/* * 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(sizeof(*mt) + num_slots * sizeof(*mt->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); copy_abs(dev, ABS_X, ABS_MT_POSITION_X); copy_abs(dev, ABS_Y, ABS_MT_POSITION_Y); copy_abs(dev, ABS_PRESSURE, ABS_MT_PRESSURE); } if (flags & INPUT_MT_POINTER) { __set_bit(BTN_TOOL_FINGER, dev->keybit); __set_bit(BTN_TOOL_DOUBLETAP, dev->keybit); if (num_slots >= 3) __set_bit(BTN_TOOL_TRIPLETAP, dev->keybit); if (num_slots >= 4) __set_bit(BTN_TOOL_QUADTAP, dev->keybit); if (num_slots >= 5) __set_bit(BTN_TOOL_QUINTTAP, dev->keybit); __set_bit(INPUT_PROP_POINTER, dev->propbit); } if (flags & INPUT_MT_DIRECT) __set_bit(INPUT_PROP_DIRECT, dev->propbit); if (flags & INPUT_MT_SEMI_MT) __set_bit(INPUT_PROP_SEMI_MT, dev->propbit); if (flags & INPUT_MT_TRACK) { unsigned int n2 = num_slots * num_slots; mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); if (!mt->red) goto err_mem; } /* Mark slots as 'inactive' */ for (i = 0; i < num_slots; i++) input_mt_set_value(&mt->slots[i], ABS_MT_TRACKING_ID, -1); /* Mark slots as 'unused' */ mt->frame = 1; dev->mt = mt; return 0; err_mem: kfree(mt); return -ENOMEM; } 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) { if (dev->mt) { kfree(dev->mt->red); kfree(dev->mt); } dev->mt = NULL; } 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 *mt = dev->mt; struct input_mt_slot *slot; int id; if (!mt) return; slot = &mt->slots[mt->slot]; slot->frame = mt->frame; if (!active) { input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); return; } id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); if (id < 0 || input_mt_get_value(slot, ABS_MT_TOOL_TYPE) != tool_type) id = input_mt_new_trkid(mt); 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 *mt = dev->mt; struct input_mt_slot *oldest; int oldid, count, i; if (!mt) return; oldest = NULL; oldid = mt->trkid; count = 0; for (i = 0; i < mt->num_slots; ++i) { struct input_mt_slot *ps = &mt->slots[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); input_event(dev, EV_ABS, ABS_X, x); input_event(dev, EV_ABS, ABS_Y, y); if (test_bit(ABS_MT_PRESSURE, dev->absbit)) { int p = input_mt_get_value(oldest, ABS_MT_PRESSURE); input_event(dev, EV_ABS, ABS_PRESSURE, p); } } else { if (test_bit(ABS_MT_PRESSURE, dev->absbit)) input_event(dev, EV_ABS, ABS_PRESSURE, 0); } } EXPORT_SYMBOL(input_mt_report_pointer_emulation); static void __input_mt_drop_unused(struct input_dev *dev, struct input_mt *mt) { int i; for (i = 0; i < mt->num_slots; i++) { if (!input_mt_is_used(mt, &mt->slots[i])) { input_mt_slot(dev, i); input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); } } } /** * 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) { struct input_mt *mt = dev->mt; if (mt) { __input_mt_drop_unused(dev, mt); mt->frame++; } } EXPORT_SYMBOL(input_mt_drop_unused); /** * 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) { struct input_mt *mt = dev->mt; bool use_count = false; if (!mt) return; if (mt->flags & INPUT_MT_DROP_UNUSED) __input_mt_drop_unused(dev, mt); if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT)) use_count = true; input_mt_report_pointer_emulation(dev, use_count); mt->frame++; } EXPORT_SYMBOL(input_mt_sync_frame); static int adjust_dual(int *begin, int step, int *end, int eq, int mu) { int f, *p, s, c; if (begin == end) return 0; f = *begin; p = begin + step; s = p == end ? f + 1 : *p; for (; p != end; p += step) if (*p < f) s = f, f = *p; else if (*p < s) s = *p; c = (f + s + 1) / 2; if (c == 0 || (c > mu && (!eq || mu > 0))) return 0; /* Improve convergence for positive matrices by penalizing overcovers */ if (s < 0 && mu <= 0) c *= 2; for (p = begin; p != end; p += step) *p -= c; return (c < s && s <= 0) || (f >= 0 && f < c); } static void find_reduced_matrix(int *w, int nr, int nc, int nrc, int mu) { int i, k, sum; for (k = 0; k < nrc; k++) { for (i = 0; i < nr; i++) adjust_dual(w + i, nr, w + i + nrc, nr <= nc, mu); sum = 0; for (i = 0; i < nrc; i += nr) sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr, mu); if (!sum) break; } } static int input_mt_set_matrix(struct input_mt *mt, const struct input_mt_pos *pos, int num_pos, int mu) { const struct input_mt_pos *p; struct input_mt_slot *s; int *w = mt->red; int x, y; for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { if (!input_mt_is_active(s)) continue; x = input_mt_get_value(s, ABS_MT_POSITION_X); y = input_mt_get_value(s, ABS_MT_POSITION_Y); for (p = pos; p != pos + num_pos; p++) { int dx = x - p->x, dy = y - p->y; *w++ = dx * dx + dy * dy - mu; } } return w - mt->red; } static void input_mt_set_slots(struct input_mt *mt, int *slots, int num_pos) { struct input_mt_slot *s; int *w = mt->red, j; for (j = 0; j != num_pos; j++) slots[j] = -1; for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { if (!input_mt_is_active(s)) continue; for (j = 0; j != num_pos; j++) { if (w[j] < 0) { slots[j] = s - mt->slots; break; } } w += num_pos; } for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { if (input_mt_is_active(s)) continue; for (j = 0; j != num_pos; j++) { if (slots[j] < 0) { slots[j] = s - mt->slots; break; } } } } /** * 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) { struct input_mt *mt = dev->mt; int mu = 2 * dmax * dmax; int nrc; if (!mt || !mt->red) return -ENXIO; if (num_pos > mt->num_slots) return -EINVAL; if (num_pos < 1) return 0; nrc = input_mt_set_matrix(mt, pos, num_pos, mu); find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc, mu); input_mt_set_slots(mt, slots, num_pos); return 0; } EXPORT_SYMBOL(input_mt_assign_slots); /** * 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) { struct input_mt *mt = dev->mt; struct input_mt_slot *s; if (!mt) return -1; for (s = mt->slots; s != mt->slots + mt->num_slots; s++) if (input_mt_is_active(s) && s->key == key) return s - mt->slots; for (s = mt->slots; s != mt->slots + mt->num_slots; s++) if (!input_mt_is_active(s) && !input_mt_is_used(mt, s)) { s->key = key; return s - mt->slots; } return -1; } EXPORT_SYMBOL(input_mt_get_slot_by_key);