diff options
| -rw-r--r-- | drivers/input/input-mt.c | 144 | ||||
| -rw-r--r-- | include/linux/input/mt.h | 21 |
2 files changed, 163 insertions, 2 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 96cc2e2a9be2..caff298832a4 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -46,7 +46,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL); if (!mt) - return -ENOMEM; + goto err_mem; mt->num_slots = num_slots; mt->flags = flags; @@ -74,6 +74,12 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, } if (flags & INPUT_MT_DIRECT) __set_bit(INPUT_PROP_DIRECT, 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 'unused' */ for (i = 0; i < num_slots; i++) @@ -81,6 +87,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, dev->mt = mt; return 0; +err_mem: + kfree(mt); + return -ENOMEM; } EXPORT_SYMBOL(input_mt_init_slots); @@ -93,7 +102,10 @@ EXPORT_SYMBOL(input_mt_init_slots); */ void input_mt_destroy_slots(struct input_dev *dev) { - kfree(dev->mt); + if (dev->mt) { + kfree(dev->mt->red); + kfree(dev->mt); + } dev->mt = NULL; } EXPORT_SYMBOL(input_mt_destroy_slots); @@ -243,3 +255,131 @@ void input_mt_sync_frame(struct input_dev *dev) mt->frame++; } EXPORT_SYMBOL(input_mt_sync_frame); + +static int adjust_dual(int *begin, int step, int *end, int eq) +{ + 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 > 0 && !eq)) + return 0; + if (s < 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 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); + sum = 0; + for (i = 0; i < nrc; i += nr) + sum += adjust_dual(w + i, 1, w + i + nr, nc <= nr); + if (!sum) + break; + } +} + +static int input_mt_set_matrix(struct input_mt *mt, + const struct input_mt_pos *pos, int num_pos) +{ + 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; + } + } + + 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, *p; + + for (p = slots; p != slots + num_pos; p++) + *p = -1; + + for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { + if (!input_mt_is_active(s)) + continue; + for (p = slots; p != slots + num_pos; p++) + if (*w++ < 0) + *p = s - mt->slots; + } + + for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { + if (input_mt_is_active(s)) + continue; + for (p = slots; p != slots + num_pos; p++) + if (*p < 0) { + *p = 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 + * + * Performs a best match against the current contacts and returns + * the slot assignment list. New 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) +{ + struct input_mt *mt = dev->mt; + 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); + find_reduced_matrix(mt->red, num_pos, nrc / num_pos, nrc); + input_mt_set_slots(mt, slots, num_pos); + + return 0; +} +EXPORT_SYMBOL(input_mt_assign_slots); diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h index 94989189878d..6b6f7c8e95bf 100644 --- a/include/linux/input/mt.h +++ b/include/linux/input/mt.h @@ -18,6 +18,8 @@ #define INPUT_MT_POINTER 0x0001 /* pointer device, e.g. trackpad */ #define INPUT_MT_DIRECT 0x0002 /* direct device, e.g. touchscreen */ #define INPUT_MT_DROP_UNUSED 0x0004 /* drop contacts not seen in frame */ +#define INPUT_MT_TRACK 0x0008 /* use in-kernel tracking */ + /** * struct input_mt_slot - represents the state of an input MT slot * @abs: holds current values of ABS_MT axes for this slot @@ -35,6 +37,7 @@ struct input_mt_slot { * @slot: MT slot currently being transmitted * @flags: input_mt operation flags * @frame: increases every time input_mt_sync_frame() is called + * @red: reduced cost matrix for in-kernel tracking * @slots: array of slots holding current values of tracked contacts */ struct input_mt { @@ -43,6 +46,7 @@ struct input_mt { int slot; unsigned int flags; unsigned int frame; + int *red; struct input_mt_slot slots[]; }; @@ -58,6 +62,11 @@ static inline int input_mt_get_value(const struct input_mt_slot *slot, return slot->abs[code - ABS_MT_FIRST]; } +static inline bool input_mt_is_active(const struct input_mt_slot *slot) +{ + return input_mt_get_value(slot, ABS_MT_TRACKING_ID) >= 0; +} + int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, unsigned int flags); void input_mt_destroy_slots(struct input_dev *dev); @@ -90,4 +99,16 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count); void input_mt_sync_frame(struct input_dev *dev); +/** + * struct input_mt_pos - contact position + * @x: horizontal coordinate + * @y: vertical coordinate + */ +struct input_mt_pos { + s16 x, y; +}; + +int input_mt_assign_slots(struct input_dev *dev, int *slots, + const struct input_mt_pos *pos, int num_pos); + #endif |
