led驱动
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/io.h>
static unsigned int led_major;
//根据自己硬件写led驱动
#define GPM4_DAT_PHYADDR 0X110002E4
#define GPM4_CON_PHYADDR 0X110002E0
typedef struct GPIO{
volatile unsigned long gpm4con;
volatile unsigned long gpm4dat;
}GPIO_t ,*GP;
static GPIO_t *GPM4=NULL;
// 7 编写文件操作函数
static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t *offsets)
{
unsigned char ledflag[2]={0};
//接收函数// 8 接收上层数据
unsigned long ret = copy_from_user(ledflag,buf,count);
printk(KERN_WARNING "driver ledflag :%d",ledflag[0]);
printk(KERN_WARNING "driver ledflag :%d\n",ledflag[1]);
if(ledflag[1]==1)
{
if (ledflag[0]==1)
GPM4->gpm4dat &=~(1<<0);
else if (ledflag[0]==2)
GPM4->gpm4dat &=~(1<<1);
else if (ledflag[0]==3)
GPM4->gpm4dat &=~(1<<2);
else if (ledflag[0]==4)
GPM4->gpm4dat &=~(1<<3);
}
else
{
if (ledflag[0]==1)
GPM4->gpm4dat |=(1<<0);
else if (ledflag[0]==2)
GPM4->gpm4dat |=(1<<1);
else if (ledflag[0]==3)
GPM4->gpm4dat |=(1<<2);
else if (ledflag[0]==4)
GPM4->gpm4dat |=(1<<3);
}
return ret;
}
// 4 构造file_operation文件操作集合
// 6 填充文件操作集合
struct file_operations led_fops =
{
.owner = THIS_MODULE,
.write = led_write,
};
// 2 编写驱动加载卸载函数
static int __init led_drv_init(void)
{
// 3 早期字符设备注册
// 参数1：主设备号 >0 静态注册 以写入的设备号注册
// =0 动态注册 自动分配一个设备号
// 参数2：名称 辅助识别
// 参数3：文件操作集合 驱动支持的上层操作接口
// 返回：静态注册 成功返回0 失败返回错误
// 动态注册 成功返回分配的主设备号
led_major= register_chrdev(0,"leddrv",&led_fops);
printk("led insmod....\n");
GPM4 = ioremap(GPM4_CON_PHYADDR, 8);
//led初始化
GPM4->gpm4con |=0X1111<<0;
GPM4->gpm4dat |=0XF<<0;
return 0;
}
static void __exit led_drv_exit(void)
{
unregister_chrdev(led_major,"leddrv");
// 9 取消硬件映射
iounmap(GPM4);
printk("led rmmod....\n");
}
//指点加载程序入口
module_init(led_drv_init);
module_exit(led_drv_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("qw");
上层应用ledapp.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
int main(int argc,char *argv[])
{
int led_fd;
unsigned char ledflag[2]={0};
if(argc !=3)
{
printf("Use: %s </dev/led> <11/10/21/20/31/30/41/40>\n",argv[0]);
}
led_fd = open(argv[1],O_WRONLY);
ledflag[0] = argv[2][0]-48;
ledflag[1] = argv[2][1]-48;
write(led_fd,ledflag,2);
}