#include "lcd.h"

#include <avr/io.h>
#include <util/delay.h>

#define B_SRCLK		PB0
#define B_LCDE		PB3
#define B_SRD_LCDRS	PB4

static void lcd_pin(bool value)
{
	/* cheat, put the clock in front.
	 * result:
	 * clk, d0 | clk, d1 | clk... d7 | clk, rs.
	 *  ^- first clk ignored            ^- last clk from setting R/S
	 */
	PORTB |= (1 << B_SRCLK);
	PORTB &= ~(1 << B_SRCLK);

	if (value)
		PORTB |= (1 << B_SRD_LCDRS);
	else
		PORTB &= ~(1 << B_SRD_LCDRS);
}

void lcd_command(uint8_t cmd, bool isdata)
{
	uint8_t i;

	for (i = 1;      i; i <<= 2)
		lcd_pin(cmd & i);
	for (i = 1 << 7; i; i >>= 2)
		lcd_pin(cmd & i);

	lcd_pin(isdata);
	__asm__ ("nop\n");
	PORTB |= (1 << B_LCDE);
	__asm__ ("nop\n");
	PORTB &= ~(1 << B_LCDE);
	__asm__ ("nop\n");
	if (!isdata)
		_delay_us(50);
}

void lcd_puts(const char * PROGMEM ptr, uint8_t cnt)
{
	while (cnt--) {
		uint8_t ch = __LPM(ptr++);
		lcd_put(ch);
	}
}

const char PROGMEM boot[] = "boot";

void lcd_init(void)
{
	PORTB &= ~((1 << B_SRCLK) | (1 << B_LCDE) | (1 << B_SRD_LCDRS));
	DDRB |= (1 << B_SRCLK) | (1 << B_LCDE) | (1 << B_SRD_LCDRS);
	_delay_ms(15);

	lcd_command(0x38, 0);
	lcd_command(0x0c, 0);
	lcd_command(0x06, 0);
	lcd_command(0x02, 0);
	_delay_ms(2);

	lcd_line1();
	lcd_puts(boot, sizeof(boot) - 1);
}