Re: [RFC] [PATCH] Device Tree on ARM platform

David Miller
2009-05-28T00:00:31Z

From: Robert Schwebel <r.schwebel@pengutronix.de>
Date: Thu, 28 May 2009 01:57:05 +0200

> On Wed, May 27, 2009 at 02:22:50PM -0600, Grant Likely wrote:
>> 2) Driver binding mechanism: device tree nodes usually have a
>> "compatible" property which is a list of strings. The first string
>> describes exactly what the device is (ie. "atmel,24c08") and an
>> optional list of other devices which it is register interface
>> backwards compatible with.
>
> This is a good example. The "exact" description above doesn't say
> anything about some of the details the driver needs to know. Here is the
> at24 driver:
>
> http://lxr.linux.no/linux+v2.6.29/include/linux/i2c/at24.h#L18
>
> Where do we get the page size & flags from?

You can use device node properties.

Every device node has mode than just a "name" and "compatible"
property. You can add arbitrary properties, which are simply name -->
value pairs. The type of the value is opaque, it can be any arbitrary
binary data, a string, a 32-bit integer, a MAC address, etc.