IMX257 Input Subsystem

struct input_dev{

const char *name; device name

const char *phys; device path in the system

const char *uniq;

struct input_id id; used to match input hander parameters

unsigned long propbit[BITS_TO_LONGS(INPUT_PROP_CNT)];

unsigned long evbit[BITS_TO_LONGS(EV_CNT)];

//Event types supported by the device, mainly EV_SYNC, EV_KEY, EV_REL, EV_ABS, etc.

unsigned long keybit[BITS_TO_LONGS(KEY_CNT)]; //The bitmap corresponding to the key

unsigned long relbit[BITS_TO_LONGS(REL_CNT)]; //Relative coordinates corresponding to the bitmap

unsigned long absbit[BITS_TO_LONGS(ABS_CNT)]; //Absolute coordinates corresponding to the bitmap

unsigned long mscbit[BITS_TO_LONGS(MSC_CNT)];

unsigned long ledbit[BITS_TO_LONGS(LED_CNT)];

unsigned long sndbit[BITS_TO_LONGS(SND_CNT)];

unsigned long ffbit[BITS_TO_LONGS(FF_CNT)];

unsigned long swbit[BITS_TO_LONGS(SW_CNT)];

unsigned int hint_events_per_packet;

unsigned int keycodemax;

unsigned int keycodesize;

void *keycode;

int (*setkeycode)(struct input_dev *dev, const struct input_keymap_entry *ke, unsigned int *old_keycode);

int (*getkeycode)(struct input_dev *dev, struct input_keymap_entry *ke);

struct ff_device *ff;

unsigned int repeat_key;

struct timer_list timer;

int rep[REP_CNT];

struct input_mt_slot *mt;

int mtsize;

int slot;

int trkid;

struct input_absinfo *absinfo;

unsigned long key[BITS_TO_LONGS(KEY_CNT)]; //Key value corresponding to the key

unsigned long led[BITS_TO_LONGS(LED_CNT)]; //LED corresponding indicator light status

unsigned long snd[BITS_TO_LONGS(SND_CNT)];

unsigned long sw[BITS_TO_LONGS(SW_CNT)];

int (*open)(struct input_dev *dev);

void (*close)(struct input_dev *dev);

int (*flush)(struct input_dev *dev, struct file *file);

int (*event)(struct input_dev *dev, unsigned int type, unsigned int code, int value);

//Event processing function, mainly receives commands issued by users, such as lighting up LEDs;

struct input_handle __rcu *grab;

spinlock_t event_lock;

struct mutex mutex;

unsigned int users;

bool going_away;

bool sync;

struct device dev;

struct list_headh_list; //input handle supported by the device;

struct list_headnode;

};

Input device information. The following parameters are mainly used when matching input hander.

struct input_id {

__u16 bustype; bus type

__u16 vendor; manufacturer number

__u16 product; Product number

__u16 version; version information

};

Data structure for input device event processing:

struct input_handler {

void *private;

void (*event)(struct input_handle *handle, unsigned int type, unsigned int code, int value);

bool (*filter)(struct input_handle *handle, unsigned int type, unsigned int code, int value);

bool (*match)(struct input_handler *handler, struct input_dev *dev);

int (*connect)(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id);

//This function is called when the input device matches the input handler;

void (*disconnect)(struct input_handle *handle);

void (*start)(struct input_handle *handle);

const struct file_operations *fops; //Supported file operation operations;

int minor;

const char *name;

const struct input_device_id *id_table; //All supported input devices;

struct list_headh_list;

struct list_headnode;

};

The data structure connecting input-dev and input handler:

struct input_handle {

void *private;

int open;

const char *name;

struct input_dev *dev; input dev

struct input_handler *handler; input handler

struct list_headd_node;

struct list_head_node;

};

int input_register_device(struct input_dev *dev)

int input_unregister_device(struct input_dev *dev)

set_bit(EV_KEY,button_dev.evbit)

Two members in struct input_dev:

evbit--event type

keybit--key type

Event Type:

EV_RST--reset

EV_REL--Relative coordinates

EV_MSC--Other

EV_SND--Sound

EV_FF--Force Feedback

EV_KEY--Key

EV_ABS--Absolute coordinates

EV_LED--led

EV_REP--repeat

When the event type is EV_KEY, the key type must also be specified:

BTN_LEFT--left mouse button

BTN_RIGHT--Right mouse button

BTN_MIDDLE--Middle mouse button

BTN_0--Digital 0 key

BTN_1--Number 1 key

Void input_event(struct input_dev *dev,unsigned int type,unsigned int code,int value);

//Report input events of specified type and code

Void input_report_key(struct input_dev *dev,unsigned int code,int value); //Report key value

Void input_report_rel(struct input_dev *dev,unsigned int code,int value); //Report relative coordinates

Void input_report_abs(struct input_dev *dev,unsigned int code,int value); //Report absolute coordinates

Void input_sync(struct input_dev *dev);

//Report synchronization events In the touch screen driver design, the entire reporting process of a coordinate and press status is as follows:

Input_report_abs(input_dev,ABS_X,x); //X coordinate

Input_report_abs(input_dev,ABS_Y,y); //Y坐标

Input_report_abs(input_dev,ABS_PRESSURE,pres); //压力

input_sync(struct input_dev *dev); //同步

structinput_event {

struct timeval time;

__u16 type;

__u16 code;

__s32 value;

};