開發板：龍芯1B

PC：ubuntu13.10

本程式為字元裝置驅動，提供控制led燈功能，如要實現控制需要自己寫應用程式，開啟驅動檔案就可控制led燈，led燈通過gpio控制

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/fcntl.h>
#include <linux/cdev.h>

#define LED_MAJOR 100
#define LED_MINOR 0
#define SET_GPIO (*(volatile unsigned *)0xbfd010C4)
#define SET_OUT (*(volatile unsigned *)0xbfd010D4)
#define SET_LED (*(volatile unsigned *)0xbfd010F4)

struct led_dev
{
	struct cdev cdev;
};

static int my_start (struct inode *, struct file *);
//static ssize_t left (struct file *, char __user *, size_t, loff_t *);

struct class *led_class;
struct led_dev *led_devices;

static struct file_operations led_fops =
{
	.owner = THIS_MODULE,
	.open = my_start,
//	.read = left,
};

static int my_start(struct inode * node, struct file * fil)
{
	SET_GPIO = (SET_GPIO | 0x000000C0);
	SET_OUT = (SET_OUT & ~(0x000000C0));
	SET_LED = (SET_LED & ~(0x000000c0));
	printk("Here is open\n");
	return 0;
}

static int __init led_init(void)
{
	int ret;
	dev_t dev = 0;
	dev = MKDEV(LED_MAJOR, LED_MINOR);
	ret = register_chrdev_region(dev, 1, "led");
	if(ret)
	{
		printk("register_fail\n");
	}else{
		printk("register_succeed\n");
	}
	led_devices = kmalloc(sizeof(struct led_dev), GFP_KERNEL);
	if(led_devices == NULL)
	{
		printk("malloc_fail\n");
	}else{
		printk("malloc_succeed\n");
	}
	memset(led_devices, 0, sizeof(struct led_dev));
	cdev_init(&led_devices->cdev, &led_fops);
	led_devices->cdev.owner = THIS_MODULE;
	led_devices->cdev.ops = &led_fops;
	ret = cdev_add(&led_devices->cdev, dev, 1);

	if(ret)
	{
		printk("add_fail\n");
	}else{
		printk("add_succeed\n");
	}
	led_class = class_create(THIS_MODULE, "led_class");
	device_create(led_class, NULL, dev, NULL, "led");
	return ret;
}

static void __exit led_exit(void)
{
	dev_t devno = MKDEV(LED_MAJOR, LED_MINOR);
	unregister_chrdev_region(devno,1);
	device_destroy(led_class, devno);
	printk("exit_succeed\n");
	class_destroy(led_class);
}

module_init(led_init);
module_exit(led_exit);
MODULE_LICENSE("GPL");