From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751142AbaKYJTe (ORCPT ); Tue, 25 Nov 2014 04:19:34 -0500 Received: from mail-lb0-f179.google.com ([209.85.217.179]:38252 "EHLO mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbaKYJTb (ORCPT ); Tue, 25 Nov 2014 04:19:31 -0500 MIME-Version: 1.0 In-Reply-To: References: <1416833572-6880-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-8-git-send-email-amit.daniel@samsung.com> Date: Tue, 25 Nov 2014 10:19:28 +0100 X-Google-Sender-Auth: uL69uYkOhPlGK7Yuvq92_67zdsQ Message-ID: Subject: Re: [PATCH RFC v2 08/12] soc: samsung: pm_domain: Add support for parent power domain From: Geert Uytterhoeven To: amit daniel kachhap Cc: Ulf Hansson , "devicetree@vger.kernel.org" , Kukjin Kim , Kevin Hilman , Pankaj Dubey , "linux-pm@vger.kernel.org" , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , linux-samsung-soc , Sylwester Nawrocki , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 25, 2014 at 9:57 AM, amit daniel kachhap wrote: >>> diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> index 00ebda1..0160bdc 100644 >>> --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> @@ -24,6 +24,7 @@ Optional Properties: >>> - pclkN, clkN: Pairs of parent of input clock and input clock to the >>> devices in this power domain. Maximum of 4 pairs (N = 0 to 3) >>> are supported currently. >>> +- parents: phandle of parent power domains. Why not using just "power-domains = <&pd_top>"? This is consistent with how clocks refer to their parent clocks. >>> Node of a device using power domains must have a samsung,power-domain property >>> defined with a phandle to respective power domain. >>> @@ -48,6 +49,7 @@ Example: >>> mfc_pd: power-domain@10044060 { >>> compatible = "samsung,exynos4210-pd", "samsung,exynos7-pd-mfc"; >>> reg = <0x10044060 0x20>; >>> + parents = <&pd_top>; >>> #power-domain-cells = <0>; >>> }; >> >> This seems like a good and generic approach to describe that a PM >> domain could have a parent. I would suggest to rename it, such it >> reflects its a PM domain binding though. > I am not sure if this is generic. I guess PD's represented like below > are more generic. > PD1 { > PD2 { > PD3 { > }; > }; > }; Such a representation is not always possible. If you have one power-controller for a hierarchy of PM domains, you can use it. If you have multiple power-controllers, the power controller nodes are at the same level in DT, so you'll have to use "power-domains" properties to link them together. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH RFC v2 08/12] soc: samsung: pm_domain: Add support for parent power domain Date: Tue, 25 Nov 2014 10:19:28 +0100 Message-ID: References: <1416833572-6880-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-8-git-send-email-amit.daniel@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org To: amit daniel kachhap Cc: Ulf Hansson , "devicetree@vger.kernel.org" , Kukjin Kim , Kevin Hilman , Pankaj Dubey , "linux-pm@vger.kernel.org" , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , linux-samsung-soc , Sylwester Nawrocki , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Tue, Nov 25, 2014 at 9:57 AM, amit daniel kachhap wrote: >>> diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> index 00ebda1..0160bdc 100644 >>> --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> @@ -24,6 +24,7 @@ Optional Properties: >>> - pclkN, clkN: Pairs of parent of input clock and input clock to the >>> devices in this power domain. Maximum of 4 pairs (N = 0 to 3) >>> are supported currently. >>> +- parents: phandle of parent power domains. Why not using just "power-domains = <&pd_top>"? This is consistent with how clocks refer to their parent clocks. >>> Node of a device using power domains must have a samsung,power-domain property >>> defined with a phandle to respective power domain. >>> @@ -48,6 +49,7 @@ Example: >>> mfc_pd: power-domain@10044060 { >>> compatible = "samsung,exynos4210-pd", "samsung,exynos7-pd-mfc"; >>> reg = <0x10044060 0x20>; >>> + parents = <&pd_top>; >>> #power-domain-cells = <0>; >>> }; >> >> This seems like a good and generic approach to describe that a PM >> domain could have a parent. I would suggest to rename it, such it >> reflects its a PM domain binding though. > I am not sure if this is generic. I guess PD's represented like below > are more generic. > PD1 { > PD2 { > PD3 { > }; > }; > }; Such a representation is not always possible. If you have one power-controller for a hierarchy of PM domains, you can use it. If you have multiple power-controllers, the power controller nodes are at the same level in DT, so you'll have to use "power-domains" properties to link them together. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Tue, 25 Nov 2014 10:19:28 +0100 Subject: [PATCH RFC v2 08/12] soc: samsung: pm_domain: Add support for parent power domain In-Reply-To: References: <1416833572-6880-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-1-git-send-email-amit.daniel@samsung.com> <1416834256-11225-8-git-send-email-amit.daniel@samsung.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Nov 25, 2014 at 9:57 AM, amit daniel kachhap wrote: >>> diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> index 00ebda1..0160bdc 100644 >>> --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt >>> @@ -24,6 +24,7 @@ Optional Properties: >>> - pclkN, clkN: Pairs of parent of input clock and input clock to the >>> devices in this power domain. Maximum of 4 pairs (N = 0 to 3) >>> are supported currently. >>> +- parents: phandle of parent power domains. Why not using just "power-domains = <&pd_top>"? This is consistent with how clocks refer to their parent clocks. >>> Node of a device using power domains must have a samsung,power-domain property >>> defined with a phandle to respective power domain. >>> @@ -48,6 +49,7 @@ Example: >>> mfc_pd: power-domain at 10044060 { >>> compatible = "samsung,exynos4210-pd", "samsung,exynos7-pd-mfc"; >>> reg = <0x10044060 0x20>; >>> + parents = <&pd_top>; >>> #power-domain-cells = <0>; >>> }; >> >> This seems like a good and generic approach to describe that a PM >> domain could have a parent. I would suggest to rename it, such it >> reflects its a PM domain binding though. > I am not sure if this is generic. I guess PD's represented like below > are more generic. > PD1 { > PD2 { > PD3 { > }; > }; > }; Such a representation is not always possible. If you have one power-controller for a hierarchy of PM domains, you can use it. If you have multiple power-controllers, the power controller nodes are at the same level in DT, so you'll have to use "power-domains" properties to link them together. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds