pdrv.c
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "head.h"
struct resource *res;
unsigned int irqno;
struct gpio_desc* gpiono1;
struct gpio_desc* gpiono2;
struct gpio_desc* gpiono3;
struct device *dev;
int major;
struct class *cls;
char kbuf[128] = {};
//定义设备树匹配的表
struct of_device_id oftable[]={
{.compatible="hqyj,myplatform",},
{.compatible="hqyj,myplatform1",},
{},//防止数组越界
};
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__);
int ret = copy_to_user(ubuf,kbuf,size);
if (ret)
{
printk("copy_to_user filed\n");
return -EIO;
}
return 0;
}
ssize_t mycdev_write(struct file *file, const char *ubuf, size_t size,loff_t *lof)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
long mycdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int which;
int ret = copy_from_user(&which,(void *)arg,4);
if(ret)
{
printk("copy_form_user success : [%d]\n",which);
}
switch(cmd)
{
case LED_ON://开灯
switch(which)
{
case 1:
gpiod_set_value(gpiono1,1);
break;
case 2:
gpiod_set_value(gpiono2,1);
break;
case 3:
gpiod_set_value(gpiono3,1);
break;
}
break;
case LED_OFF://关灯
switch(which)
{
case 1:
gpiod_set_value(gpiono1,0);
break;
case 2:
gpiod_set_value(gpiono2,0);
break;
case 3:
gpiod_set_value(gpiono3,0);
break;
}
break;
}
return 0;
}
int mycdev_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
int i;
for(i=0;i<3;i++)
{
device_destroy(cls,MKDEV(major,i));
}
//销毁目录
class_destroy(cls);
//注销驱动
unregister_chrdev(major,"mychrdev");
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,
};
//给对象分配空间并且初始化
int pdrv_probe(struct platform_device *pdev)
{
//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");
//向上提交设备节点信息
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");
//获取MEM类型的资源
res = platform_get_resource(pdev,IORESOURCE_MEM,0);
if(res == NULL)
{
printk("获取MEM类型的资源失败\n");
return -ENXIO;
}
//获取中断类型资源
irqno = platform_get_irq(pdev,0);
if(irqno < 0)
{
printk("获取中断类型资源失败\n");
return -ENXIO;
}
printk("MEM类型资源位%x\n",res->start);
printk("中断类型资源为%d\n",irqno);
//4.解析LED设备树节点获取三个关键的GPIO信息
//获取LED1的gpio信息
gpiono1 = gpiod_get_from_of_node(pdev->dev.of_node,"led1-gpio",0,GPIOD_OUT_LOW,NULL);
if(IS_ERR(gpiono1))
{
printk("LED1解析GPIO信息失败\n");
return PTR_ERR(gpiono1);
}
//获取LED2的gpio信息
gpiono2 = gpiod_get_from_of_node(pdev->dev.of_node,"led2-gpio",0,GPIOD_OUT_LOW,NULL);
if(IS_ERR(gpiono2))
{
printk("LED2解析GPIO信息失败\n");
return PTR_ERR(gpiono2);
}
//获取LED3的gpio信息
gpiono3 = gpiod_get_from_of_node(pdev->dev.of_node,"led3-gpio",0,GPIOD_OUT_LOW,NULL);
if(IS_ERR(gpiono3))
{
printk("LED3解析GPIO信息失败\n");
return PTR_ERR(gpiono3);
}
return 0;
}
int pdrv_remove(struct platform_device *pdev)
{
//释放GPIO信息
gpiod_set_value(gpiono1,0);
gpiod_set_value(gpiono2,0);
gpiod_set_value(gpiono3,0);
gpiod_put(gpiono1);
gpiod_put(gpiono2);
gpiod_put(gpiono3);
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
//分配驱动信息对象
struct platform_driver pdrv={
.probe = pdrv_probe,
.remove = pdrv_remove,
.driver={
.name="bbbbb",
.of_match_table=oftable,
},
};
//一键注册宏
module_platform_driver(pdrv);
MODULE_LICENSE("GPL");
test.c
#include
#include
#include
#include
#include
#include
#include "head.h"
int main(int argc, char const *argv[])
{
char buf[128]={0};
int fd1 = open("/dev/myled0",O_RDWR);
if(fd1 < 0)
{
printf("打开设备文件1失败\n");
return -1;
}
printf("打开设备文件1成功\n");
int fd2 = open("/dev/myled1",O_RDWR);
if(fd2 < 0)
{
printf("打开设备文件2失败\n");
return -1;
}
printf("打开设备文件2成功\n");
int fd3 = open("/dev/myled3",O_RDWR);
if(fd3 < 0)
{
printf("打开设备文件3失败\n");
return -1;
}
printf("打开设备文件3成功\n");
while(1)
{
int a,b;
printf("请输入要进行的操作的灯:1（LED1）2（LED2）3（LED3） >>> ");
scanf("%d",&a);
printf("请输入要进行的操作:0(关灯) 1(开灯) >>> ");
scanf("%d", &b);
// 向设备文件中写
switch (b)
{
case 1:
switch (a)
{
case 1: // LED1
printf("LED1_ON\n");
ioctl(fd1, LED_ON,&a);
break;
case 2: // LED2
printf("LED2_ON\n");
ioctl(fd2, LED_ON,&a);
break;
case 3: // LED3
printf("LED3_ON\n");
ioctl(fd3, LED_ON,&a);
break;
}
break;
case 0:
switch (a)
{
case 1: // LED1
printf("LED1_OFF\n");
ioctl(fd1, LED_OFF,&a);
break;
case 2: // LED2
printf("LED2_OFF\n");
ioctl(fd2, LED_OFF,&a);
break;
case 3: // LED3
printf("LED3_OFF\n");
ioctl(fd3, LED_OFF,&a);
break;
}
break;
}
}
close(fd1);
close(fd2);
close(fd3);
return 0;
}
head.h
#ifndef __HEAD_H__
#define __HEAD_H__
// 构建开灯关灯的功能码
#define LED_ON _IO('l', 1)
#define LED_OFF _IO('l', 0)
#endif
效果
