From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 1/4] documentation: add palmas dts definition Date: Thu, 28 Feb 2013 12:01:53 -0700 Message-ID: <512FA9A1.7070701@wwwdotorg.org> References: <1361164283-3133-1-git-send-email-j-keerthy@ti.com> <512E5144.9020105@wwwdotorg.org> <512F1ADF.90906@nvidia.com> <512F2A29.8080708@slimlogic.co.uk> <512F3118.6030806@nvidia.com> <512F3810.30109@slimlogic.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <512F3810.30109@slimlogic.co.uk> Sender: linux-doc-owner@vger.kernel.org To: Graeme Gregory Cc: Laxman Dewangan , J Keerthy , "grant.likely@secretlab.ca" , "rob.herring@calxeda.com" , "rob@landley.net" , "devicetree-discuss@lists.ozlabs.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "b-cousson@ti.com" List-Id: devicetree@vger.kernel.org On 02/28/2013 03:57 AM, Graeme Gregory wrote: ... > The final but of information that would be needed is some method to pass > down product_id/design_rev and for a lot of the IP blocks they could be > made independent of the actual parent. That should probably be represented in DT itself as differing compatible values. I could see the argument that this is SW-probe-able since there's a register that defines the value. However, any global ID register would apply to the top-level device, and not the version of any child IP blocks if there's the possibility of mixing/matching IP blocks. If there's a dedicated version register for a child IP block, then presumably it's already part of the child IP block's register space, and so the driver can read it, and then there perhaps wouldn't be a need to represent this using different compatible values.