diff options
Diffstat (limited to 'drivers/input/input-mt.c')
| -rw-r--r-- | drivers/input/input-mt.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c new file mode 100644 index 0000000000..14b53dac12 --- /dev/null +++ b/drivers/input/input-mt.c @@ -0,0 +1,535 @@ +// 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 ((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; + __set_bit(dst, dev->absbit); + } +} + +/** + * 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(struct_size(mt, slots, num_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. + * + * Returns true if contact is active. + */ +bool 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 false; + + slot = &mt->slots[mt->slot]; + slot->frame = mt->frame; + + if (!active) { + input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1); + return false; + } + + id = input_mt_get_value(slot, ABS_MT_TRACKING_ID); + if (id < 0) + 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); + + return true; +} +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) { + if (count == 0 && + !test_bit(ABS_MT_DISTANCE, dev->absbit) && + test_bit(ABS_DISTANCE, dev->absbit) && + input_abs_get_val(dev, ABS_DISTANCE) != 0) { + /* + * Force reporting BTN_TOOL_FINGER for devices that + * only report general hover (and not per-contact + * distance) when contact is in proximity but not + * on the surface. + */ + count = 1; + } + + 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; + + lockdep_assert_held(&dev->event_lock); + + for (i = 0; i < mt->num_slots; i++) { + if (input_mt_is_active(&mt->slots[i]) && + !input_mt_is_used(mt, &mt->slots[i])) { + input_handle_event(dev, EV_ABS, ABS_MT_SLOT, i); + input_handle_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) { + unsigned long flags; + + spin_lock_irqsave(&dev->event_lock, flags); + + __input_mt_drop_unused(dev, mt); + mt->frame++; + + spin_unlock_irqrestore(&dev->event_lock, flags); + } +} +EXPORT_SYMBOL(input_mt_drop_unused); + +/** + * 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) +{ + struct input_mt *mt = dev->mt; + + lockdep_assert_held(&dev->event_lock); + + if (mt) { + /* This will effectively mark all slots unused. */ + mt->frame++; + + __input_mt_drop_unused(dev, mt); + + if (test_bit(ABS_PRESSURE, dev->absbit)) + input_handle_event(dev, EV_ABS, ABS_PRESSURE, 0); + + mt->frame++; + } +} + +/** + * 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) { + unsigned long flags; + + spin_lock_irqsave(&dev->event_lock, flags); + __input_mt_drop_unused(dev, mt); + spin_unlock_irqrestore(&dev->event_lock, flags); + } + + 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); |