#include <stdio.h>
#include <stdint.h>

#define HIGH 1
#define LOW 0

#define GPIO_PORT_B 0x40010C00
#define GPIO_PORT_C 0x40011000
#define RCC_CLOCK 0x40021000

#define RCC_APB2 (RCC_CLOCK + 0x18)
#define GPIO_PORT_B_MODE (GPIO_PORT_B + 0x04)
#define GPIO_PORT_B_OUT (GPIO_PORT_B + 0x0C)
#define GPIO_PORT_C_MODE (GPIO_PORT_C + 0x04)
#define GPIO_PORT_C_OUT (GPIO_PORT_C + 0x0C)
#define GPIO_PORT_B_INPUT (GPIO_PORT_B + 0x08)

#define READ_INPUT ((*portBIn >> 12) & HIGH)

#define SET_BIT(reg, bit) (reg |= (HIGH << bit))
#define CLEAR_BIT(reg, bit) (reg &= ~(HIGH << bit))
#define __IO volatile

__IO void delay(uint32_t count) {
  for (__IO uint32_t i = 0; i < count; i++) {
    // printf("Count: %d \n", i);
  }
}

void setUpGPIO(uint32_t *RCC_APB2_Clock, uint32_t *portBMode, uint32_t *portBOut, uint32_t *portCMode, uint32_t *portCOut, uint32_t *portBIn  ) {
  *RCC_APB2_Clock |= (3 << 3);
  *portBMode |= (3 << 4);
  *portBMode &= ~(1 << 6);
  *portBMode &= ~(3 << 16);
  *portBMode &= ~(3 << 18);
  *portBMode |= (0x10 << 18);
  *portCMode |= (3 << 20);
  *portCMode &= ~(1 << 22);
}

int main()
{
  __IO uint32_t *RCC_APB2_Clock =  (uint32_t *)RCC_APB2;
  __IO uint32_t *portBMode = (uint32_t *)GPIO_PORT_B_MODE;
  __IO uint32_t *portBOut = (uint32_t *)GPIO_PORT_B_OUT;
  __IO uint32_t *portCMode = (uint32_t *)GPIO_PORT_C_MODE;
  __IO uint32_t *portCOut = (uint32_t *)GPIO_PORT_C_OUT;
  __IO uint32_t *portBIn = (uint32_t*)GPIO_PORT_B_INPUT;

  setUpGPIO(RCC_APB2_Clock, portBMode, portBOut, portCMode, portCOut, portBIn);
  SET_BIT(*portBOut, 9);
  SET_BIT(*portCOut, 13);
  while (1) {
    // *portBOut ^= (1 << 9);
    // *portCOut ^= (1 << 13);
    if ((READ_INPUT)) {
      SET_BIT(*portBOut, 9);
      SET_BIT(*portCOut, 13);
    } else {
      CLEAR_BIT(*portBOut, 9);
      CLEAR_BIT(*portCOut, 13);
    }
  }
}