Subject: [RFC PATCH] CLK: Allow parent clock and rate to be configured in DT.

From: [email-masked] (Martin Fuzzey)
Date: Mon, 08 Apr 2013 11:35:29 +0200

On 07/04/13 15:26, Sascha Hauer wrote:
>
> Honestly I'm annoyed by this aswell. The devicetree contains a nice and
> complete hardware description and it seems convenient to put hardware
> related configuration data there aswell.
Yes
> The problem is that hardware description and configuration data are two
> completely different sets of data. The hardware description is static
> for a given board and should (ideally) never change. The configuration
> data instead is often usecase specific and changes over the lifetime of
> a board. The configuration data can only handle a single (or maybe a
> table of) static setup(s). It's a good way to specify a sane default or
> a very special setup, but doesn't handle the case when some OS (or
> version thereof) wants to have a static setup and another wants to
> figure out the same data dynamically.
Agreed
> For these reasons I am against throwing the two data sets into a single
> pot. Still I also want to have the devicetree way to configure some
> static setup items.
Sure but why does using the DT for both mean "throwing them into a 
single pot?"

I think we need to seperate the ideas of "DT as a container format" and 
"semantics of DT nodes".

The format is the same everywhere but the semantics could change in 
different parts of the tree.

Since the DT is a tree structure surely all we need to do is agree on a 
designated configuration root node
"linux-config" for example under which we put all configuration related 
stuff specific to linux whilst
retaining the "hardware description only" rule for the rest of the DT.

Martin