Linux Device Drivers Development

Class attributes

The struct class_attribute is the base structure here:

struct class_attribute { 
        struct attribute        attr; 
        ssize_t (*show)(struct device_driver *, char * buf); 
        ssize_t (*store)(struct device_driver *, const char * buf, 
                         size_t count); 
}; 

The declaration of a class attribute relies on CLASS_ATTR:

CLASS_ATTR(_name, _mode, _show, _store) 

As the macro's definition shows, any class attribute declared with CLASS_ATTR will have the prefix class_attr_ added to the attribute variable name:

#define CLASS_ATTR(_name, _mode, _show, _store) \ 
struct class_attribute class_attr_##_name = __ATTR(_name, _mode, _show, _store) 

Finally, file creation and removal are done with the class_{create|remove}_file functions:

int class_create_file(struct ...