static void magicmouse_remove(struct hid_device *hdev)
{
        struct magicmouse_sc *msc = hid_get_drvdata(hdev);

        if (msc) {
                cancel_delayed_work_sync(&msc->work);
                if (is_usb_magicmouse2(hdev->vendor, hdev->product) ||
                    is_usb_magictrackpad2(hdev->vendor, hdev->product))
                        timer_delete_sync(&msc->battery_timer);
        }

        hid_hw_stop(hdev);
}

static const __u8 *magicmouse_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                                           unsigned int *rsize)
{
        /*
         * Change the usage from:
         *   0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page 1)  0
         *   0x09, 0x0b,       // Usage (Vendor Usage 0x0b)           3
         * To:
         *   0x05, 0x01,       // Usage Page (Generic Desktop)        0
         *   0x09, 0x02,       // Usage (Mouse)                       2
         */
        if ((is_usb_magicmouse2(hdev->vendor, hdev->product) ||
             is_usb_magictrackpad2(hdev->vendor, hdev->product)) &&
            *rsize >= 83 && rdesc[46] == 0x84 && rdesc[58] == 0x85) {
                hid_info(hdev,
                         "fixing up magicmouse battery report descriptor\n");
                *rsize = *rsize - 1;
                rdesc = rdesc + 1;

                rdesc[0] = 0x05;
                rdesc[1] = 0x01;
                rdesc[2] = 0x09;
                rdesc[3] = 0x02;
        }

        return rdesc;
}

static const struct hid_device_id magic_mice[] = {
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
        { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICMOUSE2), .driver_data = 0 },
        { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICMOUSE2), .driver_data = 0 },
        { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC), .driver_data = 0 },
        { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICMOUSE2_USBC), .driver_data = 0 },
        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .driver_data = 0 },
        { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
        { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICTRACKPAD2), .driver_data = 0 },
        { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC), .driver_data = 0 },
        { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
                USB_DEVICE_ID_APPLE_MAGICTRACKPAD2_USBC), .driver_data = 0 },
        { }
};
MODULE_DEVICE_TABLE(hid, magic_mice);

static struct hid_driver magicmouse_driver = {
        .name = "magicmouse",
        .id_table = magic_mice,
        .probe = magicmouse_probe,
        .remove = magicmouse_remove,
        .report_fixup = magicmouse_report_fixup,
        .raw_event = magicmouse_raw_event,
        .event = magicmouse_event,
        .input_mapping = magicmouse_input_mapping,
        .input_configured = magicmouse_input_configured,
};
module_hid_driver(magicmouse_driver);

MODULE_DESCRIPTION("Apple \"Magic\" Wireless Mouse driver");
MODULE_LICENSE("GPL");