Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753316AbcDVKBI (ORCPT ); Fri, 22 Apr 2016 06:01:08 -0400 Received: from foss.arm.com ([217.140.101.70]:60518 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752149AbcDVKBC (ORCPT ); Fri, 22 Apr 2016 06:01:02 -0400 Date: Fri, 22 Apr 2016 11:00:52 +0100 From: Mark Rutland To: Jon Hunter Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , Stephen Warren , Thierry Reding , Kevin Hilman , Geert Uytterhoeven , Grygorii Strashko , Lars-Peter Clausen , Linus Walleij , linux-tegra@vger.kernel.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 13/14] dt-bindings: arm-gic: Add documentation for Tegra210 AGIC Message-ID: <20160422100052.GA10606@leverpostej> References: <1461150237-15580-1-git-send-email-jonathanh@nvidia.com> <1461150237-15580-14-git-send-email-jonathanh@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461150237-15580-14-git-send-email-jonathanh@nvidia.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2650 Lines: 65 On Wed, Apr 20, 2016 at 12:03:56PM +0100, Jon Hunter wrote: > The Tegra AGIC interrupt controller is compatible with the ARM GIC-400 > interrupt controller. The cover letter says it _is_ a GIC-400, just used in a slightly unusual manner (i.e. not directly connected to CPUs). > The Tegra AGIC requires two clocks, namely the > "ape" (functional) and "apb2ape" (interface) clocks, to operate. Add > the compatible string and clock information for the AGIC to the GIC > device-tree binding documentation. The GIC-400 spec only describes "CLK" (which is what I imagine "ape" is. There isn't an APB clock described, and the manual seems to show GIC-400 directly connected to AXI rather than APB, so that doesn't seem to even be the usual "apb_pclk". Is there some wrapper logic around a GIC-400 to giove it an APB interface? Or am I misudnerstanding the spec? > Signed-off-by: Jon Hunter > --- > > I am not sure if it will be popular to add Tegra specific clock names > to the GIC DT docs. However, in that case, then possibly the only > alternative is to move the Tegra AGIC driver into its own file and > expose the GIC APIs for it to use. Then we could add our own DT doc > for the Tegra AGIC as well (based upon the ARM GIC). The clock-names don't seem right to me, as they sound like provide names or global clock line names rather than consumer-side names ("clk" and "apb_pclk"). I'm also not certain about the compatible string; if this really is a GIC-400 then I would at least expect "arm,gic-400" as a fallback. Thanks, Mark. > Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt b/Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt > index 793c20ff8fcc..6f34267f1438 100644 > --- a/Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt > +++ b/Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt > @@ -21,6 +21,7 @@ Main node required properties: > "arm,pl390" > "arm,tc11mp-gic" > "brcm,brahma-b15-gic" > + "nvidia,tegra210-agic" > "qcom,msm-8660-qgic" > "qcom,msm-qgic2" > - interrupt-controller : Identifies the node as an interrupt controller > @@ -70,6 +71,7 @@ Optional > "PERIPHCLK", "PERIPHCLKEN" (for "arm,cortex-a9-gic") > "clk" (for "arm,gic-400") > "gclk" (for "arm,pl390") > + "ape" and "apb2ape" (for "nvidia,tegra,agic") > > - power-domains : A phandle and PM domain specifier as defined by bindings of > the power controller specified by phandle, used when the GIC > -- > 2.1.4 >