LINUX学习笔记（设备模型）

linux/include/linux/kobject.h

<kobject>

59 struct kobject { 60 const char *name; 61 struct list_head entry; 62 struct kobject *parent; 63 struct kset *kset; 64 struct kobj_type *ktype; 65 struct sysfs_dirent *sd; 66 struct kref kref; 67 unsigned int state_initialized:1; 68 unsigned int state_in_sysfs:1; 69 unsigned int state_add_uevent_sent:1; 70 unsigned int state_remove_uevent_sent:1; 71 unsigned int uevent_suppress:1; 72 }; 73  

name 存放kobject的名称；

parent 指向kobject的父对象；

ktype 描述一族kobject所具有的普遍特性，在ktype结构中一次定义，然后所有“同类”的kobject都能共享一样的特性

<kobj_type>

106 107 struct kobj_type {108 void (*release)(struct kobject *kobj);109 const struct sysfs_ops *sysfs_ops;110 struct attribute **default_attrs;111 const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);112 const void *(*namespace)(struct kobject *kobj);113 };114

release指针指向在kobject应用计数减至零时需要被调用的析构函数。该函数负责释放所有kobject使用的内存和其他相关清理工作

sysfs_ops指向<sysfs_ops>结构体，该结构体描述了sysfs文件读写时的特性。

default_attrs指向一个<attribute>结构体数组。这些结构体定义了该kobject相关的默认属性。属性描述了给定对象的特征，如果该kobject被导出到sysfs中，那么这些属性都将相应地作为文件而导出，数组的最后一项必须未NULL。

 

kset是kobject对象的集合体

175 /**176 * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.177 *178 * A kset defines a group of kobjects. They can be individually179 * different "types" but overall these kobjects all want to be grouped180 * together and operated on in the same manner. ksets are used to181 * define the attribute callbacks and other common events that happen to182 * a kobject.183 *184 * @list: the list of all kobjects for this kset185 * @list_lock: a lock for iterating over the kobjects186 * @kobj: the embedded kobject for this kset (recursion, isn't it fun...)187 * @uevent_ops: the set of uevent operations for this kset. These are188 * called whenever a kobject has something happen to it so that the kset189 * can add new environment variables, or filter out the uevents if so190 * desired.191 */ 192 struct kset {193 struct list_head list;194 spinlock_t list_lock;195 struct kobject kobj;196 const struct kset_uevent_ops *uevent_ops;197 };

 

 

 

kobject通常是嵌入到其他结构中的，如字符设备结构

linux/include/linux/cdev.h

<cdev>

11 12 struct cdev { 13 struct kobject kobj; 14 struct module *owner; 15 const struct file_operations *ops; 16 struct list_head list; 17 dev_t dev; 18 unsigned int count; 19 }; 20