#ifndef _INPUT_MT_LOCAL_H
#define _INPUT_MT_LOCAL_H

/*
 * Input Multitouch Library
 *
 * Copyright (c) 2010 Henrik Rydberg
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/version.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,38)

#include <linux/input/mt.h>

#else

#include <linux/input.h>

#define MT_TOOL_MAX		1

#define TRKID_MAX	0xffff
#define TRKID_SGN	((TRKID_MAX + 1) >> 1)

static int trkid;

static inline void input_abs_set_res(struct input_dev *dev,
				     unsigned int axis, int val)
{
	dev->absres[axis] = val;
}

static inline void input_mt_set_value(struct input_mt_slot *slot,
				      unsigned code, int value)
{
	slot->abs[code - ABS_MT_FIRST] = value;
}

static inline int input_mt_get_value(const struct input_mt_slot *slot,
				     unsigned code)
{
	return slot->abs[code - ABS_MT_FIRST];
}

static inline int input_mt_new_trkid(struct input_dev *dev)
{
	return trkid++ & TRKID_MAX;
}

/**
 * input_mt_init_slots() - initialize MT input slots
 * @dev: input device supporting MT events and finger tracking
 * @num_slots: number of slots used by the device
 *
 * This function allocates all necessary memory for MT slot handling
 * in the input device, prepares the ABS_MT_SLOT and
 * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
 * May be called repeatedly. Returns -EINVAL if attempting to
 * reinitialize with a different number of slots.
 */
static int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
{
	int ret;

	if (dev->mt)
		return dev->mtsize != num_slots ? -EINVAL : 0;

	ret = input_mt_create_slots(dev, num_slots);
	if (ret)
		return ret;

	input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
	input_set_events_per_packet(dev, 6 * num_slots);

	return 0;
}

/**
 * input_mt_report_state() - report contact state
 * @dev: input device with allocated MT slots
 * @active: true if contact is active, false otherwise
 *
 * Reports an active touch via ABS_MT_TRACKING_ID. If active is
 * true and the slot is currently inactive, a new tracking id is
 * assigned to the slot.
 */
static void input_mt_report_slot_state(struct input_dev *dev, unsigned type,
				       bool active)
{
	struct input_mt_slot *mt = dev->mt;
	int id;

	if (!mt || !active) {
		input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
		return;
	}

	id = input_mt_get_value(&mt[dev->slot], ABS_MT_TRACKING_ID);
	if (id < 0)
		id = input_mt_new_trkid(dev);
	input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
}

/**
 * input_mt_report_pointer_emulation() - common pointer emulation
 * @dev: input device with allocated MT slots
 *
 * Performs legacy pointer emulation via BTN_TOUCH.
 */
static void input_mt_report_pointer_emulation(struct input_dev *dev, bool more)
{
	struct input_mt_slot *oldest = 0;
	int oldid = trkid;
	int count = 0;
	int i;

	for (i = 0; i < dev->mtsize; ++i) {
		struct input_mt_slot *ps = &dev->mt[i];
		int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);

		if (id < 0)
			continue;
		if ((id - oldid) & TRKID_SGN) {
			oldest = ps;
			oldid = id;
		}
		count++;
	}

	input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
	input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
	input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
	input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
	input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count > 3);

	if (oldest) {
		int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
		int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
		int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);

		input_event(dev, EV_ABS, ABS_X, x);
		input_event(dev, EV_ABS, ABS_Y, y);
		input_event(dev, EV_ABS, ABS_PRESSURE, p);
	} else {
		input_event(dev, EV_ABS, ABS_PRESSURE, 0);
	}
}

#endif

#endif