并口读写测试实例 - 曲径通幽论坛

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/fcntl.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#define RDWR_DEV_NAME    "rdwrdev"
#define RDWR_DEV_MAJOR      240

#define RDWR_WRITE_ADDR      0x0378
#define RDWR_READ_ADDR      0x0379

int rdwr_open (struct inode *inode, struct file *filp)
{
    return 0;
}

ssize_t    rdwr_read (struct file *filp, char *buf, size_t count, loff_t *f_ops)
{
    unsigned char status;
    int    loop;

    for (loop = 0; loop < count; loop++) {
        status = inb (RDWR_READ_ADDR);
        put_user (status, (char *) & buf [loop]);
    }

    return count;
}

ssize_t rdwr_write (struct file *filp, const char *buf, size_t count, loff_t *f_pos)
{
    unsigned char status;
    int          loop;

    for (loop = 0; loop < count; loop++) {
        get_user (status, (char *)buf);
        outb (status, RDWR_WRITE_ADDR);
    }
    return count;
}

int rdwr_release (struct inode *inode, struct file *filp)
{
    return 0;
}

struct file_operations rdwr_fops =
{
    .owner = THIS_MODULE,
    .read = rdwr_read,
    .write = rdwr_write,
    .open = rdwr_open,
    .release = rdwr_release,
};

int rdwr_init (void)
{
    int result;

    result = register_chrdev (RDWR_DEV_MAJOR, RDWR_DEV_NAME, &rdwr_fops);
    if (result < 0) return result;

    return 0;
}

void rdwr_exit (void)
{
    unregister_chrdev (RDWR_DEV_MAJOR, RDWR_DEV_NAME);
}

module_init (rdwr_init);
module_exit (rdwr_exit);

MODULE_LICENSE ("Dual BSD/GPL");

obj-m := rdwrdev.o

KDIR := /lib/modules/$(shell uname -r)/build

PWD := $(shell pwd)

default:
    $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules

clean:
    rm -rf *.ko
    rm -rf *.mod.*
    rm -rf .*.cmd
    rm -rf *.o

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>

#define DEVICE_FILENAME    "/dev/rdwrdev"

int main()
{
    int dev;
    char buff [128];
    int loop;

    dev = open (DEVICE_FILENAME, O_RDWR | O_NDELAY);
    if (dev >= 0) {

        printf ("waiting ... input\n");

        while (1) {
            if (read (dev, buff, 1) == 1) {
                printf ("read data [%02X]\n", buff [0] & 0xFF);
                if (!(buff [0] & 0x10))
                    break;
            }
        }

        printf ("input ok ... \n");
        printf ("led falshing ... \n");
        for (loop = 0; loop < 5; loop++) {
            buff [0] = 0xFF;
            write (dev, buff, 1);
            sleep (1);
            buff [0] = 0x00;
            write (dev, buff, 1);
            sleep (1);
        }
        close (dev);
    } else {
        perror ("open device");
        exit (1);
    }

    return (0);
}

read data [6F]
input ok ...
led falshing ...