Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754093Ab3ILPZU (ORCPT ); Thu, 12 Sep 2013 11:25:20 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:56589 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752961Ab3ILPZQ (ORCPT ); Thu, 12 Sep 2013 11:25:16 -0400 Message-ID: <5231DB88.90605@wwwdotorg.org> Date: Thu, 12 Sep 2013 09:19:36 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Alexander Holler CC: Javier Martinez Canillas , Linus Walleij , Laurent Pinchart , Grant Likely , 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 References: <1375101368-17645-1-git-send-email-linus.walleij@linaro.org> <344239800.bDEkDg48ZQ@avalon> <52308C91.2000105@ahsoftware.de> <523096FE.8080901@collabora.co.uk> <5230AB6E.1070807@ahsoftware.de> <5231817F.8000901@ahsoftware.de> <5231934D.4060706@collabora.co.uk> <52319741.5050407@ahsoftware.de> <5231A0F8.1070505@ahsoftware.de> <5231A4FE.1070704@ahsoftware.de> <5231A791.9080600@ahsoftware.de> In-Reply-To: <5231A791.9080600@ahsoftware.de> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3423 Lines: 78 On 09/12/2013 05:37 AM, Alexander Holler wrote: > Am 12.09.2013 13:26, schrieb Alexander Holler: >> Am 12.09.2013 13:09, schrieb Alexander Holler: >>> Am 12.09.2013 12:28, schrieb Alexander Holler: >>>> Am 12.09.2013 12:11, schrieb Javier Martinez Canillas: >>>>> On 09/12/2013 10:55 AM, Alexander Holler wrote: ... >>>>> So, if I understood the code correctly the DT IRQ core doesn't expect >>>>> a device node to have more than one "interrupt-parent" property. The root-cause is the binding definition, not the code. The interrupts property does not contain the phandle of the IRQ controller, but rather the interrupt-parent property does. Thus, there is a single interrupt parent for each node, unless you employ some tricks (see below). >>>>> It *should* work though if you have multiple "interrupts" properties >>>>> defined and >>>>> all of them have the same "interrupt-parent": >>>>> >>>>> interrupt-parent = <&gpio6>; >>>>> interrupts = <1 IRQF_TRIGGER_HIGH>; /* GPIO6_1 */ >>>>> interrupts = <2 IRQF_TRIGGER_LOW>; /* GPIO6_2 */ DT is a key/value data structure, not a list of property (name, value) pairs. In other words, you can't have multiple properties of the same name in a node. At least in the compiled DTB; you /might/ be able to compile the DT above with dtc, but if so the second definition of the property will just over-write the first. ... >> I've just seen how they solved it for dma: >> >> dmas = <&edma0 16 >> &edma0 17>; >> dma-names = "rx", "tx"; ... > And looking at how gpios are defined, I think it should be like that: > > interrupts = <&gpio6 1 IRQF_TRIGGER_HIGH > &gpio7 2 IRQF_TRIGGER_LOW > >; > interrupt-names = "foo", "bar"; > > So without that interrupt-parent. 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. -- 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/