Makefile 模板
ifneq ($(KERNELRELEASE),)
obj-m := xxx.o
else
PWD := $(shell pwd)
KVER := $(shell uname -r)
KDIR := /lib/modules/$(KVER)/build
all:
$(MAKE) -C $(KDIR) M=$(PWD) modules
clean:
rm -fr .*.cmd *.o *.mod.c *.ko .tmp_versions modules.* Module.*
endif
注意事項
- xxx.o 處是你需要編譯的驅動文件名
- $(MAKE) -C $(KDIR) M = $(PWD) modules與rm -fr .* .cmd * .o * .mod.c * .ko .tmp_versions modules.* Module. *這兩行應該按一次tab鍵進行縮進，而不是使用空格
字符驅動程序模板
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <asm/irq.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/gpio.h>
#include <linux/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>
#include <linux/device.h>
//文件名
#define DEVICE_NAME "devicename"
//預定義的主設備號,預設是0的話就會動態創建設備號
static int xxx_major = 0;
//字符設備結構體
//這一段和static struct cdev cdev;表達了一種意思
struct xxx_dev_t
{
struct cdev cdev;
}xxx_dev;
//在驅動初始化的代碼裏調用class_create爲該設備創建一個class，再爲每個設備調用device_create創建對應的設備
static struct class *xxx_class;
//文件節點，僅有一個；file結構體，追蹤文件運行時的狀態信息，可爲NULL
static int xxx_open(struct inode *inode, struct file *filp)
{
}
//清理未結束的輸入輸出操作，釋放資源，可爲null
static int xxx_realease(struct inode *inode, struct file *filp)
{
}
//目標文件結構體指針；對應放置信息的緩衝區（用戶空間）；要讀取的信息長度；讀的位置相對於文件開頭的偏移
static ssize_t xxx_read(struct file *filp, char __user *buf, size_t len, loff_t *offset)
{
}
//目標文件結構體指針；要寫入放置信息的緩衝區；要寫入的信息長度；寫的位置相對於文件開頭的偏移
static ssize_t xxx_write(struct file *filp, const char __user *buf, size_t len, loff_t *offset)
{
}
//文件操作結構體
static struct file_operations xxx_fops=
{
.owner = THIS_MODULE,
.read = xxx_read,
.write = xxx_writ,
.open = xxx_open,
.release = xxx_release,
.ioctl = xxx_ioctl,
};
//設備驅動模塊加載函數
static int __init xxx_init(void)
{
int result;
int ret;
dev_t xxx_dev_no = MKDEV(xxx_major,0); //由預定義的主設備號生成dev_t設備號
if(xxx_major)
{
result = register_chrdev_region(xxx_dev_no,1,DEVICE_NAME); //靜態申請設備號
}
else
{
result = alloc_chrdev_region(&xxx_dev_no,0,1,DEVICE_NAME); //動態分配設備號
xxx_major = MAJOR(xxx_dev_no);
}
if(result<0)
return result;
cdev_init(&xxx_dev.dev,&xxx_fops); //初始化cdev結構
xxx_dev.cdev.owner = THIS_MODULE;
ret = cdev_add(&xxx_dev.cdev,MKDEV(xxx_major,0),1); //註冊字符設備
if (ret)
{
printk("cdev add failed\n");
goto fail1;
}
xxx_class = class_create(THIS_MODULE,"xxx_class");
if(IS_ERR(xxx_class))
{
printk("Err: failed in creating class./n");
goto fail2;
}
device_create(xxx_class, NULL, MKDEV(xxx_major,0), NULL, DEVICE_NAME);
return 0;
fail2:
cdev_del(&xxx_dev.cdev);
fail1:
unregister_chrdev_region(xxx_dev_no, 1);
return result;
}
//設備驅動模塊卸載函數
static void __exit xxx_exit(void)
{
device_destory(xxx_class,MKDEV(xxx_major,0));
class_destroy(xxx_class);
cdev_del(&xxx_dev.cdev);
unregister_chrdev_region(MKDEV(xxx_major,0), 1);
}
module_init(xxx_init);
module_exit(xxx_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("your_name"); //標明作者信息