From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758729AbcIHSFF (ORCPT ); Thu, 8 Sep 2016 14:05:05 -0400 Received: from arroyo.ext.ti.com ([198.47.19.12]:50386 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256AbcIHSFD (ORCPT ); Thu, 8 Sep 2016 14:05:03 -0400 Subject: Re: [PATCH 3/3] soc: ti: Add ti_sci_pm_domains driver To: Kevin Hilman , Ulf Hansson References: <20160819235653.26355-1-nm@ti.com> <20160819235653.26355-4-nm@ti.com> <57C0D2C9.1030801@ti.com> <57C5E1DA.2040405@ti.com> <57CF26DB.4020807@ti.com> <7h4m5rv9kz.fsf@baylibre.com> CC: Nishanth Menon , "Rafael J. Wysocki" , Keerthy , Peter Ujfalusi , Tero Kristo , Russell King , Sudeep Holla , Santosh Shilimkar , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-pm@vger.kernel.org" , Jon Hunter From: Dave Gerlach Message-ID: <57D1A821.3010904@ti.com> Date: Thu, 8 Sep 2016 13:04:17 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [128.247.83.19] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 09/08/2016 12:38 PM, Kevin Hilman wrote: > Ulf Hansson writes: > >> [...] >> >>> >>> One more idea... >>> >>> Since you don't really have a domain (a group of devices), what you >>> really have is each device having an independent power switch, so as Ulf >>> suggested, what you really need is for all the devices to share the same >>> set of runtime PM callbacks that call SCI. The only difference is the >>> unique ID. >>> >>> Rather than using all of genpd, you could also just use a pm_domain >>> which is what genpd is built on top of (and also omap_device, which >>> you're probably familiar with also.) >> >> Even if this would work as well, the downside would be that you need >> to re-invent the parts related to the DT parsing, the probing/removal >> and attaching/detaching of the device to the PM domain. >> >> You probably don't want to go there... :-) > > All you'd need to read from DT would be the device-specific ID for > TI-SCI, and that could be done at bind time with a notifier. The, in > that same notifier, if a TI-SCI ID exists, it would get added to the > pm_domain. > > Anyways, your original proposal is much preferred if it can work. I'm > just throwing out another option because I really don't like one genpd > per device. > > Kevin > I am first trying to leverage the dev_attach/detach and start/stop callbacks that Ulf suggested without creating a single genpd per device and it looks like it will work for us. I appreciate the alternative suggestions but I agree we'd like to leverage as much of the existing genpd framework as we can and avoid going down the omap_device style implementation path. Regards, Dave