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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F5A8C4724C for ; Fri, 1 May 2020 13:53:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55B8620836 for ; Fri, 1 May 2020 13:53:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731648AbgEANxT (ORCPT ); Fri, 1 May 2020 09:53:19 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:60231 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729727AbgEANxN (ORCPT ); Fri, 1 May 2020 09:53:13 -0400 X-Originating-IP: 86.202.105.35 Received: from localhost (lfbn-lyo-1-9-35.w86-202.abo.wanadoo.fr [86.202.105.35]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 3553820003; Fri, 1 May 2020 13:53:10 +0000 (UTC) Date: Fri, 1 May 2020 15:53:09 +0200 From: Alexandre Belloni To: Rob Herring Cc: Thierry Reding , Lee Jones , Alessandro Zummo , Jon Hunter , devicetree@vger.kernel.org, "open list:REAL TIME CLOCK (RTC) SUBSYSTEM" , linux-tegra , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/3] dt-bindings: mfd: Document the RTC present on MAX77620 Message-ID: <20200501135309.GC51277@piout.net> References: <20200417170825.2551367-1-thierry.reding@gmail.com> <20200430140701.GA21776@bogus> <20200430141520.GA101194@piout.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/05/2020 08:00:11-0500, Rob Herring wrote: > > I don't think this is true because in the case of a discrete RTC, its > > interrupt pin can be connected directly to a PMIC to power up a board > > instead of being connected to the SoC. In that case we don't have an > > interrupt property but the RTC is still a wakeup source. This is the > > usual use case for wakeup-source in the RTC subsystem. Else, if there is > > an interrupt, then we assume the RTC is a wakeup source and there is no > > need to have the wakeup-source property. > > Yes, that would be an example of "unless the wakeup mechanism is > somehow not an interrupt". I guess I should add not an interrupt from > the perspective of the OS. > > So if the wakeup is self contained within the PMIC, why do we need a > DT property? The capability is always there and enabling/disabling > wakeup from it is userspace policy. > Yes, for this particular case, I'm not sure wakeup-source is actually necessary. If the interrupt line is used to wakeup the SoC, then the presence of the interrupts property is enough to enable wakeup. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com