On Tue, Feb 19, 2013 at 03:28:17PM +0000, Arnd Bergmann wrote:
> On Tuesday 19 February 2013, Felipe Balbi wrote:
> > On Tue, Feb 19, 2013 at 02:34:40PM +0000, Arnd Bergmann wrote:
> > > On Tuesday 19 February 2013, Felipe Balbi wrote:
> > > > On Tue, Feb 19, 2013 at 12:33:54PM +0000, Arnd Bergmann wrote:
> > > It's a fine line, but I think a phy is something that resembles a device
> > > more than an LED does. When I read patch 1, I also noticed and commented
> > > on the fact that it does use a 'class'. Now, according to Greg, we should
> > > use 'bus_type' instead of 'class' in new code. I originally disagreed with
> > > that concept, but he's the boss here and it's good if he has a vision
> > > how things should be lined out.
> > >
> > > In practice, there is little difference between a 'bus_type' and a 'class',
> > > so just replace any instance of the former with the latter in your head
> > > when reading the code ;-)
> >
> > it's not so simple :-) if we must use bus_type we need to introduce all
> > the device/driver matching mechanism which isn't necessary with a class.
>
> I think the idea is to use a bus_type that has devices but no drivers
> associated with it, but I might be misremembering things.
but then drivers wouldn't probe ever, although devices would get
created, so maybe it'll work...
> > Greg, can you pitch your suggestion here ? It would be great to hear
> > your rationale behind dropping class infrastructure, couldn't find
> > anything through Google and since feature-removal-schedule.txt has been
> > removed (without adding it to feature-removal-schedule.txt, I must add
> > :-) I don't know what's the idea behind removing classes.
>
> I believe for now, the idea is to not add any new classes, but keep
> the existing ones for compatibility. 'struct class_device' however
> was already removed and got turned into 'struct device'.
was there ever a "struct class_device".
What about struct class ?
<linux/device.h> ::
334 struct class {
335 const char *name;
336 struct module *owner;
337
338 struct class_attribute *class_attrs;
339 struct device_attribute *dev_attrs;
340 struct bin_attribute *dev_bin_attrs;
341 struct kobject *dev_kobj;
342
343 int (*dev_uevent)(struct device *dev, struct kobj_uevent_env *env);
344 char *(*devnode)(struct device *dev, umode_t *mode);
345
346 void (*class_release)(struct class *class);
347 void (*dev_release)(struct device *dev);
348
349 int (*suspend)(struct device *dev, pm_message_t state);
350 int (*resume)(struct device *dev);
351
352 const struct kobj_ns_type_operations *ns_type;
353 const void *(*namespace)(struct device *dev);
354
355 const struct dev_pm_ops *pm;
356
357 struct subsys_private *p;
358 };
--
balbi
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