From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH v4 1/4] regulator: helper routine to extract regulator_init_data Date: Fri, 4 Nov 2011 22:35:19 +0000 Message-ID: <20111104223518.GC16978@opensource.wolfsonmicro.com> References: <1319721864-30067-1-git-send-email-rnayak@ti.com> <20111104202905.GA3918@quad.lixom.net> <20111104211447.GC2541@opensource.wolfsonmicro.com> <20111104212216.GA5756@quad.lixom.net> <20111104212910.GB8266@opensource.wolfsonmicro.com> <20111104214650.GC8266@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Olof Johansson Cc: patches@linaro.org, tony@atomide.com, devicetree-discuss@lists.ozlabs.org, Rajendra Nayak , linux-kernel@vger.kernel.org, grant.likely@secretlab.ca, linux-omap@vger.kernel.org, lrg@ti.com, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org On Fri, Nov 04, 2011 at 03:16:12PM -0700, Olof Johansson wrote: > On Fri, Nov 4, 2011 at 2:46 PM, Mark Brown > >> Describing that in the device tree using regulator-specifiers > >> shouldn't be too bad? The LDO will reference the DCDC as the parent > >> supply (or input or whatever language you prefer). They don't have to > >> be in the same topology, they will instead be under whatever > >> controller/bus they are on for control -- i2c, etc. > > That's not great as it means you've got a separate binding for supplies > > that happen to be connected to another regulator from that used for > > other supplies on the device which is particularly confusing in the > > fairly common case where a regulator chip has multiple supplies. =A0Usi= ng > > the same method for binding all supplies seems much neater. > I'm not following the above 100%, but I think you are saying that you > would prefer to describe the regulator / power hierarchy in the > functional topology instead of how the various regulators and supplies > are organized on i2c busses and other controllers? And the obvious > one that would be less than trivial to find a home for would be the > top-level or freestanding fixed regulators that don't sit on a > controlling bus. No, that's not the issue at all. The issue is that we want a single way of describing the supplies a device has regardless of their function (which is what the existing stuff does). Consider the case of a simple regulator with register control. It is going to have a supply used for the regulator itself and almost certainly also a separate digital buffer supply used to reference the digital I/O. It seems bad to specify the first supply in a different manner to the second, and there are more complex examples where a supply can be both a regulator input and also a more general purpose supply.