root/include/linux/input/mt.h

DEFINITIONS

1. input_mt_set_value
2. input_mt_get_value
3. input_mt_is_active
4. input_mt_is_used
5. input_mt_new_trkid
6. input_mt_slot
7. input_is_mt_value
8. input_is_mt_axis

#ifndef _INPUT_MT_H
#define _INPUT_MT_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/input.h>

#define TRKID_MAX       0xffff

#define INPUT_MT_POINTER        0x0001  /* pointer device, e.g. trackpad */
#define INPUT_MT_DIRECT         0x0002  /* direct device, e.g. touchscreen */
#define INPUT_MT_DROP_UNUSED    0x0004  /* drop contacts not seen in frame */
#define INPUT_MT_TRACK          0x0008  /* use in-kernel tracking */
#define INPUT_MT_SEMI_MT        0x0010  /* semi-mt device, finger count handled manually */

/**
 * struct input_mt_slot - represents the state of an input MT slot
 * @abs: holds current values of ABS_MT axes for this slot
 * @frame: last frame at which input_mt_report_slot_state() was called
 * @key: optional driver designation of this slot
 */
struct input_mt_slot {
        int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
        unsigned int frame;
        unsigned int key;
};

/**
 * struct input_mt - state of tracked contacts
 * @trkid: stores MT tracking ID for the next contact
 * @num_slots: number of MT slots the device uses
 * @slot: MT slot currently being transmitted
 * @flags: input_mt operation flags
 * @frame: increases every time input_mt_sync_frame() is called
 * @red: reduced cost matrix for in-kernel tracking
 * @slots: array of slots holding current values of tracked contacts
 */
struct input_mt {
        int trkid;
        int num_slots;
        int slot;
        unsigned int flags;
        unsigned int frame;
        int *red;
        struct input_mt_slot slots[];
};

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 bool input_mt_is_active(const struct input_mt_slot *slot)
{
        return input_mt_get_value(slot, ABS_MT_TRACKING_ID) >= 0;
}

static inline bool input_mt_is_used(const struct input_mt *mt,
                                    const struct input_mt_slot *slot)
{
        return slot->frame == mt->frame;
}

int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
                        unsigned int flags);
void input_mt_destroy_slots(struct input_dev *dev);

static inline int input_mt_new_trkid(struct input_mt *mt)
{
        return mt->trkid++ & TRKID_MAX;
}

static inline void input_mt_slot(struct input_dev *dev, int slot)
{
        input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
}

static inline bool input_is_mt_value(int axis)
{
        return axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST;
}

static inline bool input_is_mt_axis(int axis)
{
        return axis == ABS_MT_SLOT || input_is_mt_value(axis);
}

void input_mt_report_slot_state(struct input_dev *dev,
                                unsigned int tool_type, bool active);

void input_mt_report_finger_count(struct input_dev *dev, int count);
void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);
void input_mt_drop_unused(struct input_dev *dev);

void input_mt_sync_frame(struct input_dev *dev);

/**
 * struct input_mt_pos - contact position
 * @x: horizontal coordinate
 * @y: vertical coordinate
 */
struct input_mt_pos {
        s16 x, y;
};

int input_mt_assign_slots(struct input_dev *dev, int *slots,
                          const struct input_mt_pos *pos, int num_pos);

int input_mt_get_slot_by_key(struct input_dev *dev, int key);

#endif