Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751879AbdFIPrB (ORCPT ); Fri, 9 Jun 2017 11:47:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:55538 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751611AbdFIPq7 (ORCPT ); Fri, 9 Jun 2017 11:46:59 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 846F523698 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=robh@kernel.org MIME-Version: 1.0 In-Reply-To: <955d2903-9057-919b-004d-b1f5985dca5c@baylibre.com> References: <1496742340-10307-1-git-send-email-narmstrong@baylibre.com> <1496742340-10307-2-git-send-email-narmstrong@baylibre.com> <20170609133717.gkqnyatqezkrcaeg@rob-hp-laptop> <955d2903-9057-919b-004d-b1f5985dca5c@baylibre.com> From: Rob Herring Date: Fri, 9 Jun 2017 10:46:37 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 1/3] dt-bindings: arm: amlogic: Add SoC information bindings To: Neil Armstrong Cc: Kevin Hilman , Carlo Caione , linux-amlogic@lists.infradead.org, "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.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: 2660 Lines: 68 On Fri, Jun 9, 2017 at 8:58 AM, Neil Armstrong wrote: > On 06/09/2017 03:37 PM, Rob Herring wrote: >> On Tue, Jun 06, 2017 at 11:45:38AM +0200, Neil Armstrong wrote: >>> Add bindings for the SoC information register of the Amlogic SoCs. >>> >>> Signed-off-by: Neil Armstrong >>> --- >>> Documentation/devicetree/bindings/arm/amlogic.txt | 32 +++++++++++++++++++++++ >>> 1 file changed, 32 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/arm/amlogic.txt b/Documentation/devicetree/bindings/arm/amlogic.txt >>> index 5c01e65..ae3e8ed 100644 >>> --- a/Documentation/devicetree/bindings/arm/amlogic.txt >>> +++ b/Documentation/devicetree/bindings/arm/amlogic.txt >>> @@ -60,3 +60,35 @@ Board compatible values (alphabetically, grouped by SoC): >>> - "amlogic,q201" (Meson gxm s912) >>> - "kingnovel,r-box-pro" (Meson gxm S912) >>> - "nexbox,a1" (Meson gxm s912) >>> + >>> +Amlogic Meson Firmware registers Interface >>> +------------------------------------------ >>> + >>> +The Meson SoCs have a register bank with status and data shared with the >>> +secure firmware. >>> + >>> +Required properties: >>> + - compatible: For Meson GX SoCs, must be "amlogic,meson-gx-ao-secure", "syscon", "simple-mfd" >>> + >>> +Sub-nodes should indentify components of this register interface : >>> + >>> +Meson GX SoC Information >>> +------------------------ >>> +A firmware register encodes the SoC type, package and revision information on >>> +the Meson GX SoCs. >>> +If present, a device node for this register should be added. >>> + >>> +Required properties: >>> + - compatible: For Meson GX SoCs, must be "amlogic,meson-gx-chipid". >>> + >>> +Example >>> +------- >>> + >>> +ao-secure@140 { >>> + compatible = "amlogic,meson-gx-ao-secure", "syscon", "simple-mfd"; >>> + reg = <0x0 0x140 0x0 0x140>; >>> + >>> + chipid { >>> + compatible = "amlogic,meson-gx-chipid"; >> >> No registers for this block? If not, this node is pointless. >> "amlogic,meson-gx-ao-secure" should be specific enough to determine if >> you have this block or not and the driver for it can create a device if >> the OS needs it. >> >> Rob >> > > Well OK, but since it's a firmware interface, it can be handy to list the > possible capabilities, not especially tied to a driver. A "has-chip-id;" property would do that. It would be better to just be very explicit about what version of firmware you have and that can imply anything and everything you need to know about the firmware without needing to up date the dtb every time you need to provide a new (to Linux) firmware capability. Rob