嵌入式学习——硬件（Linux内核驱动编程LED、蜂鸣器、按键）——day59

最新推荐文章于 2025-03-21 08:37:14 发布

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最新推荐文章于 2025-03-21 08:37:14 发布

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文章标签：学习 linux 驱动开发

本文链接：https://blog.youkuaiyun.com/qq_47798402/article/details/140217629

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1. 编写LED驱动（初始化所有子设备号）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON  (0x56000010)
#define GPBDAT  (0x56000014)
static unsigned int *regGPBCON;
static unsigned int *regGPBDAT;

int led_driver_open(struct inode *p_node, struct file *fp)
{
	printk("open\n");
	return 0;
}

ssize_t led_driver_read(struct file *fp, char __user *user_buffer, size_t n, loff_t * offset)
{
	printk("read\n");
	return 0;
}

void ledOn(unsigned int n)
{
	*regGPBDAT |= (0x0F << 5);
	if(n < 1 || n > 4)
	{
		return;
	}
	*regGPBDAT &= ~(1 << (n + 4));
}

ssize_t led_driver_write(struct file *fp, const char __user *user_buffer, size_t n, loff_t *offset)
{
	char s[10];
	
	copy_from_user(s, user_buffer, n);
	ledOn(s[0]);

	printk("write\n");
	return n;
}

int led_driver_close(struct inode *p_node, struct file *fp)
{
	printk("close\n");
	return 0;
}

struct file_operations fops =
{	
	.owner = THIS_MODULE,
	.release = led_driver_close,
	.open = led_driver_open,
	.read = led_driver_read,
	.write = led_driver_write,
};

static int __init led_driver_init(void)
{	
	int ret;
	printk("init\n");
	ret = register_chrdev(200, "first driver", &fops);
	if(ret != 0)
	{
		return ret;
	}

	regGPBCON = ioremap(GPBCON, 4);
	regGPBDAT = ioremap(GPBDAT, 4);

	*regGPBCON &= ~((3 << 10) | (3 << 12) | (3 << 14) | (3 << 16));
	*regGPBCON |= (1 << 10) | (1 << 12) | (1 << 14) | (1 << 16);

	*regGPBDAT |= (0x0F << 5);
	return 0;
}

static void __exit led_driver_exit(void)
{
	iounmap(regGPBDAT);
	iounmap(regGPBCON);

	unregister_chrdev(200, "first driver");
	printk("exit\n");
}

module_init(led_driver_init);
module_exit(led_driver_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("PuTe");

2. 编写LED驱动（初始化一个子设备号）

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#define GPBCON  (0x