点灯liunx驱动代码
时间: 2023-10-07 22:10:25 浏览: 38
下面是一个简单的Linux点灯驱动代码示例,使用GPIO接口控制点灯的开关状态:
```c
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/gpio.h>
#include <linux/uaccess.h>
#define LED_PIN 17 // GPIO17
static int led_open(struct inode *inode, struct file *file) {
printk(KERN_INFO "LED driver opened.\n");
return 0;
}
static int led_release(struct inode *inode, struct file *file) {
printk(KERN_INFO "LED driver closed.\n");
return 0;
}
static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) {
char value;
gpio_direction_output(LED_PIN, 0);
if (copy_from_user(&value, buf, sizeof(char))) {
printk(KERN_ALERT "Failed to write LED driver.\n");
return -EFAULT;
}
if (value == '1') {
gpio_set_value(LED_PIN, 1);
} else {
gpio_set_value(LED_PIN, 0);
}
return sizeof(char);
}
static struct file_operations led_fops = {
.owner = THIS_MODULE,
.open = led_open,
.release = led_release,
.write = led_write,
};
static int __init led_init(void) {
int ret;
printk(KERN_INFO "LED driver initialized.\n");
ret = gpio_request(LED_PIN, "LED");
if (ret < 0) {
printk(KERN_ALERT "Failed to request GPIO pin.\n");
return ret;
}
gpio_direction_output(LED_PIN, 0);
register_chrdev(0, "led", &led_fops);
return 0;
}
static void __exit led_exit(void) {
printk(KERN_INFO "LED driver exited.\n");
gpio_free(LED_PIN);
unregister_chrdev(0, "led");
}
module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("Linux LED Driver");
```
这个示例代码使用GPIO17作为控制点灯的引脚,提供了文件操作函数`open`、`release`和`write`,分别用于打开、关闭和写入点灯状态。在驱动的初始化函数中,使用`gpio_request`函数请求GPIO引脚,使用`gpio_direction_output`函数将引脚设置为输出模式,并且使用`register_chrdev`函数注册设备驱动程序。在驱动的退出函数中,则使用`gpio_free`函数释放GPIO引脚,并且使用`unregister_chrdev`函数注销设备驱动程序。