I'm trying to connect 16*2 LCD and tm4c123gxl but It's not working - c

Question

I tried to connect tm4c123gxl microcontroller with 16*2 LCD to print some letter. But some for some reason, my LCD does not work and only displays black boxes on the 1st row.
As you can see, I am using 3 pins of PORT A to connect RS, R/W, EN. And I use all 8 pins of PORT B to connect 7~14pins of LCD (data).
And this is the code I wrote on CCS
//rcgcgpio
#define RCGCGPIO (*((volatile unsigned long *) 0x400FE608))
//LCD
//PORTA 2,3,4
#define GPIODEN_PORTA (*((volatile unsigned long *) 0x4000451C))
#define GPIODIR_PORTA (*((volatile unsigned long *) 0x40004400))
#define GPIODATA_PORTA (*((volatile unsigned long*) 0x40004070))//1110000
//PORTB 0,1,2,3,4,5,6,7
#define GPIODEN_PORTB (*((volatile unsigned long *) 0x4000551C))
#define GPIODIR_PORTB (*((volatile unsigned long *) 0x40005400))
#define GPIODATA_PORTB (*((volatile unsigned long *) 0x400053FC))//11111111
//instruction, put this into portB
#define LCD_clear_display 0x1
#define LCD_return_home 0x2
#define LCD_display_shift_right 0x5
#define LCD_cursor_line1_position0 0x80
void LCD_setup();
void LCD_write_IR(unsigned char inst);
void LCD_write_DR(unsigned char data);
void Keypad_setup();
char Keypad_read();
void Delay(unsigned int t);
/**
* main.c
*/
int main(void)
{
LCD_setup();
LCD_write_IR(LCD_cursor_line1_position0);
LCD_write_IR(LCD_clear_display);
while(1){
LCD_write_DR('A');
}
}
void LCD_setup(){
RCGCGPIO |= 0x3;//000011 Port A and Port B
GPIODEN_PORTA |= 0x1C;//11100
GPIODIR_PORTA |= 0x1C;//11100
GPIODEN_PORTB |= 0xFF;//11111111
GPIODIR_PORTB |= 0xFF;//11111111
}
void Delay(unsigned int t){//ms delay
int i;
int j;
for(i=0;i<t;i++){
for(j=0;j<16000;++j){
}
}
}
void LCD_write_IR(unsigned char inst){
GPIODATA_PORTA = 0x10;//EN:1, R/W:0, RS:0, 0, 0
GPIODATA_PORTB = inst;
Delay(2);
/*
if(inst < 4){//clear display
Delay(2);
}else{
Delay(1)//entry mode set
}
*/
}
void LCD_write_DR(unsigned char data){
GPIODATA_PORTA = 0x14;//10100
GPIODATA_PORTB = data;
Delay(2);
}
Unfortunately, LCD is not working just like this picture
What I should do to print some letter on the LCD?