#include<linux/init.h>
#include<linux/module.h>
#include<linux/kobject.h>
#include<linux/sysfs.h>
#include<linux/string.h>
extern int scan_type;
static ssize_t scan_type_show(struct kobject *kobj, struct kobj_attribute *attr, //6.具体的读取函数
char *buf)
{
return sprintf(buf, "%d\n", scan_type);
}
/* Sysfs attributes cannot be world-writable. */ //5.属性对应的操作函数,可以向这几个属性节点读取或写入数据
static struct kobj_attribute scantype_attribute =
__ATTR(scanner_type, 0664, scan_type_show, NULL);
static struct attribute *attrs[] = { //4.一组属性
&scantype_attribute.attr,
NULL,
};
static struct attribute_group attr_group = {
.attrs = attrs,
};
static struct kobject *scanner_led_kobj;
static int __init scanner_led_init(void)
{
int retval;
scanner_led_kobj = kobject_create_and_add("kobject_scanner_led", kernel_kobj);//2.在/sys/kernel下建立一个kobject_scanner_led的目录项
if (!scanner_led_kobj)
return -ENOMEM;
retval = sysfs_create_group(scanner_led_kobj, &attr_group);//3.建立一个属性文件函数组
if (retval)
kobject_put(scanner_led_kobj);
return retval;
}
static void __exit scanner_led_exit(void)
{
kobject_put(scanner_led_kobj);
}
module_init(scanner_led_init);//1.程序入口
module_exit(scanner_led_exit);