led_dev.c源碼：

#include "linux/module.h"

#include "linux/moduleparam.h"

#include "linux/ioport.h"

#include "linux/init.h"

#include "linux/delay.h"

#include "linux/platform_device.h"

// 1. 分配一個platform_device 

// 2. 設置 

static struct resource led_resoures[] = {

    [0] = {

        .start  = 0x7F008820,  // GPMCON 

        .end    = 0x7F008827,

        .flags  = IORESOURCE_MEM,

    },

    [1] = {

        .start  = 1,

        .end    = 1,

        .flags  = IORESOURCE_IRQ,

    },

};

static void led_release(struct device *dev)

{

}

static struct platform_device led_dev = {

    .name           = "up6410_led",

    .id             = 0,

    .num_resources  = 2,

    .resource       = led_resoures,

    .dev            = {

            .release = led_release,

    },

};

// 3. 注冊 

static int led_dev_init(void)

{

    platform_device_register(&led_dev);

    return 0;

}

static void led_dev_exit(void)

{

    platform_device_del(&led_dev);

}

module_init(led_dev_init);

module_exit(led_dev_exit);

MODULE_LICENSE("GPL");

=====================================================================

led_drv.c源碼：

#include "linux/module.h"

#include "linux/compat.h"

#include "linux/types.h"

#include "linux/errno.h"

#include "linux/smp_lock.h"

#include "linux/kernel.h"

#include "linux/major.h"

#include "linux/slab.h"

#include "linux/mm.h"

#include "linux/mman.h"

#include "linux/vt.h"

#include "linux/init.h"

#include "linux/linux_logo.h"

#include "linux/proc_fs.h"

#include "linux/seq_file.h"

#include "linux/console.h"

#include "linux/kmod.h"

#include "linux/err.h"

#include "linux/device.h"

#include "asm/uaccess.h"

#include "asm/io.h"

#include "linux/platform_device.h"

static int major  = 0;

static volatile unsigned long *gpxcon;

static volatile unsigned long *gpxdat;

static int pin;

static struct class *cls;

static int led_open(struct inode *inode, struct file *file)

{

    *gpxcon &= ~(0xf << (pin * 4));

    *gpxcon |= (0x1 << (pin * 4));

    return 0;

}

static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)

{

    char val;

    copy_from_user(&val, buf, 1);

    if (val == 0)

    {

        // 開燈 

        *gpxdat &= ~(1<

    }

    else

    {

        *gpxdat |= (1<

    }

    return 1;    

}

static struct file_operations led_fops = {

    .owner    = THIS_MODULE,

    .open     = led_open,

    .write    = led_write,

};

static int led_probe(struct platform_device *dev)

{

    struct resource *res;

    res = platform_get_resource(dev, IORESOURCE_MEM, 0);

    gpxcon = ioremap(res->start, res->end - res->start + 1);

    gpxdat = gpxcon + 1;

    res = platform_get_resource(dev, IORESOURCE_IRQ, 0);

    pin = res->start;

    major = register_chrdev(0, "led", &led_fops);

    cls = class_create(THIS_MODULE, "led"); // sysfs 

    device_create(cls, NULL, MKDEV(major, 0), NULL, "led");

    return 0;

}

static int led_remove(struct platform_device *dev)

{

    device_destroy(cls, MKDEV(major, 0));

    class_destroy(cls);

    unregister_chrdev(major, "led");

    iounmap(gpxcon);

    return 0;

}

// 1. 分配一個platform_driver 

// 2. 設置 

static struct platform_driver led_drv = {

    .probe       = led_probe,

    .remove      = __devexit_p(led_remove),

    .driver      = {

        .name    = "up6410_led",

        .owner   = THIS_MODULE,

    },

};

// 3. 注冊 

static int led_drv_init(void)

{

    platform_driver_register(&led_drv);

    return 0;

}

static void led_drv_exit(void)

{

    platform_driver_unregister(&led_drv);

}

module_init(led_drv_init);

module_exit(led_drv_exit);

MODULE_LICENSE("GPL");

=====================================================================

led_test.c源碼：

#include "sys/types.h"

#include "sys/stat.h"

#include "fcntl.h"

#include "sys/mman.h"

#include "stdio.h"

#include "stdlib.h"

#include "string.h"

void print_usage(char *file)

{

    printf("Usage:\n");

    printf("%s \n", file);

}

int main(int argc, char **argv)

{

    int fd;

    char val;

    if (argc != 2)

    {

        print_usage(argv[0]);

        return -1;

    }

    fd = open("/dev/led", O_RDWR);

    if (fd < 0)

    {

        printf("can't open /dev/led\n");

        return -1;

    }

    if (strcmp(argv[1], "on") == 0)

    {

        val = 0;

    }

    else

    {

        val = 1;

    }

    write(fd, &val, 1);

    return 0;

}

====================================================================

Makefile文件：

KERN_DIR = /home/linux/linux-3.0.1

all:

    make -C $(KERN_DIR) M=`pwd` modules 

clean:

    make -C $(KERN_DIR) M=`pwd` modules clean

    rm -rf modules.order

obj-m += led_drv.o

obj-m += led_dev.o

====================================================================

編譯驅動程序：make

編譯應用程序：arm-linux-gcc led_test led_test.c