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 7014454658; Mon, 5 Aug 2024 10:11:21 +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=1722852681; cv=none; b=AyGnOKc2Ft7hqLRtwQ6FFoyiqYyQBSjvMuJ04K7MnK1O/HS8VwKKXrjSDNKL1llnBqxGLlNcxa42k+fmo0HUAOsSbkdJDzCFknojF1LChY61Kbg0FX1KsVSij8KYEJtZadeCy9zEViUlqKe58NMfgYwpNg+jflLq/co5AoPUfJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722852681; c=relaxed/simple; bh=Y0Xi9lYKmT1BemQ3hyO64BittxZDFwIlR/Mz+JVojBE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Rf+1RDZpZovNglFkJTUksZeU5m20XIMcwSnenU9F4cZxVFNjAKn1E8Nf0hDMQvuMTgp0o2A9yP35EeK6B23uSCR+mzl4BCcxLLQO5i2l3NIa2luq+uWovxd0i3C8hItQUK4R/QhrwBW9Bzruf5nOFxY/JCTfjcZr44DQelZVg2k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sbv+3rne; 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="sbv+3rne" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A092AC32782; Mon, 5 Aug 2024 10:11:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722852681; bh=Y0Xi9lYKmT1BemQ3hyO64BittxZDFwIlR/Mz+JVojBE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sbv+3rneucVIfs/QIVqv5N/lw/ShNIZSNt63f3w3XnwTYBCypUDdbP/DMLVWO2T7Z Ui9du5WInuuFGKbUlv6wwwUuFlU/0pNhGcasoIZrXDv5q2+Yk51hqo5Cjy/EL8s7yj jYeh0DXPPLkXdgyCZvf1aGkSmno9gIZ1kR+u0zUuujwDggvotVoJ7a3LIs2g7zuXbQ sX77ytC20GGjEPRNguj0WxbrwVFJyUXg62T2XUYAQ4QIxBEyfNvqYipXoJrs1ITUEp 5JY7dynJpIx/FWGoFqvgANLpF7yR7l5ZGm7olvAm6v1W23Kb41vAOWreQojPm+1H3/ 8GgQ8YfUr6U7w== Date: Mon, 5 Aug 2024 11:11:16 +0100 From: Conor Dooley To: Ilya Orazov Cc: Geert Uytterhoeven , mkl@pengutronix.de, mailhol.vincent@wanadoo.fr, vkoul@kernel.org, kishon@kernel.org, robh@kernel.org, krzk+dt@kernel.org, a-govindraju@ti.com, linux-can@vger.kernel.org, linux-phy@lists.infradead.org, devicetree@vger.kernel.org Subject: Re: [PATCH 1/2] dt-bindings: phy: ti,tcan104x-can: Document Microchip ATA6561 Message-ID: <20240805-fruit-chip-cf08a0e166a3@spud> References: <20240718210322.37492-2-ilordash02@gmail.com> <20240719-ahead-kiwi-995e52bf3e74@spud> <20240723-dinginess-john-608d0b28293b@spud> <20240723-municipal-snowy-136b08b6db90@spud> <20240801-disarray-gesture-ebad121272b0@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="YyeTlPVfQTmwF6a8" Content-Disposition: inline In-Reply-To: --YyeTlPVfQTmwF6a8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Aug 03, 2024 at 03:31:52PM +0300, Ilya Orazov wrote: > > > > > > I made my patch according to a similar one that adds support for > > > > > > nxp,tjr1443. You can find it's conversation on > > > > > > https://lore.kernel.org/all/6ee5e2ce00019bd3f77d6a702b38bab1a45= f3bb0.1674037830.git.geert+renesas@glider.be/t/#u. > > > > > > > > > > > I thought we want to hold all PHY chip names in one compatible = enum > > > > > > and each in its own of_device_id struct in driver and extend th= em > > > > > > where appropriate. > > > > > > > > > > Nah, fallbacks are preferred when the programming model is either > > > > > identical or a "compatible superset" of an existing device. New > > > > > of_device_id structs should only be used where we need to account= for > > > > > differences in the programming model. > > > > > > > > However, I am curious as to why the NXP CAN PHY transceiver was not > > > > included as fallback compatible. Geert, could you please share your > > > > thoughts on this matter? > > > > > > The TJR1443 looked sufficiently similar to the TCAN1043 to use the > > > same driver configuration (which is limited to having standby and/or > > > enable signals or not). However, I'm not sure it behaves exactly > > > the same, e.g. in case of reporting an error condition (which is not > > > yet supported by the driver). The part numbers are also different, > > > so this is not a simple case of SN74HCxx vs. CD74HCxx. > > > > > > Summary: I don't know if they are identical, or if TJR1443 is a > > > compatible superset of TCAN1043, or vice versa. Hence I went for the > > > safest way.... > > > > If we don't know for sure what the craic is with compatibility, then we > > should leave the existing tjr1443 compatible as-is I think. >=20 > If I understood the kernel documentation correctly, we use fallback > compatibles when devices are similar or there is an iterative > relationship between them. In my case, the TCAN1042 and ATA6561 are > from different manufacturers, and I'm not sure about their fully > identical functionality. It's about programming models being compatible, not identical. The manufacturer also doesn't matter. > Therefore, I'll go back to the original idea where I shouldn't use a > fallback compatible here and must leave it as another compatible > property with its own of_device_id struct. >=20 > What do you think about it? In my opinion, this is not a case for > fallback compatibility. Why is it not a case, other than the reasons you already mentioned that I don't agree with? Cheers, Conor. --YyeTlPVfQTmwF6a8 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZrClRAAKCRB4tDGHoIJi 0hoDAQCY9tO8kPi4NhrIx+5mjOkSmk71Pj6nhwPqPT96T/A2HAD/fEckjh30gAdM GbuWPs3jBEGfjSY/AAttPREvcluSuQ0= =kMK7 -----END PGP SIGNATURE----- --YyeTlPVfQTmwF6a8--