Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371AbcD0SCz (ORCPT ); Wed, 27 Apr 2016 14:02:55 -0400 Received: from mail-io0-f193.google.com ([209.85.223.193]:36780 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752176AbcD0SCw (ORCPT ); Wed, 27 Apr 2016 14:02:52 -0400 MIME-Version: 1.0 In-Reply-To: <20160427173810.GC7359@leverpostej> References: <1461150237-15580-1-git-send-email-jonathanh@nvidia.com> <1461150237-15580-14-git-send-email-jonathanh@nvidia.com> <20160422100052.GA10606@leverpostej> <571A0739.3090502@nvidia.com> <20160422112239.GF10606@leverpostej> <5720DC1D.1080802@nvidia.com> <20160427173810.GC7359@leverpostej> Date: Wed, 27 Apr 2016 20:02:51 +0200 X-Google-Sender-Auth: 1m3X_cSL5mIZxrkF1jj71_dcE7c Message-ID: Subject: Re: [PATCH V2 13/14] dt-bindings: arm-gic: Add documentation for Tegra210 AGIC From: Geert Uytterhoeven To: Mark Rutland Cc: Jon Hunter , Thomas Gleixner , Jason Cooper , Marc Zyngier , Rob Herring , Pawel Moll , Ian Campbell , Kumar Gala , Stephen Warren , Thierry Reding , Kevin Hilman , 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" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3979 Lines: 90 On Wed, Apr 27, 2016 at 7:38 PM, Mark Rutland wrote: > On Wed, Apr 27, 2016 at 04:34:53PM +0100, Jon Hunter wrote: >> On 22/04/16 12:22, Mark Rutland wrote: >> [snip] >> >> >>>> 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"). >> >> >> >> Yes that would be fine with me. >> > >> > Ok; if we model the apb_pclk as owned by the AXI switch (which it is), >> > then there's no change for the GIC binding, short of the additional >> > compatible string as an extension of "arm,gic-400", as we already model >> > that clock in the GIC-400 binding. >> >> I have been re-working this based upon the feedback received. In the GIC >> driver we have the following definitions ... >> >> IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init); >> IRQCHIP_DECLARE(arm11mp_gic, "arm,arm11mp-gic", gic_of_init); >> IRQCHIP_DECLARE(arm1176jzf_dc_gic, "arm,arm1176jzf-devchip-gic", gic_of_init); >> IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init); >> IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init); >> IRQCHIP_DECLARE(cortex_a7_gic, "arm,cortex-a7-gic", gic_of_init); >> IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init); >> IRQCHIP_DECLARE(msm_qgic2, "qcom,msm-qgic2", gic_of_init); >> IRQCHIP_DECLARE(pl390, "arm,pl390", gic_of_init); >> >> >> If I have something like the following in my dts ... >> >> agic: interrupt-controller@702f9000 { >> compatible = "nvidia,tegra210-agic", "arm,gic-400"; >> ... >> }; >> >> The problem with this is that it tries to register the interrupt controller >> early during of_irq_init() before the platform driver has chance to >> initialise it. > > Probe order strikes again... > >> To avoid this I got rid of the "nvidia,tegra210-agic" string and added >> the following for the platform driver ... >> >> static const struct of_device_id gic_match[] = { >> { .compatible = "arm,arm11mp-gic-pm", .data = &arm11mp_gic_data }, >> { .compatible = "arm,cortex-a15-gic-pm", .data = &cortexa15_gic_data }, >> { .compatible = "arm,cortex-a9-gic-pm", .data = &cortexa9_gic_data }, >> { .compatible = "arm,gic400-pm", .data = &gic400_data }, >> { .compatible = "arm,pl390-pm", .data = &pl390_data }, >> {}, >> }; >> >> It is not ideal as now we have a *-pm variant of each compatible string :-( > > Yeah, that's a non-starter. :( > >> Another option would be to add some code in gic_of_init() to check for the >> presence of a "clocks" node in the DT binding and bail out of the early >> initialisation if found but may be that is a bit of a hack. Or the presence of a power-domains property... > I fear that someone may validly have a clocks property in their root GIC > node, at which point things would fall apart. I was under the impression > this was the case for some Renesas boards (though I didn't find an > example in tree). We don't have the GIC clocks in the GIC nodes yet, as there's no suitable mechanism (e.g. CLK_ENABLE_HAND_OFF) in upstream yet to prevent them from being disabled ("unused" clocks are disabled). Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds