platform点灯
驱动程序 ：
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define CNAME "irq_led"
int major;
struct class *cls;
struct device *dev;
wait_queue_head_t wq;
unsigned int condition=0;
unsigned int status=0;
struct device_node *node;
struct gpio_desc *desc;
unsigned int irqno;
struct resource *res;
irqreturn_t irq_led_handle(int irq, void *dev)
{
status = gpiod_get_value(desc);
status = !status;
gpiod_set_value(desc,status);
condition=1;
wake_up_interruptible(&wq);
return IRQ_HANDLED;
}
int irq_led_open(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
}
ssize_t irq_led_read(struct file *file,
char __user *ubuf, size_t size, loff_t *offs)
{
int ret;
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
if(file->f_flags & O_NONBLOCK){
//非阻塞
return 1H-EINVAL;
}else{
//阻塞
ret = wait_event_interruptible(wq,condition);
if(ret < 0){
printk("receive signal....\n");
return ret;
}
}
//将数据拷贝到用户空间
if(size > sizeof(status)) size = sizeof(status);
ret = copy_to_user(ubuf,(void *)&status,size);
if(ret){
printk("copy data to user error\n");
return -EIO;
}
//4.将条件清零
condition = 0;
return size;
}
int irq_led_close(struct inode *inode, struct file *file)
{
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
} cvgtr54hg
bv xrywe0-t6struct file_operations fops = {
.open = irq_led_open,
.read = irq_led_read,
.release = irq_led_close,
};
//封装probe函数和remove函数
int pdrv_probe(struct platform_device *pdev)
{
int ret;
//1.注册字符设备驱动
major = register_chrdev(0,CNAME,&fops);
if(major < 0){
printk("register char device driver error\n");
ret = major;
goto ERR1;
}
//2.创建设备节点
cls = class_create(THIS_MODULE,CNAME);
if(IS_ERR(cls)){
printk("class create error\n");
ret = PTR_ERR(cls);
goto ERR2;
}
dev = device_create(cls,NULL,MKDEV(major,0),NULL,CNAME);
if(IS_ERR(dev)){
printk("device create error\n");
ret = PTR_ERR(dev);
goto ERR3;
}
//3.初始化等待队列头
init_waitqueue_head(&wq);
//4.解析设备树节点，申请使用的中断和led
node = of_find_node_by_path("/irq_led");
if(node == NULL){
printk("get node error");
ret = -EAGAIN;
goto ERR4;
}
//获取gpio结构体信息
desc = gpiod_get_from_of_node(node,"led1",0,GPIOD_OUT_LOW,NULL);
if(IS_ERR(desc)){
printk("get gpiod error\n");
ret = PTR_ERR(desc);
goto ERR4;
}
//获取软中断号
irqno = irq_of_parse_and_map(node,0);
if(irqno == 0){
printk("irq get number error\n");
ret = -EAGAIN;
goto ERR5;
}
//注册中断
ret = request_irq(irqno,irq_led_handle,IRQF_TRIGGER_FALLING,CNAME,NULL);
if(ret){
printk("request irq error\n");
goto ERR5;
}
return 0;
ERR5:
gpiod_put(desc);
ERR4:
device_destroy(cls,MKDEV(major,0));
ERR3:
class_destroy(cls);
ERR2:
register_chrdev(major,CNAME);
ERR1:
return ret;
};
int pdr_remove(struct platform_device *pdev)
{
gpiod_set_value(desc,0);
free_irq(irqno,NULL);
gpiod_put(desc);
device_destroy(cls,MKDEV(major,0));
class_destroy(cls);
unregister_chrdev(major,CNAME);
printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
return 0;
};
struct of_device_id oftable[]=
{
{.compatible="hqyj,irq_led",},
{.compatible="hqyj,irq_led1",},
{.compatible="hqyj,irq_led2",},
{},
};
struct platform_driver pdrv=
{
.probe=pdrv_probe,
.remove=pdrv_remove,
.driver={
.name="aaaa",
.of_match_table=oftable,
},
};
//一键注册宏
module_platform_driver(pdrv);
MODULE_LICENSE("GPL"); class_destroy(cls);
设备树添加：
irq_led{
compatible = "hqyj,irq_led"; //用于获取节点
interrupt-parent = <&gpiof>; //引用父节点
interrupts = <9 0>; //这个节点引入的中断管脚
led1=<&gpioe 10 0>;
}；