Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752212AbbG1PgE (ORCPT ); Tue, 28 Jul 2015 11:36:04 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:35362 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783AbbG1PgB (ORCPT ); Tue, 28 Jul 2015 11:36:01 -0400 MIME-Version: 1.0 In-Reply-To: <20150728143919.GW14943@x1> References: <1438010430-5802-1-git-send-email-lee.jones@linaro.org> <1438010430-5802-2-git-send-email-lee.jones@linaro.org> <20150728143919.GW14943@x1> From: Rob Herring Date: Tue, 28 Jul 2015 10:35:41 -0500 Message-ID: Subject: Re: [PATCH v4 2/2] dt: power: st: Provide bindings for ST's OPPs To: Lee Jones Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , kernel@stlinux.com, "linux-pm@vger.kernel.org" , Dmitry Eremin-Solenikov , Viresh Kumar , Rafael Wysocki , Sebastian Reichel , ajitpal.singh@st.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3429 Lines: 92 On Tue, Jul 28, 2015 at 9:39 AM, Lee Jones wrote: > On Tue, 28 Jul 2015, Rob Herring wrote: > >> On Mon, Jul 27, 2015 at 10:20 AM, Lee Jones wrote: >> > These OPPs are used in ST's CPUFreq implementation. >> > >> > Signed-off-by: Lee Jones >> > --- >> > >> > Changelog: >> > - None, new patch >> > >> > Documentation/devicetree/bindings/power/opp-st.txt | 76 ++++++++++++++++++++++ >> > 1 file changed, 76 insertions(+) >> > create mode 100644 Documentation/devicetree/bindings/power/opp-st.txt >> > >> > diff --git a/Documentation/devicetree/bindings/power/opp-st.txt b/Documentation/devicetree/bindings/power/opp-st.txt >> > new file mode 100644 >> > index 0000000..6eb2a91 >> > --- /dev/null >> > +++ b/Documentation/devicetree/bindings/power/opp-st.txt >> > @@ -0,0 +1,76 @@ >> > +STMicroelectronics OPP (Operating Performance Points) Bindings >> > +-------------------------------------------------------------- >> > + >> > +Frequency Scaling only >> > +---------------------- >> > + >> > +Located in CPU's node: >> > + >> > +- operating-points : [See: ./opp.txt] >> > + >> > +Example [safe] >> > +-------------- >> > + >> > +cpus { >> > + cpu@0 { >> > + /* kHz uV */ >> > + operating-points = <1500000 0 >> > + 1200000 0 >> > + 800000 0 >> > + 500000 0>; >> > + }; >> > +}; >> > + >> > +Dynamic Voltage and Frequency Scaling (DVFS) >> > +-------------------------------------------- >> > + >> > +Located in 'cpu0-opp-list' node [to be provided ONLY by the bootloader]: >> > + >> > +- compatible : Should be "operating-points-v2-sti" >> > +- opp{1..N} : Each 'oppX' subnode will contain the following properties: >> > + - opp-hz : CPU frequency [Hz] for this OPP [See: ./opp.txt] >> > + - st,avs : List of available voltages [uV] indexed by process code >> >> Add a unit suffix (-microvolt). > > Sure. > >> > + - st,cuts : Cut version this OPP is suitable for [0xFF means ALL] >> > + - st,substrate : Substrate version this OPP is suitable for [0xFF means ALL] >> >> How about not present means all? > > I think that would be an unsafe assumption. If it's forgotten, then > we may try to run an invalid/dangerous voltage/frequency combination. > > I'd really like 'all' to be defined an deliberate. Okay. >> > +- st,syscfg : Phandle to Major number register >> > + First cell: offset to major number >> > +- st,syscfg-eng : Phandle to Minor number and Pcode registers >> > + First cell: offset to process code >> > + Second cell: offset to minor number >> >> Would the proposed nvmem binding work for this? > > We already use sysconf for all of this type of stuff, as this > information is contained in ST's Sysconf banks. Moving over to a new > API would be a huge move and would require lots of planning > discussions with ST. Okay. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/