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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A5CFC4332F for ; Sun, 7 Nov 2021 19:03:21 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 46A0B604D7 for ; Sun, 7 Nov 2021 19:03:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 46A0B604D7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=crapouillou.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A4B5E6E1F5; Sun, 7 Nov 2021 19:03:20 +0000 (UTC) Received: from aposti.net (aposti.net [89.234.176.197]) by gabe.freedesktop.org (Postfix) with ESMTPS id 122AE6E1F5 for ; Sun, 7 Nov 2021 19:03:19 +0000 (UTC) Date: Sun, 07 Nov 2021 19:03:03 +0000 From: Paul Cercueil Subject: Re: [PATCH v5 3/7] dt-bindings: display: Add ingenic,jz4780-dw-hdmi DT Schema To: "H. Nikolaus Schaller" Message-Id: <39U72R.F9FBQRJUWY9W2@crapouillou.net> In-Reply-To: References: <518d5db83e84e3f0326854c5afb53a92e7ae4e41.1633436959.git.hns@goldelico.com> <8XUI0R.KDQ64KIMI9BU@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Paul Boddie , Geert Uytterhoeven , Neil Armstrong , David Airlie , dri-devel , linux-mips , Laurent Pinchart , Miquel Raynal , Sam Ravnborg , Jernej Skrabec , OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS , Kees Cook , Jonas Karlman , Mark Brown , Maxime Ripard , Discussions about the Letux Kernel , Ezequiel Garcia , Thomas Bogendoerfer , Liam Girdwood , Robert Foss , linux-kernel , Rob Herring , "Eric W. Biederman" , Hans Verkuil Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Nikolaus, Le dim., nov. 7 2021 at 14:43:33 +0100, H. Nikolaus Schaller=20 a =E9crit : > Hi, >=20 >> Am 05.10.2021 um 22:43 schrieb Paul Cercueil : >>=20 >> Hi Nikolaus, >>=20 >> Le mar., oct. 5 2021 at 14:29:15 +0200, H. Nikolaus Schaller=20 >> a =E9crit : >>> From: Sam Ravnborg >>> Add DT bindings for the hdmi driver for the Ingenic JZ4780 SoC. >>> Based on .txt binding from Zubair Lutfullah Kakakhel >>> Signed-off-by: Sam Ravnborg >>> Signed-off-by: H. Nikolaus Schaller >>> Cc: Rob Herring >>> Cc: devicetree@vger.kernel.org >>> --- >>> .../bindings/display/ingenic-jz4780-hdmi.yaml | 79=20 >>> +++++++++++++++++++ >>> 1 file changed, 79 insertions(+) >>> create mode 100644=20 >>> Documentation/devicetree/bindings/display/ingenic-jz4780-hdmi.yaml >>> diff --git=20 >>> a/Documentation/devicetree/bindings/display/ingenic-jz4780-hdmi.yaml=20 >>> b/Documentation/devicetree/bindings/display/ingenic-jz4780-hdmi.yaml >>> new file mode 100644 >>> index 000000000000..5bcb342da86f >>> --- /dev/null >>> +++=20 >>> b/Documentation/devicetree/bindings/display/ingenic-jz4780-hdmi.yaml >>> @@ -0,0 +1,79 @@ >>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) >>> +%YAML 1.2 >>> +--- >>> +$id:=20 >>> http://devicetree.org/schemas/display/ingenic-jz4780-hdmi.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: Bindings for Ingenic JZ4780 HDMI Transmitter >>> + >>> +maintainers: >>> + - H. Nikolaus Schaller >>> + >>> +description: | >>> + The HDMI Transmitter in the Ingenic JZ4780 is a Synopsys=20 >>> DesignWare HDMI 1.4 >>> + TX controller IP with accompanying PHY IP. >>=20 >> My dmesg disagrees: >> dw-hdmi-ingenic 10180000.hdmi: Detected HDMI TX controller v1.31a=20 >> with HDCP (DWC HDMI 3D TX PHY) >=20 > mine as well. >=20 >>=20 >> Or am I comparing apples to oranges? >=20 > There is a document called "JZ4780 High Efficiency Engine for Mobile=20 > Device" > (JZ4780_PB.pdf) which says >=20 > "24-bit parallel/serial TFT interface, HDMI 1.4a interface, LVDS=20 > interface" >=20 > And the data sheet ("JZ4780 Mobile Application Processor Data Sheet=20 > ") says: "Support HDMI 1.4a Interface" >=20 > Finally, the programming manual also says "Support HDMI 1.4a=20 > Interface". >=20 > So what is correct? >=20 > dmesg may return something else. E.g. silicon revision 1.31a > while the interface is HDMI protocol revision 1.4a compatible? >=20 > Trying to find something about "hdmi 1.31a" did only lead to some > "Synopsys' HAPS-51 eval platform" [1]. >=20 > Looking at HDMI standards [2] I can only find HDMI 1.3 and 1.3a but=20 > no HDMI 1.31a. >=20 > [1]=20 > https://www.digital-cp.com/hdcp-products/haps51-hdmi-tx-platform-dwc-hdmi= -tx-controller-131a-ea-hdmi-3d-tx-phy-tsmc40g-ip > [2] https://en.wikipedia.org/wiki/HDMI#Version_1.3 >=20 > Well it may also be some Synopsys-internal designation 1.31a=20 > referring so something > newer than HDMI 1.3a which became the HDMI 1.4 standard (released=20 > June 2009)... >=20 > Whom should we believe? What the chip tells or what the data sheet=20 > and programming > manual says? >=20 > I tend to keep confusion low and stay with "HDMI 1.4" in the bindings=20 > because > there is no offical "HDMI 1.31a" standard. And HDMI 1.4 was already=20 > some years old > when the jz4780 was released. So it is likely that the chip=20 > identification just > returns 1.31a (maybe Ingenic licenced an interim release VHDL)=20 > although the standard > was later officially named 1.4a. Fair enough. Let's keep "HDMI 1.4" until proven otherwise. Cheers, -Paul >>=20 >>> + >>> +allOf: >>> + - $ref: bridge/synopsys,dw-hdmi.yaml# >>> + >>> +properties: >>> + compatible: >>> + const: ingenic,jz4780-dw-hdmi >>> + >>> + reg-io-width: >>> + const: 4 >>> + >>> + clocks: >>> + maxItems: 2 >>> + >>> + hdmi-5v-supply: >>> + description: Optional regulator to provide +5V at the=20 >>> connector >>> + >>> + ddc-i2c-bus: >>> + description: An I2C interface if the internal DDC I2C driver=20 >>> is not to be used >>=20 >> This property is used within=20 >> (drivers/gpu/drm/bridge/synopsys/dw-hdmi.c); I think it would make=20 >> sense to move it to bridge/synopsys,dw-hdmi.yaml. >=20 > It is indeed more general and not jz4780 specific. I'll move it for=20 > v6. >=20 > BR and thanks, > Nikolaus >=20