Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993741AbdDZIHc (ORCPT ); Wed, 26 Apr 2017 04:07:32 -0400 Received: from mail-it0-f53.google.com ([209.85.214.53]:38796 "EHLO mail-it0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1956777AbdDZIGW (ORCPT ); Wed, 26 Apr 2017 04:06:22 -0400 MIME-Version: 1.0 In-Reply-To: References: <1490710443-27425-1-git-send-email-jonathanh@nvidia.com> From: Geert Uytterhoeven Date: Wed, 26 Apr 2017 10:06:20 +0200 X-Google-Sender-Auth: pYkUJ-a5uE_Ptgt-PjgGrkhYnfQ Message-ID: Subject: Re: [RFC PATCH 0/4] PM / Domains: Add support for explicit control of PM domains To: Ulf Hansson Cc: Jon Hunter , "Rafael J . Wysocki" , Kevin Hilman , Rajendra Nayak , Stanimir Varbanov , Stephen Boyd , Marek Szyprowski , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-tegra@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 Content-Length: 1442 Lines: 34 Hi Ulf, On Tue, Apr 25, 2017 at 9:34 PM, Ulf Hansson wrote: > However, we currently know about at least two different SoCs that need > this. Perhaps we can extend the below list to justify adding a new > framework/APIs. Something along the lines what you propose in $subject > patchset. > > 1) Nvidia; to solve the USB super-speed host/device problem. > 2) QCOM, which has pointed to several cases where the PM topology is > laid out like devices having two PM domains.. > 3?) I don't fully remember - but I think Geert also pointed to some > examples where a device could reside in a clock domain but also in > power domain for a Renesas SoC!? > 4) ? Most Renesas SoCs have module clocks, which we model as a clock domain. Some Renesas SoCs have power domains for CPUs, others have them for devices as well. As we always provide a virtual "always-on" power domain in the power domain controller, all devices can refer to it using "power-domains" properties, and the driver for the power domain controller can just forward the clock domain operations to the clock driver. 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