#include "main.h"
#include "lcd.h"
#include "generic_macros.h"

void display_init(void)
{
	// switch to 4-bit 2-line mode
	  display_write_instruction_byte(0x28);

	  // clear display
	  display_write_instruction_byte(0x01);

	  // enable display
	  display_write_instruction_byte(0x0C);

	  // move cursor to first line
	  display_write_instruction_byte(0x80);
}

uint8_t display_read_status(void)
{
	// make sure GPIOE is in correct mode
	GPIOE->MODER = 0x00504000;

	if (GPIOE->MODER != 0x00504000)
		PANIC(0x4000);

	uint8_t status = 0;

	GPIOE->ODR = 0x0;
	GPIOE->BSRR = DISPLAY_RW;

	GPIOE->BSRR = DISPLAY_ENA;
	status |= (GPIOE->IDR & 0xF000) >> 8;
	GPIOE->BSRR = (DISPLAY_ENA << 16);

	GPIOE->BSRR = DISPLAY_ENA;
	status |= (GPIOE->IDR & 0xF000) >> 12;
	GPIOE->BSRR = (DISPLAY_ENA << 16);

	GPIOE->ODR = 0x0;

	return status;
}

void display_write_instruction_byte(uint8_t code)
{
	DISPLAY_POLL_UNTIL_READY;

	// make sure GPIOE is in correct mode
	GPIOE->MODER = 0x55504000;

	if (GPIOE->MODER != 0x55504000)
		PANIC(0x4000);

	GPIOE->ODR = (code & 0xF0) << 8;
	GPIOE->BSRR = DISPLAY_ENA;
	GPIOE->BSRR = (DISPLAY_ENA << 16);

	GPIOE->ODR = (code & 0x0F) << 12;
	GPIOE->BSRR = DISPLAY_ENA;
	GPIOE->BSRR = (DISPLAY_ENA << 16);
}

void display_write_data_byte(uint8_t code)
{
	DISPLAY_POLL_UNTIL_READY;

	// make sure GPIOE is in correct mode
	GPIOE->MODER = 0x55504000;

	if (GPIOE->MODER != 0x55504000)
		PANIC(0x4000);

	GPIOE->ODR = ((code & 0xF0) << 8) | (DISPLAY_RS);
	GPIOE->BSRR = DISPLAY_ENA;
	GPIOE->BSRR = DISPLAY_ENA << 16;

	GPIOE->ODR = ((code & 0x0F) << 12) | (DISPLAY_RS);
	GPIOE->BSRR = DISPLAY_ENA;
	GPIOE->BSRR = DISPLAY_ENA << 16;
}

void display_write_data_seq(char *codes)
{
	for (size_t i = 0; i < 16; i++) {
		if (codes[i] != 0)
			display_write_data_byte(codes[i]);
		else
			break;
	}
}