drivers/hid/hid-magicmouse.c - kernel/msm-4.19 - Gitiles

 /*
  *   Apple "Magic" Wireless Mouse driver
  *
  *   Copyright (c) 2010 Michael Poole <mdpoole@troilus.org>
  *   Copyright (c) 2010 Chase Douglas <chase.douglas@canonical.com>
  */

 /*
  * 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 "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 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 - 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.
  */
 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;
 		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 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 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_input_configured(struct hid_device *hdev,
 		struct hid_input *hi)

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

 	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_probe(struct hid_device *hdev,
 	const struct hid_device_id *id)
 {
 	const u8 feature[] = { 0xd7, 0x01 };
 	u8 *buf;
 	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->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 (!msc->input) {
 		hid_err(hdev, "magicmouse input not registered\n");
 		ret = -ENOMEM;
 		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;

 	buf = kmemdup(feature, sizeof(feature), GFP_KERNEL);
 	if (!buf) {
 		ret = -ENOMEM;
 		goto err_stop_hw;
 	}

 	/*
 	 * 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 = hid_hw_raw_request(hdev, buf[0], buf, sizeof(feature),
 				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 	kfree(buf);
 	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);
 	return ret;
 }

 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,
 	.raw_event = magicmouse_raw_event,
 	.input_mapping = magicmouse_input_mapping,
 	.input_configured = magicmouse_input_configured,
 };
 module_hid_driver(magicmouse_driver);

 MODULE_LICENSE("GPL");
	/*
	* Apple "Magic" Wireless Mouse driver
	*
	* Copyright (c) 2010 Michael Poole <mdpoole@troilus.org>
	* Copyright (c) 2010 Chase Douglas <chase.douglas@canonical.com>
	*/

	/*
	* 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 "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 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 - 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.
	*/
	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 N9 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 MOUSE_REPORT_ID:
	/* Expect six bytes of prefix, and N8 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 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_input_configured(struct hid_device *hdev,
	struct hid_input *hi)

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

	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_probe(struct hid_device *hdev,
	const struct hid_device_id *id)
	{
	const u8 feature[] = { 0xd7, 0x01 };
	u8 *buf;
	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->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 (!msc->input) {
	hid_err(hdev, "magicmouse input not registered\n");
	ret = -ENOMEM;
	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;

	buf = kmemdup(feature, sizeof(feature), GFP_KERNEL);
	if (!buf) {
	ret = -ENOMEM;
	goto err_stop_hw;
	}

	/*
	* 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 = hid_hw_raw_request(hdev, buf[0], buf, sizeof(feature),
	HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
	kfree(buf);
	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);
	return ret;
	}

	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,
	.raw_event = magicmouse_raw_event,
	.input_mapping = magicmouse_input_mapping,
	.input_configured = magicmouse_input_configured,
	};
	module_hid_driver(magicmouse_driver);

	MODULE_LICENSE("GPL");