/* * 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) /** * 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. */int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots){	int i; 	if (!num_slots)		return 0;	if (dev->mt)		return dev->mtsize != num_slots ? -EINVAL : 0; 	dev->mt = kcalloc(num_slots, sizeof(struct input_mt_slot), GFP_KERNEL);	if (!dev->mt)		return -ENOMEM; 	dev->mtsize = num_slots;	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);	input_set_events_per_packet(dev, 6 * num_slots); 	/* Mark slots as 'unused' */	for (i = 0; i < num_slots; i++)		input_mt_set_value(&dev->mt[i], ABS_MT_TRACKING_ID, -1); 	return 0;}EXPORT_SYMBOL(input_mt_init_slots); /** * input_mt_destroy_slots() - frees the MT slots of the input device * @dev: input device with allocated MT slots * * This function is only needed in error path as the input core will * automatically free the MT slots when the device is destroyed. */void input_mt_destroy_slots(struct input_dev *dev){	kfree(dev->mt);	dev->mt = NULL;	dev->mtsize = 0;	dev->slot = 0;	dev->trkid = 0;}EXPORT_SYMBOL(input_mt_destroy_slots); /** * input_mt_report_slot_state() - report contact state * @dev: input device with allocated MT slots * @tool_type: the tool type to use in this slot * @active: true if contact is active, false otherwise * * Reports a contact via ABS_MT_TRACKING_ID, and optionally * ABS_MT_TOOL_TYPE. If active is true and the slot is currently * inactive, or if the tool type is changed, a new tracking id is * assigned to the slot. The tool type is only reported if the * corresponding absbit field is set. */void input_mt_report_slot_state(struct input_dev *dev,				unsigned int tool_type, bool active){	struct input_mt_slot *mt;	int id; 	if (!dev->mt || !active) {		input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);		return;	} 	mt = &dev->mt[dev->slot];	id = input_mt_get_value(mt, ABS_MT_TRACKING_ID);	if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type)		id = input_mt_new_trkid(dev); 	input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);	input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);}EXPORT_SYMBOL(input_mt_report_slot_state); /** * input_mt_report_finger_count() - report contact count * @dev: input device with allocated MT slots * @count: the number of contacts * * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP. * * The input core ensures only the KEY events already setup for * this device will produce output. */void input_mt_report_finger_count(struct input_dev *dev, int count){	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 == 4);	input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5);}EXPORT_SYMBOL(input_mt_report_finger_count); /** * input_mt_report_pointer_emulation() - common pointer emulation * @dev: input device with allocated MT slots * @use_count: report number of active contacts as finger count * * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true. * * The input core ensures only the KEY and ABS axes already setup for * this device will produce output. */void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count){	struct input_mt_slot *oldest = NULL;	int oldid = dev->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);	if (use_count)		input_mt_report_finger_count(dev, count); 	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);	}}EXPORT_SYMBOL(input_mt_report_pointer_emulation);