linux-imx

/*

 * Input Multitouch Library

 *

 * Copyright (c) 2008-2010 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/mt.h>

#include <linux/export.h>

#include <linux/slab.h>

​

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

​

static void copy_abs(struct input_dev *dev, unsigned int dst, unsigned int src)

{

    if (dev->absinfo && test_bit(src, dev->absbit)) {

        dev->absinfo[dst] = dev->absinfo[src];

        dev->absinfo[dst].fuzz = 0;

        dev->absbit[BIT_WORD(dst)] |= BIT_MASK(dst);

    }

}

​

/**

 * 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

 * @flags: mt tasks to handle in core

 *

 * 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.

 * Depending on the flags set, it also performs pointer emulation and

 * frame synchronization.

 *

 * May be called repeatedly. Returns -EINVAL if attempting to

 * reinitialize with a different number of slots.

 */

int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,

            unsigned int flags)

{

    struct input_mt *mt = dev->mt;

    int i;

​

    if (!num_slots)

        return 0;

    if (mt)

        return mt->num_slots != num_slots ? -EINVAL : 0;

​

    mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);

    if (!mt)

        goto err_mem;

​

    mt->num_slots = num_slots;

    mt->flags = flags;

    input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);

    input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);

​

    if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) {

        __set_bit(EV_KEY, dev->evbit);

        __set_bit(BTN_TOUCH, dev->keybit);