dm6430-digital-interrupt.c

rt 6430 采集卡 linux下驱动源代码

/*
	FILE NAME: dm6430-digital-interrupt.c

	FILE DESCRIPTION:	Example program showing how to use advanced
				digital interrupts.

	PROJECT NAME: Linux DM6430 Driver, Library, and Example Programs

	PROJECT VERSION: (Defined in README.TXT)

	Copyright 2004 RTD Embedded Technologies, Inc.  All Rights Reserved.
*/


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <dm6430lib.h>


#define INTERRUPT_CIRCUIT DM6430HR_INT1


int	descriptor;


static void
verify_success(int status, const char *message_p) {
    if (status == -1) {
	perror(message_p);
	exit(EXIT_FAILURE);
    }
}

/*
static void
print_status(void) {
    int		status;
    u_int16_t	status_reg;

    status = ReadStatus6430(descriptor, &status_reg);
    verify_success(status, "ReadStatus6430() FAILED");

    fprintf(stdout, "Status: %x\n", status_reg);
}

static void
print_dio_status(void) {
    int		status;
    u_int8_t	dio_status;

    status = DIOReadStatus6430(descriptor, &dio_status);
    verify_success(status, "DIOReadStatus6430() failed");

    fprintf(stdout, "DIO status: %x\n", dio_status);
}
*/


/******************************************************************************
Interrupt callback

This callback routine does the following:
    - Prints a message that a digital interrupt occurred.
    - Verifies that Digital Status Register indicates an interrupt occurred.
    - Verifies that Status Register indicates an interrupt occurred.
    - Reads the digital Compare Register to get the digital input value.
    - Disables interrupts on interrupt circuit 1.
    - Removes the interrupt callback function.
    - Disables advanced digital interrupts.
    - Exits the program.
 ******************************************************************************/

void
interrupt_handler(void) {
    int		int_flag;
    int		status;
    u_int8_t	value;

    fprintf(stdout, "\n");
    fprintf(stdout, "interrupt_handler(): Interrupt occurred.\n");

    /*
     * Sanity check that both the Digital Status Register and Status Register
     * indicate an advanced digital interrupt occurred
     */

    status = DIOIsChipIrq6430(descriptor, &int_flag);
    verify_success(status, "DIOIsChipIrq6430() failed");

    if (!int_flag) {
	fprintf(
	    stderr,
	    "FAILURE: Digital Status Register says no interrupt occurred.\n"
	);
	exit(EXIT_FAILURE);
    }

    status = IsDigitalIRQ6430(descriptor, &int_flag);
    verify_success(status, "IsDigitalIRQ6430() failed");

    if (!int_flag) {
	fprintf(
	    stderr,
	    "FAILURE: Status Register says no interrupt occurred.\n"
	);
	exit(EXIT_FAILURE);
    }

    /*
     * The digital value which caused the interrupt is latched into the
     * Compare Register, so read that value
     */

    status = DIOReadCompareRegister6430(descriptor, &value);
    verify_success(status, "DIOReadCompareRegister6430() failed");

    fprintf(stdout, "Digital data: %x\n", value);

    status = DisableIRQ6430(descriptor, INTERRUPT_CIRCUIT);
    verify_success(status, "DisableIRQ6430() FAILED");

    status = RemoveIRQHandler6430(descriptor, INTERRUPT_CIRCUIT);
    verify_success(status, "RemoveIRQHandler6430() FAILED");

    status = DIOEnableIrq6430(descriptor, 0);
    verify_success(status, "DIOEnableIrq6430() FAILED");

    exit(EXIT_SUCCESS);
}


/******************************************************************************
And now ... the real program

This example program does the following:
    - Opens /dev/rtd-dm6430-0.
    - Initializes the device.
    - Sets the source of interrupts on interrupt circuit 1 to be digital
      interrupts.
    - Sets digital interrupt mode to "event" so that an interrupt is generated
      whenever any port 0 bit changes state.
    - Sets all port 0 bits to input.
    - Uses the 8 MHz system clock to drive digital sampling.
    - Enables advanced digital interrupts.
    - Installs a callback function to be invoked whenever an interrupt occurs
      on interrupt circuit 1.
    - Enables interrupts on interrupt circuit 1.
    - Clears the digital interrupt status flag.
    - Waits for a single digital interrupt to occur.
 ******************************************************************************/

int
main(void) {
    int	status;
    int	int_flag;

    descriptor = OpenBoard6430(0);
    verify_success(descriptor, "OpenBoard6430() FAILED");

    status = InitBoard6430(descriptor);
    verify_success(status, "InitBoard6430() FAILED");

    status = SetIRQ0Source6430(descriptor, IRQS_DIGITAL_6430);
    verify_success(status, "SetIRQ0Source6430() FAILED");

    status = DIOSelectIrqMode6430(descriptor, DM6430HR_DIO_IRQ_EVENT);
    verify_success(status, "DIOSelectIrqMode6430() FAILED");

    /*
     * Sanity check that board thinks it's in Event Mode
     */

    status = DIOIsChipIRQEventMode6430(descriptor, &int_flag);
    verify_success(status, "DIOIsChipIRQEventMode6430() FAILED");

    if (!int_flag) {
	fprintf(
	    stderr,
	    "FAILURE: board says it is not in digital event mode.\n"
	);
	exit(EXIT_FAILURE);
    }

    status = DIOSetPort0Direction6430(descriptor, 0x0);
    verify_success(status, "DIOSetPort0Direction6430() FAILED");

    status = DIOSelectClock6430(descriptor, DM6430HR_CLOCK_TC);
    verify_success(status, "DIOSelectClock6430() FAILED");

    /*
     * Sanity check that board thinks 8 MHz system clock is driving sampling
     */

    status = DIOIsChipSystemClock6430(descriptor, &int_flag);
    verify_success(status, "DIOIsChipSystemClock6430() FAILED");

    if (!int_flag) {
	fprintf(
	    stderr,
	    "FAILURE: board says 8 MHz system clock not in use.\n"
	);
	exit(EXIT_FAILURE);
    }

    status = DIOEnableIrq6430(descriptor, 1);
    verify_success(status, "DIOEnableIrq6430() FAILED");

    /*
     * Sanity check that board thinks advanced digital interrupts are enabled
     */

    status = DIOIsChipIRQEnabled6430(descriptor, &int_flag);
    verify_success(status, "DIOIsChipIRQEnabled6430() FAILED");

    if (!int_flag) {
	fprintf(
	    stderr,
	    "FAILURE: board says digital interrupts are disabled.\n"
	);
	exit(EXIT_FAILURE);
    }

    status = InstallCallbackIRQHandler6430(
	descriptor,
	interrupt_handler,
	INTERRUPT_CIRCUIT
    );
    verify_success(status, "InstallCallbackIRQHandler6430() FAILED");

    status = EnableIRQ6430(descriptor, INTERRUPT_CIRCUIT);
    verify_success(status, "EnableIRQ6430() FAILED");

    status = DIOClearIrq6430(descriptor);
    verify_success(status, "DIOClearIrq6430() FAILED");

    fprintf(stdout, "Waiting for interrupt.  Hit return to quit ...");

    (void) fgetc(stdin);

    fprintf(stdout, "\n");
    fprintf(stdout, "Quitting at user's request.\n");

    exit(EXIT_SUCCESS);
}