From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07DB4CA9EC4 for ; Wed, 30 Oct 2019 09:28:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD132208C0 for ; Wed, 30 Oct 2019 09:28:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="q4vfihaI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726032AbfJ3J2A (ORCPT ); Wed, 30 Oct 2019 05:28:00 -0400 Received: from mail-vk1-f196.google.com ([209.85.221.196]:34170 "EHLO mail-vk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726065AbfJ3J2A (ORCPT ); Wed, 30 Oct 2019 05:28:00 -0400 Received: by mail-vk1-f196.google.com with SMTP id d126so321017vkb.1 for ; Wed, 30 Oct 2019 02:27:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MN5/XA2iWTn3JwsaVPfUNETYKLVHfkkM5TGKnq2qWow=; b=q4vfihaI5SgnZO1mREK0EE92a2TcRqe5YARf2JUxGWe8b3RCSilUTop4ZV/z3M/1Ia weN9ltfEM6u2b4/2t7/tw+Nxzk9cRD14JW13Kz1VeE42C+IfgQ/qD2/hYVUPK3BAQwqG tlqjEzGFBCSsTNQ14MgdrT4ebi23gasDFuGezAvuHNHJVgg3LEBNiT6EXtL0homvbZhl mio1vgHviIVlTCyvDstI8u54o+OZPUxbYIwR8RMJpDrxPfE5AB+uNioto7r5yR/eGy3p WyJYHYunxFfhqU8bWoLWNd6oujzPiq2P6zitBof1M66HTaRyvjAV9LM2oWjqPhZdzTpp LUnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MN5/XA2iWTn3JwsaVPfUNETYKLVHfkkM5TGKnq2qWow=; b=iNakuY1l6xTTUaHLPvimqBUKMo4ZWB9gok509kC8uykCBhICpD9LQpaN7fE8eiRPDC jN9hw2nilyAGuXr80XLV+SRlw/OeynPXlc8t1GcAmOUiZJsiRUegu/jREq0hffbDYTv0 tGkJ6A24lJokZuoif/rvlnYl6K/7E8QxUUQlkJuN/SsTHaGa/QgiLhTyhxQd8vCsK9Ec oZIlpkJVaArPzN4OdUXFmDI4m3lJ0QQHtOTw0sxD5I3XAkrhQ3VgWbmUn37F2WBncyu8 VdTC/InqI82MZtAdXxizj5Za/Gem8izdmEw3sf3nYuHXy5XJkCEYfxbEog0sn9q3VBaT YUOQ== X-Gm-Message-State: APjAAAWvLwOTxvnMeWIPbYqK+yFwGAd9vA6I/8jOJykVBAyveEZZO8Vu 1Fjnl4O0M2b+UkzcCQMmik0DlHhKN/mWJKHifxJrSQ== X-Google-Smtp-Source: APXvYqzSHup2gFA5wBykiES6RNVVoT6htSpGRNx96Dg7POOVg6LTuWNWzkXHYGZc5adR+GHSe5AntmF9j9UEzqu7mqI= X-Received: by 2002:a1f:b202:: with SMTP id b2mr14227092vkf.59.1572427678476; Wed, 30 Oct 2019 02:27:58 -0700 (PDT) MIME-Version: 1.0 References: <1571254641-13626-1-git-send-email-thara.gopinath@linaro.org> <1571254641-13626-7-git-send-email-thara.gopinath@linaro.org> <5DA88892.5000408@linaro.org> <5DA89267.30806@linaro.org> <20191029013648.GB27045@bogus> In-Reply-To: From: Ulf Hansson Date: Wed, 30 Oct 2019 10:27:21 +0100 Message-ID: Subject: Re: [PATCH v3 6/7] dt-bindings: soc: qcom: Extend RPMh power controller binding to describe thermal warming device To: Rob Herring Cc: Thara Gopinath , Eduardo Valentin , Zhang Rui , Daniel Lezcano , Bjorn Andersson , Andy Gross , Amit Kucheria , Mark Rutland , "Rafael J. Wysocki" , Linux PM , DTML , linux-arm-msm , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, 29 Oct 2019 at 21:16, Rob Herring wrote: > > On Tue, Oct 29, 2019 at 5:07 AM Ulf Hansson wrote: > > > > On Tue, 29 Oct 2019 at 02:36, Rob Herring wrote: > > > > > > On Thu, Oct 17, 2019 at 12:10:15PM -0400, Thara Gopinath wrote: > > > > On 10/17/2019 11:43 AM, Ulf Hansson wrote: > > > > > On Thu, 17 Oct 2019 at 17:28, Thara Gopinath wrote: > > > > >> > > > > >> Hello Ulf, > > > > >> Thanks for the review! > > > > >> > > > > >> On 10/17/2019 05:04 AM, Ulf Hansson wrote: > > > > >>> On Wed, 16 Oct 2019 at 21:37, Thara Gopinath wrote: > > > > >>>> > > > > >>>> RPMh power controller hosts mx domain that can be used as thermal > > > > >>>> warming device. Add a sub-node to specify this. > > > > >>>> > > > > >>>> Signed-off-by: Thara Gopinath > > > > >>>> --- > > > > >>>> Documentation/devicetree/bindings/power/qcom,rpmpd.txt | 10 ++++++++++ > > > > >>>> 1 file changed, 10 insertions(+) > > > > >>>> > > > > >>>> diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > > >>>> index eb35b22..fff695d 100644 > > > > >>>> --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > > >>>> +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.txt > > > > >>>> @@ -18,6 +18,16 @@ Required Properties: > > > > >>>> Refer to for the level values for > > > > >>>> various OPPs for different platforms as well as Power domain indexes > > > > >>>> > > > > >>>> += SUBNODES > > > > >>>> +RPMh alsp hosts power domains that can behave as thermal warming device. > > > > >>>> +These are expressed as subnodes of the RPMh. The name of the node is used > > > > >>>> +to identify the power domain and must therefor be "mx". > > > > >>>> + > > > > >>>> +- #cooling-cells: > > > > >>>> + Usage: optional > > > > >>>> + Value type: > > > > >>>> + Definition: must be 2 > > > > >>>> + > > > > >>> > > > > >>> Just wanted to express a minor thought about this. In general we use > > > > >>> subnodes of PM domain providers to represent the topology of PM > > > > >>> domains (subdomains), this is something different, which I guess is > > > > >>> fine. > > > > >>> > > > > >>> I assume the #cooling-cells is here tells us this is not a PM domain > > > > >>> provider, but a "cooling device provider"? > > > > >> Yep. > > > > >>> > > > > >>> Also, I wonder if it would be fine to specify "power-domains" here, > > > > >>> rather than using "name" as I think that is kind of awkward!? > > > > >> Do you mean "power-domain-names" ? I am using this to match against the > > > > >> genpd names defined in the provider driver. > > > > > > > > > > No. If you are using "power-domains" it means that you allow to > > > > > describe the specifier for the provider. > > > > Yep. But won't this look funny in DT ? The provider node will have a sub > > > > node with a power domain referencing to itself Like below: Is this ok ? > > > > > > > > rpmhpd: power-controller { > > > > compatible = "qcom,sdm845-rpmhpd"; > > > > #power-domain-cells = <1>; > > > > > > > > ... > > > > ... > > > > mx_cdev: mx { > > > > #cooling-cells = <2>; > > > > power-domains = <&rpmhpd SDM845_MX>; > > > > }; > > > > > > > > > > The whole concept here seems all wrong to me. Isn't it what's in the > > > power domain that's the cooling device. A CPU power domain is not a > > > cooling device, the CPU is. Or we wouldn't make a clock a cooling > > > device, but what the clock drives. > > > > Well, I don't think that's entirely correct description either. > > > > As I see it, it's really the actual PM domain (that manages voltages > > for a power island), that needs to stay in full power state and > > increase its voltage level, as to warm up some of the silicon. It's > > not a regular device, but more a characteristics of how the PM domain > > can be used. > > First I've heard of Si needing warming... I guess people go to cooler places with their devices. :-) > > I think I'd just expect the power domain provider to know which > domains to power on then. Yeah, I agree. This seems reasonable. Thanks! Kind regards Uffe