Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751623AbaK0OUp (ORCPT ); Thu, 27 Nov 2014 09:20:45 -0500 Received: from mail-qg0-f43.google.com ([209.85.192.43]:55132 "EHLO mail-qg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751195AbaK0OUn (ORCPT ); Thu, 27 Nov 2014 09:20:43 -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> <1416834256-11225-7-git-send-email-amit.daniel@samsung.com> Date: Thu, 27 Nov 2014 15:20:42 +0100 Message-ID: Subject: Re: [PATCH RFC v2 07/12] PM / Domains: export pm_genpd_lookup_name From: Ulf Hansson To: amit daniel kachhap Cc: "linux-arm-kernel@lists.infradead.org" , linux-samsung-soc , Kukjin Kim , "linux-kernel@vger.kernel.org" , Sylwester Nawrocki , Pankaj Dubey , Kevin Hilman , "linux-pm@vger.kernel.org" , Geert Uytterhoeven , "Rafael J. Wysocki" , "devicetree@vger.kernel.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 25 November 2014 at 09:48, amit daniel kachhap wrote: > On Tue, Nov 25, 2014 at 1:05 PM, Ulf Hansson wrote: >> On 24 November 2014 at 14:04, Amit Daniel Kachhap >> wrote: >>> This API may be needed to set the power domain parent/child relationship >>> in the power domain platform driver. The parent relationship is >>> generally set after the child power domain is registered with the power >>> domain subsystem. In this case, pm_genpd_lookup_name API might be >>> useful. >> >> I think this is a step in the wrong direction. Instead we should be >> working on removing the "name" based APIs from genpd. >> >> The proper way should be to pass the PM domain as a parameter to the >> APIs instead. > Yes i understand but i had a special requirement for using this API > during pd probe. > I cannot use hierarchy to represent parent/child pd nodes as it will > break the existing SoC's. In my case all the PD nodes are linear. The > parent/child relationship are established in the second pass after all > the PD entries are registered with the help of this API. > Although there a way that i can always keep parent PD's before the > child PD's in DT in linear order. Will check this approach. I had some thinking around this, could the below approach work? I just posted a patch[1] adding a new pm_genpd_lookup() API, which is using a "DT device node" to fetch the genpd. The idea is to use that API to get the genpd handle which is needed to configure a subdomain through pm_genpd_add_subdomain() API. In principle you will have to walk through the DT a couple of times, initialize those domains (and subdomains) which either don't have a parent domain or which parent domain already has been initialized. I guess you need a somewhat clever loop to do that, but I think it's doable. Obviously we also need to have a generic binding for a "parent domain". I like Geert's proposal from the other patch, which means using "power-domains = <&pd_xyz>". Kind regards Uffe [1] http://marc.info/?l=linux-pm&m=141709766008458&w=2 -- 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/