From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FB49C77B7A for ; Wed, 7 Jun 2023 20:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231659AbjFGUES (ORCPT ); Wed, 7 Jun 2023 16:04:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230006AbjFGUER (ORCPT ); Wed, 7 Jun 2023 16:04:17 -0400 Received: from mail-io1-f54.google.com (mail-io1-f54.google.com [209.85.166.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7752E19AC; Wed, 7 Jun 2023 13:04:08 -0700 (PDT) Received: by mail-io1-f54.google.com with SMTP id ca18e2360f4ac-77a62a84855so85602539f.1; Wed, 07 Jun 2023 13:04:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686168247; x=1688760247; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=raWNAi0peUWVI3Y9OrLkCkchq3HuytUBPEeFbP0ENuk=; b=RT/4Ansqnewawi4SZqN3dWQjT4XFkbrds9oSySi+YlzIbjd3NhBGhCubFhRokcLzBZ 50FN5hB0LC0VN9nVTtp18s+R+k5rDL7aGGP4Q+3bjylbEq209aHiujMFFT0mbP3ze/nC H9XBWjEEhb7MkrZ5ViQSMIi66xgnXPC8Jx4rSRpshJ1q3YY0mv/P4avt7q+b2guKbOQf 5KY6kErl8Q/j1IosGYH6vsclY4givoxYL9TU5r9+Y4rSBWN+1OkPMUEAl7HQzoMIuP7q 0F/Y1215t9y6keFIb/JPp+Gi3EDD/F1Uct0DT5ny8My4SkRHBX8nHZwr9ZxdmYVJhOhR vvJQ== X-Gm-Message-State: AC+VfDzxYHsebiOpfm6ad6csyxWuqnJgqpAyMhXNNGcA6DThD1zj37YM mm4O1Fw5edYDmbgcpRuxCrb3Nl+TYg== X-Google-Smtp-Source: ACHHUZ45IDkIGT2Q9JMkxSSYM+aG/391kCQL1L54WXzc5BgP8ucqjIEn8nrFNK3DEjXExINnGSY8NQ== X-Received: by 2002:a5d:8703:0:b0:776:fc02:184e with SMTP id u3-20020a5d8703000000b00776fc02184emr6236322iom.14.1686168247383; Wed, 07 Jun 2023 13:04:07 -0700 (PDT) Received: from robh_at_kernel.org ([64.188.179.250]) by smtp.gmail.com with ESMTPSA id n7-20020a02cc07000000b0041cce10544dsm3696709jap.123.2023.06.07.13.04.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jun 2023 13:04:06 -0700 (PDT) Received: (nullmailer pid 3931893 invoked by uid 1000); Wed, 07 Jun 2023 20:04:03 -0000 Date: Wed, 7 Jun 2023 14:04:03 -0600 From: Rob Herring To: Samuel Holland Cc: Jisheng Zhang , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-serial@vger.kernel.org, Palmer Dabbelt , Conor Dooley , Thomas Gleixner , Marc Zyngier , Palmer Dabbelt , Paul Walmsley , Albert Ou , Greg Kroah-Hartman , Jiri Slaby Subject: Re: [PATCH v4 06/10] dt-bindings: riscv: Add bouffalolab bl808 board compatibles Message-ID: <20230607200403.GA3909108-robh@kernel.org> References: <20230518152244.2178-1-jszhang@kernel.org> <20230518152244.2178-7-jszhang@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, May 18, 2023 at 10:31:35PM -0500, Samuel Holland wrote: > Hi Jisheng, DT maintainers, > > On 5/18/23 10:22, Jisheng Zhang wrote: > > Several SoMs and boards are available that feature the Bouffalolab > > bl808 SoC. Document the compatible strings. > > > > Signed-off-by: Jisheng Zhang > > Acked-by: Palmer Dabbelt > > Reviewed-by: Conor Dooley > > --- > > .../bindings/riscv/bouffalolab.yaml | 29 +++++++++++++++++++ > > 1 file changed, 29 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/riscv/bouffalolab.yaml > > > > diff --git a/Documentation/devicetree/bindings/riscv/bouffalolab.yaml b/Documentation/devicetree/bindings/riscv/bouffalolab.yaml > > new file mode 100644 > > index 000000000000..3b25d1a5d04a > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/riscv/bouffalolab.yaml > > @@ -0,0 +1,29 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/riscv/bouffalolab.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Bouffalo Lab Technology SoC-based boards > > + > > +maintainers: > > + - Jisheng Zhang > > + > > +description: > > + Bouffalo Lab Technology SoC-based boards > > + > > +properties: > > + $nodename: > > + const: '/' > > + compatible: > > + oneOf: > > + - description: Carrier boards for the Sipeed M1s SoM > > + items: > > + - enum: > > + - sipeed,m1s-dock > > + - const: sipeed,m1s > > + - const: bouffalolab,bl808 > > As mentioned in the message for patch 5, "The Bouffalolab bl808 SoC > contains three riscv CPUs, namely M0, D0 and LP. The D0 is 64bit RISC-V > GC compatible, so can run linux." > > I have also been running U-Boot and NOMMU Linux on the less powerful, > but still quite fast, "M0" core. However, this core needs a different > DTB because: > 1) The CPU is different (T-HEAD E907 instead of C906). > 2) The interrupt routing is completely different. > a. The M0 core contains a CLIC instead of a PLIC. > b. The peripherals in the SoC are split between two buses. Those > on one bus have their IRQs directly connected to M0, and share > a multiplexed IRQ connection to D0; and vice versa for the > other bus. So each bus's interrupt-parent needs to be swapped. Can't you include the dts file and then just override 'interrupt-parent'? > Using some preprocessor magic like we did for Allwinner and Renesas, I > was able to share most of the SoC and board DTs between the cores[1]. > However, this still ends up with two DTs for each board. So here are my > questions: > - Is this acceptable? > - Is there precedent for how we should name the two board DTs? > - How does this affect the board and SoC compatible strings? > - Should there be a separate "bouffalolab,bl808-d0" in addition to > "bouffalolab,bl808"? Probably. A DT is ultimately the view of the hardware from a CPU's perspective. Different views, different compatibles. > - Is it acceptable to use the same board compatible string for both, > since the _board_ part of the DT does not change, only things > inside the SoC? Yes. > > It would be possible to avoid having two DTs per board by guarding all > of the differences behind "#ifdef CONFIG_64BIT", but that seems wrong > because you would end up with two totally incompatible DTBs named the > same thing, depending on how the DTB was built. You can't have CONFIG_ options in .dts files. Rob