From patchwork Tue Apr 28 09:20:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ricardo_Ca=C3=B1uelo?= X-Patchwork-Id: 11514107 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F21014B4 for ; Tue, 28 Apr 2020 09:21:28 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7A881206D6 for ; Tue, 28 Apr 2020 09:21:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nqRdM2fs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A881206D6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Y0TjuG/0Nef9yr4fjczgumhIdEWdNUc9s7yyx3sSMaE=; b=nqRdM2fsTkrdDU q5TUP9vvHDJAVHz+SpjZH4SunDWBqFjlt3M76KpsHSNdtSPmjbboZTGKhG+9iHMHZiokacgQGXPvk 5lbp5MCrxNiFoa6JpOn99XAUSTHSthvGD23P8t8LOk/F7g0vdjG1+Ool+q9Xz5MmdtQAPMA4JAPMJ wPvRQNfyk4gGq3HCaIDNSbz41D+ZN31BMe+srw6mYsEVys1FdSyS8DaFWNOmBGcwtJbJewtRCNlyo ojJGxm5ydm9D0F0nwSK8RaEfawkMU1BRN2qMbRjY6yt/16QNOFOzImzYXtEEPIodh/T2BefcGKecs e9q6fNGHPugebm4QzQjg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTMQd-0000XX-Ho; Tue, 28 Apr 2020 09:21:23 +0000 Received: from bhuna.collabora.co.uk ([46.235.227.227]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jTMQa-0000Vf-1Z for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2020 09:21:22 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: rcn) with ESMTPSA id E9CE82A15C3 From: =?utf-8?q?Ricardo_Ca=C3=B1uelo?= To: robh+dt@kernel.org Subject: [RFC PATCH] dt-bindings: display: ti,tfp410.txt: convert to yaml Date: Tue, 28 Apr 2020 11:20:48 +0200 Message-Id: <20200428092048.14939-1-ricardo.canuelo@collabora.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200428_022120_357330_A400DBD4 X-CRM114-Status: GOOD ( 23.36 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [46.235.227.227 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, jason@lakedaemon.net, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, kernel@collabora.com, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Convert the DT binding documentation for the TI TFP410 DPI-to-DVI encoder to json-schema. Signed-off-by: Ricardo Cañuelo --- Hi all, I found some issues while converting this binding and I'd like to know your opinions on how to tackle them. 1) dtbs_check fails for arch/arm/boot/dts/dove-sbc-a510.dts This board uses the TFP410 encoder but it doesn't define any ports for it. I can't find any suitable remote endpoints in its description either. Maybe this board description should be reworked? The current driver won't handle the device if it doesn't define any ports or endpoints anyway. It also uses the 'powerdown-gpio' property instead of 'powerdown-gpios'. AFAICT this shouldn't be a problem from the driver point of view, but the general standard in DT bindings is to use the plural. This is trivial to fix. 2) The definition of ti,deskew in the original binding seems to be tailored to the current driver and the way it's defined may not be very DT-friendly. This parameter maps to a 3-bit field in a hardware register that takes a value from 0 to 7, so the [-4, 3] range described for this would map to [000, 111]: -4 -> 000, -3 -> 001, -2 -> 010, ... 3 -> 111. Then, the driver parses the parameter (unsigned) and casts it to a signed integer to get a number in the [-4, 3] range. A vendor-specific property must have a type definition in json-schema, so if I translate the original bindings semantics directly, I should define ti,deskew as an int32, but this makes dt_binding_check fail if the property has a negative value in the example because of the internal representation of cells as unsigned integers: ti,deskew:0:0: 4294967293 is greater than the maximum of 2147483647 So I can think of two solutions to this: a) Keep the ti,deskew property as an uint32 and document the valid range ([-4, 3]) in the property description (this is what this patch does currently). b) Redefine this property to be closer to the datasheet description (ie. unsigned integers from 0 to 7) and adapt the driver accordingly. This would also let us define its range properly using minimum and maximum properties for it. I think (b) is the right thing to do but I want to know your opinion. Besides, I don't have this hardware at hand and if I updated the driver I wouldn't be able to test it. Thanks. Patch tested with: make dt_binding_check ARCH=arm DT_SCHEMA_FILES=<.../ti,tfp410.yaml> make dtbs_check ARCH=arm DT_SCHEMA_FILES=<.../ti,tfp410.yaml> .../bindings/display/bridge/ti,tfp410.txt | 66 ---------- .../bindings/display/bridge/ti,tfp410.yaml | 121 ++++++++++++++++++ 2 files changed, 121 insertions(+), 66 deletions(-) delete mode 100644 Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt create mode 100644 Documentation/devicetree/bindings/display/bridge/ti,tfp410.yaml diff --git a/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt deleted file mode 100644 index 5ff4f64ef8e8..000000000000 --- a/Documentation/devicetree/bindings/display/bridge/ti,tfp410.txt +++ /dev/null @@ -1,66 +0,0 @@ -TFP410 DPI to DVI encoder -========================= - -Required properties: -- compatible: "ti,tfp410" - -Optional properties: -- powerdown-gpios: power-down gpio -- reg: I2C address. If and only if present the device node should be placed - into the I2C controller node where the TFP410 I2C is connected to. -- ti,deskew: data de-skew in 350ps increments, from -4 to +3, as configured - through th DK[3:1] pins. This property shall be present only if the TFP410 - is not connected through I2C. - -Required nodes: - -This device has two video ports. Their connections are modeled using the OF -graph bindings specified in [1]. Each port node shall have a single endpoint. - -- Port 0 is the DPI input port. Its endpoint subnode shall contain a - pclk-sample and bus-width property and a remote-endpoint property as specified - in [1]. - - If pclk-sample is not defined, pclk-sample = 0 should be assumed for - backward compatibility. - - If bus-width is not defined then bus-width = 24 should be assumed for - backward compatibility. - bus-width = 24: 24 data lines are connected and single-edge mode - bus-width = 12: 12 data lines are connected and dual-edge mode - -- Port 1 is the DVI output port. Its endpoint subnode shall contain a - remote-endpoint property is specified in [1]. - -[1] Documentation/devicetree/bindings/media/video-interfaces.txt - - -Example -------- - -tfp410: encoder@0 { - compatible = "ti,tfp410"; - powerdown-gpios = <&twl_gpio 2 GPIO_ACTIVE_LOW>; - ti,deskew = <4>; - - ports { - #address-cells = <1>; - #size-cells = <0>; - - port@0 { - reg = <0>; - - tfp410_in: endpoint@0 { - pclk-sample = <1>; - bus-width = <24>; - remote-endpoint = <&dpi_out>; - }; - }; - - port@1 { - reg = <1>; - - tfp410_out: endpoint@0 { - remote-endpoint = <&dvi_connector_in>; - }; - }; - }; -}; diff --git a/Documentation/devicetree/bindings/display/bridge/ti,tfp410.yaml b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.yaml new file mode 100644 index 000000000000..79666ee540f9 --- /dev/null +++ b/Documentation/devicetree/bindings/display/bridge/ti,tfp410.yaml @@ -0,0 +1,121 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/bridge/ti,tfp410.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: TFP410 DPI to DVI encoder + +maintainers: + - Tomi Valkeinen + - Jyri Sarha + +properties: + compatible: + const: "ti,tfp410" + + reg: + description: I2C address of the device. + maxItems: 1 + + powerdown-gpios: + maxItems: 1 + + ti,deskew: + description: + Data de-skew in 350ps increments, from -4 to +3, as configured + through the DK[3:1] pins. This property shall be present only if + the TFP410 is not connected through I2C. + maxItems: 1 + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + + ports: + description: + A node containing input and output port nodes with endpoint + definitions as documented in + Documentation/devicetree/bindings/media/video-interfaces.txt + type: object + + properties: + port@0: + description: DPI input port. + type: object + + properties: + reg: + const: 0 + + endpoint: + type: object + + properties: + pclk-sample: + description: Endpoint sampling edge. + enum: + - 0 # Falling edge + - 1 # Rising edge + + bus-width: + description: Endpoint bus width. + enum: [ 12, 24 ] + + required: + - endpoint + + port@1: + description: DVI output port. + type: object + + properties: + reg: + const: 1 + + endpoint: + type: object + + required: + - endpoint + + required: + - port@0 + - port@1 + +required: + - compatible + - ports + +additionalProperties: false + +examples: + - | + #include + + tfp410: encoder { + compatible = "ti,tfp410"; + powerdown-gpios = <&twl_gpio 2 GPIO_ACTIVE_LOW>; + ti,deskew = <3>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + port@0 { + reg = <0>; + tfp410_in: endpoint { + pclk-sample = <1>; + bus-width = <24>; + remote-endpoint = <&dpi_out>; + }; + }; + + port@1 { + reg = <1>; + tfp410_out: endpoint { + remote-endpoint = <&dvi_connector_in>; + }; + }; + }; + }; + +...