From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9753F20408D; Wed, 6 Nov 2024 16:41:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730911261; cv=none; b=TJSYjEDCA7jU1FY1B8ua1BnE931mcKC0LhcAaod1R4d/9zRSok2tZHfIMXRfDSPD1bAOQjskzo99iJdgeByRxvwQQP11/h8/BPGsXaoS3NTgaoC+iwiy9na0QoeuZ/HdKJQY/NAStpmrsfLSMvSHWV5lNoVS0aR9LbkkiW95x1E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730911261; c=relaxed/simple; bh=/GIrb8lH6MtB9ni0oZQC5O1PWk0ZuEvid3uRJD/gFEk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cIzq9bOs0FZbvQA8Sd+Ob2kY0p16cqfa2BVvUFp90Byd2YEIVgAo8mbDT6uEzca10OG/o0uH1hKMYOSsuuEGq3KtEkzp/KowsC4M9/ZfqPaNux8qXTB3SRBeLFdvp/oPTod7kELPMs3qkNpxw+C4p3EdvVob3ZG3V0vr67HQ4Us= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a/tDVlPs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a/tDVlPs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FC78C4CEC6; Wed, 6 Nov 2024 16:40:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1730911260; bh=/GIrb8lH6MtB9ni0oZQC5O1PWk0ZuEvid3uRJD/gFEk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=a/tDVlPsFSxqrW/jxij2IoAoHIVPLSEYkIWy4w1eFfFs8RoMwmk3WbWBgmUVjitiR kYy7iRQs/rx0N5huEMCFuFRGHgVPtI7vVGbJfPS3N5bBwlcJA+3f02facNV4Y5RjBG o5UbkUB3XNhvFIjFLP0CsZwXriRM66aWfZYgBnRtIc9IgJ7ykIXwD2XPHBNoGbhQk0 urJvbUcOaX0rmlSegERf/yG2qsPlR5Fl9OuKadaKKd7O18Q17zVcmszNnzVjeswddX El3xioF32fP6OkqbGaQdE+AqbuyJv92rowbq5itKl41dC3ZvJwaoQVjb3ro9SAgKTa yGUO3AyedBd/A== Date: Wed, 6 Nov 2024 16:40:54 +0000 From: Conor Dooley To: Matthias Schiffer Cc: Nishanth Menon , Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Greg Kroah-Hartman , Kees Cook , Tony Luck , "Guilherme G. Piccoli" , Felipe Balbi , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-hardening@vger.kernel.org, Devarsh Thakkar , Hari Nagalla , linux@ew.tq-group.com Subject: Re: [PATCH 2/5] dt-bindings: arm: ti: Add compatible for AM625-based TQMa62xx SOM family and carrier board Message-ID: <20241106-happy-anything-46f7293f6aca@spud> References: <4f5ad877f44df35a3b2c7f336647f057c4e6377d.1730299760.git.matthias.schiffer@ew.tq-group.com> <20241104-floral-dexterous-7d3fee2ff616@spud> <20241105-tinsmith-countable-fbb51045bc98@spud> <7286141141fe4930cd2581dac7a1fb36a98e62c4.camel@ew.tq-group.com> Precedence: bulk X-Mailing-List: linux-usb@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="oJ2Y6Urhi+vkl28I" Content-Disposition: inline In-Reply-To: <7286141141fe4930cd2581dac7a1fb36a98e62c4.camel@ew.tq-group.com> --oJ2Y6Urhi+vkl28I Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 06, 2024 at 01:03:08PM +0100, Matthias Schiffer wrote: > On Tue, 2024-11-05 at 18:55 +0000, Conor Dooley wrote: > > On Tue, Nov 05, 2024 at 11:40:20AM +0100, Matthias Schiffer wrote: > > > On Mon, 2024-11-04 at 18:47 +0000, Conor Dooley wrote: > > > > On Mon, Nov 04, 2024 at 10:47:25AM +0100, Matthias Schiffer wrote: > > > > > The TQMa62xx is a SoM family with a pluggable connector. The MBa6= 2xx is > > > > > the matching reference/starterkit carrier board. > > > >=20 > > > > Why all the wildcards? Why isn't there a compatible per device in t= he > > > > family? >=20 > Because all variants use the same Device Tree. There is also only one com= patible and one (main) DTSI > for the AM62 SoC family, which our Device Trees are based on. So what varies between the members of the family? > > > For the compatible string we've chosen the TQMa6254 as the representa= tive for the TQMa62xx family. > >=20 > > And all the boards in the family are the exact same? >=20 > There is a single TQMa62xx PCB, which has some AM62 family SoC installed = (AM6254 in the case of the > TQMa6254, but all AM62 are possible). TQMa62xx is also the name used for = marketing when not talking > about a specific SoC variant: > https://www.tq-group.com/en/products/tq-embedded/arm-architecture/tqma62x= x/ >=20 > Some SoM variants with different RAM/eMMC/SPI-NOR/... do exist, but they = don't have separate device > trees (firmware may patch some variant information into the DTB however, = like the correct RAM size). >=20 > Choosing one representative for the family including the SoC variant numb= er, but not distinguishing > minor variants matches the level of detail used for our other SOMs alread= y supported by mainline > Linux (like the TQMa64xxL and various i.MX-based platforms). I don't like any of this wildcard stuff at all, who is to say that the next soc you put on your SoM won't be an am62a7, which has a specific compatible in the kernel? Your fallback then would be ti,am62a7 not ti,am625. Probably someone will say "that's the am62a family not the am62 family" - but that exact thing is why I hate all of this wildcarding. It's barely any more effort to have a tqm6231 and a tqm6254 compatible than what you're doing with wildcard but it is unambiguous. --oJ2Y6Urhi+vkl28I Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZyucFgAKCRB4tDGHoIJi 0nTOAP49AhXzVo1rMKvtd3ePJuffEjuHdGlp/GqT6bBrNTGtFwD/eogtLPtuaM+U fil0gvlsrbgOMKWtdE3BthhK3ZCfvQw= =yzQZ -----END PGP SIGNATURE----- --oJ2Y6Urhi+vkl28I--