v4.19.13 snapshot.
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
new file mode 100644
index 0000000..6c7326c
--- /dev/null
+++ b/drivers/input/input-mt.c
@@ -0,0 +1,495 @@
+/*
+ * 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(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;
+
+ 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);