include/linux/input/mt.h

Source file repositories/reference/linux-study-clean/include/linux/input/mt.h

File Facts

System
Linux kernel
Corpus path
include/linux/input/mt.h
Extension
.h
Size
3563 bytes
Lines
131
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct input_mt_slot {
	int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
	unsigned int frame;
	unsigned int key;
};

/**
 * struct input_mt - state of tracked contacts
 * @trkid: stores MT tracking ID for the next contact
 * @num_slots: number of MT slots the device uses
 * @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 {
	int trkid;
	int num_slots;
	int slot;
	unsigned int flags;
	unsigned int frame;
	int *red;
	struct input_mt_slot slots[] __counted_by(num_slots);
};

static inline void input_mt_set_value(struct input_mt_slot *slot,
				      unsigned code, int value)
{
	slot->abs[code - ABS_MT_FIRST] = value;
}

static inline int input_mt_get_value(const struct input_mt_slot *slot,
				     unsigned code)
{
	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;
}

static inline bool input_mt_is_used(const struct input_mt *mt,
				    const struct input_mt_slot *slot)
{
	return slot->frame == mt->frame;
}

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);

static inline int input_mt_new_trkid(struct input_mt *mt)
{
	return mt->trkid++ & TRKID_MAX;
}

static inline void input_mt_slot(struct input_dev *dev, int slot)
{
	input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
}

static inline bool input_is_mt_value(int axis)
{
	return axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST;
}

static inline bool input_is_mt_axis(int axis)
{
	return axis == ABS_MT_SLOT || input_is_mt_value(axis);
}

bool input_mt_report_slot_state(struct input_dev *dev,
				unsigned int tool_type, bool active);

static inline void input_mt_report_slot_inactive(struct input_dev *dev)
{
	input_mt_report_slot_state(dev, 0, false);
}

void input_mt_report_finger_count(struct input_dev *dev, int count);
void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);
void input_mt_drop_unused(struct input_dev *dev);

void input_mt_sync_frame(struct input_dev *dev);

/**
 * struct input_mt_pos - contact position
 * @x: horizontal coordinate

Annotation

Implementation Notes