驱动开发day8

O WL2023-10-28 8:21

任务 : 基于GPIO子系统编写LED驱动，编写应用程序进行测试设置定时器，LED每秒翻转引脚状态，并且每五秒打印一次hello world

驱动代码

cs 复制代码

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>

struct device_node *dnode;
struct gpio_desc *ionum;

struct timer_list mtimer;
struct timer_list timer_5;

void my_timer_fun(struct timer_list *timer)
{
    gpiod_set_value(ionum,!gpiod_get_value(ionum));
	printk("__led_timer__\n");
    mod_timer(timer,jiffies + HZ);
}

void timer_5_fun(struct timer_list *timer)
{
	printk("hello world\n");
	mod_timer(timer,jiffies + 5 * HZ);
}


static int __init my_init(void)
{
    dnode = of_find_node_by_path("/myled");
    if(dnode == NULL)
    {
        printk("of_find_node_by_path failed\n");
        return -1;
    }
    printk("of_find_node_by_path success\n");

	ionum = gpiod_get_from_of_node(dnode,"led1-gpioe",0,GPIOD_OUT_LOW,NULL);
	if(IS_ERR(ionum))
	{
		printk("gpiod_get_from_of_node failed\n");
		return -PTR_ERR(ionum);
	}
	printk("gpiod_get_from_of_node success\n");

    timer_setup(&mtimer,my_timer_fun,0);
	timer_setup(&timer_5,timer_5_fun,0);

    mtimer.expires = jiffies + HZ;
	timer_5.expires = jiffies + 5 * HZ;

    add_timer(&mtimer);
	add_timer(&timer_5);

    

	//gpiod_set_value(ionum,1);

    return 0;
}

static void __exit my_exit(void)
{
    gpiod_set_value(ionum,0);
    gpiod_put(ionum);
    del_timer(&mtimer);
	del_timer(&timer_5);
}

module_init(my_init);
module_exit(my_exit);
MODULE_LICENSE("GPL");

现象 :

本文是转载文章，点击查看原文

如有侵权，请联系 xyy@jishuzhan.net 删除