中断子系统用驱动控制led实验
驱动代码
#include <linux/init.h>
#include <linux/module.h>
#include<linux/interrupt.h>
#include<linux/gpio.h>
#include<linux/timer.h>
#include<linux/of.h>
#include<linux/of_irq.h>
#include<linux/of_gpio.h>
/*
myirq{
compatible = "hqyj,myirq";
interrupt-parent=<&gpiof>;
interrupts=<9 0>,<7 0>,<8 0>;
led1-gpio=<&gpioe 10 0>;
led2-gpio=<&gpiof 10 0>;
led3-gpio=<&gpioe 8 0>;
};
*/
struct device_node *dnode;
struct gpio_desc *lednode1;
struct gpio_desc *lednode2;
struct gpio_desc *lednode3;
unsigned int irq_id1;
unsigned int irq_id2;
unsigned int irq_id3;
//中断处理函数
irqreturn_t myirq_handle1(int irq,void *dev)
{
//反转电平
gpiod_set_value(lednode1,!gpiod_get_value(lednode1));
//防止其他灯亮
gpiod_set_value(lednode2,0);
gpiod_set_value(lednode3,0);
return IRQ_HANDLED;
}
irqreturn_t myirq_handle2(int irq,void *dev)
{
//反转电平
gpiod_set_value(lednode2,!gpiod_get_value(lednode2));
//防止其他灯亮
gpiod_set_value(lednode1,0);
gpiod_set_value(lednode3,0);
return IRQ_HANDLED;
}
irqreturn_t myirq_handle3(int irq,void *dev)
{
//反转电平
gpiod_set_value(lednode3,!gpiod_get_value(lednode3));
//防止其他灯亮
gpiod_set_value(lednode1,0);
gpiod_set_value(lednode2,0);
return IRQ_HANDLED;
}
static int __init mycdev_init(void)
{
//根据compatible解析设备节点
dnode=of_find_compatible_node(NULL,NULL,"hqyj,myirq");
if(NULL==dnode)
{
printk("of_find_compatible_node error\n");
return -ENXIO;
}
printk("解析设备节点成功\n");
//设备树节点解析
lednode1=gpiod_get_from_of_node(dnode,"led1-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode1==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
//设备树节点解析
lednode2=gpiod_get_from_of_node(dnode,"led2-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode2==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
//设备树节点解析
lednode3=gpiod_get_from_of_node(dnode,"led3-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode3==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
//解析按键1的软中断
irq_id1=irq_of_parse_and_map(dnode,0);
if(!irq_id1)
{
printk("解析软中断失败\n");
return -ENXIO;
}
//解析按键2的软中断
irq_id2=irq_of_parse_and_map(dnode,1);
if(!irq_id2)
{
printk("解析软中断失败\n");
return -ENXIO;
}
//解析按键3的软中断
irq_id3=irq_of_parse_and_map(dnode,2);
if(!irq_id3)
{
printk("解析软中断失败\n");
return -ENXIO;
}
printk("解析软中断成功\n");
//注册按键1请求中断
int ret=request_irq(irq_id1,myirq_handle1,IRQF_TRIGGER_FALLING,"key1",(void*)1);
if(ret)
{
printk("注册按键请求中断失败\n");
return ret;
}
//注册按键2请求中断
ret=request_irq(irq_id2,myirq_handle2,IRQF_TRIGGER_FALLING,"key2",(void*)2);
if(ret)
{
printk("注册按键请求中断失败\n");
return ret;
}
//注册按键3请求中断
ret=request_irq(irq_id3,myirq_handle3,IRQF_TRIGGER_FALLING,"key3",(void*)3);
if(ret)
{
printk("注册按键请求中断失败\n");
return ret;
}
printk("注册按键请求中断成功\n");
return 0;
}
static void __exit mycdev_exit(void)
{
//关灯
gpiod_set_value(lednode1,0);
gpiod_set_value(lednode2,0);
gpiod_set_value(lednode3,0);
//清空中断号
free_irq(irq_id1,(void*)1);
free_irq(irq_id2,(void*)2);
free_irq(irq_id3,(void*)3);
//释放设备树节点空间
gpiod_put(lednode1);
gpiod_put(lednode2);
gpiod_put(lednode3);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");串口led点灯实验（驱动+应用层）
驱动代码
#include <linux/init.h>
#include <linux/module.h>
#include<linux/fs.h>
#include<linux/io.h>
#include<linux/device.h>
#include<linux/gpio.h>
#include<linux/of.h>
#include<linux/of_gpio.h>
#include"head.h"
int major;
char kbuf[128]={0};
struct class *cls;
struct device *dev;
struct device_node *dnode;
struct gpio_desc *lednode1;
struct gpio_desc *lednode2;
struct gpio_desc *lednode3;
int mycdev_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t mycdev_read(struct file *file, char *ubuf, size_t size, loff_t *lof)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
unsigned long ret;
//向用户空间读取拷贝
if(size>sizeof(kbuf))//用户空间期待读取的大小内核满足不了，那就给内核支持的最大大小
size=sizeof(kbuf);
ret=copy_to_user(ubuf,kbuf,size);
if(ret)//拷贝失败
{
printk("copy_to_user filed\n");
return ret;
}
return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size, loff_t *lof)
{
unsigned long ret;
//从用户空间读取数据
if(size>sizeof(kbuf))//用户空间期待读取的大小内核满足不了，那就给内核支持的最大大小
size=sizeof(kbuf);
ret=copy_from_user(kbuf,ubuf,size);
if(ret)//拷贝失败
{
printk("copy_to_user filed\n");
return ret;
}
return 0;
}
long mycdev_ioctl (struct file * file, unsigned int cmd, unsigned long arg)
{
switch (cmd)
{
case LED_OFF:
switch (arg)
{
case 1:
gpiod_set_value(lednode1,0);
break;
case 2:
gpiod_set_value(lednode2,0);
break;
case 3:
gpiod_set_value(lednode3,0);
break;
}
break;
case LED_ON:
switch (arg)
{
case 1:
gpiod_set_value(lednode1,1);
break;
case 2:
gpiod_set_value(lednode2,1);
break;
case 3:
gpiod_set_value(lednode3,1);
break;
}
break;
default:
break;
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
//定义操作方法结构体变量并赋值
struct file_operations fops={
.open=mycdev_open,
.read=mycdev_read,
.write=mycdev_write,
.unlocked_ioctl=mycdev_ioctl,
.release=mycdev_close,
};
static int __init mycdev_init(void)
{
//字符设备驱动注册
major=register_chrdev(0,"mychrdev",&fops);
if(major<0)
{
printk("字符设备驱动注册失败\n");
return major;
}
printk("字符设备驱动注册成功:major=%d\n",major);
//向上提交目录
cls=class_create(THIS_MODULE,"mychrdev");
if(IS_ERR(cls))
{
printk("向上提交目录失败\n");
return -PTR_ERR(cls);
}
printk("向上提交目录成功\n");
int i;//向上提交三次设备节点信息
for(i=0;i<3;i++)
{
dev=device_create(cls,NULL,MKDEV(major,i),NULL,"myled%d",i);
if(IS_ERR(dev))
{
printk("向上提交设备节点失败\n");
return -PTR_ERR(dev);
}
}
printk("向上提交设备节点成功\n");
dnode=of_find_compatible_node(NULL,NULL,"hqyj,myirq");
if(NULL==dnode)
{
printk("of_find_compatible_node error\n");
return -ENXIO;
}
printk("解析设备节点成功\n");
//设备树节点解析
lednode1=gpiod_get_from_of_node(dnode,"led1-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode1==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
//设备树节点解析
lednode2=gpiod_get_from_of_node(dnode,"led2-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode2==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
//设备树节点解析
lednode3=gpiod_get_from_of_node(dnode,"led3-gpio",0,GPIOD_OUT_LOW,NULL);
if(lednode3==NULL)
{
printk("设备树节点解析失败\n");
return ENXIO;
}
printk("设备树节点解析成功\n");
return 0;
}
static void __exit mycdev_exit(void)
{
//关灯
gpiod_set_value(lednode1,0);
gpiod_set_value(lednode2,0);
gpiod_set_value(lednode3,0);
//释放设备树节点空间
gpiod_put(lednode1);
gpiod_put(lednode2);
gpiod_put(lednode3);
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
//销毁目录
class_destroy(cls);
//注销字符设备驱动
unregister_chrdev(major,"mychrdev");
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");头文件
#ifndef __HEAD_H__
#define __HEAD_H__
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif应用层
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<fcntl.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<sys/ioctl.h>
#include"head.h"
int main(int argc, char const *argv[])
{
int fd;
fd=open("/dev/myled0",O_RDWR);
if(fd<0)
{
perror("open error:");
return -1;
}
int a;
int b;
while (1)
{
out:
printf("选择要实现的功能\n");
printf("请输入0关灯 1开灯\n");
scanf("%d",&a);
printf("LED 1,LED 2 LED 3");
printf("请输入:");
scanf("%d",&b);
switch (a)
{
case 0:
ioctl(fd,LED_OFF,b);
break;
case 1:
ioctl(fd,LED_ON,b);
break;
default:
printf("输入错误请重新输入\n");
goto out;
break;
}
}
return 0;
}
中断运用驱动控制led实验
串口led点灯实验结果
