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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=merlin.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject: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=y+f0rIQHwuvThJfqmySi4KFT8jp+dXYuNVaMHCdVqF4=; b=fpknoGs+IdGfpXd03v60KWuqF pPPtc/dYGxFh+A+ghZ/hgvDcfcx83OEExnYXbK0M6ERjH3hy+pT1qwBflmNZ2kFMwXPV8UU/gYD1V yKrMCLaCdJ+gcqpfVE8UBi0BhV8yqqhPaGsD79lpWeDmOpu+giC/rw/rPoyuklXUcNfPDXOF1k2UN Q2xrYjg9mSZLqwav69KjEVz7zwSA3/9YhnoRLLh9O77ADPX6OC2U/NlFinvpDrEYopTVy/vzCRyEo Z+nwMjd3Jl0DvpA28U+TytNCsdb6pDo7EmmUNXY/33tJpDNCN6yqZ5MFLYwS0fHcY2OnusGW4QFNK QE3pWbfww==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkSya-0003vT-1X; Wed, 02 Dec 2020 14:19:24 +0000 Received: from relay6-d.mail.gandi.net ([217.70.183.198]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kkSyW-0003uO-9t for linux-arm-kernel@lists.infradead.org; Wed, 02 Dec 2020 14:19:21 +0000 X-Originating-IP: 93.29.109.196 Received: from aptenodytes (196.109.29.93.rev.sfr.net [93.29.109.196]) (Authenticated sender: paul.kocialkowski@bootlin.com) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 4856DC0007; Wed, 2 Dec 2020 14:19:12 +0000 (UTC) Date: Wed, 2 Dec 2020 15:19:11 +0100 From: Paul Kocialkowski To: Maxime Ripard Subject: Re: [PATCH v2 07/19] media: sun6i-csi: Add support for MIPI CSI-2 bridge input Message-ID: References: <20201128142839.517949-1-paul.kocialkowski@bootlin.com> <20201128142839.517949-8-paul.kocialkowski@bootlin.com> <20201201121241.cyafjhot45puusfc@gilmour> MIME-Version: 1.0 In-Reply-To: <20201201121241.cyafjhot45puusfc@gilmour> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201202_091920_532754_DFA69789 X-CRM114-Status: GOOD ( 31.27 ) 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: Dafna Hirschfeld , linux-doc@vger.kernel.org, linux-sunxi@googlegroups.com, Thomas Petazzoni , kevin.lhopital@hotmail.com, devel@driverdev.osuosl.org, Jonathan Corbet , Kishon Vijay Abraham I , Chen-Yu Tsai , Hans Verkuil , linux-media@vger.kernel.org, devicetree@vger.kernel.org, Sakari Ailus , Helen Koike , Rob Herring , Yong Deng , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, Jernej Skrabec , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Vinod Koul , Philipp Zabel Content-Type: multipart/mixed; boundary="===============3103666126933812346==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============3103666126933812346== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="tDn8NpJ7qnoGqYpK" Content-Disposition: inline --tDn8NpJ7qnoGqYpK Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Tue 01 Dec 20, 13:12, Maxime Ripard wrote: > Hi, >=20 > On Sat, Nov 28, 2020 at 03:28:27PM +0100, Paul Kocialkowski wrote: > > The A31 CSI controller supports a MIPI CSI-2 bridge input, which has > > its own dedicated port in the fwnode graph. > >=20 > > Support for this input is added with this change: > > - two pads are defined for the media entity instead of one > > and only one needs to be connected at a time; > > - the pads currently match the fwnode graph representation; > > - links are created between our pads and the subdevs for each > > interface and are no longer immutable so that userspace can select > > which interface to use in case both are bound to a subdev; > > - fwnode endpoints are parsed and stored for each interface; > > - the active subdev (and fwnode endpoint) is retrieved when validating > > the media link at stream on time and cleared at stream off; > > - an error is raised if both links are active at the same time; > > - the MIPI interface bit is set if the MIPI CSI-2 bridge endpoint is > > active. > >=20 > > In the future, the media entity representation might evolve to: > > - distinguish the internal parallel bridge and data formatter; > > - represent each of the 4 internal channels that can exist between > > the parallel bridge (for BT656 time-multiplex) and MIPI CSI-2 > > (internal channels can be mapped to virtual channels); > > - connect the controller's output to the ISP instead of its > > DMA engine. > >=20 > > Finally note that the MIPI CSI-2 bridges should not be linked in > > the fwnode graph unless they have a sensor subdev attached. >=20 > I'll leave most of the review to Laurent and Sakari, but I'm not quite > sure what you meant in the last paragraph. Did you mean that the > MIPI-CSI controller in the Allwinner SoC should only be linked if it has > a sensor attached, or did you mean that any MIPI-CSI2 bridge cannot be > attached to the controller? So the use of plural was a mistake and your first understanding is the corr= ect one: if the bridge is linked to the CSI controller in the OF graph but the bridge doesn't have a sensor attached, the CSI controller driver will fail to probe, as far as I could see. I haven't investigated much but it looks like this is expected behavior. > Also, having somewhere (like your cover letter) the media-ctl setup you > tested with would be great. Understood! Cheers, Paul --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --tDn8NpJ7qnoGqYpK Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAl/Hol8ACgkQ3cLmz3+f v9EqPAf/X3YxsNi+JcqhfeAseKXD/cboW7DdagCpjzxZ/RZN8sjOJGOKhxrKkxw5 wkAPyF/nPPaqeSUF20XtgSx/rwQqMrOb1efwgUY22v7rq1u4Kw4kcVl9iLfS3xpo B2fcBhgLvne3l6tpGUiKoQS7cNTiVMAYw6scpEPCpZ/mA6pV02upCEFcrZkGUw7i scOA6986c3kONoWQQ6Zu5x7J7DMklN/+kc+zkZt/Vb6ZwSOO+/DMopUMsbhv0Op3 FBYySRjzikhFTMYjtLWvIqihnpaCr3OXroEMgS1sGIpsUepFeMvVbL1ihmgNo7vh T9iQ6dPLnWvDl4gg4XMefkTAB4BRUg== =iVuy -----END PGP SIGNATURE----- --tDn8NpJ7qnoGqYpK-- --===============3103666126933812346== 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 --===============3103666126933812346==--