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 16 GPIO signals per bank
• Supports up to 9 banks of interrupt and DMA trigger capable GPIOs
• 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
• Configuring pinmux based on selected pin

Features NOT Supported

NA

Important Usage Guidelines

• Note: Not all GPIO pins, banks 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_pinOutValueRead(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 bank interrupt

static void GPIO_bankIsrFxn(void *args)
{
    uint32_t    pinNum = (uint32_t) args, bankNum;
    uint32_t    intrStatus, pinMask = GPIO_GET_BANK_BIT_MASK(pinNum);
 
    bankNum = GPIO_GET_BANK_INDEX(pinNum);
    intrStatus = GPIO_getBankIntrStatus(gGpioBaseAddr, bankNum);
    GPIO_clearBankIntrStatus(gGpioBaseAddr, bankNum, intrStatus);
 
    if(intrStatus & pinMask)
    {
        /*
        * Handle all the expected pin interrupts within a bank using intrStatus flag
        */
    }
}
 
void gpio_bank_interrupt_init(void)
{
    int32_t         retVal;
    uint32_t        pinNum = gGpioPinNum, bankNum;
    HwiP_Params     hwiPrms;
 
    bankNum = GPIO_GET_BANK_INDEX(pinNum);
 
    /* Interrupt setup */
    GPIO_setDirMode(gGpioBaseAddr, pinNum, GPIO_DIRECTION_INPUT);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_RISE_EDGE);
    GPIO_bankIntrEnable(gGpioBaseAddr, bankNum);
 
    /* Register bank interrupt */
    HwiP_Params_init(&hwiPrms);
    hwiPrms.intNum = gGpioBankIntrNum;
    hwiPrms.callback = &GPIO_bankIsrFxn;
    hwiPrms.args = (void *) pinNum;
    retVal = HwiP_construct(&gGpioHwiObject, &hwiPrms);
    if(SystemP_SUCCESS != retVal)
    {
        DebugP_assert(FALSE);
    }
}
 
void gpio_bank_interrupt_deinit(void)
{
    uint32_t        pinNum = gGpioPinNum, bankNum, intrStatus;
 
    bankNum = GPIO_GET_BANK_INDEX(pinNum);
 
    /* Interrupt disable and clear any pending interrupts */
    GPIO_bankIntrDisable(gGpioBaseAddr, bankNum);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_NONE);
    intrStatus = GPIO_getBankIntrStatus(gGpioBaseAddr, bankNum);
    GPIO_clearBankIntrStatus(gGpioBaseAddr, bankNum, intrStatus);
 
    /* Unregister interrupt */
    HwiP_destruct(&gGpioHwiObject);
}

GPIO configuration for per pin interrupt

static void GPIO_pinIsrFxn(void *args)
{
    /*
     * Handle pin interrupt - This is pulse interrupt. No need to clear status
     */
}
 
void gpio_pin_interrupt_init(void)
{
    int32_t         retVal;
    uint32_t        pinNum = gGpioPinNum, bankNum;
    HwiP_Params     hwiPrms;
 
    bankNum = GPIO_GET_BANK_INDEX(pinNum);
 
    /* Interrupt setup */
    GPIO_setDirMode(gGpioBaseAddr, pinNum, GPIO_DIRECTION_INPUT);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_RISE_EDGE);
    GPIO_bankIntrEnable(gGpioBaseAddr, bankNum);
 
    /* Register pin interrupt */
    HwiP_Params_init(&hwiPrms);
    hwiPrms.intNum = gGpioPinIntrNum;
    hwiPrms.callback = &GPIO_pinIsrFxn;
    hwiPrms.args = (void *) pinNum;
    retVal = HwiP_construct(&gGpioHwiObject, &hwiPrms);
    if(SystemP_SUCCESS != retVal)
    {
        DebugP_assert(FALSE);
    }
}
 
void gpio_pin_interrupt_deinit(void)
{
    uint32_t        pinNum = gGpioPinNum, bankNum;
 
    bankNum = GPIO_GET_BANK_INDEX(pinNum);
 
    /* Interrupt disable and clear any pending interrupts */
    GPIO_bankIntrDisable(gGpioBaseAddr, bankNum);
    GPIO_setTrigType(gGpioBaseAddr, pinNum, GPIO_TRIG_TYPE_NONE);
    GPIO_clearIntrStatus(gGpioBaseAddr, pinNum);
 
    /* Unregister interrupt */
    HwiP_destruct(&gGpioHwiObject);
}

API

APIs for GPIO