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 77AC33A1DA; Thu, 1 Aug 2024 15:12:59 +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=1722525179; cv=none; b=ITBVLYMjGYLAIJPdsqg3z9C4veb27W9+hMaNEM/ljvjifgwFaFTB+PuyR1wFIPs6W/DRdteJtQu/edY5M8JIscKdTJ7JOGElTeTp3/gJbOjT/DntgLfvLPmNWRjmVjpFL5hqRwL3K05JKV/hDIf5UwUZCga1XpWX7bivAuM39z8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722525179; c=relaxed/simple; bh=MgNLHjJvnDe0EuUg81NvPG2LQI8S/TfbtVY9t/RZ/wQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gj8usDqDqTl9KPJWWDvkOibQE18lIJAj/nDLXwPD4i19ZbLtIRVn/4F4FwZdCQiDDAUereAwatcilm9v4PlMU1wKBe5g+xjsdny9ApGGU1r13TTeCKA/bt6T9xD2Kj6Vgv+gM6tXp8JItnDfxWP09RgUdppXhoX/z6OBFjp642I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mCwaaZSZ; 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="mCwaaZSZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A86C1C32786; Thu, 1 Aug 2024 15:12:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722525179; bh=MgNLHjJvnDe0EuUg81NvPG2LQI8S/TfbtVY9t/RZ/wQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mCwaaZSZWOik+AbxKZ+zpMU9p0teppstVuMfMtbyed/cC19ANBBdY2cB41fpUAx6Y 5cyhKCRjEB+xKVjmhVjJ0T7MOUMVh7Bqkt/8U4eDqovGi2bDmMiV6xnzPGQT0wPVhD HKPv20pk5IoRcyf6qw2lxHMSI05l2QYzy3xTwL0cB9i3lSI637Oz1/hRk3zbg8NUHF OVwKICwHl+I91CyAqcgLl9hz8N6lrBRjqqWA5w9fKaIoPf+h574pq8bMkrxMrG2MUb 92QvJeKeaqLlty5b9BLx9Skuurn29/3nqFDrM56j9ie+ibDrh/XZ7Pj7jCSdHGQJ3b H+F43gLlvCT+g== Date: Thu, 1 Aug 2024 16:12:54 +0100 From: Conor Dooley To: Geert Uytterhoeven Cc: Ilya Orazov , 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: <20240801-disarray-gesture-ebad121272b0@spud> References: <20240718210322.37492-1-ilordash02@gmail.com> <20240718210322.37492-2-ilordash02@gmail.com> <20240719-ahead-kiwi-995e52bf3e74@spud> <20240723-dinginess-john-608d0b28293b@spud> <20240723-municipal-snowy-136b08b6db90@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="2u/IhLrXAClqQ7yY" Content-Disposition: inline In-Reply-To: --2u/IhLrXAClqQ7yY Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 29, 2024 at 10:51:50AM +0200, Geert Uytterhoeven wrote: > Hi Ilya, >=20 > On Sun, Jul 28, 2024 at 10:52=E2=80=AFAM Ilya Orazov wrote: > > On Tue, 23 Jul 2024 at 23:14, Conor Dooley wrote: > > > On Tue, Jul 23, 2024 at 10:55:17PM +0300, Ilya Orazov wrote: > > > > On Tue, 23 Jul 2024 at 21:50, Conor Dooley wrote: > > > > > On Tue, Jul 23, 2024 at 08:20:04PM +0300, IlorDash wrote: > > > > > > On Fri, 19 Jul 2024 at 18:07, Conor Dooley w= rote: > > > > > > > > > > > > > > On Fri, Jul 19, 2024 at 12:03:21AM +0300, Ilya Orazov wrote: > > > > > > > > Microchip ATA6561 is High-Speed CAN Transceiver with Standb= y Mode. > > > > > > > > It is pin-compatible with TI TCAN1042. > > > > > > > > > > > > > > > > Signed-off-by: Ilya Orazov > > > > > > > > --- > > > > > > > > Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml= | 1 + > > > > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/phy/ti,tcan1= 04x-can.yaml b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml > > > > > > > > index 79dad3e89aa6..03de361849d2 100644 > > > > > > > > --- a/Documentation/devicetree/bindings/phy/ti,tcan104x-can= =2Eyaml > > > > > > > > +++ b/Documentation/devicetree/bindings/phy/ti,tcan104x-can= =2Eyaml > > > > > > > > @@ -18,6 +18,7 @@ properties: > > > > > > > > - nxp,tjr1443 > > > > > > > > - ti,tcan1042 > > > > > > > > - ti,tcan1043 > > > > > > > > + - microchip,ata6561 > > > > > > > > > > > > > > Given that your driver patch has > > > > > > > | diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/ph= y/phy-can-transceiver.c > > > > > > > | index ee4ce4249698..dbcd99213ba1 100644 > > > > > > > | --- a/drivers/phy/phy-can-transceiver.c > > > > > > > | +++ b/drivers/phy/phy-can-transceiver.c > > > > > > > | @@ -89,6 +89,10 @@ static const struct of_device_id can_tra= nsceiver_phy_ids[] =3D { > > > > > > > | .compatible =3D "nxp,tjr1443", > > > > > > > | .data =3D &tcan1043_drvdata > > > > > > > | }, > > > > > > > | + { > > > > > > > | + .compatible =3D "microchip,ata6561", > > > > > > > | + .data =3D &tcan1042_drvdata > > > > > > > | + }, > > > > > > > | { } > > > > > > > | }; > > > > > > > > > > > > > > the driver patch is actually not needed at all, and you just = need to > > > > > > > allow ti,tcan1042 as fallback compatible in the binding, so s= omething > > > > > > > like: > > > > > > > > > > > > > > compatible: > > > > > > > oneOf: > > > > > > > - enum: > > > > > > > - nxp,tjr1443 > > > > > > > - ti,tcan1042 > > > > > > > - ti,tcan1043 > > > > > > > - items: > > > > > > > - const: microchip,ata6561 > > > > > > > - const: ti,tcan1042 > > > > > > > > > > > > > > '#phy-cells': > > > > > > > const: 0 > > > > > > > > > > > > I tested the build with fallback compatible: > > > > > > > > > > > > compatible: > > > > > > oneOf: > > > > > > - items: > > > > > > - enum: > > > > > > - microchip,ata6561 > > > > > > - const: ti,tcan1042 > > > > > > - items: > > > > > > - enum: > > > > > > - nxp,tjr1443 > > > > > > - const: ti,tcan1043 > > > > > > > > > > > > and modified compatible property in DTS: > > > > > > > > > > > > compatible =3D "microchip,ata6561", "ti,tcan1042"; > > > > > > > > > > > > Build succeeded, phy-can-transceiver driver was used. So I woul= d like > > > > > > to add a fallback compatible for both "microchip,ata6561" and > > > > > > "nxp,tjr1443" in this binding and modify other DTS files with > > > > > > compatible =3D "nxp,tjr1443". What do you think? > > > > > > > > > > This is wrong on two counts. Firstly, were what you have correct,= you > > > > > should > > > > > squash the two: > > > > > - items: > > > > > - enum: > > > > > - nxp,tjr1443 > > > > > - microchip,ata6561 > > > > > - const: ti,tcan1042 > > > > > > > > > > However, that does not allow the TI compatibles in isolation, so = you > > > > > still need to allow that for the actual TI devices, so you need: > > > > > > > > > > oneOf: > > > > > - items: > > > > > - enum: > > > > > - microchip,ata6561 > > > > > - nxp,tjr1443 > > > > > - ti,tcan1043 > > > > > - const: ti,tcan1042 > > > > > - const: ti,tcan1042 > > > > > > > > > > There's probably some devicetrees that would need to be fixed up.= I'm > > > > > just not convinced that this is worth retrofitting however. > > > > > > > > But nxp,tjr1443 is pin compatible with ti,tcan1043, so it should > > > > fallback only to ti,tcan1043 and not ti,tcan1042. That's why I deci= ded > > > > to split them into different enums. > > > > > > Ah, sorry I missed that. I misread the match data. Then you need: > > > compatible: > > > oneOf: > > > - items: > > > - enum: > > > - microchip,ata6561 > > > - const: ti,tcan1042 > > > - items: > > > - enum: > > > - nxp,tjr1443 > > > - const: ti,tcan1043 > > > - enum: > > > const: ti,tcan1042 > > > const: ti,tcan1043 > > > > > > because the TI devices exist and we still need to be able to > > > differentiate the TI and NXP devices. If you have > > > compatible =3D "nxp,tjr1443", "ti,tcan1042"; > > > that means the device is an nxp,tjr1443. If you have > > > compatible =3D "ti,tcan1042"; > > > then that's a tcan1042. > > > > > > > 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/6ee5e2ce00019bd3f77d6a702b38bab1a45f3bb= 0.1674037830.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 them > > > > 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? >=20 > 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. >=20 > 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. --2u/IhLrXAClqQ7yY Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZqul9gAKCRB4tDGHoIJi 0ihGAP9ycLYTw4OBALYRGnPOgdIt80DioV5tkzE3ZMnbzlDyUQD/ddqPhRdRL6BW 4hQVPcQtVHP4d8p76tUJ59Dyz6rY5gg= =n1kR -----END PGP SIGNATURE----- --2u/IhLrXAClqQ7yY--