From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 99029C44501 for ; Thu, 9 Jul 2026 08:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=E+NtRvec8F8aekKuz6iezeEslYswvJ60lH8RuxMxcZU=; b=iQ2mWE82KgIoCpSzZWiQ0WScpD f7wFiToVdOwRfw/EXw0b9ytXqcjX8aGhlfvVkcuW1pLzlSY1IT+8J48rIAhhMsB1qVfo6HjFMONFh sZRH1lKnRApBjmLQFCUTLavF3S/lYts5n0mxSRWP21hbeKGffCW2Z0IJRfr1q1LC+9fjbflVYknQI 9zZKIXQIWEq7RCd7LNAG29IakWiYox0oIJDITQspNFVk7yWQ0Ff8v6yUO0dsLbwN00jL8YvX+VixB f9Ty78xQeHDDIYakQkoIwoGATxWXqGeP1SERyPAG6kTX1+ABqGOdLV7A/PcA2NcDmUxwjHV/LzVJT gtL7TOkQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whkXX-00000001gGm-1Xfq; Thu, 09 Jul 2026 08:55:27 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1whkX4-00000001f1A-0cor for linux-arm-kernel@lists.infradead.org; Thu, 09 Jul 2026 08:54:58 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id B656243F84; Thu, 9 Jul 2026 08:54:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A2D41F0155C; Thu, 9 Jul 2026 08:54:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783587297; bh=E+NtRvec8F8aekKuz6iezeEslYswvJ60lH8RuxMxcZU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Ev/MX5jc/Q/G6Qw04KbVPZw5mRQE+925mjjdbilnfAAOVJNfB1vqvULVLTCS81vKk wN2ytgPlflg25QwFvcSP2Mv0/Og4TU7H5c3xEcu8NHXE2ECgL5+5plo48ZJQVghFzF ARE7QFfwFhP2oxWPJQtYxV8h4ax//Sd33HlQF2Bo5rtU+5NcVs10Z9Cev8yw3fQhzM 74/hC6VBgPCPGTR9nk/d7uzrDgXFSYvRHsdwaKfU4yNLh06rO1EPX2L5jhL+ypVDGJ d3Hgo4aJ7/3SoluWgBzvIxxhHBj0j/dKNRgKt+m0jpCu4Y9TGMHVfy4bB/NJB0jyl8 5sg4Dq9ZRwf1A== Date: Thu, 9 Jul 2026 10:54:53 +0200 From: Krzysztof Kozlowski To: =?utf-8?B?R3LDqWdvaXJl?= Layet Cc: joel@jms.id.au, andrew@codeconstruct.com.au, lkundrak@v3.sk, devicetree@vger.kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, andrew@lunn.ch, jacky_chou@aspeedtech.com, yh_chung@aspeedtech.com, ninad@linux.ibm.com, anirudhsriniv@gmail.com, linux-serial@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 2/7] dt-bindings: serial: 8250: aspeed: add aspeed,vuart-over-pci bool prop Message-ID: <20260709-shaggy-discreet-dodo-e5ffbb@quoll> References: <501428d6a6cb1548bf357c25313dbc319724ead2.1783524645.git.gregoire.layet@9elements.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <501428d6a6cb1548bf357c25313dbc319724ead2.1783524645.git.gregoire.layet@9elements.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 08, 2026 at 03:35:54PM +0000, Gr=C3=A9goire Layet wrote: > The ASPEED AST2600 has 2 Virtual UARTs accessible over PCI. > The ASPEED AST2600 can be used as a PCI device. > 2 Virtual UART can be exposed to the host via this PCI device. > These are 8250-compatible register sets and can be used to have UART > communication between the PCI BMC and the host. >=20 > This boolean can be set to specify if a VUART is used over PCI. A VUART > over PCI needs a syscon phandle. The syscon gives a regmap to the SCU, > which is used to set the enable bits of the PCI device. > On the aspeed's chips, the clocks phandle already points at the SCU node. > But deriving the regmap from the clock provider would misuse the clocks > binding. An explicit syscon phandle states the dependency directly. >=20 > Signed-off-by: Gr=C3=A9goire Layet > --- > .../devicetree/bindings/serial/8250.yaml | 22 +++++++++++++++++++ > 1 file changed, 22 insertions(+) >=20 > diff --git a/Documentation/devicetree/bindings/serial/8250.yaml b/Documen= tation/devicetree/bindings/serial/8250.yaml > index 8f22121381fc..2ea8981bba80 100644 > --- a/Documentation/devicetree/bindings/serial/8250.yaml > +++ b/Documentation/devicetree/bindings/serial/8250.yaml > @@ -27,6 +27,16 @@ allOf: > enum: > - aspeed,ast2500-vuart > - aspeed,ast2600-vuart > + - if: > + required: > + - aspeed,vuart-over-pci > + then: > + required: > + - syscon > + properties: > + compatible: > + contains: > + const: aspeed,ast2600-vuart else: =2E.. disallow new properties (see example-schema) > - if: > properties: > compatible: > @@ -223,6 +233,12 @@ properties: > - const: uartclk > - const: reg > =20 > + syscon: That's explicitly forbidden by writing bindings (and mentioned as the antipattern in my older talks about DT). > + $ref: /schemas/types.yaml#/definitions/phandle > + description: > + Phandle to the SCU syscon, used to enable the VUART over the BMC P= CI > + device. Only applicable to aspeed,ast2600-vuart. > + > dmas: > minItems: 1 > maxItems: 4 > @@ -316,6 +332,12 @@ properties: > polarity (IRQ_TYPE_LEVEL_LOW or IRQ_TYPE_LEVEL_HIGH). Only > applicable to aspeed,ast2500-vuart and aspeed,ast2600-vuart. > =20 > + aspeed,vuart-over-pci: > + type: boolean > + description: > + Enable the VUART over the BMC PCI device. Only applicable to > + aspeed,ast2600-vuart. > + > required: > - reg > - interrupts > --=20 > 2.54.0 >=20