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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B9B5DC07E9C for ; Tue, 6 Jul 2021 07:24:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A05586198E for ; Tue, 6 Jul 2021 07:24:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230225AbhGFH06 (ORCPT ); Tue, 6 Jul 2021 03:26:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230203AbhGFH06 (ORCPT ); Tue, 6 Jul 2021 03:26:58 -0400 Received: from mail-vk1-xa2b.google.com (mail-vk1-xa2b.google.com [IPv6:2607:f8b0:4864:20::a2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B9DEC06175F for ; Tue, 6 Jul 2021 00:24:20 -0700 (PDT) Received: by mail-vk1-xa2b.google.com with SMTP id u24so345596vkn.9 for ; Tue, 06 Jul 2021 00:24:20 -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=BXh3LzMCPP9L3ynAA0aGj0fxSvyTuYRtJFcDwUyQ7PM=; b=ZIphNHFNEE+seeFzTENuNO09jbaTUpM+qAatBWg9z0OBgpHgSDgYdxW/N8q56+yYjC uFfkpNkI5HG0/PJylwJ99SjyHOUMS7/0SNzBdfl+5gxYPRY5LZu9wDrC/DrNrxI8oHYk h9YxZ4nWUZcRKcPPdkO+43Z3EaDuswEjNlmgrDAZp2h6jPXSVfLLsnQxmaGSN5BxM8dS 9dPZPCGZ4SHklmfPXQRNDi2qGu5GVV+icfOyhgKcIk3E/5LFYYekvWLRh/ylqotC+lSw m/oiXlzuHBBJIokhaULIVJnKw64+77TX5fY18Gx014ybnp4b/q7iwFHjLN7we8/jn6ER /t2w== 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=BXh3LzMCPP9L3ynAA0aGj0fxSvyTuYRtJFcDwUyQ7PM=; b=bHXNUOHqAwVUkgMDqybRh69tAMvBYCnXfNf6ZuoTWCA4J7/c4hA8dqBBW+8cYYuY+5 /rvZkP5DkxyAP9kHwCga9jyYs7h5eP9Uek7cZ4D50ZJnQWKoJ2faqDx5zRt4E6PLzh75 1564rXdUU3gUcKZ9kqhcNbHUFM4JQqQGmUjCeODb5pqWnry/7feCd0/tu998OdalnV01 PhEVRIqyO55RwHsIfoSKHiKH8ZvatecNUPnguMN2jHHY8p/ivi3Q/nyWomhrl8SxdGdj ZkPu0TiJjjkQACVxZpttqmn5ZU4/bOxJMKZdWm5TlwK8I0fsjNSVh0koScCixbqkNCk0 NCMQ== X-Gm-Message-State: AOAM531/k0Xbj7BIq229CDxR0xlttmT0stdtSNSe9wrZcFQEziHBlefB YpROjSP2KV1Ib1VitkWwNnA/C6WH26WXUn9aKokAMw== X-Google-Smtp-Source: ABdhPJyZeMUXryowDLyT5UVj1MHKnIf7P7os2mdRoNlHRDoSTvU/zN5waPK5F8cB2dqXSY/D/fBD96r1SW3yJTF2u+U= X-Received: by 2002:a05:6122:588:: with SMTP id i8mr1747116vko.6.1625556259411; Tue, 06 Jul 2021 00:24:19 -0700 (PDT) MIME-Version: 1.0 References: <20210630133149.3204290-1-dmitry.baryshkov@linaro.org> <20210630133149.3204290-2-dmitry.baryshkov@linaro.org> In-Reply-To: From: Ulf Hansson Date: Tue, 6 Jul 2021 09:23:42 +0200 Message-ID: Subject: Re: [PATCH 1/6] dt-bindings: clock: qcom,dispcc-sm8x50: add mmcx power domain To: Bjorn Andersson Cc: Dmitry Baryshkov , Andy Gross , Rob Herring , Stephen Boyd , Taniya Das , Jonathan Marek , Michael Turquette , linux-arm-msm , DTML , linux-clk , "Bryan O'Donoghue" , Mark Brown , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 1 Jul 2021 at 21:26, Bjorn Andersson wrote: > > On Thu 01 Jul 11:58 CDT 2021, Ulf Hansson wrote: > > > On Thu, 1 Jul 2021 at 18:39, Dmitry Baryshkov > > wrote: > > > > > > On Thu, 1 Jul 2021 at 19:17, Ulf Hansson wrote: > > > > > > > > On Wed, 30 Jun 2021 at 15:31, Dmitry Baryshkov > > > > wrote: > > > > > > > > > > On sm8250 dispcc requires MMCX power domain to be powered up before > > > > > clock controller's registers become available. For now sm8250 was using > > > > > external regulator driven by the power domain to describe this > > > > > relationship. Switch into specifying power-domain and required opp-state > > > > > directly. > > > > > > > > > > Signed-off-by: Dmitry Baryshkov > > > > > --- > > > > > .../bindings/clock/qcom,dispcc-sm8x50.yaml | 19 +++++++++++++++++++ > > > > > 1 file changed, 19 insertions(+) > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml b/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml > > > > > index 0cdf53f41f84..48d86fb34fa7 100644 > > > > > --- a/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml > > > > > +++ b/Documentation/devicetree/bindings/clock/qcom,dispcc-sm8x50.yaml > > > > > @@ -55,6 +55,16 @@ properties: > > > > > reg: > > > > > maxItems: 1 > > > > > > > > > > + power-domains: > > > > > + description: > > > > > + A phandle and PM domain specifier for the MMCX power domain. > > > > > + maxItems: 1 > > > > > + > > > > > > > > Should you perhaps state that this is a parent domain? Or it isn't? > > > > > > > > Related to this and because this is a power domain provider, you > > > > should probably reference the common power-domain bindings somewhere > > > > here. Along the lines of this: > > > > > > > > - $ref: power-domain.yaml# > > > > > > > > As an example, you could have a look at > > > > Documentation/devicetree/bindings/power/pd-samsung.yaml. > > > > > > I'll take a look. > > > > > > > > > > > > + required-opps: > > > > > + description: > > > > > + Performance state to use for MMCX to enable register access. > > > > > + maxItems: 1 > > > > > > > > According to the previous discussions, I was under the assumption that > > > > this property belongs to a consumer node rather than in the provider > > > > node, no? > > > > > > It is both a consumer and a provider. It consumes SM8250_MMCX from > > > rpmhpd and provides MMSC_GDSC. > > > > That sounds a bit weird to me. > > > > dispcc is a hardware block powered by MMCX, so it is a consumer of it > and needs to control MMCX. Right, that sounds reasonable. > > > In my view and per the common power domain bindings (as pointed to > > above): If a power domain provider is a consumer of another power > > domain, that per definition means that there is a parent domain > > specified. > > > > And in addition to needing MMCX to access the dispcc, the exposed > power-domain "MDSS_GDSC" is powered by the same MMCX and as such > MDSS_GDSC should be a subdomain of MMCX. What do you mean by "exposed"? It sounds like you are saying that "MDSS_GDSC" is an artificial power domain, no? If that's the case, more exactly, why is it like this? My apologies if I bother you with details, but as a maintainer of genpd, it is very useful to me to have the complete picture. > > > But what I was trying to say yesterday is that the power-domain property > should be sufficient and that we shouldn't need to drive MMCX to a > particular performance_state in order to access the registers. > > Then as clients make votes on clock rates that requires higher > performance_state, they would describe this in their opp-tables etc. > > > But without any performance_state requests, pd->corner will in > rpmhpd_power_on() be 0 and as such powering on the power-domain won't > actually do anything. Similarly dev_pm_genpd_set_performance_state(dev, > 0) on an active power-domain from rpmhpd will turn it off. Yes, I noticed the patches you posted. Thanks for helping out here! > > > So the reason why Dmitry is adding the required-opps to the binding is > to get rpmhpd to actually tell the hardware to turn on the power domain. > And I don't think this is in accordance with the framework's > expectations. I agree! > > Regards, > Bjorn Kind regards Uffe