Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751328Ab3JTPvt (ORCPT ); Sun, 20 Oct 2013 11:51:49 -0400 Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:18805 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112Ab3JTPvr (ORCPT ); Sun, 20 Oct 2013 11:51:47 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 50.131.214.131 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX1/vZlIAQMJ04IGTmZ/uN0NU Date: Sun, 20 Oct 2013 08:51:35 -0700 From: Tony Lindgren To: Laurent Pinchart Cc: Grant Likely , Alexander Holler , Stephen Warren , Javier Martinez Canillas , Linus Walleij , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , Linux-OMAP , "devicetree@vger.kernel.org" , Enric Balletbo i Serra , Jean-Christophe PLAGNIOL-VILLARD , Santosh Shilimkar , Kevin Hilman , Balaji T K , Jon Hunter Subject: Re: [PATCH] RFC: interrupt consistency check for OF GPIO IRQs Message-ID: <20131020155135.GW12599@atomide.com> References: <1375101368-17645-1-git-send-email-linus.walleij@linaro.org> <5231E44C.9070800@ahsoftware.de> <20130918003632.CBF48C42BC5@trevor.secretlab.ca> <1805938.y3dym69kEh@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1805938.y3dym69kEh@avalon> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3801 Lines: 91 * Laurent Pinchart [131020 05:41]: > Hi Grant, > > On Tuesday 17 September 2013 17:36:32 Grant Likely wrote: > > On Thu, 12 Sep 2013 17:57:00 +0200, Alexander Holler wrote: > > > Am 12.09.2013 17:19, schrieb Stephen Warren: > > > > IRQs, DMA channels, and GPIOs are all different things. Their bindings > > > > are defined independently. While it's good to define new types of > > > > bindings consistently with other bindings, this hasn't always happened, > > > > so you can make zero assumptions about the IRQ bindings by reading the > > > > documentation for any other kind of binding. > > > > > > > > Multiple interrupts are defined as follows: > > > > // Optional; otherwise inherited from parent/grand-parent/... > > > > interrupt-parent = <&gpio6>; > > > > // Must be in a fixed order, unless binding defines that the > > > > // optional interrupt-names property is to be used. > > > > interrupts = <1 IRQF_TRIGGER_HIGH> <2 IRQF_TRIGGER_LOW>; > > > > // Optional; binding for device defines whether it must > > > > // be present > > > > interrupt-names = "foo", "bar"; > > > > > > > > If you need multiple interrupts, each with a different parent, you need > > > > to use an interrupt-map property (Google it for a more complete > > > > explanation I guess). Unlike "interrupts", "interrupt-map" has a phandle > > > > in each entry, and hence each entry can refer to a different IRQ > > > > controller. You end up defining a dummy interrupt controller node (which > > > > may be the leaf node with multiple IRQ outputs, which then points at > > > > itself as the interrupt parent), pointing the leaf node's > > > > interrupt-parent at that node, and then having interrupt-map "demux" the > > > > N interrupt outputs to the various interrupt controllers. > > > > > > What a mess. I assume that is the price that bindings don't have to > > > change. > > > > > > Thanks for clarifying that, > > > > > > Alexander Holler > > > > Actually, I think it is solveable but doing so requires a new binding > > for interrupts. I took a shot at implementing it earlier this week and > > I've got working patches that I'll be posting soon. I created a new > > "interrupts-extended" property that uses a phandle+args type of > > binding like this: > > > > intc1: intc@1000 { > > interrupt-controller; > > #interrupt-cells = <1>; > > }; > > > > intc2: intc@2000 { > > interrupt-controller; > > #interrupt-cells = <2>; > > }; > > > > device@3000 { > > interrupts-extended = <&intc1 5> <&intc2 3 4> <&intc1 6>; > > }; > > > > 'interrupts-extended' will be proposed as a directly replacement of the > > 'interrupts' property and it will eliminate the need for an > > interrupt-map property. A node will be allowed to have one or the other, > > but not both. > > > > I'll write up a proper binding document and post for review. > > Any progress on this ? I'll need to use multiple interrupts with different > parents in the near future, I can take this over if needed. Grant posted the interrupts-extended binding few days ago: http://lkml.org/lkml/2013/10/15/760 > I've also been thinking that we could possibly reuse the "interrupts" property > without defining a new "interrupts-extended". When parsing the property the > code would use the current DT bindings if an interrupt-parent is present, and > the new DT bindings if it isn't. That could lead to mysterious failures easily as the binding behaves in two different ways :) Probably best to have a separate binding for it. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/