Subject: Re: RFC: new device types in the device tree (RE: [PATCH] powerpc: Add EDAC platform devices for 85xx)

From: Segher Boessenkool <[email-masked]>
Date: Thu, 3 May 2007 02:54:11 +0200

> But, don't we want to keep standardized sets of properties for
> certain classes/types of devices?

Sure.

> Defining a standardized,
> required set of properties for a "network", "rom", or "i2c"
> class of device is helpful.

Only if such a device binding is generic enough to actually
handle all such devices.  Sure a specific device may have
some extra properties, but all the basic stuff should be
in standard properties.

> Without a standardized 'template'
> of properties, developers may make up whatever properties they
> want and things will work fine as long as the device tree and
> driver are in sync.  It works, but you wind up with a plethora
> of properties each describing the same thing.

You might think this is bad, but IMO it is better to
have several drivers doing similar things in different
ways, than to force all drivers to use a binding that
doesn't fit them well.

> If we do away with device_type,
> what is it that defines a particular node to be a certain class
> of device.

The matching device driver knows (and it knows a great
deal more about the device, hopefully ;-) )

Segher