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495 lines
12 KiB
495 lines
12 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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#include <linux/input/mt.h> |
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#include <linux/export.h> |
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#include <linux/slab.h> |
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#define TRKID_SGN ((TRKID_MAX + 1) >> 1) |
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static void copy_abs(struct input_dev *dev, unsigned int dst, unsigned int src) |
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{ |
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if (dev->absinfo && test_bit(src, dev->absbit)) { |
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dev->absinfo[dst] = dev->absinfo[src]; |
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dev->absinfo[dst].fuzz = 0; |
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__set_bit(dst, dev->absbit); |
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} |
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} |
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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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* @flags: mt tasks to handle in core |
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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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* Depending on the flags set, it also performs pointer emulation and |
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* frame synchronization. |
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* |
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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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unsigned int flags) |
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{ |
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struct input_mt *mt = dev->mt; |
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int i; |
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if (!num_slots) |
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return 0; |
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if (mt) |
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return mt->num_slots != num_slots ? -EINVAL : 0; |
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mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL); |
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if (!mt) |
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goto err_mem; |
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mt->num_slots = num_slots; |
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mt->flags = flags; |
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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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if (flags & (INPUT_MT_POINTER | INPUT_MT_DIRECT)) { |
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__set_bit(EV_KEY, dev->evbit); |
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__set_bit(BTN_TOUCH, dev->keybit); |
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copy_abs(dev, ABS_X, ABS_MT_POSITION_X); |
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copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y); |
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copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE); |
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} |
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if (flags & INPUT_MT_POINTER) { |
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__set_bit(BTN_TOOL_FINGER, dev->keybit); |
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__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit); |
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if (num_slots >= 3) |
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__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit); |
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if (num_slots >= 4) |
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__set_bit(BTN_TOOL_QUADTAP, dev->keybit); |
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if (num_slots >= 5) |
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__set_bit(BTN_TOOL_QUINTTAP, dev->keybit); |
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__set_bit(INPUT_PROP_POINTER, dev->propbit); |
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} |
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if (flags & INPUT_MT_DIRECT) |
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__set_bit(INPUT_PROP_DIRECT, dev->propbit); |
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if (flags & INPUT_MT_SEMI_MT) |
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__set_bit(INPUT_PROP_SEMI_MT, dev->propbit); |
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if (flags & INPUT_MT_TRACK) { |
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unsigned int n2 = num_slots * num_slots; |
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mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); |
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if (!mt->red) |
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goto err_mem; |
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} |
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/* Mark slots as 'inactive' */ |
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for (i = 0; i < num_slots; i++) |
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input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); |
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/* Mark slots as 'unused' */ |
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mt->frame = 1; |
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dev->mt = mt; |
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return 0; |
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err_mem: |
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kfree(mt); |
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return -ENOMEM; |
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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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if (dev->mt) { |
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kfree(dev->mt->red); |
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kfree(dev->mt); |
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} |
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dev->mt = NULL; |
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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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* Returns true if contact is active. |
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*/ |
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bool 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 *mt = dev->mt; |
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struct input_mt_slot *slot; |
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int id; |
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if (!mt) |
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return false; |
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slot = &mt->slots[mt->slot]; |
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slot->frame = mt->frame; |
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if (!active) { |
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input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); |
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return false; |
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} |
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id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); |
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if (id < 0) |
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id = input_mt_new_trkid(mt); |
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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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return true; |
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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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input_event(dev, EV_KEY, BTN_TOOL_QUINTTAP, count == 5); |
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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 *mt = dev->mt; |
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struct input_mt_slot *oldest; |
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int oldid, count, i; |
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if (!mt) |
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return; |
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oldest = NULL; |
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oldid = mt->trkid; |
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count = 0; |
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for (i = 0; i < mt->num_slots; ++i) { |
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struct input_mt_slot *ps = &mt->slots[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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if (count == 0 && |
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!test_bit(ABS_MT_DISTANCE, dev->absbit) && |
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test_bit(ABS_DISTANCE, dev->absbit) && |
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input_abs_get_val(dev, ABS_DISTANCE) != 0) { |
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/* |
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* Force reporting BTN_TOOL_FINGER for devices that |
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* only report general hover (and not per-contact |
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* distance) when contact is in proximity but not |
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* on the surface. |
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*/ |
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count = 1; |
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} |
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input_mt_report_finger_count(dev, count); |
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} |
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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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input_event(dev, EV_ABS, ABS_X, x); |
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input_event(dev, EV_ABS, ABS_Y, y); |
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if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { |
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int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); |
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input_event(dev, EV_ABS, ABS_PRESSURE, p); |
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} |
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} else { |
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if (test_bit(ABS_MT_PRESSURE, dev->absbit)) |
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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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static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) |
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{ |
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int i; |
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for (i = 0; i < mt->num_slots; i++) { |
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if (!input_mt_is_used(mt, &mt->slots[i])) { |
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input_mt_slot(dev, i); |
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input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); |
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} |
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} |
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} |
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/** |
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* input_mt_drop_unused() - Inactivate slots not seen in this frame |
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* @dev: input device with allocated MT slots |
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* |
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* Lift all slots not seen since the last call to this function. |
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*/ |
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void input_mt_drop_unused(struct input_dev *dev) |
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{ |
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struct input_mt *mt = dev->mt; |
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if (mt) { |
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__input_mt_drop_unused(dev, mt); |
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mt->frame++; |
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} |
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} |
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EXPORT_SYMBOL(input_mt_drop_unused); |
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/** |
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* input_mt_sync_frame() - synchronize mt frame |
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* @dev: input device with allocated MT slots |
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* |
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* Close the frame and prepare the internal state for a new one. |
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* Depending on the flags, marks unused slots as inactive and performs |
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* pointer emulation. |
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*/ |
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void input_mt_sync_frame(struct input_dev *dev) |
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{ |
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struct input_mt *mt = dev->mt; |
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bool use_count = false; |
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if (!mt) |
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return; |
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if (mt->flags & INPUT_MT_DROP_UNUSED) |
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__input_mt_drop_unused(dev, mt); |
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if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT)) |
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use_count = true; |
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input_mt_report_pointer_emulation(dev, use_count); |
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mt->frame++; |
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} |
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EXPORT_SYMBOL(input_mt_sync_frame); |
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static int adjust_dual(int *begin, int step, int *end, int eq, int mu) |
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{ |
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int f, *p, s, c; |
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if (begin == end) |
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return 0; |
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f = *begin; |
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p = begin + step; |
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s = p == end ? f + 1 : *p; |
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for (; p != end; p += step) { |
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if (*p < f) { |
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s = f; |
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f = *p; |
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} else if (*p < s) { |
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s = *p; |
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} |
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} |
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c = (f + s + 1) / 2; |
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if (c == 0 || (c > mu && (!eq || mu > 0))) |
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return 0; |
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/* Improve convergence for positive matrices by penalizing overcovers */ |
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if (s < 0 && mu <= 0) |
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c *= 2; |
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for (p = begin; p != end; p += step) |
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*p -= c; |
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return (c < s && s <= 0) || (f >= 0 && f < c); |
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} |
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static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) |
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{ |
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int i, k, sum; |
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for (k = 0; k < nrc; k++) { |
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for (i = 0; i < nr; i++) |
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adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu); |
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sum = 0; |
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for (i = 0; i < nrc; i += nr) |
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sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu); |
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if (!sum) |
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break; |
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} |
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} |
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static int input_mt_set_matrix(struct input_mt *mt, |
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const struct input_mt_pos *pos, int num_pos, |
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int mu) |
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{ |
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const struct input_mt_pos *p; |
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struct input_mt_slot *s; |
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int *w = mt->red; |
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int x, y; |
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for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { |
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if (!input_mt_is_active(s)) |
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continue; |
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x = input_mt_get_value(s, ABS_MT_POSITION_X); |
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y = input_mt_get_value(s, ABS_MT_POSITION_Y); |
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for (p = pos; p != pos + num_pos; p++) { |
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int dx = x - p->x, dy = y - p->y; |
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*w++ = dx * dx + dy * dy - mu; |
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} |
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} |
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return w - mt->red; |
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} |
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static void input_mt_set_slots(struct input_mt *mt, |
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int *slots, int num_pos) |
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{ |
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struct input_mt_slot *s; |
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int *w = mt->red, j; |
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for (j = 0; j != num_pos; j++) |
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slots[j] = -1; |
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for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { |
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if (!input_mt_is_active(s)) |
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continue; |
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for (j = 0; j != num_pos; j++) { |
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if (w[j] < 0) { |
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slots[j] = s - mt->slots; |
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break; |
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} |
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} |
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w += num_pos; |
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} |
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for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { |
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if (input_mt_is_active(s)) |
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continue; |
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for (j = 0; j != num_pos; j++) { |
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if (slots[j] < 0) { |
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slots[j] = s - mt->slots; |
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break; |
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} |
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} |
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} |
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} |
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/** |
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* input_mt_assign_slots() - perform a best-match assignment |
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* @dev: input device with allocated MT slots |
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* @slots: the slot assignment to be filled |
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* @pos: the position array to match |
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* @num_pos: number of positions |
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* @dmax: maximum ABS_MT_POSITION displacement (zero for infinite) |
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* |
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* Performs a best match against the current contacts and returns |
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* the slot assignment list. New contacts are assigned to unused |
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* slots. |
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* |
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* The assignments are balanced so that all coordinate displacements are |
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* below the euclidian distance dmax. If no such assignment can be found, |
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* some contacts are assigned to unused slots. |
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* |
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* Returns zero on success, or negative error in case of failure. |
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*/ |
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int input_mt_assign_slots(struct input_dev *dev, int *slots, |
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const struct input_mt_pos *pos, int num_pos, |
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int dmax) |
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{ |
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struct input_mt *mt = dev->mt; |
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int mu = 2 * dmax * dmax; |
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int nrc; |
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if (!mt || !mt->red) |
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return -ENXIO; |
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if (num_pos > mt->num_slots) |
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return -EINVAL; |
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if (num_pos < 1) |
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return 0; |
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nrc = input_mt_set_matrix(mt, pos, num_pos, mu); |
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find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu); |
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input_mt_set_slots(mt, slots, num_pos); |
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return 0; |
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} |
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EXPORT_SYMBOL(input_mt_assign_slots); |
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/** |
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* input_mt_get_slot_by_key() - return slot matching key |
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* @dev: input device with allocated MT slots |
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* @key: the key of the sought slot |
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* |
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* Returns the slot of the given key, if it exists, otherwise |
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* set the key on the first unused slot and return. |
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* |
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* If no available slot can be found, -1 is returned. |
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* Note that for this function to work properly, input_mt_sync_frame() has |
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* to be called at each frame. |
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*/ |
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int input_mt_get_slot_by_key(struct input_dev *dev, int key) |
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{ |
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struct input_mt *mt = dev->mt; |
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struct input_mt_slot *s; |
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if (!mt) |
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return -1; |
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for (s = mt->slots; s != mt->slots + mt->num_slots; s++) |
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if (input_mt_is_active(s) && s->key == key) |
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return s - mt->slots; |
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for (s = mt->slots; s != mt->slots + mt->num_slots; s++) |
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if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) { |
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s->key = key; |
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return s - mt->slots; |
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} |
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return -1; |
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} |
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EXPORT_SYMBOL(input_mt_get_slot_by_key);
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