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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26C3EC43217 for ; Wed, 27 Oct 2021 03:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 063CE610F8 for ; Wed, 27 Oct 2021 03:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239155AbhJ0DlE (ORCPT ); Tue, 26 Oct 2021 23:41:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232661AbhJ0DlE (ORCPT ); Tue, 26 Oct 2021 23:41:04 -0400 Received: from mail.marcansoft.com (marcansoft.com [IPv6:2a01:298:fe:f::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 989CDC061570; Tue, 26 Oct 2021 20:38:39 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: marcan@marcan.st) by mail.marcansoft.com (Postfix) with ESMTPSA id 3469A421F5; Wed, 27 Oct 2021 03:38:30 +0000 (UTC) To: Rob Herring Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , Arnd Bergmann , Linus Walleij , Alyssa Rosenzweig , Krzysztof Kozlowski , Greg Kroah-Hartman , Mark Kettenis , Philipp Zabel , "Rafael J. Wysocki" , Johan Hovold , devicetree@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org, Mark Kettenis References: <20211025144718.157794-1-marcan@marcan.st> <20211025144718.157794-3-marcan@marcan.st> From: Hector Martin Subject: Re: [PATCH v2 2/8] dt-bindings: arm: apple: Add apple,pmgr binding Message-ID: Date: Wed, 27 Oct 2021 12:38:31 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: es-ES Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 27/10/2021 03.25, Rob Herring wrote: > On Mon, Oct 25, 2021 at 11:47:12PM +0900, Hector Martin wrote: >> + compatible: >> + items: >> + - enum: >> + - apple,t8103-pmgr >> + - apple,t8103-minipmgr >> + - const: apple,pmgr >> + - const: syscon >> + - const: simple-mfd > > > 'simple-mfd' means 'there's nothing in this node that any of the child > nodes depend on'. You should be somewhat certain as dropping it later > creates compatibility issues. Hmm, I see simple-mfd turns this into a bus which I guess allows child nodes to be probed without the parent node doing anything special (then we use syscon_node_to_regmap to get the syscon instantiated). Do you have a example use case for doing this without simple-mfd? At this point I can't think of anything we'd need from the parent node, especially if we end up using this syscon strictly for pwrstate subnodes (which seems likely at this point). One thing that comes to mind is telling the PMP (a coprocessor in charge of power metrics/management) about some domains being turned on/off, which is apparently a thing, but that wouldn't even be in this node; that'd have to be a phandle property in the child nodes referencing a PMP/coprocessor node elsewhere (none of which is implemented right now, and which should be backwards compatible once it is). If it turns out we do have a dep of some sort in the end, could we just have the child node driver return -EPROBE_DEFER until the parent is probed and has made whatever service available? That would allow us to keep simple-mfd, right? If it works for you, I'll also just squash the two bindings into one commit for the next spin, since there is a direct dependency at this point and it should make things easier. Otherwise, I can just swap the order if you prefer it that way. Ack on the other formatting changes; if the rest of the series looks good to the other folks I'll try to respin this into a v3 soon, to see if we can sneak it in by 5.16, since it'd be nice to have the power domain stuff in there :) -- Hector Martin (marcan@marcan.st) Public Key: https://mrcn.st/pub