#include <stm32f0xx.h>
#include <stm-periph/stm32-gpio-macros.h>
#include <systick.h>

static void setup_pins(void)
{
	uint32_t tmp;
	
	RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN;
	
	tmp = GPIOA->MODER;
	
	/* Reset all used port pins */
	tmp &= MODER_DELETE(0) & MODER_DELETE(1) & MODER_DELETE(2) & MODER_DELETE(3) & \
		MODER_DELETE(4) & MODER_DELETE(5) & MODER_DELETE(6) & MODER_DELETE(7) & \
		MODER_DELETE(8) & MODER_DELETE(9) & MODER_DELETE(10); 
	
	/* Analog ports for POTIs */
	tmp |= ANALOG(0) | ANALOG(1) | ANALOG(4);
	
	/* Setup USART1 RX/TX (AF1) */
	tmp |= ALTFUNC(2) | ALTFUNC(3);
	SETAF(GPIOA, 2, 1);
	SETAF(GPIOA, 3, 1);
	
	/* LED enables for Potentiometers */
	tmp |= OUTPUT(5) | OUTPUT(6) | OUTPUT(7);
	GPIOA->ODR &= ~((1 << 5) | (1 << 6) | (1 << 7));
	
	/* Setup I2C pins (AF4) */
	tmp |= ALTFUNC(9) | ALTFUNC(10);
	SETAF(GPIOA, 9, 4);
	SETAF(GPIOA, 10, 4);
	
	/* Set I2C Pins to open drain. Others are push pull */
	GPIOA->OTYPER = OTYP_OPENDRAIN(9) | OTYP_OPENDRAIN(10);
	
	/* Write changes to GPIOA mode register */
	GPIOA->MODER = tmp;
	
	/* PB1 Input with pullup */
	GPIOB->MODER &= MODER_DELETE(1);
	GPIOB->PUPDR = PULLUP(1);
}

int main(void)
{
	setup_pins();
	SysTick_Config(48000000UL/1000);
	
	GPIOA->ODR |= (1<<5) | (1<<7);

	/* Blink the LEDs */	
	while (1) {
		systick_wait_ms(250);
		GPIOA->ODR ^= (1 << 5) | (1 << 6) | (1 << 7);
	}
}