From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C25C1F09A8; Mon, 3 Mar 2025 09:09:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.154.123 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740992968; cv=none; b=hSkDWBu/9WMHcUm+Uvc26wsH8ge1hisAD5vuPVCHlRYGUvJb4HlofMoYdEs0ORD2hOEfb5JfNDR2Dy7WxzCLK+rM2EoQrRecC1F2bATsPqGG7y3dN54Z1p2wGvIEjn7yRHkjAnu4hp2WKfcyv5eiJ6Ar92p5E60Vp9d/5YKAzGE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740992968; c=relaxed/simple; bh=eLPVTYCLr/v+z3Rpfjq9386InLTsMCaOhJxCahwa3fE=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=vC3Hh2T1EcHM2OTXDwvG+uWpNSgT0Dq39nZaBir1H6qDCgTnA+WiUC/Y9d6FYcE182HgwN7S4RvTEPd+gJKPXjJ5OF5BpTgHLqJj1TrdTItYSpTRzmanZiswiNtsRFtqOYwUwFB+EcnJnlFBxJ1/E/oI+MGUuQKfAz6Ljl7qkjQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com; spf=pass smtp.mailfrom=microchip.com; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b=1ORyGz++; arc=none smtp.client-ip=68.232.154.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="1ORyGz++" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1740992966; x=1772528966; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=eLPVTYCLr/v+z3Rpfjq9386InLTsMCaOhJxCahwa3fE=; b=1ORyGz++BGcPpsBaNrjBX6oYxf1PMx5yWTVExleoTj5SdvKjSPAwkgp7 afOHMT/ieCCyc+GOJVhcydpyHgVy2v9zsKBOX9uvCNl90T8MqDcNdmhdl kBly+DwmTmqbsfgyJRhMHTzCAzzkvvb2kOcE+ilcUNOMtiOEQtWUozTw4 SQxpuL+6x7wYNo8rToK47nZnknn840oqgY5rBxZSFIZl1xYl23rk1Xs5N IeRrXAV77WLgdDHO44yKcl1BX7131mLj1kU99CEsulwYsOMLIVgRk9sQa V4OnC1yjMkLMmMdJ2za1G1Sq0otS3NCQB06CnvOx1Ilo9zQZAt3wuBl+N A==; X-CSE-ConnectionGUID: vdV2+gEUTw2O2FxCKkKLiw== X-CSE-MsgGUID: bSWdOAdmQv+RmLfY7KSCNA== X-IronPort-AV: E=Sophos;i="6.13,329,1732604400"; d="asc'?scan'208";a="38764365" X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa2.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 03 Mar 2025 02:09:20 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 3 Mar 2025 02:09:14 -0700 Received: from wendy (10.10.85.11) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35 via Frontend Transport; Mon, 3 Mar 2025 02:09:11 -0700 Date: Mon, 3 Mar 2025 09:08:16 +0000 From: Conor Dooley To: Chen Wang CC: Conor Dooley , Zixian Zeng , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Inochi Amaoto , Alexandre Ghiti , , , , , , Subject: Re: [PATCH v2] riscv: sophgo: dts: Add spi controller for SG2042 Message-ID: <20250303-recital-crunchy-6f7806987da0@wendy> References: <20250228-sfg-spi-v2-1-8bbf23b85d0e@gmail.com> <20250228-factual-rage-0e1e1e48b009@spud> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Ow63fKL/6QkVXSRs" Content-Disposition: inline In-Reply-To: --Ow63fKL/6QkVXSRs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Mar 01, 2025 at 09:58:24AM +0800, Chen Wang wrote: >=20 > On 2025/3/1 2:22, Conor Dooley wrote: > [......] > > > + > > > + spi0: spi@7040004000 { > > > + compatible =3D "snps,dw-apb-ssi"; > > I thought were were dropping the use of "snps,dw-abp-ssi" in isolation, > > and starting to require soc-specific compatibles now. > >=20 > > Rob, Krzysztof? > I'm also very interested to know why we can't just use "snps,dw-abp-ssi", > maybe I missed some discussion ... Ordinarily you're not allowed to use generic compatibles at all, the dw stuff has kinda been an ?unofficial? exception for a while and not just for spi. I think that "exception" has been withdrawn though, and dw stuff is being brought in line with everything else, but cannot remember where that started. > I googled examples of soc-specific defined in the code, and it doesn't se= em > to be much, only arch/mips/boot/dts/mscc/ocelot.dtsi and > arch/riscv/boot/dts/thead/th1520.dtsi. > Specially, I looked at the commits for th1520 and saw this https://lore.k= ernel.org/linux-riscv/20240703-garbage-explicit-bd95f8deb716@wendy/. > It tells if the fallback works identically, then the specific compatible = is > not needed. This link is talking about the driver, not the dts/binding. Adding the device-specific compatible to the driver is only needed if the specific one has some extra features above and beyond the compatible used as the fallback. Cheers, Conor. --Ow63fKL/6QkVXSRs Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZ8VxcwAKCRB4tDGHoIJi 0lX/AQDJBY3641IPRBtubqSLaUcbCrjzlLFp3F9Lw+Wi6rDPSAEA8dXwvoY2dJWS Vy+cEBykB0x0CsyGnioS7rl+yMdBqwk= =upyW -----END PGP SIGNATURE----- --Ow63fKL/6QkVXSRs--