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/*****************************************************************************/
/**
* @file xgpio_intr_example.c
*
* This file contains a design example using the GPIO driver (XGpio) in an
* interrupt driven mode of operation. This example does assume that there is
* an interrupt controller in the hardware system and the GPIO device is
* connected to the interrupt controller.
*
* This example is designed to work on the Xilinx ML300 board using the PowerPC
* 405 processor present in the VirtexIIPro device. The example uses the
* interrupt capability of the GPIO to detect push button presses and control the
* LEDs on the board. When a button is pressed it will turn on and LED located
* closest to it. When the button is released it will turn off the LED.
* This examples uses two channels of a GPIO such that it is necessary to have
* dual channel capabilities.
*
* The buttons and LEDs are on 2 seperate channels of the GPIO so that interrupts
* are not caused when the LEDs are turned on and off.
*
* At the start of execution all LEDs will be turned on, then each one by itself,
* and then all on again followed by all turned off. After this sequence, button
* presses are processed by interrupts.
*
* The following snippet from the UCF file of the hardware build indicates the
* way the GPIO channels are connected to the ML300 for the LEDs and buttons.
*
*<pre>
* Net LEDs_Push_Buttons_GPIO_IO<0> LOC=C4;
* Net LEDs_Push_Buttons_GPIO_IO<1> LOC=L8;
* Net LEDs_Push_Buttons_GPIO_IO<2> LOC=F8;
* Net LEDs_Push_Buttons_GPIO_IO<3> LOC=J7;
* Net LEDs_Push_Buttons_GPIO_IO<4> LOC=K7;
* Net LEDs_Push_Buttons_GPIO_IO<5> LOC=E7;
* Net LEDs_Push_Buttons_GPIO_IO<6> LOC=D3;
* Net LEDs_Push_Buttons_GPIO_IO<7> LOC=C6;
* Net LEDs_Push_Buttons_GPIO_IO<8> LOC=E8;
* Net LEDs_Push_Buttons_GPIO_IO<9> LOC=B3;
* Net LEDs_Push_Buttons_GPIO_IO<10> LOC=E9;
* Net LEDs_Push_Buttons_GPIO_IO<11> LOC=G9;
* Net LEDs_Push_Buttons_GPIO_IO<12> LOC=A3;
* Net LEDs_Push_Buttons_GPIO_IO<13> LOC=F9;
* Net LEDs_Push_Buttons_GPIO_IO<14> LOC=D6;
* Net LEDs_Push_Buttons_GPIO_IO<15> LOC=G10;
* Net LEDs_Push_Buttons_GPIO2_IO<0> LOC=G6;
* Net LEDs_Push_Buttons_GPIO2_IO<1> LOC=L7;
* Net LEDs_Push_Buttons_GPIO2_IO<2> LOC=G5;
* Net LEDs_Push_Buttons_GPIO2_IO<3> LOC=M8;
* Net LEDs_Push_Buttons_GPIO2_IO<4> LOC=H6;
* Net LEDs_Push_Buttons_GPIO2_IO<5> LOC=M7;
* Net LEDs_Push_Buttons_GPIO2_IO<6> LOC=H5;
* Net LEDs_Push_Buttons_GPIO2_IO<7> LOC=N8;
* Net LEDs_Push_Buttons_GPIO2_IO<8> LOC=J6;
* Net LEDs_Push_Buttons_GPIO2_IO<9> LOC=M5;
* Net LEDs_Push_Buttons_GPIO2_IO<10> LOC=J5;
* Net LEDs_Push_Buttons_GPIO2_IO<11> LOC=M2;
* Net LEDs_Push_Buttons_GPIO2_IO<12> LOC=K6;
* Net LEDs_Push_Buttons_GPIO2_IO<13> LOC=M1;
* Net LEDs_Push_Buttons_GPIO2_IO<14> LOC=K5;
* Net LEDs_Push_Buttons_GPIO2_IO<15> LOC=P6;
*
* MODIFICATION HISTORY:
*
* Ver Who Date Changes
* ----- ---- -------- -----------------------------------------------
* 2.00a jhl 12/01/03 First release
* 2.00a sv 04/15/05 Minor changes to comply to Doxygen and coding guidelines
* 3.00a ktn 11/21/09 Updated to use HAL Processor APIs and minior changes
* as per coding guidelines.
* 3.00a sdm 02/16/11 Updated to support ARM Generic Interrupt Controller
*</pre>
*
******************************************************************************/
/***************************** Include Files *********************************/
#include "xparameters.h"
#include "xgpio.h"
#include "xil_exception.h"
#ifdef XPAR_INTC_0_DEVICE_ID
#include "xintc.h"
#else
#include "xscugic.h"
#endif
/************************** Constant Definitions *****************************/
/*
* The following constants map to the names of the hardware instances that
* were created in the EDK XPS system. They are only defined here such that
* a user can easily change all the needed device IDs in one place.
*/
#define GPIO_DEVICE_ID XPAR_PUSH_BUTTONS_4BITS_DEVICE_ID
#define INTC_GPIO_INTERRUPT_ID XPAR_INTC_0_GPIO_2_VEC_ID
#ifdef XPAR_INTC_0_DEVICE_ID
#define INTC_DEVICE_ID XPAR_INTC_0_DEVICE_ID
#define INTC XIntc
#define INTC_HANDLER XIntc_InterruptHandler
#else
#define INTC_DEVICE_ID XPAR_SCUGIC_SINGLE_DEVICE_ID
#define INTC XScuGic
#define INTC_HANDLER XScuGic_InterruptHandler
#endif
/*
* The following constants define the positions of the buttons and LEDs each
* channel of the GPIO
*/
#define GPIO_ALL_LEDS 0xFFFF
#define GPIO_ALL_BUTTONS 0xFFFF
/*
* The following constants define the GPIO channel that is used for the buttons
* and the LEDs. They allow the channels to be reversed easily.
*/
#define BUTTON_CHANNEL 1 /* Channel 1 of the GPIO Device */
#define LED_CHANNEL 2 /* Channel 2 of the GPIO Device */
#define BUTTON_INTERRUPT XGPIO_IR_CH1_MASK /* Channel 1 Interrupt Mask */
/*
* The following constant is used to wait after an LED is turned on to make
* sure that it is visible to the human eye. This constant might need to be
* tuned for faster or slower processor speeds.
*/
#define LED_DELAY 1000000
/**************************** Type Definitions *******************************/
typedef struct
{
u32 ButtonMask; /* The bit corresponding to the button */
u32 LedMask; /* The bit corresponding to the LED */
} MapButtonTable;
/***************** Macros (Inline Functions) Definitions *********************/
/************************** Function Prototypes ******************************/
int MapButton2Led(u32 Buttons, u32 *ButtonFoundPtr);
void SequenceLeds();
void GpioIsr(void *InstancePtr);
int SetupInterruptSystem();
/************************** Variable Definitions *****************************/
/*
* The following are declared globally so they are zeroed and so they are
* easily accessible from a debugger
*/
static XGpio Gpio; /* The Instance of the GPIO Driver */
static INTC Intc; /* The Instance of the Interrupt Controller Driver */
volatile int InterruptCount; /* Count of interrupts that have occured */
/*
* The following table contains the masks for the buttons and LEDS
* that are connected on the board. It's purpose is to map a button
* to a specific LED.
*/
MapButtonTable Button2LedTable[] =
{ { 0x1, 0x1 },
{ 0x2, 0x2 },
{ 0x4, 0x4 },
{ 0x8, 0x8 },
{ 0x10, 0x8 },
{ 0x20, 0x8 },
{ 0x40, 0x8 },
{ 0x100, 0x10 },
{ 0x200, 0x20 },
{ 0x400, 0x40 },
{ 0x800, 0x80 },
{ 0x1000, 0x80 },
{ 0x2000, 0x80 },
{ 0x4000, 0x80 } };
/****************************************************************************/
/**
* This function is the main function of the GPIO example. It is responsible
* for initializing the GPIO device, setting up interrupts and providing a
* foreground loop such that interrupt can occur in the background.
*
* @param None.
*
* @return
* - XST_SUCCESS to indicate success.
* - XST_FAILURE to indicate Failure.
*
* @note None.
*
*
*****************************************************************************/
int main(void)
{
int Status;
/* Initialize the GPIO driver. If an error occurs then exit */
Status = XGpio_Initialize(&Gpio, GPIO_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Perform a self-test on the GPIO. This is a minimal test and only
* verifies that there is not any bus error when reading the data
* register
*/
XGpio_SelfTest(&Gpio);
/*
* Setup direction register so the switch is an input and the LED is
* an output of the GPIO
*/
XGpio_SetDataDirection(&Gpio, BUTTON_CHANNEL, GPIO_ALL_BUTTONS);
XGpio_SetDataDirection(&Gpio, LED_CHANNEL, ~GPIO_ALL_LEDS);
/* Sequence the LEDs to show this example is starting to run */
SequenceLeds();
/*
* Setup the interrupts such that interrupt processing can occur. If
* an error occurs then exit
*/
Status = SetupInterruptSystem();
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*
* Loop forever while the button changes are handled by the interrupt
* level processing
*/
while (1) {
}
return XST_SUCCESS;
}
/****************************************************************************/
/**
* This function sequences the LEDs by turning them all on, the turning each
* one on individually, then turning them all on, and finally off.
*
* @param None.
*
* @return None.
*
* @note None.
*
*****************************************************************************/
void SequenceLeds()
{
u32 Mask = 0x8000;
int Led;
volatile int Delay;
/* Turn on all the LEDS to show starting the sequence */
XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, GPIO_ALL_LEDS);
for (Delay = 0; Delay < LED_DELAY; Delay++);
/* Sequence thru turning each LED on one at a time */
for (Led = 1; Led <= 16; Led++) {
XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, Mask);
Mask >>= 1;
/* Wait a small amount of time so the LED is visible */
for (Delay = 0; Delay < LED_DELAY; Delay++);
}
/* Turn on all LEDS to show stopping the sequence */
XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, GPIO_ALL_LEDS);
for (Delay = 0; Delay < LED_DELAY; Delay++);
/* Turn off all the LEDs */
XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, 0);
XGpio_InterruptClear(&Gpio, XGPIO_IR_MASK);
}
/****************************************************************************/
/**
* This function maps each button on the board to an LED.
*
* @param Buttons contains the buttons that have changed.
* @param ButtonFoundPtr is a pointer to allow this function to indicate
* the button that was associated with the returned LED. This
* input is needed to allow muliple buttons to change
* simulataneously.
*
* @return
*
* The Led that is associated with the first button that was found to be
* changed. A value of zero indicates no LED was found.
*
* @note None.
*
*****************************************************************************/
int MapButton2Led(u32 Buttons, u32 *ButtonFoundPtr)
{
int Index;
/* Look thru the table to map the button to an LED */
for (Index = 0; Index < sizeof(Button2LedTable)/ sizeof(MapButtonTable);
Index++) {
/*
* Determine which LED corresponds to the button being careful
* because more than one button could have changed
*/
if (Button2LedTable[Index].ButtonMask ==
(Buttons & Button2LedTable[Index].ButtonMask)) {
/*
* If the button was found then return the
* associated LED
*/
*ButtonFoundPtr = Button2LedTable[Index].ButtonMask;
return Button2LedTable[Index].LedMask;
}
}
/* If no button was found in the table, then indicate no LED */
return 0;
}
/****************************************************************************/
/**
* This function is the Interrupt Service Routine for the GPIO device. It
* will be called by the processor whenever an interrupt is asserted by the
* device.
*
* This function will detect the push button on the board has changed state
* and then turn on or off the LED.
*
* @param InstancePtr is the GPIO instance pointer to operate on.
* It is a void pointer to meet the interface of an interrupt
* processing function.
*
* @return None.
*
* @note None.
*
*****************************************************************************/
void GpioIsr(void *InstancePtr)
{
XGpio *GpioPtr = (XGpio *)InstancePtr;
u32 Led;
u32 LedState;
u32 Buttons;
u32 ButtonFound;
u32 ButtonsChanged = 0;
static u32 PreviousButtons;
/*
* Disable the interrupt
*/
XGpio_InterruptDisable(GpioPtr, BUTTON_INTERRUPT);
/* Keep track of the number of interrupts that occur */
InterruptCount++;
/*
* There should not be any other interrupts occuring other than the
* the button changes
*/
if ((XGpio_InterruptGetStatus(GpioPtr) & BUTTON_INTERRUPT) !=
BUTTON_INTERRUPT) {
return;
}
/*
* Read state of push buttons and determine which ones changed
* states from the previous interrupt. Save a copy of the buttons
* for the next interrupt
*/
Buttons = XGpio_DiscreteRead(GpioPtr, BUTTON_CHANNEL);
ButtonsChanged = Buttons ^ PreviousButtons;
PreviousButtons = Buttons;
/*
* Handle all button state changes that occurred since the last
* interrupt
*/
while (ButtonsChanged != 0) {
/*
* Determine which button changed state and then get
* the current state of the associated LED
*/
Led = MapButton2Led(ButtonsChanged, &ButtonFound);
LedState = XGpio_DiscreteRead(GpioPtr, LED_CHANNEL) & Led;
/*
* Clear the button that is being processed so that it is
* done and others can be handled also
*/
ButtonsChanged &= ~ButtonFound;
/* Toggle the state of the LED */
if (LedState) {
XGpio_DiscreteClear(GpioPtr, LED_CHANNEL, Led);
} else {
XGpio_DiscreteSet(GpioPtr, LED_CHANNEL, Led);
}
}
/* Clear the interrupt such that it is no longer pending in the GPIO */
(void)XGpio_InterruptClear(GpioPtr, BUTTON_INTERRUPT);
/*
* Enable the interrupt
*/
XGpio_InterruptEnable(GpioPtr, BUTTON_INTERRUPT);
}
/****************************************************************************/
/**
* This function sets up the interrupt system for the example. The processing
* contained in this funtion assumes the hardware system was built with
* and interrupt controller.
*
* @param None.
*
* @return A status indicating XST_SUCCESS or a value that is contained in
* xstatus.h.
*
* @note None.
*
*****************************************************************************/
int SetupInterruptSystem()
{
int Result;
INTC *IntcInstancePtr = &Intc;
#ifdef XPAR_INTC_0_DEVICE_ID
/*
* Initialize the interrupt controller driver so that it's ready to use.
* specify the device ID that was generated in xparameters.h
*/
Result = XIntc_Initialize(IntcInstancePtr, INTC_DEVICE_ID);
if (Result != XST_SUCCESS) {
return Result;
}
/* Hook up interrupt service routine */
XIntc_Connect(IntcInstancePtr, INTC_GPIO_INTERRUPT_ID,
(Xil_ExceptionHandler)GpioIsr, &Gpio);
/* Enable the interrupt vector at the interrupt controller */
XIntc_Enable(IntcInstancePtr, INTC_GPIO_INTERRUPT_ID);
/*
* Start the interrupt controller such that interrupts are recognized
* and handled by the processor
*/
Result = XIntc_Start(IntcInstancePtr, XIN_REAL_MODE);
if (Result != XST_SUCCESS) {
return Result;
}
#else
XScuGic_Config *IntcConfig;
/*
* Initialize the interrupt controller driver so that it is ready to
* use.
*/
IntcConfig = XScuGic_LookupConfig(INTC_DEVICE_ID);
if (NULL == IntcConfig) {
return XST_FAILURE;
}
Result = XScuGic_CfgInitialize(IntcInstancePtr, IntcConfig,
IntcConfig->CpuBaseAddress);
if (Result != XST_SUCCESS) {
return XST_FAILURE;
}
XScuGic_SetPriorityTriggerType(IntcInstancePtr, INTC_GPIO_INTERRUPT_ID,
0xA0, 0x3);
/*
* Connect the interrupt handler that will be called when an
* interrupt occurs for the device.
*/
Result = XScuGic_Connect(IntcInstancePtr, INTC_GPIO_INTERRUPT_ID,
(Xil_ExceptionHandler)GpioIsr, &Gpio);
if (Result != XST_SUCCESS) {
return Result;
}
/*
* Enable the interrupt for the GPIO device.
*/
XScuGic_Enable(IntcInstancePtr, INTC_GPIO_INTERRUPT_ID);
#endif
/*
* Enable the GPIO channel interrupts so that push button can be
* detected and enable interrupts for the GPIO device
*/
XGpio_InterruptEnable(&Gpio, BUTTON_INTERRUPT);
XGpio_InterruptGlobalEnable(&Gpio);
/*
* Initialize the exception table and register the interrupt
* controller handler with the exception table
*/
Xil_ExceptionInit();
Xil_ExceptionRegisterHandler(XIL_EXCEPTION_ID_INT,
(Xil_ExceptionHandler)INTC_HANDLER, IntcInstancePtr);
/* Enable non-critical exceptions */
Xil_ExceptionEnable();
return XST_SUCCESS;
}