From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laxman Dewangan Subject: Re: [PATCH V2 3/3] ARM: dts: db8500: add node property "regulator-compatible" regulator node Date: Wed, 20 Jun 2012 13:49:08 +0530 Message-ID: <4FE1877C.4090103@nvidia.com> References: <1340116099-17629-1-git-send-email-ldewangan@nvidia.com> <1340116099-17629-4-git-send-email-ldewangan@nvidia.com> <4FE0A546.1010707@linaro.org> <4FE0B79D.4090201@wwwdotorg.org> <4FE1772A.2010806@linaro.org> <4FE17E24.8050702@nvidia.com> <4FE18371.2020602@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4FE18371.2020602@linaro.org> Sender: linux-doc-owner@vger.kernel.org To: Lee Jones Cc: Stephen Warren , "broonie@opensource.wolfsonmicro.com" , "grant.likely@secretlab.ca" , "rob.herring@calxeda.com" , "arnd@arndb.de" , "linus.walleij@linaro.org" , "lrg@ti.com" , "devicetree-discuss@lists.ozlabs.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On Wednesday 20 June 2012 01:31 PM, Lee Jones wrote: > On 20/06/12 08:39, Laxman Dewangan wrote: >> On Wednesday 20 June 2012 12:39 PM, Lee Jones wrote: >>> On 19/06/12 18:32, Stephen Warren wrote: >>>> On 06/19/2012 10:13 AM, Lee Jones wrote: >>>>>> On 19/06/12 15:28, Laxman Dewangan wrote: >>>>>>>> Device's regulator matches their hardware counterparts with the >>>>>>>> property "regulator-compatible" of each child regulator node in >>>>>>>> place of the child node. >>>>>>>> Add the property "regulator-compatible" for each regulator with >>>>>>>> their name. >>>>>>>> >>>>>>>> Signed-off-by: Laxman Dewangan >>>>>>>> --- >>>>>>>> Changes from V1: >>>>>>>> - This is new change in V2. >>>>>>>> >>>>>>>> arch/arm/boot/dts/db8500.dtsi | 128 >>>>>>>> +++++++++++++++++++++++++++++++---------- >>>>>>>> 1 files changed, 97 insertions(+), 31 deletions(-) >>>>>>>> >>>>>>>> diff --git a/arch/arm/boot/dts/db8500.dtsi >>>>>>>> b/arch/arm/boot/dts/db8500.dtsi >>>>>>>> index 4ad5160..9548f80 100644 >>>>>>>> --- a/arch/arm/boot/dts/db8500.dtsi >>>>>>>> +++ b/arch/arm/boot/dts/db8500.dtsi >>>>>>>> @@ -203,107 +203,149 @@ >>>>>>>> >>>>>>>> db8500-prcmu-regulators { >>>>>>>> compatible = "stericsson,db8500-prcmu-regulator"; >>>>>>>> + #address-cells =<1>; >>>>>>>> + #size-cells =<0>; >>>>>> Why are these and the reg properties required? >>>> DT nodes should be named after the type of object they describe (e.g. >>>> "regulator") rather than the name of the object they're describing (e.g. >>>> "vape"). >>>> >>>> Once you've made that change, you end up with many nodes with the same >>>> name in the same parent, so you need to make their names unique. You do >>>> this by adding a "unit address" to each of them - "@0", "@1", ... But, >>>> in order to be "allowed" to use such a unit address, you need a reg >>>> property that matches the unit address, and #address-cells/#size-cells >>>> in the parent node. >>> I don't like it. By doing this you are preventing any regulator from >>> being registered by of_platform_populate(). Also, the nodes are already >>> placed under an identifying node "db8500-prcmu-regulators", so we know >>> they are regulators, making the regulator@x, the reg property and the >>> *-cells properties unnecessary cruft. >>> >>> I'd prefer to have the second label removed and just to call the >>> regulators by their correct name. The property names become functionally >>> redundant after the previous patch has been applied in any case. >>> >>> Something like this: >>> >>>> db8500-prcmu-regulators { >>>> compatible = "stericsson,db8500-prcmu-regulator"; >>>> >>>> // DB8500_REGULATOR_VAPE >>>> - db8500_vape_reg: db8500_vape { >>>> + db8500_vape { >>>> + regulator-compatible = "db8500_vape"; >>>> regulator-name = "db8500-vape"; >>>> regulator-always-on; >>>> }; >> >> You will require a label so that it can refer by the consumer. > Don't they both act as labels? Thus if you removed the second one, the > phandle will be taken from the remaining label? It's not something I've > tried, so I'm happy to be wrong here. > > If I'm wrong about that, can't we just omit the reg and *-size > properties? They are meaningless and restrictive. > We need to have the label. The name can not act as label. I tried following and got compilation error for dts file. Tried following way reg_vdd1 { regulator-compatible = "vdd1"; ::::::::::::::::: }; reg_vdd2: regulator@1 { regulator-compatible = "vdd2"; ::::::::::::::::: }; reg_vddctrl: regulator@2 { regulator-compatible = "vddctrl"; ::::::::::::::::: vin-supply = <®_vdd1>; }; And got build error as ********** DTC: dts->dtb on file "arch/arm/boot/dts/tegra30-cardhu.dts" ERROR (phandle_references): Reference to non-existent node or label "reg_vdd1" ERROR: Input tree has errors, aborting (use -f to force output) ******* Are you OK to have the first patch with adding property "regulator-compatible" on each of child node so that I can go ahead with this patch and regulator core/documentation patch along with changes in my board to enable regulators. Once we will conclude on the child name either like vdd1 or regulator@0, we can have modification accordingly. This will also need to avoid bi-sect issue as Stephen's suggested patch 1: Add regulator-property on each child node of db8500. patch 2: modify the regulator/core and documentation. Patch3 and onwards: Based on discussion, name the child node. Patch1 and 2 will not break anything and with this I can enable regulator on my boards. Thanks, Laxman