#include <linux/module.h>
#include <linux/kernel.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>
#include <asm/arch/regs-gpio.h>
#include <asm/hardware.h>
static struct class *firstdrv_class;
static struct class_device *firstdrv_class_dev;
volatile unsigned long *gpfcon =NULL;
volatile unsigned long *gpfdat =NULL;
static int first_drv_init(void);
static int first_drv_open(struct inode *inode, struct file *file )
{ //printk("first_drv_open\n");
/*配置GPF4,5,6 为输出*/
//初始状态为输入
*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,低电平点灯
*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,
.open = first_drv_open,
.write=first_drv_write,
};
int major;
static int first_drv_init(void) {
/* 系统自动分配主设备号 */
major=register_chrdev(0,"first_drv ",&first_drv_fops );
//注册驱动程序
firstdrv_class = class_create(THIS_MODULE, "firstdrv");
//创建设备节点
firstdrv_class_dev= class_device_create(firstdrv_class, NULL, MKDEV(major, 0), NULL, "xyz");
/*if (unlikely(IS_ERR(firstdrv_class_dev))) return PTR_ERR(firstdrv_class_dev);*/
//映射寄存器的地址到内核
gpfcon =(volatile unsigned long * )ioremap(0x56000050,16);
gpfdat=gpfcon+1;
return 0;
}
void first_drv_exit(void) {
unregister_chrdev(major,"first_drv");
//卸载驱动
class_device_unregister(firstdrv_class_dev);
class_destroy(firstdrv_class); iounmap(gpfcon); }
module_init( first_drv_init);
module_exit(first_drv_exit);
MODULE_LICENSE("GPL");
来源：https://www.cnblogs.com/kingqinwang/p/5147379.html