embeddedsw/XilinxProcessorIPLib/drivers/gpiops/examples/xgpiops_intr_example.c

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/*****************************************************************************/
/**
* @file xgpiops_intr_example.c
*
* This file contains a design example using the GPIO driver (XGpioPs) in an
* interrupt driven mode of operation.
*
* The example uses the interrupt capability of the GPIO to detect push button
* events and set the output LEDs based on the input . The user needs to press
* all the switches SW1-SW5 on the evaluation board to exit from this example.
*
* @note
* This example assumes that there is a Uart device in the HW design.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- -----------------------------------------------
* 1.00a sv   01/18/10 First Release
*</pre>
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xparameters.h"
#include "xgpiops.h"
#include "xscugic.h"
#include "xil_exception.h"
#include <xil_printf.h>

/************************** Constant Definitions *****************************/

/*
 * The following constants map to the names of the hardware instances that
 * were created in the EDK XPS system.  They are defined here such that
 * the user can easily change all the needed device IDs in one place.
 */
#define GPIO_DEVICE_ID		XPAR_XGPIOPS_0_DEVICE_ID
#define INTC_DEVICE_ID		XPAR_SCUGIC_SINGLE_DEVICE_ID
#define GPIO_INTERRUPT_ID	XPAR_XGPIOPS_0_INTR

/*
 * The following constants define the GPIO banks that are used.
 */
#define INPUT_BANK	XGPIOPS_BANK0  /* Bank 0 of the GPIO Device */
#define OUTPUT_BANK	XGPIOPS_BANK1  /* Bank 1 of the GPIO Device */

/*
 * The following constants define the positions of the buttons of the GPIO.
 */
#define GPIO_ALL_BUTTONS	0xFFFF

/*
 * The following constant determines which buttons must be pressed to cause
 * interrupt processing to stop.
 */
#define GPIO_EXIT_CONTROL_VALUE	0x1F

#define printf			xil_printf	/* Smalller foot-print printf */

/**************************** Type Definitions *******************************/

/***************** Macros (Inline Functions) Definitions *********************/

/************************** Function Prototypes ******************************/

static int GpioIntrExample(XScuGic *Intc, XGpioPs *Gpio, u16 DeviceId,
			   u16 GpioIntrId);
static void IntrHandler(void *CallBackRef, int Bank, u32 Status);
static int SetupInterruptSystem(XScuGic *Intc, XGpioPs *Gpio, u16 GpioIntrId);

/************************** Variable Definitions *****************************/

/*
 * The following are declared globally so they are zeroed and so they are
 * easily accessible from a debugger.
 */
static XGpioPs Gpio; /* The Instance of the GPIO Driver */

static XScuGic Intc; /* The Instance of the Interrupt Controller Driver */

static u32 AllButtonsPressed; /* Intr status of the bank */

/****************************************************************************/
/**
*
* Main function that invokes the GPIO Interrupt example.
*
* @param	None.
*
* @return
*		- XST_SUCCESS if the example has completed successfully.
*		- XST_FAILURE if the example has failed.
*
* @note		None.
*
*****************************************************************************/
int main(void)
{
	int Status;

	xil_printf("GPIO Interrupt Example Test \r\n");

	/*
	 * Run the GPIO interrupt example, specify the parameters that
	 * are generated in xparameters.h.
	 */
	Status = GpioIntrExample(&Intc, &Gpio, GPIO_DEVICE_ID,
				 GPIO_INTERRUPT_ID);

	if (Status != XST_SUCCESS) {
		xil_printf("GPIO Interrupt Example Test Failed\r\n");
		return XST_FAILURE;
	}

	xil_printf("Successfully ran GPIO Interrupt Example Test\r\n");
	return XST_SUCCESS;
}

/****************************************************************************/
/**
* This function shows the usage of interrupt fucntionality of the GPIO device.
* It is responsible for initializing the GPIO device, setting up interrupts and
* providing a foreground loop such that interrupts can occur in the background.
*
* @param	Intc is a pointer to the XScuGic driver Instance.
* @param	Gpio is a pointer to the XGpioPs driver Instance.
* @param	DeviceId is the XPAR_<Gpio_Instance>_PS_DEVICE_ID value
*		from xparameters.h.
* @param	GpioIntrId is XPAR_<GIC>_<GPIO_Instance>_VEC_ID value
*		from xparameters.h
*
* @return	- XST_SUCCESS if the example has completed successfully.
*		- XST_FAILURE if the example has failed.
*
* @note		None
*
*****************************************************************************/
int GpioIntrExample(XScuGic *Intc, XGpioPs *Gpio, u16 DeviceId, u16 GpioIntrId)
{
	XGpioPs_Config *ConfigPtr;
	int Status;

	/*
	 * Initialize the Gpio driver.
	 */
	ConfigPtr = XGpioPs_LookupConfig(DeviceId);
	if (ConfigPtr == NULL) {
		return XST_FAILURE;
	}
	XGpioPs_CfgInitialize(Gpio, ConfigPtr, ConfigPtr->BaseAddr);

	/*
	 * Run a self-test on the GPIO device.
	 */
	Status = XGpioPs_SelfTest(Gpio);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}

	/*
	 * Setup direction register of bank0, so
	 * that all the pins are configured as inputs.
	 */
	XGpioPs_SetDirection(Gpio, INPUT_BANK, ~GPIO_ALL_BUTTONS);


	/*
	 * Set the direction for all signals to be
	 * outputs and Enable the Output enable for the LED Pins.
	 */
	XGpioPs_SetDirection(Gpio, OUTPUT_BANK, GPIO_ALL_BUTTONS);
	XGpioPs_SetOutputEnable(Gpio, OUTPUT_BANK, GPIO_ALL_BUTTONS);

	/*
	 * Setup the interrupts such that interrupt processing can occur. If
	 * an error occurs then exit.
	 */
	Status = SetupInterruptSystem(Intc, Gpio, GPIO_INTERRUPT_ID);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}

	printf("\n\rPush each of the 5 buttons once to exit\n\r");
	AllButtonsPressed = FALSE;

	/*
	 * Loop forever while the button changes are handled by the interrupt
	 * level processing.
	 */
	while(AllButtonsPressed == FALSE);

	printf("\n\r The GPIO Interrupt example has passed Successfully.\n\r");

	return XST_SUCCESS;
}

/****************************************************************************/
/**
* This function is the user layer callback function for the bank 0 interrupts of
* the GPIO device. It checks if all the switches have been pressed to stop the
* interrupt processing and exit from the example.
*
* @param	CallBackRef is a pointer to the upper layer callback reference.
* @param	Status is the Interrupt status of the GPIO bank.
*
* @return	None.
*
* @note		None.
*
******************************************************************************/
static void IntrHandler(void *CallBackRef, int Bank, u32 Status)
{
	XGpioPs *Gpio = (XGpioPs *)CallBackRef;
	static u32 ButtonsChanged;

	/*
	 * Do nothing if the intr is generated for a different bank.
	 */
	if (Bank != INPUT_BANK) {
		return;
	}

	ButtonsChanged |= Status;

	/*
	 * Set the LEDs.
	 */
	XGpioPs_Write(Gpio, OUTPUT_BANK, ButtonsChanged);

	if (ButtonsChanged == GPIO_EXIT_CONTROL_VALUE) {
		/*
		 * Five buttons are pressed to mark the completion of the test.
		 */
		AllButtonsPressed = TRUE;
		ButtonsChanged = 0;
	}
}


/*****************************************************************************/
/**
*
* This function sets up the interrupt system for the example. It enables falling
* edge interrupts for all the pins of bank 0 in the GPIO device.
*
* @param	GicInstancePtr is a pointer to the XScuGic driver Instance.
* @param	GpioInstancePtr contains a pointer to the instance of the GPIO
*		component which is going to be connected to the interrupt
*		controller.
* @param	GpioIntrId is the interrupt Id and is typically
*		XPAR_<GICPS>_<GPIOPS_instance>_VEC_ID value from
*		xparameters.h.
*
* @return	XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note		None.
*
****************************************************************************/
static int SetupInterruptSystem(XScuGic *GicInstancePtr, XGpioPs *Gpio,
				u16 GpioIntrId)
{
	int Status;

	XScuGic_Config *IntcConfig; /* Instance of the interrupt controller */

	Xil_ExceptionInit();

	/*
	 * Initialize the interrupt controller driver so that it is ready to
	 * use.
	 */
	IntcConfig = XScuGic_LookupConfig(INTC_DEVICE_ID);
	if (NULL == IntcConfig) {
		return XST_FAILURE;
	}

	Status = XScuGic_CfgInitialize(GicInstancePtr, IntcConfig,
					IntcConfig->CpuBaseAddress);
	if (Status != XST_SUCCESS) {
		return XST_FAILURE;
	}


	/*
	 * Connect the interrupt controller interrupt handler to the hardware
	 * interrupt handling logic in the processor.
	 */
	Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
				(Xil_ExceptionHandler)XScuGic_InterruptHandler,
				GicInstancePtr);

	/*
	 * Connect the device driver handler that will be called when an
	 * interrupt for the device occurs, the handler defined above performs
	 * the specific interrupt processing for the device.
	 */
	Status = XScuGic_Connect(GicInstancePtr, GpioIntrId,
				(Xil_ExceptionHandler)XGpioPs_IntrHandler,
				(void *)Gpio);
	if (Status != XST_SUCCESS) {
		return Status;
	}

	/*
	 * Enable falling edge interrupts for all the pins in bank 0.
	 */
	XGpioPs_SetIntrType(Gpio, INPUT_BANK, 0x00, 0x00, 0x00);

	/*
	 * Set the handler for gpio interrupts.
	 */
	XGpioPs_SetCallbackHandler(Gpio, (void *)Gpio, IntrHandler);


	/*
	 * Enable the GPIO interrupts of Bank 0.
	 */
	XGpioPs_IntrEnable(Gpio, INPUT_BANK, 0xFFFFFFFF);


	/*
	 * Enable the interrupt for the GPIO device.
	 */
	XScuGic_Enable(GicInstancePtr, GpioIntrId);


	/*
	 * Enable interrupts in the Processor.
	 */
	Xil_ExceptionEnableMask(XIL_EXCEPTION_IRQ);

	return XST_SUCCESS;
}