Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751082Ab3JTMlX (ORCPT ); Sun, 20 Oct 2013 08:41:23 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:51634 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767Ab3JTMlV (ORCPT ); Sun, 20 Oct 2013 08:41:21 -0400 From: Laurent Pinchart To: Grant Likely Cc: 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 , Tony Lindgren , Jon Hunter Subject: Re: [PATCH] RFC: interrupt consistency check for OF GPIO IRQs Date: Sun, 20 Oct 2013 14:41:41 +0200 Message-ID: <1805938.y3dym69kEh@avalon> User-Agent: KMail/4.10.5 (Linux/3.10.7-gentoo-r1; KDE/4.10.5; x86_64; ; ) In-Reply-To: <20130918003632.CBF48C42BC5@trevor.secretlab.ca> References: <1375101368-17645-1-git-send-email-linus.walleij@linaro.org> <5231E44C.9070800@ahsoftware.de> <20130918003632.CBF48C42BC5@trevor.secretlab.ca> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3361 Lines: 82 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. 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. -- Regards, Laurent Pinchart -- 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/