sys/dev/led.c

   1 #include <led.h>
   2 #include <stm32f411.h>
   3
   4 void
   5 led_init (void)
   6 {
   7   /* GPIOCEN: IO port C clock enable  */
   8   *RCC_AHB1ENR |= (1u << 2); /* 1: IO port C clock enabled  */
   9
  10   /* Default to LED being turned off  */
  11   *GPIOC_ODR |= (1u << 13);
  12
  13   /* MODERy[1:0]: Port x configuration bits (y = 0..15)  */
  14   *GPIOC_MODER &= ~(0b11u << 26); /* Clear PC13 bits  */
  15   *GPIOC_MODER |= (1u << 26); /* 01: General purpose output mode  */
  16
  17   /* PC13: 0 = LED on
  18    *       1 = LED off  */
  19 }
  20
  21 void
  22 led_on (void)
  23 {
  24   *GPIOC_ODR &= ~(1u << 13);
  25 }
  26
  27 void
  28 led_off (void)
  29 {
  30   *GPIOC_ODR |= (1u << 13);
  31 }
  32
  33 void
  34 led_toggle (void)
  35 {
  36   *GPIOC_ODR ^= (1u << 13);
  37 }