From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Cousson, Benoit" Subject: Re: [PATCH 2/9] regulator: helper routine to extract regulator_init_data Date: Fri, 30 Sep 2011 13:35:40 +0200 Message-ID: <4E85A98C.9060702@ti.com> References: <1317118372-17052-1-git-send-email-rnayak@ti.com> <1317118372-17052-3-git-send-email-rnayak@ti.com> <20110927121003.GB4289@opensource.wolfsonmicro.com> <4E81E224.2070408@ti.com> <20110927150511.GM4289@opensource.wolfsonmicro.com> <4E854532.6080605@ti.com> <20110930102849.GA4195@opensource.wolfsonmicro.com> <20110930104820.GE2085@sirena.org.uk> <4E85A34E.9070203@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4E85A34E.9070203@ti.com> 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: "Nayak, Rajendra" Cc: "patches@linaro.org" , "tony@atomide.com" , "devicetree-discuss@lists.ozlabs.org" , Mark Brown , "grant.likely@secretlab.ca" , "linux-omap@vger.kernel.org" , "Girdwood, Liam" , "linux-arm-kernel@lists.infradead.org" List-Id: linux-omap@vger.kernel.org On 9/30/2011 1:09 PM, Nayak, Rajendra wrote: > On Friday 30 September 2011 04:18 PM, Mark Brown wrote: >> On Fri, Sep 30, 2011 at 11:28:49AM +0100, Mark Brown wrote: >>> On Fri, Sep 30, 2011 at 09:57:30AM +0530, Rajendra Nayak wrote: >> >>>>>> + init_data->supply_regulator = (char *)of_get_property(dev->of_node, >>>>>> + "regulator-supplies", NULL); >> >>>> Mark, I still seem to be a little confused with this one as to why >>>> we would need a phandle *and* a supply-name to reference a parent >>>> regulator/supply. >>>> The phandle would point to a regulator dt node and that node internally >>>> would have just one name associated with it. >> >>> To repeat: the supply name is for the consumer. It is needed so that >>> the consumer can tell which supply is provided by which regulator. >>> Almost all devices have more than one supply and if the device does >>> anything more complicated than just turning on all the supplies when the >>> device is active it's going to need to figure out which supply is which. >> >> Hang on, I now have no idea what this is supposed to be doing. Later on >> in the series you had examples in your commit logs with perfectly >> sensible bindings for supplies: >> >> vmmc-supply =<®ulator1>; >> vpll-supply =<®ulator1>; >> >> which have both a unique name and a direct reference to the supplying >> regulator. What are these "regulator-supplies" properties supposed to >> be? > > :-), yes, I was confused for a while as well after reading your response. > > The "regulator-supplies" is used to specific the regulator *parent*. > Same as what was earlier passed by using the > "supply_regulator" field of regulator_init_data structure. > Grant wanted the bindings to support specifying multiple parents > and hence I was thinking of either a list of names *or* > a list of phandles to specify multiple parents to a regulator. I'm confused too now :-) You can not have multiple to one kind of connection from a power supply to a single power rail of an IP (vmmc, vpll...). So I do not see the need for more any other binding that the one you did: vmmc-supply = <®ulator1>; That kind of binding does not really exist in the real world: vmmc-supply = <®ulator1 ®ulator2>; At least not without a power switch in between. Regards, Benoit