From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753786AbaI2Lxq (ORCPT ); Mon, 29 Sep 2014 07:53:46 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:63166 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751949AbaI2Lxo (ORCPT ); Mon, 29 Sep 2014 07:53:44 -0400 Message-ID: <54294832.8000702@i2se.com> Date: Mon, 29 Sep 2014 13:53:22 +0200 From: Stefan Wahren User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Mark Rutland CC: "lgirdwood@gmail.com" , "broonie@kernel.org" , "shawn.guo@linaro.org" , "robh+dt@kernel.org" , Pawel Moll , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "festevam@gmail.com" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "kernel@pengutronix.de" Subject: Re: [PATCH 1/2] DT: add binding for mxs regulator References: <1411779588-22031-1-git-send-email-stefan.wahren@i2se.com> <1411779588-22031-2-git-send-email-stefan.wahren@i2se.com> <20140929110919.GB2432@leverpostej> In-Reply-To: <20140929110919.GB2432@leverpostej> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Provags-ID: V02:K0:K/wZJejKX1I0U03IfKYdL4xhRKitQT0byx5nU1qYUOg 7CrJHnsM22tKc/5sxnGxhTDW8/Uuk7UuIzS2oKcXNAf6QLm+2G wQ27oD/JAj6e8JNAMOu6plYUeedzDebs/DrnRVuELTfvDKofxE o7A9H5N1lBxbmprgqn2prmvajs3Ip7zhffyb5B8hJ+vPCAWrVR oouvwVYcqUWYlVCeF0C/UbQIm4LR6t8oSGXU1ohpNf2raSbR6Q syGdJK7FYuc9ilWTUEpbfq8KXLluj53wDopUz/2LqNK7BjL0TI siJgkJf26nB53MFNhiHVg3lnjh17xBKTQV6d14rr6rAbK8lRRQ MQXCtxOpIr+0QuSF+l6w= X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mark, Am 29.09.2014 um 13:09 schrieb Mark Rutland: > On Sat, Sep 27, 2014 at 01:59:47AM +0100, Stefan Wahren wrote: >> This patch adds the Device tree bindings for the Freescale MXS >> on-chip regulators. >> >> Signed-off-by: Stefan Wahren >> --- >> .../bindings/regulator/mxs-regulator.txt | 36 ++++++++++++++++++++ >> 1 file changed, 36 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> >> diff --git a/Documentation/devicetree/bindings/regulator/mxs-regulator.txt b/Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> new file mode 100644 >> index 0000000..e3133a4 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> @@ -0,0 +1,36 @@ >> +MXS regulators >> + >> +Required node properties: >> +- compatible: Should be "simple-bus" > This does not look like an appropriate use of simple-bus. > > Why do you want the parent node to be a simple-bus? the current parent node in imx28.dtsi looks like a placeholder for the power sub system: power: power@80044000 { reg = <0x80044000 0x2000>; status = "disabled"; }; I want to trigger the probing of the child nodes (regulators) without writing a driver for the complete power sub system. The simple-bus avoids that. Do we need a extra driver? > >> +- #address-cells: Number of cells required to define regulator register, >> + must be 1 >> +- #size-cells: Number of cells required to define register size, must be 1 > Why must this be the case, given that the child node expects an absolute > physical address? I need a property to define the control register for the regulators without defining vendor specific properties like "fsl,mxs-control-reg" or something. > What's wrong with #address-cells = <2>, for example? Nothing > >> +- reg: Absolute physical address and size of the register set for the device > Why is this here _and_ in the child node(s)? The parent of the power node is also a simple bus. I use this to calculate the power status register per offset. > What is the difference between this node and its children? The parent node represent the power sub system and the regulators are part of this sub system. > Can there be more than one sub-node? In the i.MX28 are at least 4 voltage regulators, 1 current regulator and many more. At first, the driver should implement only 3 voltage regulators (vddd, vdda, vddio). > Mark. > Best regards Stefan