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 B366C2A8D7; Thu, 29 Feb 2024 18:26:15 +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=1709231175; cv=none; b=rk36zvD4PgzKsW/vwXWKhPILXNGUhiNTqzF32U+zrDxlkBM8zP+KMp6l04HhM07J6UrkXb0pke6hkGsQFwss6iQoHpR6K2jghFOrciyP3gqvDFT4dmuD/VRJXAqvpLgC/wdw0eXEEMYkNn7LVcANyjf8aJv9ZUj+mjfeBUa0OZg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709231175; c=relaxed/simple; bh=Vgq4hnQMw27GH6PkaZfA5dT6KlUr9HO4n6N8lO1OUZQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Og/HNEkguYqOl+YE/JfDvWNMwH5EszwXxEvgN9hOi805d46qFrSaFubWfm12zUNQ/44Z4yvr+nDDbP7zZjsNen0kvpXMu55m++SLS4wZlOORNyKkWHxotGl9qgMTNRXQmLTzEKESSTXtmglCe1RR6y51x5xz6fMXJMw7YuaYQZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bFrtT96X; 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="bFrtT96X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 31C1DC433F1; Thu, 29 Feb 2024 18:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709231175; bh=Vgq4hnQMw27GH6PkaZfA5dT6KlUr9HO4n6N8lO1OUZQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bFrtT96Xq64H+T6w/LgvmGQcoep03LjgB30PBEddTKmTqkdMUU2vRqeODlsoNU9lJ KAOLtXcJW6sqkjVJ6iGi5/U3whxLZpxfvHZV96TcS7EUqoQn53KTCW83bibg2mSXU9 kZ8vLNptyVMM25I29+7bMbkO06IThF02QLUjr824P7ibSitzCWzbKRBEQmdCOJBFFs Sdp6jiww/LXGOogKQcsZUcNT+Zn2HJaA4FSSTvxE9keuvto74s7rFM0nofqEd+4t8H S0yXl3wGjNlViVie5Ml0fcVYTqJGUgi96C3a75HCe1+6VsHKwKZlc5N13NkNuCaZ91 q5HFNa7Cpf8jA== Date: Thu, 29 Feb 2024 18:26:09 +0000 From: Conor Dooley To: Varshini.Rajendran@microchip.com Cc: radu_nicolae.pirea@upb.ro, richard.genoud@gmail.com, gregkh@linuxfoundation.org, jirislaby@kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, Nicolas.Ferre@microchip.com, alexandre.belloni@bootlin.com, claudiu.beznea@tuxon.dev, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v4 12/39] dt-bindings: serial: atmel,at91-usart: add compatible for sam9x7. Message-ID: <20240229-champion-vengeful-4612cee0d678@spud> References: <20240223171342.669133-1-varshini.rajendran@microchip.com> <20240223172559.672142-1-varshini.rajendran@microchip.com> <20240224-kimono-stress-898eae80abd3@spud> <20240228-capital-nickname-696dfcd655de@spud> <16e37a0e-74d0-4632-b0a2-403f74a3a379@microchip.com> Precedence: bulk X-Mailing-List: linux-kernel@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="27icH3WNe5d1kQpd" Content-Disposition: inline In-Reply-To: <16e37a0e-74d0-4632-b0a2-403f74a3a379@microchip.com> --27icH3WNe5d1kQpd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Feb 29, 2024 at 08:55:11AM +0000, Varshini.Rajendran@microchip.com = wrote: > Hi Conor, >=20 > On 28/02/24 5:19 pm, Conor Dooley wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you know = the content is safe > > On Wed, Feb 28, 2024 at 07:03:01AM +0000, Varshini.Rajendran@microchip.= com wrote: > >> Hi Conor, > >> > >> On 25/02/24 1:32 am, Conor Dooley wrote: > >>> EXTERNAL EMAIL: Do not click links or open attachments unless you kno= w the content is safe > >>> On Fri, Feb 23, 2024 at 10:55:59PM +0530, Varshini Rajendran wrote: > >>>> Add sam9x7 compatible to DT bindings documentation. > >>>> > >>>> Signed-off-by: Varshini Rajendran > >>>> --- > >>>> Changes in v4: > >>>> - Fixed the wrong addition of compatible > >>>> - Added further compatibles that are possible correct (as per DT) > >>>> --- > >>>> .../devicetree/bindings/serial/atmel,at91-usart.yaml | 12 +++++++++= --- > >>>> 1 file changed, 9 insertions(+), 3 deletions(-) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/serial/atmel,at91-usa= rt.yaml b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml > >>>> index 65cb2e5c5eee..30af537e8e81 100644 > >>>> --- a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml > >>>> +++ b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml > >>>> @@ -23,11 +23,17 @@ properties: > >>>> - const: atmel,at91sam9260-dbgu > >>>> - const: atmel,at91sam9260-usart > >>>> - items: > >>>> - - const: microchip,sam9x60-usart > >>>> + - enum: > >>>> + - microchip,sam9x60-usart > >>>> + - microchip,sam9x7-usart > >>>> - const: atmel,at91sam9260-usart > >>>> - items: > >>>> - - const: microchip,sam9x60-dbgu > >>>> - - const: microchip,sam9x60-usart > >>>> + - enum: > >>>> + - microchip,sam9x60-dbgu > >>>> + - microchip,sam9x7-dbgu > >>> > >>>> + - enum: > >>>> + - microchip,sam9x60-usart > >>>> + - microchip,sam9x7-usart > >>> > >>> This doesn't make sense - this enum should be a const. > >>> I don't really understand the idea behind of the original binding her= e that > >>> allowed: > >>> "microchip,sam9x60-dbgu", "microchip,sam9x60-usart", "atmel,at91sam92= 60-dbgu", "atmel,at91sam9260-usart" > >>> > >>> Specifically, I don't get the purpose of the "microchip,sam9x60-usart= ". > >>> Either make it > >>> - items: > >>> - enum: > >>> - microchip,sam9x60-dbgu > >>> - microchip,sam9x7-dbgu > >>> - const: microchip,sam9x60-usart > >>> - const: atmel,at91sam9260-dbgu > >>> - const: atmel,at91sam9260-usart > >>> or add > >>> - items: > >>> - const: microchip,sam9x60-dbgu > >>> - const: atmel,at91sam9260-dbgu > >>> - const: atmel,at91sam9260-usart > >>> or explain exactly why this needs to be > >>> "chipa-dgbu", "chipa-usart", "chipb-dbgu", "chipb-dbgu" > >> The compatible has to be "chipa-usart", "chipb-usart", "chipa-dbgu",= =20 > >> "chipb-dbgu" for the device to work as a debug console over UART > >> wher the chipa- is the device specific compatible > >> and the chipb- is the fallback compatible that the driver=20 > >> actually uses. > >=20 > > This examples why you have "microchip,sam9x60-dbgu", "atmel,at91sam9260= -dbgu" > > and "atmel,at91sam9260-usart". > > It does not explain "microchip,sam9x60-usart" though, I don't see what > > purpose that serves. If used as a debug uart, you fall back to the > > sam9260 debug uart compatible and if not you fall back to the sam9260 > > usart compatible. > >=20 > Here, if it is not used as debug uart it has to fallback to the default= =20 > usart compatible which in this case should have a device specific=20 > compatible too right? >=20 > The common usart compatible looks as follows, >=20 > compatible =3D "microchip,sam9x60-usart", "atmel,at91sam9260-usart"; >=20 > meaning the 1st one is the device specific usart compatible and the 2nd= =20 > one is the fallback compatible which the driver actually supports. >=20 > The debug uart looks as follows, >=20 > compatible =3D "microchip,sam9x60-dbgu", "atmel,at91sam9260-dbgu",=20 > "microchip,sam9x60-usart", "atmel,at91sam9260-usart"; This version here makes a lot more sense than what is currently in use and what is being added in your original patch. I wouldn't object to this being used. > In this case, there is a device specific debug uart compatible, a=20 > fallback tot he debug uart compatible and as you said if not used as a=20 > debug uart it should fallback and work as a normal uart device which has= =20 > both a device specific compatible and a fallback to work. >=20 > In case the device specific compatible is supported with some other=20 > features in the driver in the future, the debug uart also should get its= =20 > perk. Does this make sense? >=20 >=20 > > In addition, the current setup implies that sam9x60 usart supports all > > the features that the sam9260 debug usart does. I doubt that that is > > true. --27icH3WNe5d1kQpd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZeDMQQAKCRB4tDGHoIJi 0p5MAQDmJ9VKwmndXGtuYADUIRc9WGk25Ny/CCPltwAriEMOYwD+PPAQ6NAoy6jt WUaQKjRkDFQpmgCzd1Fn+JVDmsW/NgA= =vhzy -----END PGP SIGNATURE----- --27icH3WNe5d1kQpd--