Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966286AbcKKDL3 (ORCPT ); Thu, 10 Nov 2016 22:11:29 -0500 Received: from mail-pf0-f182.google.com ([209.85.192.182]:35152 "EHLO mail-pf0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965255AbcKKDL1 (ORCPT ); Thu, 10 Nov 2016 22:11:27 -0500 Date: Fri, 11 Nov 2016 08:41:20 +0530 From: Viresh Kumar To: Stephen Boyd Cc: Mark Brown , Rafael Wysocki , nm@ti.com, Viresh Kumar , linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Guittot , robh@kernel.org, d-gerlach@ti.com, devicetree@vger.kernel.org Subject: Re: [PATCH V3 1/9] PM / OPP: Reword binding supporting multiple regulators per device Message-ID: <20161111031120.GE11670@vireshk-i7> References: <28119b44689921f3c3cc00be49bff2bb99b32162.1477463128.git.viresh.kumar@linaro.org> <20161109145828.p6vvsd5bygkzjcmh@sirena.org.uk> <20161110040440.GA11670@vireshk-i7> <20161110163659.rk67qrmnrovq2ktf@sirena.org.uk> <20161110180940.GD11670@vireshk-i7> <20161110225126.GK16026@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161110225126.GK16026@codeaurora.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3209 Lines: 72 On 10-11-16, 14:51, Stephen Boyd wrote: > On 11/10, Viresh Kumar wrote: > > On 10-11-16, 16:36, Mark Brown wrote: > > > On Thu, Nov 10, 2016 at 09:34:40AM +0530, Viresh Kumar wrote: > > > > On 09-11-16, 14:58, Mark Brown wrote: > > > > > On Wed, Oct 26, 2016 at 12:02:56PM +0530, Viresh Kumar wrote: > > > > > > > > > + Entries for multiple regulators shall be provided in the same field separated > > > > > > + by angular brackets <>. The OPP binding doesn't provide any provisions to > > > > > > + relate the values to their power supplies or the order in which the supplies > > > > > > + need to be configured. > > > > > > > > I don't understand how this works. If we have an unordered list of > > > > > values to set for regulators how will we make sense of them? > > > > > > > The platform driver is responsible to identify the order and pass it on to the > > > > OPP core. And the platform driver needs to have that hard coded. > > > > > > That *really* should be in the binding. > > > > Okay, how do you suggest doing that? Will a property like supply-names > > in the OPP table be fine? Like this: > > > > @@ -369,13 +378,16 @@ Example 4: Handling multiple regulators > > compatible = "arm,cortex-a7"; > > ... > > > > - cpu-supply = <&cpu_supply0>, <&cpu_supply1>, <&cpu_supply2>; > > + vcc0-supply = <&cpu_supply0>; > > + vcc1-supply = <&cpu_supply1>; > > + vcc2-supply = <&cpu_supply2>; > > operating-points-v2 = <&cpu0_opp_table>; > > }; > > }; > > > > cpu0_opp_table: opp_table0 { > > compatible = "operating-points-v2"; > > + supply-names = "vcc0", "vcc1", "vcc2"; > > opp-shared; > > > > No. The supply names (and also clock names/index) should be left > up to the consumer of the OPP table. We don't want to encode any > sort of details like this between the OPP table and the consumer > of it in DT because then it seriously couples the OPP table to > the consumer device. "The binding" in this case that needs to be > updated is the consumer binding, to indicate that it correlated > foo-supply and bar-supply to index 0 and 1 of the OPP table > voltages. Are you saying that we shall have a property like this then? diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt index ee91cbdd95ee..733946df2fb8 100644 --- a/Documentation/devicetree/bindings/opp/opp.txt +++ b/Documentation/devicetree/bindings/opp/opp.txt @@ -389,7 +389,10 @@ Example 4: Handling multiple regulators compatible = "arm,cortex-a7"; ... - cpu-supply = <&cpu_supply0>, <&cpu_supply1>, <&cpu_supply2>; + vcc0-supply = <&cpu_supply0>; + vcc1-supply = <&cpu_supply1>; + vcc2-supply = <&cpu_supply2>; + opp-supply-names = "vcc0", "vcc1", "vcc2"; operating-points-v2 = <&cpu0_opp_table>; }; }; -- viresh