#include"usart.h"
#include"pin.h"



#define USART2_EN (1U << 17)
#define CR1_TE_EN (1U << 3)
#define CR1_UE_EN (1U << 0)

#define ISR_TXE (1U << 7)

#define UART_BAUD 115200
#define SYST_CLK 8000000


void usartSetBaudRate(uint32_t baud);

void usartInit()
{
	/* COnfiguring teh pins for the uart*/ 
	//pinConfig(pinA2, alternate, none, none, normal);
	//pinConfig(pinA15, alternate, none, none, normal);
	
	//Sets pina2 to alternate mode as UART_TX
	//pinSetAlternate(pinA2, 1);
	
	GPIOA->MODER &= ~(1u <<4); 
	GPIOA->MODER |= (1u <<5); 
	
	GPIOA->AFR[0] &= ~(1u<<11);
	GPIOA->AFR[0] &= ~(1u<<10);
	GPIOA->AFR[0] &= ~(1u<<9);
	GPIOA->AFR[0] |= (1u<<8);

	//Enable the priferas bus and UART
	RCC->APB1ENR |= USART2_EN; 	

	usartSetBaudRate(UART_BAUD);
	
	//enables the transmit and sets all the other values to 0 = Default 
	USART2->CR1 = 0; // The = 0 is on purpose to set uart to default mode.    
	USART2->CR1 |= CR1_TE_EN; // The = 0 is on purpose to set uart to default mode.    
	
	//UART Enable
	USART2->CR1 |= CR1_UE_EN; 	
}

static uint16_t usartComputeBaudRate(uint32_t clk, uint32_t baud)
{
	return((clk + (baud/2U))/baud);
}	

void usartSetBaudRate(uint32_t baud)
{
	USART2->BRR = usartComputeBaudRate(baud, SYST_CLK); 
}

void usartSendChar(int ch)
{
	// Make sure that TX buffer is empty 
	while(!(USART2->ISR & ISR_TXE)){}
	USART2->TDR = (ch & 0xFF); 
}