gpio.c File Reference

HAL GPIO driver implementation for STM32F4 series. More...

#include "core/cortex-m4/gpio.h"
#include "core/cortex-m4/gpio_reg.h"
#include "core/cortex-m4/rcc_reg.h"

Include dependency graph for gpio.c:

Functions
void	hal_gpio_setmode (hal_gpio_pin pin, hal_gpio_mode mode, hal_gpio_pullup_pulldown pupd)
	Configure the mode and pull-up/pull-down for a GPIO pin.
hal_gpio_mode	hal_gpio_getmode (hal_gpio_pin pin)
	Get the current mode of a GPIO pin.
void	hal_gpio_digitalwrite (hal_gpio_pin pin, hal_gpio_state state)
	Write a digital value to a GPIO pin.
hal_gpio_state	hal_gpio_digitalread (hal_gpio_pin pin)
	Read the digital value from a GPIO pin.
void	hal_gpio_enable_rcc (hal_gpio_pin pin)
	Enable the RCC clock for a GPIO port.
void	hal_gpio_set_alternate_function (hal_gpio_pin pin, hal_gpio_alternate_function_t alt_fn)
	Configure alternate function for a GPIO pin.
void	hal_gpio_set_output_type (hal_gpio_pin pin, hal_gpio_output_type otyper)
	Configure GPIO output type.
void	hal_gpio_set_output_speed (hal_gpio_pin pin, hal_gpio_output_speed speed)
	Configure GPIO output speed.

Detailed Description

HAL GPIO driver implementation for STM32F4 series.

This file contains the implementation of GPIO hardware abstraction layer functions for STM32F4 microcontrollers. It provides complete GPIO pin configuration and control capabilities including:

• Pin mode configuration (input/output/alternate/analog)
• Digital input/output operations
• Alternate function selection
• Output speed and type configuration
• Built-in pull-up/pull-down resistor control

All functions handle the required RCC clock enabling automatically.

Copyright

© NAVROBOTEC PVT. LTD.

Function Documentation

hal_gpio_digitalread()

hal_gpio_state hal_gpio_digitalread

(

hal_gpio_pin

pin

)

Read the digital value from a GPIO pin.

Read the digital state from a GPIO pin.

Parameters

pin	Pin identifier to read

Returns

Current digital state of the pin (HIGH or LOW)

Reads the IDR register for the specified pin and returns the current input state.

< GPIOA base address

hal_gpio_digitalwrite()

void hal_gpio_digitalwrite	(	hal_gpio_pin	pin,
		hal_gpio_state	state )

Write a digital value to a GPIO pin.

Write a digital state to a GPIO pin.

Parameters

pin	Pin identifier to control
state	Desired output state (HIGH or LOW)

Uses the BSRR register for atomic set/reset operations to avoid read-modify-write sequences.

// Example: Set PA5 high
hal_gpio_digitalwrite(PA5, HAL_GPIO_HIGH);

< GPIOA base address

< GPIOA base address

hal_gpio_enable_rcc()

void hal_gpio_enable_rcc

(

hal_gpio_pin

pin

)

Enable the RCC clock for a GPIO port.

Enable the RCC clock for a specific GPIO pin's port.

Parameters

pin	Pin identifier whose port clock should be enabled

Enables the AHB1 peripheral clock for the GPIO port containing the specified pin. This is automatically called by other GPIO functions when needed.

hal_gpio_getmode()

hal_gpio_mode hal_gpio_getmode

(

hal_gpio_pin

pin

)

Get the current mode of a GPIO pin.

Parameters

pin	Pin identifier to query

Returns

Current GPIO mode of the specified pin

Reads the MODER register for the specified pin and returns the current mode configuration.

< GPIOA base address

hal_gpio_set_alternate_function()

void hal_gpio_set_alternate_function	(	hal_gpio_pin	pin,
		hal_gpio_alternate_function_t	alt_fn )

Configure alternate function for a GPIO pin.

Set the alternate function for a GPIO pin.

Parameters

pin	Pin identifier to configure
alt_fn	Alternate function number/type to assign

Configures the specified pin for alternate function mode and sets the appropriate alternate function selection in AFRL/AFRH. Automatically enables the GPIO port clock if needed.

// Example: Set PA2 to USART2_TX alternate function
hal_gpio_set_alternate_function(PA2, HAL_GPIO_AF_USART2);

< GPIOA base address

< GPIOA base address

< GPIOA base address

< GPIOA base address

hal_gpio_set_output_speed()

void hal_gpio_set_output_speed	(	hal_gpio_pin	pin,
		hal_gpio_output_speed	speed )

Configure GPIO output speed.

Set the output speed for a GPIO pin.

Parameters

pin	Pin identifier to configure
speed	Desired output speed (low/medium/high/very high)

Sets the output speed in the OSPEEDR register for the specified pin. Does not change the pin mode - must be configured separately.

< GPIOA base address

< GPIOA base address

hal_gpio_set_output_type()

void hal_gpio_set_output_type	(	hal_gpio_pin	pin,
		hal_gpio_output_type	otyper )

Configure GPIO output type.

Set the output type for a GPIO pin.

Parameters

pin	Pin identifier to configure
otyper	Output type (push-pull or open-drain)

Sets the output type in the OTYPER register for the specified pin. Does not change the pin mode - must be configured separately.

< GPIOA base address

< GPIOA base address

hal_gpio_setmode()

void hal_gpio_setmode	(	hal_gpio_pin	pin,
		hal_gpio_mode	mode,
		hal_gpio_pullup_pulldown	pupd )

Configure the mode and pull-up/pull-down for a GPIO pin.

Set the mode of a GPIO pin.

Parameters

pin	Pin identifier (e.g., PA5, PC13)
mode	Desired pin mode (input/output/alternate/analog)
pupd	Pull-up/pull-down configuration

This function:

1. Enables the GPIO port clock via RCC
2. Configures the pin mode in MODER register
3. Sets pull-up/pull-down resistors in PUPDR register

Note

Automatically enables the GPIO port clock if not already enabled

// Example: Configure PA5 as output with no pull-up/pull-down
hal_gpio_setmode(PA5, HAL_GPIO_MODE_OUTPUT, HAL_GPIO_NO_PULL);

< GPIOA base address

< GPIOA base address

< GPIOA base address

< GPIOA base address