platform device as parent of a miscdevice

[Greg KH]

On Tue, Mar 30, 2021 at 09:27:17PM +0200, Martin Kaiser wrote:
> > What in-kernel misc drivers do not do that that you feel should?
> 
> My misunderstanding was that quite a few drivers set the parent pointer
> but hardly anyone uses the parent pointer in the file_operations.

What parent pointer in struct file_operations?  I don't see one...

> It seems that most drivers have their miscdevice as part of their global
> structure and use container_of in the file_operations, e.g. ipmb_read in
> drivers/char/ipmi/ipmb_dev_int.c.

That's one way to use it, there are I think at least 3 ways to use it,
maybe more...

Don't confuse the struct device parent pointer with the private pointer
to get back to your local device-specific data.  They are different
things.

thanks,

greg k-h