// SPDX-License-Identifier: GPL-2.0-only /* * Input Multitouch Library * * Copyright (c) 2008-2010 Henrik Rydberg */ #include <linux/input/mt.h> #include <linux/export.h> #include <linux/slab.h> #include "input-core-private.h" #define TRKID_SGN … static void copy_abs(struct input_dev *dev, unsigned int dst, unsigned int src) { … } /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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. * * Returns true if contact is active. */ bool input_mt_report_slot_state(struct input_dev *dev, unsigned int tool_type, bool active) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * 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) { … } EXPORT_SYMBOL(…); static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) { … } /** * input_mt_drop_unused() - Inactivate slots not seen in this frame * @dev: input device with allocated MT slots * * Lift all slots not seen since the last call to this function. */ void input_mt_drop_unused(struct input_dev *dev) { … } EXPORT_SYMBOL(…); /** * input_mt_release_slots() - Deactivate all slots * @dev: input device with allocated MT slots * * Lift all active slots. */ void input_mt_release_slots(struct input_dev *dev) { … } /** * input_mt_sync_frame() - synchronize mt frame * @dev: input device with allocated MT slots * * Close the frame and prepare the internal state for a new one. * Depending on the flags, marks unused slots as inactive and performs * pointer emulation. */ void input_mt_sync_frame(struct input_dev *dev) { … } EXPORT_SYMBOL(…); static int adjust_dual(int *begin, int step, int *end, int eq, int mu) { … } static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) { … } static int input_mt_set_matrix(struct input_mt *mt, const struct input_mt_pos *pos, int num_pos, int mu) { … } static void input_mt_set_slots(struct input_mt *mt, int *slots, int num_pos) { … } /** * input_mt_assign_slots() - perform a best-match assignment * @dev: input device with allocated MT slots * @slots: the slot assignment to be filled * @pos: the position array to match * @num_pos: number of positions * @dmax: maximum ABS_MT_POSITION displacement (zero for infinite) * * Performs a best match against the current contacts and returns * the slot assignment list. New contacts are assigned to unused * slots. * * The assignments are balanced so that all coordinate displacements are * below the euclidian distance dmax. If no such assignment can be found, * some contacts are assigned to unused slots. * * Returns zero on success, or negative error in case of failure. */ int input_mt_assign_slots(struct input_dev *dev, int *slots, const struct input_mt_pos *pos, int num_pos, int dmax) { … } EXPORT_SYMBOL(…); /** * input_mt_get_slot_by_key() - return slot matching key * @dev: input device with allocated MT slots * @key: the key of the sought slot * * Returns the slot of the given key, if it exists, otherwise * set the key on the first unused slot and return. * * If no available slot can be found, -1 is returned. * Note that for this function to work properly, input_mt_sync_frame() has * to be called at each frame. */ int input_mt_get_slot_by_key(struct input_dev *dev, int key) { … } EXPORT_SYMBOL(…);
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