From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f41.google.com ([74.125.83.41]:48909 "EHLO mail-ee0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751417Ab3HTHN5 (ORCPT ); Tue, 20 Aug 2013 03:13:57 -0400 Received: by mail-ee0-f41.google.com with SMTP id d17so25466eek.0 for ; Tue, 20 Aug 2013 00:13:56 -0700 (PDT) Date: Tue, 20 Aug 2013 08:13:51 +0100 From: Lee Jones Subject: Re: [PATCH v2] max77693: added device tree support Message-ID: <20130820071351.GE23699@lee--X1> References: <20130819104409.GA21520@lee--X1> <1376912426-14747-1-git-send-email-a.hajda@samsung.com> <52128BAD.6020903@wwwdotorg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <52128BAD.6020903@wwwdotorg.org> Sender: devicetree-owner@vger.kernel.org To: Stephen Warren Cc: Andrzej Hajda , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Rob Landley , Samuel Ortiz , Grant Likely , Sylwester Nawrocki , Jonghwa Lee , Kyungmin Park , "open list:OPEN FIRMWARE AND..." , open list List-ID: On Mon, 19 Aug 2013, Stephen Warren wrote: > On 08/19/2013 05:40 AM, Andrzej Hajda wrote: > > max77693 mfd main device uses only wakeup field > > from max77693_platform_data. This field is mapped > > to wakeup-source common property in device tree. > > > diff --git a/Documentation/devicetree/bindings/mfd/max77693.txt b/Documentation/devicetree/bindings/mfd/max77693.txt > > > Optional properties: > > - regulators : The regulators of max77693 have to be instantiated under subnod > > named "regulators" using the following format. > > +- wakeup-source : Indicates if the device can wakeup the system from the sleep > > + state. > > Does the property mean "can" or "should"? > > "Can" implies that the property means something about the HW. What > exactly does it mean; perhaps that some specific output pin of the chip > has been wired to an input IRQ/GPIO of the SoC or PMIC that (can) wake > up the system? If so, which pin, signal, ...? Also, doesn't this also > depend on the SoC itself supporting its input IRQ/GPIO as a wakeup > source, so isn't some co-ordination required between the SoC and chip, > such that this property doesn't mean "can wakeup the system", but simply > "a signal is routed to the SoC, so perhaps it can wakeup the system". > > "Should" implies policy, which probably shouldn't be represented in > device tree, since DT should describe the HW and not how it should be used. > > Finally, if there was already a binding for max77693.txt, I don't think > the patch subject "added device tree support" is entirely accurate; this > change to the binding document seems to be more about adding a new > feature than adding DT support to the driver... I'm taking this as a NACK. Once Stephen is happy I'll reapply any RESEND with his Ack. -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog