Line data    Source code

       1             : /**
       2             :  * @file stm32f4_gpio.c
       3             :  * @brief Implementation for toggling the red LED onboard the
       4             :  * stm32f446re development board.
       5             :  *
       6             :  * Copyright (c) 2025 Cory McKiel.
       7             :  * Licensed under the MIT License. See LICENSE file in the project root.
       8             :  */
       9             : #ifdef DESKTOP_BUILD
      10             : #include "registers.h"
      11             : #else
      12             : #include "stm32f4xx.h"
      13             : #endif /* DESKTOP_BUILD */
      14             : 
      15             : #include "gpio.h"
      16             : 
      17             : #define GPIOAEN (1U << 0) /*!< Bit to enable GPIO port A. */
      18             : #define PIN5    (1U << 5) /*!< Pin five for GPIO port A. */
      19             : #define LED_PIN    (PIN5) /*!< The onboard LED is wired to GPIO port A, pin 5. */
      20             : 
      21           1 : hal_status_t hal_gpio_init()
      22             : {
      23             :         // Enable the peripheral bus clock.
      24           1 :         RCC->AHB1ENR |= GPIOAEN;
      25             : 
      26             :         // Configure the GPIO.
      27           1 :         GPIOA->MODER &=~ (1U << 11);
      28           1 :         GPIOA->MODER |= (1U << 10);
      29             : 
      30             :         // Return HAL_STATUS_OK unconditionally.
      31             :         // This implementation does not support the interface's full error reporting capability.
      32           1 :         return HAL_STATUS_OK;
      33             : }
      34             : 
      35           2 : hal_status_t hal_gpio_toggle_led()
      36             : {
      37             :         // XOR flips bit each call.
      38           2 :         GPIOA->ODR ^= LED_PIN;
      39             : 
      40             :         // Return HAL_STATUS_OK unconditionally.
      41             :         // This implementation does not support the interface's full error reporting capability.
      42           2 :         return HAL_STATUS_OK;
      43             : }