From mboxrd@z Thu Jan  1 00:00:00 1970
From: segher@kernel.crashing.org (Segher Boessenkool)
Date: Sat, 21 May 2011 06:00:05 +0200
Subject: [PATCH 2/2] drivers/amba: probe via device tree
In-Reply-To: <4DD68614.6090209@gmail.com>
References: <1305829704-11774-1-git-send-email-robherring2@gmail.com>
	<20110519233958.GB18181@ponder.secretlab.ca>
	<4DD66B8A.5040404@gmail.com> <201105201621.03801.arnd@arndb.de>
	<4DD68614.6090209@gmail.com>
Message-ID: <80f20ac921a33e9f0bf3e249f539a8ef@kernel.crashing.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

> The ARM definition of AMBA encompasses a lot of things. It is the 
> definition of the AXI, AHB and APB buses.

So the device tree, which describes the hardware, should call the buses
axi, ahb or apb as appropriate, and describe the actual physical 
connections.
The Linux kernel is free to ignore that if it so wishes.

>  It also has the definition of the peripheral ID register definitions 
> which primarily only ARM Ltd peripherals implement. You can have those 
> bus types yet not have any peripherals with the ID registers.

The devices are identified in the device tree, you do not need to read
the ID registers to find them.  You should have some way of figuring out
which devices have the AMBA ID block; maybe add something to the 
"compatible"
property and have all devices that use this have this register block as 
the
first entry in the "reg" property?


Segher