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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 978A7C47082 for ; Wed, 26 May 2021 15:35:31 +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 547BE60FEB for ; Wed, 26 May 2021 15:35:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 547BE60FEB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: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-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WtgIft0Ye8ZrDd85cPYkGjXRNmsDsU05DUvT7U2IiNw=; b=WiDunqm1TiloXZvESyGhasQzDH ilm2CRsDeJA2Fy88Cirow3TchWqPC7jT2MEMQEncO4M9vY6AmyY+kYUMPhcVONiBCZM8W+lMqJEXW AeARLbqRcg/2om3SnzXF/0s3jHXZIcW3kfyjII2euQO+r0IbnPWrkrisD3byGD2aWXVmwtNp5lDIM r8b4kQdtKC0JTKqMb6iJGVsuAUjfu9DiPE4g0wRsiqoYRcd7MMRJMwhLPtXiLEAJkAbqNc2lLb1NF dAhIPlbjanuvs4Iuo5m8JvQ4NiDUnw7+eqWUFwW6seRTBWJmf8VONlsJugbbBi9RgvZ3Ur6/x/bK/ s4l6fv+g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1llvXM-00FP0l-Cm; Wed, 26 May 2021 15:33:37 +0000 Received: from relay8-d.mail.gandi.net ([217.70.183.201]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lluS6-00EqYs-DN for linux-arm-kernel@lists.infradead.org; Wed, 26 May 2021 14:24:08 +0000 Received: (Authenticated sender: paul.kocialkowski@bootlin.com) by relay8-d.mail.gandi.net (Postfix) with ESMTPSA id 743A61BF210; Wed, 26 May 2021 14:24:00 +0000 (UTC) Date: Wed, 26 May 2021 16:24:00 +0200 From: Paul Kocialkowski To: linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, devel@driverdev.osuosl.org, linux-sunxi@googlegroups.com Cc: Yong Deng , Mauro Carvalho Chehab , Rob Herring , Maxime Ripard , Chen-Yu Tsai , Jernej Skrabec , Jonathan Corbet , Kishon Vijay Abraham I , Vinod Koul , Helen Koike , Dafna Hirschfeld , Greg Kroah-Hartman , Philipp Zabel , Sakari Ailus , Hans Verkuil , Thomas Petazzoni , kevin.lhopital@hotmail.com, Ezequiel Garcia , Laurent Pinchart Subject: Re: [PATCH v5 02/16] phy: Distinguish between Rx and Tx for MIPI D-PHY with submodes Message-ID: References: <20210115200141.1397785-1-paul.kocialkowski@bootlin.com> <20210115200141.1397785-3-paul.kocialkowski@bootlin.com> MIME-Version: 1.0 In-Reply-To: <20210115200141.1397785-3-paul.kocialkowski@bootlin.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210526_072406_778832_B0A77A38 X-CRM114-Status: GOOD ( 26.15 ) 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: multipart/mixed; boundary="===============1929958841904974135==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============1929958841904974135== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7zgmf44zur7folx5" Content-Disposition: inline --7zgmf44zur7folx5 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi everyone, On Fri 15 Jan 21, 21:01, Paul Kocialkowski wrote: > As some D-PHY controllers support both Rx and Tx mode, we need a way for > users to explicitly request one or the other. For instance, Rx mode can > be used along with MIPI CSI-2 while Tx mode can be used with MIPI DSI. >=20 > Introduce new MIPI D-PHY PHY submodes to use with PHY_MODE_MIPI_DPHY. > The default (zero value) is kept to Tx so only the rkisp1 driver, which > uses D-PHY in Rx mode, needs to be adapted. I think it was Laurent who brought up on IRC that using a submode is probab= ly not a correct way to distinguish between Rx and Tx modes. Thinking about it again, it feels like selecting the direction at run-time would only be relevant if there's D-PHY hardware than can do both Tx and Rx *and* that can be muxed to either a MIPI DSI and a CSI-2 controller at run-time. For the Allwinner case, the D-PHY is the same hardware for both but there w= ill be one instance attached to each controller, not a single shared instance. It feels rather unlikely that a device with both MIPI DSI and CSI-2 would o= nly have one PHY for the two as this wouldn't allow concurrent use of the two controllers. Even in a case where there'd be n controllers and m < n bi-directional PHYs, it feels safe to assume that a static attribution would be sufficient. =20 As a result it feels more relevant to have this distinction in device-tree rather than via the PHY API. What do you think? Any suggestion on how this should be represented in device-tree? Cheers, Paul > Signed-off-by: Paul Kocialkowski > Acked-by: Helen Koike > --- > drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c | 3 ++- > include/linux/phy/phy-mipi-dphy.h | 13 +++++++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c b/driver= s/media/platform/rockchip/rkisp1/rkisp1-isp.c > index 2e5b57e3aedc..cab261644102 100644 > --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c > +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-isp.c > @@ -948,7 +948,8 @@ static int rkisp1_mipi_csi2_start(struct rkisp1_isp *= isp, > =20 > phy_mipi_dphy_get_default_config(pixel_clock, isp->sink_fmt->bus_width, > sensor->lanes, cfg); > - phy_set_mode(sensor->dphy, PHY_MODE_MIPI_DPHY); > + phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY, > + PHY_MIPI_DPHY_SUBMODE_RX); > phy_configure(sensor->dphy, &opts); > phy_power_on(sensor->dphy); > =20 > diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mi= pi-dphy.h > index a877ffee845d..0f57ef46a8b5 100644 > --- a/include/linux/phy/phy-mipi-dphy.h > +++ b/include/linux/phy/phy-mipi-dphy.h > @@ -6,6 +6,19 @@ > #ifndef __PHY_MIPI_DPHY_H_ > #define __PHY_MIPI_DPHY_H_ > =20 > +/** > + * enum phy_mipi_dphy_submode - MIPI D-PHY sub-mode > + * > + * A MIPI D-PHY can be used to transmit or receive data. > + * Since some controllers can support both, the direction to enable is s= pecified > + * with the PHY sub-mode. Transmit is assumed by default with phy_set_mo= de. > + */ > + > +enum phy_mipi_dphy_submode { > + PHY_MIPI_DPHY_SUBMODE_TX =3D 0, > + PHY_MIPI_DPHY_SUBMODE_RX, > +}; > + > /** > * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set > * > --=20 > 2.30.0 >=20 --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --7zgmf44zur7folx5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAmCuWgAACgkQ3cLmz3+f v9FhsAf+LCjDsXEPBS3IEa3r1GuNV4LBCN/X+lLIeNTjDh6K2INIlcpTAQKOFukJ SpuPbpbstXPTy9/vCtFP/DlZL1Oh2LO0HtXUlcb3rGEFO+1I4HUlOemAjl4TLbIv E0b9iFY1splxVIehgB1+IGh0+OeiFr/d5GegzOggbhxTN9Et1Ag43WAWglT86XcY MClLNUG8uVl86H83cFVP2AVzPj4GSmgiydKVcH8mLG6PE7DD3PfH5VzkDb2fAmMg uXJGP2qJCEXMAHwz6GFxEDArK22vzR7kzw3VAZWIwnBYP58QW/ifeL4D0Ak1aDbD wlmzQmgw2dpbHuESesA/00xaqumugA== =/RYX -----END PGP SIGNATURE----- --7zgmf44zur7folx5-- --===============1929958841904974135== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============1929958841904974135==--