hid-magicmouse.c

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/*
 *   Apple "Magic" Wireless Mouse driver
 *
 *   Copyright (c) 2010 Michael Poole <[email protected]>
 *   Copyright (c) 2010 Chase Douglas <[email protected]>
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 */

#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/usb.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, struct kernel_param *kp) {
    unsigned long speed;
    if (!val || strict_strtoul(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 TRACKPAD_REPORT_ID 0x28
#define MOUSE_REPORT_ID    0x29
#define DOUBLE_REPORT_ID   0xf7
/* 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

#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))

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;
        u8 size;
    } touches[16];
    int tracking_ids[16];
};

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;

    if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
        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 { /* 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) {
        unsigned long now = jiffies;
        int step_x = msc->touches[id].scroll_x - x;
        int step_y = msc->touches[id].scroll_y - 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;

            /* 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);
            }
            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 (report_undeciphered) {
            if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
                input_event(input, EV_MSC, MSC_RAW, tdata[7]);
            else /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
                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:
        /* 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;
        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 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;
        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 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]);
        break;
    default:
        return 0;
    }

    if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
        magicmouse_emit_buttons(msc, clicks & 3);
        input_report_rel(input, REL_X, x);
        input_report_rel(input, REL_Y, y);
    } 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_setup_input(struct input_dev *input, struct hid_device *hdev)
{
    int error;

    __set_bit(EV_KEY, input->evbit);

    if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
        __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);
        }
    } 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, 0);
    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);
    input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 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_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 { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
        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) {
        __set_bit(EV_MSC, input->evbit);
        __set_bit(MSC_RAW, input->mscbit);
    }

    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 &&
        field->flags & HID_MAIN_ITEM_RELATIVE)
        return -1;

    return 0;
}

static int magicmouse_probe(struct hid_device *hdev,
    const struct hid_device_id *id)
{
    __u8 feature[] = { 0xd7, 0x01 };
    struct magicmouse_sc *msc;
    struct hid_report *report;
    int ret;

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

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

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

    /* We do this after hid-input is done parsing reports so that
     * hid-input uses the most natural button and axis IDs.
     */
    if (msc->input) {
        ret = magicmouse_setup_input(msc->input, hdev);
        if (ret) {
            hid_err(hdev, "magicmouse setup input failed (%d)\n", ret);
            goto err_stop_hw;
        }
    }

    if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
        report = hid_register_report(hdev, HID_INPUT_REPORT,
            MOUSE_REPORT_ID);
    else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
        report = hid_register_report(hdev, HID_INPUT_REPORT,
            TRACKPAD_REPORT_ID);
        report = hid_register_report(hdev, HID_INPUT_REPORT,
            DOUBLE_REPORT_ID);
    }

    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 = hdev->hid_output_raw_report(hdev, feature, sizeof(feature),
            HID_FEATURE_REPORT);
    if (ret != -EIO && ret != sizeof(feature)) {
        hid_err(hdev, "unable to request touch data (%d)\n", ret);
        goto err_stop_hw;
    }

    return 0;
err_stop_hw:
    hid_hw_stop(hdev);
err_free:
    kfree(msc);
    return ret;
}

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

    hid_hw_stop(hdev);
    kfree(msc);
}

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(USB_VENDOR_ID_APPLE,
        USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .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,
    .raw_event = magicmouse_raw_event,
    .input_mapping = magicmouse_input_mapping,
};

static int __init magicmouse_init(void)
{
    int ret;

    ret = hid_register_driver(&magicmouse_driver);
    if (ret)
        pr_err("can't register magicmouse driver\n");

    return ret;
}

static void __exit magicmouse_exit(void)
{
    hid_unregister_driver(&magicmouse_driver);
}

module_init(magicmouse_init);
module_exit(magicmouse_exit);
MODULE_LICENSE("GPL");