171 lines
5.0 KiB
C
171 lines
5.0 KiB
C
/*
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* Input Multitouch Library
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*
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* Copyright (c) 2008-2010 Henrik Rydberg
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/input/mt.h>
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#include <linux/slab.h>
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#define TRKID_SGN ((TRKID_MAX + 1) >> 1)
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/**
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* input_mt_init_slots() - initialize MT input slots
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* @dev: input device supporting MT events and finger tracking
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* @num_slots: number of slots used by the device
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*
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* This function allocates all necessary memory for MT slot handling
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* in the input device, prepares the ABS_MT_SLOT and
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* ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
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* May be called repeatedly. Returns -EINVAL if attempting to
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* reinitialize with a different number of slots.
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*/
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int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
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{
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int i;
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if (!num_slots)
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return 0;
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if (dev->mt)
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return dev->mtsize != num_slots ? -EINVAL : 0;
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dev->mt = kcalloc(num_slots, sizeof(struct input_mt_slot), GFP_KERNEL);
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if (!dev->mt)
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return -ENOMEM;
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dev->mtsize = num_slots;
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input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
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input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
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input_set_events_per_packet(dev, 6 * num_slots);
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/* Mark slots as 'unused' */
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for (i = 0; i < num_slots; i++)
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input_mt_set_value(&dev->mt[i], ABS_MT_TRACKING_ID, -1);
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return 0;
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}
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EXPORT_SYMBOL(input_mt_init_slots);
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/**
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* input_mt_destroy_slots() - frees the MT slots of the input device
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* @dev: input device with allocated MT slots
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*
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* This function is only needed in error path as the input core will
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* automatically free the MT slots when the device is destroyed.
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*/
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void input_mt_destroy_slots(struct input_dev *dev)
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{
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kfree(dev->mt);
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dev->mt = NULL;
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dev->mtsize = 0;
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dev->slot = 0;
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dev->trkid = 0;
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}
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EXPORT_SYMBOL(input_mt_destroy_slots);
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/**
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* input_mt_report_slot_state() - report contact state
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* @dev: input device with allocated MT slots
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* @tool_type: the tool type to use in this slot
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* @active: true if contact is active, false otherwise
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*
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* Reports a contact via ABS_MT_TRACKING_ID, and optionally
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* ABS_MT_TOOL_TYPE. If active is true and the slot is currently
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* inactive, or if the tool type is changed, a new tracking id is
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* assigned to the slot. The tool type is only reported if the
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* corresponding absbit field is set.
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*/
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void input_mt_report_slot_state(struct input_dev *dev,
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unsigned int tool_type, bool active)
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{
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struct input_mt_slot *mt;
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int id;
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if (!dev->mt || !active) {
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input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
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return;
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}
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mt = &dev->mt[dev->slot];
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id = input_mt_get_value(mt, ABS_MT_TRACKING_ID);
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if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type)
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id = input_mt_new_trkid(dev);
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input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
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input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
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}
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EXPORT_SYMBOL(input_mt_report_slot_state);
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/**
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* input_mt_report_finger_count() - report contact count
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* @dev: input device with allocated MT slots
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* @count: the number of contacts
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*
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* Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP,
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* BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP.
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*
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* The input core ensures only the KEY events already setup for
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* this device will produce output.
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*/
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void input_mt_report_finger_count(struct input_dev *dev, int count)
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{
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input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
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input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
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input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
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input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4);
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}
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EXPORT_SYMBOL(input_mt_report_finger_count);
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/**
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* input_mt_report_pointer_emulation() - common pointer emulation
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* @dev: input device with allocated MT slots
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* @use_count: report number of active contacts as finger count
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*
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* Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
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* ABS_PRESSURE. Touchpad finger count is emulated if use_count is true.
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*
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* The input core ensures only the KEY and ABS axes already setup for
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* this device will produce output.
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*/
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void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
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{
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struct input_mt_slot *oldest = 0;
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int oldid = dev->trkid;
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int count = 0;
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int i;
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for (i = 0; i < dev->mtsize; ++i) {
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struct input_mt_slot *ps = &dev->mt[i];
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int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
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if (id < 0)
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continue;
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if ((id - oldid) & TRKID_SGN) {
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oldest = ps;
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oldid = id;
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}
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count++;
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}
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input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
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if (use_count)
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input_mt_report_finger_count(dev, count);
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if (oldest) {
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int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
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int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
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int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);
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input_event(dev, EV_ABS, ABS_X, x);
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input_event(dev, EV_ABS, ABS_Y, y);
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input_event(dev, EV_ABS, ABS_PRESSURE, p);
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} else {
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input_event(dev, EV_ABS, ABS_PRESSURE, 0);
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}
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}
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EXPORT_SYMBOL(input_mt_report_pointer_emulation);
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