GPIO

Table of Contents

• Features Supported
• SysConfig Features
• Features NOT Supported
• Important Usage Guidelines
• Example Usage
• API

The General-Purpose Input/Output (GPIO) driver provides API to configure general-purpose pins as either inputs or outputs. It also provided API to configure GPIO to produce host CPU interrupts and DMA synchronization events in different interrupt/event generation modes.

Features Supported

• Supports up to 8-bit ports for a total of 64 GPIO
• Supports up to 32 GPIO's which can be configured as interrupt
• Supports up to 32 interrupt generating GPIO's.
• Set/clear functionality

SysConfig Features

Note

It is strongly recommend to use SysConfig where it is available instead of using direct SW API calls. This will help simplify the SW application and also catch common mistakes early in the development cycle.

• Set pin direction: input or output
• Set interrupt trigger type
• Set openDrain: enable or disable
• Set interrupt level: high or low
• Configuring pinmux based on selected pin

Features NOT Supported

NA

Important Usage Guidelines

• Note: Not all GPIO pins, are present in a particular device. Refer device TRM for actual GPIO instances and pins supported

Example Usage

Include the below file to access the APIs

#include <drivers/gpio.h>

GPIO configuration as output

    uint32_t pinNum = gGpioPinNum, pinValue;
 
    GPIO_setDirMode(gGpioBaseAddr, pinNum, GPIO_DIRECTION_OUTPUT);
 
    GPIO_pinWriteHigh(gGpioBaseAddr, pinNum);
    ClockP_sleep(1);
    GPIO_pinWriteLow(gGpioBaseAddr, pinNum);
 
    /* Check output value */
    pinValue = GPIO_pinRead(gGpioBaseAddr, pinNum);
    if(pinValue != GPIO_PIN_LOW)
    {
        DebugP_assert(FALSE);
    }

GPIO configuration as input

    uint32_t pinNum = gGpioPinNum, pinValue;
 
    GPIO_setDirMode(gGpioBaseAddr, pinNum, GPIO_DIRECTION_INPUT);
 
    pinValue = GPIO_pinRead(gGpioBaseAddr, pinNum);
    if(pinValue == GPIO_PIN_HIGH)
    {
        DebugP_log("Pin value is HIGH\r\n");
    }
    else
    {
        DebugP_log("Pin value is LOW\r\n");
    }

GPIO configuration for interrupt

static void GPIO_portIsrFxn(void *args)
{
    uint32_t    pinNum = (uint32_t) args;
    uint32_t    pendingInterrupt;
 
    pendingInterrupt = GPIO_getHighLowLevelPendingInterrupt(gGpioBaseAddr,GPIO_INTR_LEVEL_LOW);
    GPIO_clearInterrupt(gGpioBaseAddr, pinNum);
 
    if(pendingInterrupt )
    {
        /*
        * Handle all the expected  interrupts
        */
    }
}
 
void gpio_interrupt_init(void)
{
    int32_t         retVal;
    uint32_t        pinNum = gGpioIntrPinNum;
    HwiP_Params     hwiPrms;
 
    /* Interrupt setup */
    GPIO_setDirMode(gGpioBaseAddr, pinNum, GPIO_DIRECTION_INPUT);
    GPIO_ignoreOrHonorPolarity(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_RISE_EDGE);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_RISE_EDGE);
    GPIO_markHighLowLevelInterrupt(gGpioBaseAddr, pinNum, GPIO_INTR_LEVEL_LOW);
    GPIO_enableInterrupt(gGpioBaseAddr, pinNum);
 
    /* Register interrupt */
    HwiP_Params_init(&hwiPrms);
    hwiPrms.intNum = gGpioIntrNum;
    hwiPrms.callback = &GPIO_portIsrFxn;
    hwiPrms.args = (void *) pinNum;
    retVal = HwiP_construct(&gGpioHwiObject, &hwiPrms);
    if(SystemP_SUCCESS != retVal)
    {
        DebugP_assert(FALSE);
    }
}
 
void gpio_interrupt_deinit(void)
{
    uint32_t        pinNum = gGpioIntrPinNum, pendingInterrupt;
 
    /* Interrupt disable and clear any pending interrupts */
    GPIO_disableInterrupt(gGpioBaseAddr, pinNum);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_NONE);
    pendingInterrupt = GPIO_getHighLowLevelPendingInterrupt(gGpioBaseAddr,GPIO_INTR_LEVEL_LOW);
    (void)pendingInterrupt; /* kill warning about variable set but not used */
    GPIO_clearInterrupt(gGpioBaseAddr, pinNum);
 
    /* Unregister interrupt */
    HwiP_destruct(&gGpioHwiObject);
}

API

APIs for GPIO