3.4.2点灯驱动（完成）

开发板：jz2440
内核：3.4.2
芯片：S3C2440
/***********应用测试程序**************/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
/* firstdrvtest on
  * firstdrvtest off
  */
int main(int argc, char **argv)
{
    int fd;
    int val = 1;
    fd = open("/dev/xyz", O_RDWR);    //打开文件
    if (fd < 0)
    {
        printf("can't open!\n");
    }
    if (argc != 2)        //判断执行时是否2个字符串
    {
        printf("Usage :\n");
        printf("%s <on|off>\n", argv[0]);
        return 0;
    }
    if (strcmp(argv[1], "on") == 0)     //比较第二个字符串，相同为0 
    {
        val  = 1;
    }
    else
    {
        val = 0;
    }
    
    write(fd, &val, 4);
    return 0;
}
/********************操作********************/
//编译---arm-linux-gcc -o firstdrvtest firstdrvtest.c
//开灯---./firstdrvtest on
//关灯---./firstdrvtest off
/********************************************/

/*****************驱动程序如下******************/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/io.h>

static struct class *firstdrv_class;  //分配一个类
static struct device    *firstdrv_class_dev;
volatile unsigned long *gpfcon = NULL;
volatile unsigned long *gpfdat = NULL;

static int first_drv_open(struct inode *inode, struct file *file)
{
    //printk("first_drv_open\n");
    /* 配置GPF4,5,6为输出 */
    *gpfcon &= ~((0x3<<(4*2)) | (0x3<<(5*2)) | (0x3<<(6*2)));
    *gpfcon |= ((0x1<<(4*2)) | (0x1<<(5*2)) | (0x1<<(6*2)));
    return 0;
}

static ssize_t first_drv_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{
    int val;
    //printk("first_drv_write\n");
    copy_from_user(&val, buf, count); //    copy_to_user();
    if (val == 1)
    {
        // 点灯
        *gpfdat &= ~((1<<4) | (1<<5) | (1<<6));
    }
    else
    {
        // 灭灯
        *gpfdat |= (1<<4) | (1<<5) | (1<<6);
    }
    
    return 0;
}

static struct file_operations first_drv_fops = {
    .owner  =   THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */
    .open   =   first_drv_open,     
    .write    =    first_drv_write,       
};

int major;

static int first_drv_init(void)
{
    major = register_chrdev(0, "first_drv", &first_drv_fops); // 注册, 告诉内核
                        //参数为0是系统随机分配主设备号
    firstdrv_class = class_create(THIS_MODULE, "firstdrv");
    firstdrv_class_dev = device_create(firstdrv_class, NULL, MKDEV(major, 0), NULL, "xyz"); /* /dev/xyz */
    //功能是让系统自动生成设备节点
    gpfcon = (volatile unsigned long *)ioremap(0x56000050, 16);
    gpfdat = gpfcon + 1;
    return 0;
}

static void first_drv_exit(void)
{
    unregister_chrdev(major, "first_drv"); // 卸载
    device_destroy(firstdrv_class_dev, MKDEV(major, 0));
    class_destroy(firstdrv_class);
    iounmap(gpfcon);
}

module_init(first_drv_init);
module_exit(first_drv_exit);
MODULE_LICENSE("GPL");//这是一个协议
/**********************操作***********************/
安装---insmod first_drv.ko
卸载---rmmod first_drv
/*************************************************/



/*************************Makefile如下****************************/
KERN_DIR = /work/system/linux-3.4.2

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

clean:
    make -C $(KERN_DIR) M=`pwd` modules clean
    rm -rf modules.order

obj-m    += first_drv.o
/*******************操作*******************/
//make---生成.ko文件
//make clean---删除.ko文件
/******************************************/