From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753493Ab3ISMBH (ORCPT ); Thu, 19 Sep 2013 08:01:07 -0400 Received: from mail-ea0-f176.google.com ([209.85.215.176]:45775 "EHLO mail-ea0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752720Ab3ISMBE (ORCPT ); Thu, 19 Sep 2013 08:01:04 -0400 Date: Thu, 19 Sep 2013 13:00:51 +0100 From: Lee Jones To: Mark Brown Cc: Laxman Dewangan , sameo@linux.intel.com, rob.herring@calxeda.com, pawel.moll@arm.com, mark.rutland@arm.com, swarren@wwwdotorg.org, ijc+devicetree@hellion.org.uk, rob@landley.net, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mfd: core: introduce of_node_name for mfd sub devices Message-ID: <20130919120051.GG22389@lee--X1> References: <1379579392-1794-1-git-send-email-ldewangan@nvidia.com> <20130919083050.GH16984@lee--X1> <20130919115501.GM21013@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20130919115501.GM21013@sirena.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Sep 2013, Mark Brown wrote: > On Thu, Sep 19, 2013 at 09:30:50AM +0100, Lee Jones wrote: > > > I'm not entirely sure this is what Mark was saying. I think he was > > complaining about the existence of the sub-nodes rather than how the > > MFD Core assigns their of_node. My take is that the chip is really a > > single device which provides different bits of functionality. To break > > that functionality up and disperse the drivers into various subsystems > > is a Linuxisum. By providing each functional block with its own node > > you're describing how we do things in Linux, rather than specifying a > > single node for the AS3722 which would probably be the norm. > > Yes, that's exactly what I was thinking of. > > > Do the sub-nodes have their own properties? If so, it would be worth > > breaking them up as other OSes could reuse the specifics. If they do, > > then you need so put them in the binding. If they don't, then you do > > not require sub-nodes. The MFD core will ensure the sub-devices are > > probed and there is no requirement for the of_node to be assigned. > > You do see some reusable IP blocks (like the regualtors on the wm831x > PMICs for example, they're repeated blocks) which can be reused but > generally they have a register base as part of the binding. Personally > if it's just a property or two I'd probably just put them on the root > node for the device. Agreed. Besides, there doesn't seem to be *any* sub-device properties defined in the binding document. So what are you trying to achieve with the child nodes? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog