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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFBF7C2BB86 for ; Fri, 10 Apr 2020 12:57:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B72382082D for ; Fri, 10 Apr 2020 12:57:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="pkttQCJg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726651AbgDJM5q (ORCPT ); Fri, 10 Apr 2020 08:57:46 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:40774 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbgDJM5q (ORCPT ); Fri, 10 Apr 2020 08:57:46 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id DA103329; Fri, 10 Apr 2020 14:57:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1586523463; bh=wpQ82QATi4alR1bb+eXRfi5VKbVrOyAy7Q4s86mBDgE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pkttQCJgLw+HsTn71GwKJ2kr/Hx31jj5l726KgpmktJcHgaqMs0LAHGhD110tqV6y kmy3FVOug6AnJ2Pc1xubcJ5grgbi9a/MQSoK4lLjPbXMTDk3KeK7HUMRmw21jRj1AT Fgt8r+RDTs5UDkbAV/s3mjjxmZipiId5v5NuwrJw= Date: Fri, 10 Apr 2020 15:57:32 +0300 From: Laurent Pinchart To: Guido =?utf-8?Q?G=C3=BCnther?= Cc: David Airlie , Daniel Vetter , Rob Herring , Mark Rutland , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Andrzej Hajda , Neil Armstrong , Jonas Karlman , Jernej Skrabec , Lee Jones , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Robert Chiras , Sam Ravnborg , Arnd Bergmann Subject: Re: [PATCH v11 1/2] dt-bindings: display/bridge: Add binding for NWL mipi dsi host controller Message-ID: <20200410125732.GE4751@pendragon.ideasonboard.com> References: <147ffc1e4dee3a623e5dca25d84565d386a34112.1586427783.git.agx@sigxcpu.org> <20200410112342.GB4751@pendragon.ideasonboard.com> <20200410124516.GA27532@bogon.m.sigxcpu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200410124516.GA27532@bogon.m.sigxcpu.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Guido, On Fri, Apr 10, 2020 at 02:45:16PM +0200, Guido Günther wrote: > On Fri, Apr 10, 2020 at 02:23:42PM +0300, Laurent Pinchart wrote: > > On Thu, Apr 09, 2020 at 12:42:01PM +0200, Guido Günther wrote: > > > The Northwest Logic MIPI DSI IP core can be found in NXPs i.MX8 SoCs. > > > > > > Signed-off-by: Guido Günther > > > Tested-by: Robert Chiras > > > Reviewed-by: Rob Herring > > > Acked-by: Sam Ravnborg > > > Reviewed-by: Fabio Estevam > > > --- > > > .../bindings/display/bridge/nwl-dsi.yaml | 226 ++++++++++++++++++ > > > 1 file changed, 226 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml > > > > > > diff --git a/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml b/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml > > > new file mode 100644 > > > index 000000000000..8aff2d68fc33 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/display/bridge/nwl-dsi.yaml > > > @@ -0,0 +1,226 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/display/bridge/nwl-dsi.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Northwest Logic MIPI-DSI controller on i.MX SoCs > > > + > > > +maintainers: > > > + - Guido Gúnther > > > + - Robert Chiras > > > + > > > +description: | > > > + NWL MIPI-DSI host controller found on i.MX8 platforms. This is a dsi bridge for > > > + the SOCs NWL MIPI-DSI host controller. > > > + > > > +properties: > > > + compatible: > > > + const: fsl,imx8mq-nwl-dsi > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + interrupts: > > > + maxItems: 1 > > > + > > > + '#address-cells': > > > + const: 1 > > > + > > > + '#size-cells': > > > + const: 0 > > > + > > > + clocks: > > > + items: > > > + - description: DSI core clock > > > + - description: RX_ESC clock (used in escape mode) > > > + - description: TX_ESC clock (used in escape mode) > > > + - description: PHY_REF clock > > > + - description: LCDIF clock > > > + > > > + clock-names: > > > + items: > > > + - const: core > > > + - const: rx_esc > > > + - const: tx_esc > > > + - const: phy_ref > > > + - const: lcdif > > > + > > > + mux-controls: > > > + description: > > > + mux controller node to use for operating the input mux > > > + > > > + phys: > > > + maxItems: 1 > > > + description: > > > + A phandle to the phy module representing the DPHY > > > + > > > + phy-names: > > > + items: > > > + - const: dphy > > > + > > > + power-domains: > > > + maxItems: 1 > > > + > > > + resets: > > > + items: > > > + - description: dsi byte reset line > > > + - description: dsi dpi reset line > > > + - description: dsi esc reset line > > > + - description: dsi pclk reset line > > > + > > > + reset-names: > > > + items: > > > + - const: byte > > > + - const: dpi > > > + - const: esc > > > + - const: pclk > > > + > > > + ports: > > > + type: object > > > + description: > > > + A node containing DSI input & output port nodes with endpoint > > > + definitions as documented in > > > + Documentation/devicetree/bindings/graph.txt. > > > + properties: > > > + port@0: > > > + type: object > > > + description: > > > + Input port node to receive pixel data from the > > > + display controller. Exactly one endpoint must be > > > + specified. > > > + properties: > > > + '#address-cells': > > > + const: 1 > > > + > > > + '#size-cells': > > > + const: 0 > > > + > > > + endpoint@0: > > > + description: sub-node describing the input from LCDIF > > > + type: object > > > + > > > + endpoint@1: > > > + description: sub-node describing the input from DCSS > > > + type: object > > > > This models the two inputs to the IP core, that are connected to a mux > > internally, controlled through mux-controls, right ? Why is a single > > endpoint supported then, if there are two connections at the hardware > > level, and why is this using endpoints instead of ports as there are > > really two input ports ? > > That came out of > > https://lore.kernel.org/linux-arm-kernel/c86b7ca2-7799-eafd-c380-e4b551520837@samsung.com/ > > # If the ip has separate lines for DCSS and LCDIF you should distinguish > # by port number. If they are shared > # you can use endpoint number to specify DCSS or LCDIF, in both cases > # bindings should be adjusted. > > I read that as > > - distinguish by endpoint number: > > eLCDIF--\ | > ----| nwl > DCSS----/ | > > - distinguish by port number: > > eLCDIF-------| > | nwl > DCSS --------| I fully agree with you here, but in the first case I would expect the mux to be outside of the NWL, while in the second case it would be inside. If I understand the issue correctly, the mux is not part of the NWL, right ? The endpoint model would then be good, but leaves the issue of where to control the mux. There's a DT binding for video muxes in Documentation/devicetree/bindings/media/video-mux.txt, but that would require some support on the driver side. Do you think it would be a good way forward ? The alternative is to consider the mux + NWL as one device (more or less an i.MX8M-specific integration wrapper of the NWL), but in that case there should be two ports I believe. > From the imx8mq ref manual i didn't see separate input lines for DCSS vs > eLCDIF the the NWL IP so i went with endpoints instead of ports. I'm > happy to change that if i got it wrong. > > > Apart from that the bindings look ok to me. > > > > > + > > > + reg: > > > + const: 0 > > > + > > > + required: > > > + - '#address-cells' > > > + - '#size-cells' > > > + - reg > > > + > > > + oneOf: > > > + - required: > > > + - endpoint@0 > > > + - required: > > > + - endpoint@1 > > > + > > > + additionalProperties: false > > > + > > > + port@1: > > > + type: object > > > + description: > > > + DSI output port node to the panel or the next bridge > > > + in the chain > > > + > > > + '#address-cells': > > > + const: 1 > > > + > > > + '#size-cells': > > > + const: 0 > > > + > > > + required: > > > + - '#address-cells' > > > + - '#size-cells' > > > + - port@0 > > > + - port@1 > > > + > > > + additionalProperties: false > > > + > > > +patternProperties: > > > + "^panel@[0-9]+$": > > > + type: object > > > + > > > +required: > > > + - '#address-cells' > > > + - '#size-cells' > > > + - clock-names > > > + - clocks > > > + - compatible > > > + - interrupts > > > + - mux-controls > > > + - phy-names > > > + - phys > > > + - ports > > > + - reg > > > + - reset-names > > > + - resets > > > + > > > +additionalProperties: false > > > + > > > +examples: > > > + - | > > > + > > > + #include > > > + #include > > > + #include > > > + > > > + mipi_dsi: mipi_dsi@30a00000 { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + compatible = "fsl,imx8mq-nwl-dsi"; > > > + reg = <0x30A00000 0x300>; > > > + clocks = <&clk IMX8MQ_CLK_DSI_CORE>, > > > + <&clk IMX8MQ_CLK_DSI_AHB>, > > > + <&clk IMX8MQ_CLK_DSI_IPG_DIV>, > > > + <&clk IMX8MQ_CLK_DSI_PHY_REF>, > > > + <&clk IMX8MQ_CLK_LCDIF_PIXEL>; > > > + clock-names = "core", "rx_esc", "tx_esc", "phy_ref", "lcdif"; > > > + interrupts = ; > > > + mux-controls = <&mux 0>; > > > + power-domains = <&pgc_mipi>; > > > + resets = <&src IMX8MQ_RESET_MIPI_DSI_RESET_BYTE_N>, > > > + <&src IMX8MQ_RESET_MIPI_DSI_DPI_RESET_N>, > > > + <&src IMX8MQ_RESET_MIPI_DSI_ESC_RESET_N>, > > > + <&src IMX8MQ_RESET_MIPI_DSI_PCLK_RESET_N>; > > > + reset-names = "byte", "dpi", "esc", "pclk"; > > > + phys = <&dphy>; > > > + phy-names = "dphy"; > > > + > > > + panel@0 { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + compatible = "rocktech,jh057n00900"; > > > + reg = <0>; > > > + port@0 { > > > + reg = <0>; > > > + panel_in: endpoint { > > > + remote-endpoint = <&mipi_dsi_out>; > > > + }; > > > + }; > > > + }; > > > + > > > + ports { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + port@0 { > > > + #size-cells = <0>; > > > + #address-cells = <1>; > > > + reg = <0>; > > > + mipi_dsi_in: endpoint@0 { > > > + reg = <0>; > > > + remote-endpoint = <&lcdif_mipi_dsi>; > > > + }; > > > + }; > > > + port@1 { > > > + reg = <1>; > > > + mipi_dsi_out: endpoint { > > > + remote-endpoint = <&panel_in>; > > > + }; > > > + }; > > > + }; > > > + }; -- Regards, Laurent Pinchart