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 94440C433F5 for ; Fri, 11 Feb 2022 20:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To: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=7/z+mDv/NfuPbBuCYzc1b2vsTXqA6tO2ougskMCrhsI=; b=h+6Ph+s4P9EU9h R8ZSwCWnHwSexrWJ+YcWvr0NbW89nO/6Xjd+AOFhh/nAirPZ13KwCQSz+2sTStN94weZ9SzFRz2p5 /NYBI/cbkPhRolQYG19EKRx5s5HX94bbMpA4+x03rR1k7VlUDFAqOlIX2XZinl22h40RkEh4G9da1 jqXdxmEkX34h4Hjie8c38v3qfNKbiFKLlCCu/kuxt2Q34PTQ4UJK6ANGJQeE9al+JhejCQ8YEuQM9 +/4ovvCwEi5tlttZSsPPWrvOAMensQOE4DfNM8+1FqDCGDy3mwDg8Zg7nD5WA+t1/dgds8jsobgv4 6eH7sNqLF4ebAgiWs2lA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIcpm-008ixx-27; Fri, 11 Feb 2022 20:48:02 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIcpi-008iwo-VV; Fri, 11 Feb 2022 20:48:00 +0000 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 752CC93; Fri, 11 Feb 2022 21:47:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1644612477; bh=ehf6vTlCeB9+XYe9AmuIirbghRbW0KEWGRwclDo3v5c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IMLv4XNB8rkEmEcFHY5ynpBplZLVhBle485lTzKMlvpAAGn8QYGGIggZx6kaNBarf +6zUn47Uo7bvLS58Y0bNE5kfUt9FKGWXHaOW258MJlIJyhoN7xVL+B77t/BA/yUAfD HSd3OL2ofQH601HhtMr2CDJwBnFFHjt1kybXQLVM= Date: Fri, 11 Feb 2022 22:47:53 +0200 From: Laurent Pinchart To: Paul Kocialkowski Cc: Rob Herring , linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, linux-clk@vger.kernel.org, linux-staging@lists.linux.dev, Yong Deng , Mauro Carvalho Chehab , Maxime Ripard , Sakari Ailus , Hans Verkuil , Chen-Yu Tsai , Jernej Skrabec , Greg Kroah-Hartman , Helen Koike , Thomas Petazzoni Subject: Re: [PATCH v2 05/66] dt-bindings: sun6i-a31-mipi-dphy: Add optional direction property Message-ID: References: <20220205185429.2278860-1-paul.kocialkowski@bootlin.com> <20220205185429.2278860-6-paul.kocialkowski@bootlin.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220211_124759_187623_95099C0A X-CRM114-Status: GOOD ( 28.64 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Feb 11, 2022 at 04:12:29PM +0100, Paul Kocialkowski wrote: > Hi Rob, > > On Fri 11 Feb 22, 09:03, Rob Herring wrote: > > On Sat, Feb 05, 2022 at 07:53:28PM +0100, Paul Kocialkowski wrote: > > > The Allwinner A31 MIPI D-PHY block supports both tx and rx directions, > > > although each instance of the block is meant to be used in one > > > direction only. There will typically be one instance for MIPI DSI and > > > one for MIPI CSI-2 (it seems unlikely to ever see a shared instance). > > > > > > Describe the direction with a new allwinner,direction property. > > > For backwards compatibility, the property is optional and tx mode > > > should be assumed by default. > > > > > > Signed-off-by: Paul Kocialkowski > > > --- > > > .../bindings/phy/allwinner,sun6i-a31-mipi-dphy.yaml | 12 ++++++++++++ > > > 1 file changed, 12 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/phy/allwinner,sun6i-a31-mipi-dphy.yaml b/Documentation/devicetree/bindings/phy/allwinner,sun6i-a31-mipi-dphy.yaml > > > index d0b541a461f3..22636c9fdab8 100644 > > > --- a/Documentation/devicetree/bindings/phy/allwinner,sun6i-a31-mipi-dphy.yaml > > > +++ b/Documentation/devicetree/bindings/phy/allwinner,sun6i-a31-mipi-dphy.yaml > > > @@ -37,6 +37,18 @@ properties: > > > resets: > > > maxItems: 1 > > > > > > + allwinner,direction: > > > + $ref: '/schemas/types.yaml#/definitions/string' > > > + description: | > > > + Direction of the D-PHY: > > > + - "rx" for receiving (e.g. when used with MIPI CSI-2); > > > + - "tx" for transmitting (e.g. when used with MIPI DSI). > > > + > > > + enum: > > > + - tx > > > + - rx > > > + default: tx > > > > Can you the phy mode to imply the direction? > > So there was a first attempt at this which introduced a PHY submode but > it was concluded after discussions that the direction is not really a > mode of operation choice, in the sense that the D-PHY cannot be reconfigured > to behave in Rx or Tx mode: it is instead statically assigned to one role > or the other. This is why it feels more appropriate to describe it in the > device-tree. Another option could be different compatible strings, as the RX and TX PHYs actually have very little in common. I don't mind much either way. > See this thread from the previous iteration: > https://patchwork.linuxtv.org/project/linux-media/patch/20210115200141.1397785-3-paul.kocialkowski@bootlin.com/#128800 -- Regards, Laurent Pinchart _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel