4.7. GPIO

4.7.1. Introduction

GPIO module allows application to manage General Purpose I/O  instances and pins via simple portable APIs. Because of its simplicity, APIs are pin based and does not follow model of other drivers inside PDK which requires handle abstraction.

Modes of Operation

Following modes of operations are supported Input or Output Each gpio pin can be configured as either input: GPIO_CFG_INPUT or output: GPIO_CFG_OUTPUT. If it is configured as an output then pin level can be additionally configured

Interrupt support Each gpio pin can be configured to generate interrupts based on event type GPIO_CFG_IN_INT_XXX configuration. To generate interrupt, gpio pin has to be configured as input pin.

Driver Configuration

Board Specific Configuration

All board specific configurations like enabling clock and pin-mux are required before calling any driver APIs. By default Board_Init() API available under board module supports all initialization sequence for TI supported EVMs. In addition it initializes UART instance for Console/STDIO. Refer PDK Board Support for additional details.

GPIO Configuration Structure

GPIO_soc.c binds driver with hardware attributes on the board. Hardware attributes includes base address, interrupt number etc. GPIO pin behavior can be configured statically, or alternatively dynamically during runtime.

GPIO_init () API triggers all static configuration information available through hardware attributes. Once initialization is complete additional APIs can be used to configure and access pins.

4.7.2. User Interface

For details about individual fields of this library structure, see the PDK doxygen documentation

4.7.2.1. APIs

API reference for Application:

#include <ti/drv/gpio/GPIO.h>

Below sequence indicates API calling sequence for a simple use case of LED toggling

...
Board_init(boardCfg);
GPIO_init();
While(1)
{
GPIO_write(Board_LED1, GPIO_PIN_VAL_HIGH);
Delay();
GPIO_write(Board_LED1, GPIO_PIN_VAL_LOW);
Delay();
}

4.7.3. Application

4.7.3.1. Examples

Refer SDK Release Note for GPIO support across different EVMs.

Name	Description	Expected Results	SoC Supported	Build Type
GPIO_LedBlink	Simple example demonstrating LED Toggling	Following LED blinks based on EVM being used. AM335x ICEv2: USER  LED 1 AM437x EVM: USER  LED 1 AM572x IDK : STATUS LED 1 Yellow AM572x GP EVM : USER LED1 AM574x IDK : STATUS LED 1 Yellow AM572x GP EVM : USER LED1 AM571x IDK : Industrial LED 3 Red K2H EVM: USER LED 2 Blue K2E EVM: USER LED 1 Blue K2G EVM: USER LED 1 Yellow AM65xx EVM: USER LD16, LD17 J721E EVM: USER LED 1 J7200 EVM: USER LED 1 AM64x EVM: USER LED 1	AM335x, AM437x, AM571x, AM572x, AM574x, k2g, k2hk, k2l, k2e, c6657, c6678, omapl137,	CCS project
			am65xx j721e tpr12 j7200 am64x	makefile

4.7.4. FAQ