any history to class.txt's "devclass_attribute"?

[Robert P. J. Day]

  currently writing an extensive tutorial for all of kobjects and
ktypes and sysfs and attributes and so on, so i'm perusing the stuff
under Documentation/driver-model, and i read this in "class.txt":

... snip ...
Exporting Attributes
~~~~~~~~~~~~~~~~~~~~
struct devclass_attribute {
        struct attribute        attr;
        ssize_t (*show)(struct device_class *, char * buf, size_t count, loff_t off);
        ssize_t (*store)(struct device_class *, const char * buf, size_t count, loff_t off);
};

Class drivers can export attributes using the DEVCLASS_ATTR macro that works
similarly to the DEVICE_ATTR macro for devices. For example, a definition
like this:

static DEVCLASS_ATTR(debug,0644,show_debug,store_debug);

is equivalent to declaring:

static devclass_attribute devclass_attr_debug;
... etc etc ...

  until now, i'd never heard of a "devclass_attribute", and "git log"
certainly doesn't appear to explain how it came to be.  anyone know
what the story is behind "devclass_attribute"?  methinks it can be
tossed from the current Documentation.  thoughts?

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
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