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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 C6AE1C2D0A3 for ; Wed, 4 Nov 2020 11:14:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 667F721556 for ; Wed, 4 Nov 2020 11:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729227AbgKDLOz (ORCPT ); Wed, 4 Nov 2020 06:14:55 -0500 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:48975 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728345AbgKDLOz (ORCPT ); Wed, 4 Nov 2020 06:14:55 -0500 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 relay1-d.mail.gandi.net (Postfix) with ESMTPSA id C124724000D; Wed, 4 Nov 2020 11:14:46 +0000 (UTC) Date: Wed, 4 Nov 2020 12:14:46 +0100 From: Paul Kocialkowski To: Helen Koike Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, linux-sunxi@googlegroups.com, Mauro Carvalho Chehab , Rob Herring , Maxime Ripard , Chen-Yu Tsai , Yong Deng , Kishon Vijay Abraham I , Vinod Koul , Greg Kroah-Hartman , Philipp Zabel , Hans Verkuil , Sakari Ailus , Thomas Petazzoni , Hans Verkuil , kevin.lhopital@hotmail.com Subject: Re: [PATCH 00/14] Allwinner MIPI CSI-2 support for A31/V3s/A83T Message-ID: <20201104111446.GA287014@aptenodytes> References: <20201023174546.504028-1-paul.kocialkowski@bootlin.com> <20201104111137.GH285779@aptenodytes> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="BXVAT5kNtrzKuDFl" Content-Disposition: inline In-Reply-To: <20201104111137.GH285779@aptenodytes> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org --BXVAT5kNtrzKuDFl Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi again, On Wed 04 Nov 20, 12:11, Paul Kocialkowski wrote: > Hi Helen, >=20 > On Fri 30 Oct 20, 19:44, Helen Koike wrote: > > Hi Paul, > >=20 > > I have some comments through the series, I hope this helps. >=20 > Thanks for your comments :) >=20 > > On 10/23/20 2:45 PM, Paul Kocialkowski wrote: > > > This series introduces support for MIPI CSI-2, with the A31 controlle= r that is > > > found on most SoCs (A31, V3s and probably V5) as well as the A83T-spe= cific > > > controller. While the former uses the same MIPI D-PHY that is already= supported > > > for DSI, the latter embeds its own D-PHY. > > >=20 > > > In order to distinguish the use of the D-PHY between Rx mode (for MIP= I CSI-2) > > > and Tx mode (for MIPI DSI), a submode is introduced for D-PHY in the = PHY API. > > > This allows adding Rx support in the A31 D-PHY driver. > > >=20 > > > A few changes and fixes are applied to the A31 CSI controller driver,= in order > > > to support the MIPI CSI-2 use-case. > > >=20 > > > Follows is the V4L2 device topology representing the interactions bet= ween > > > the MIPI CSI-2 sensor, the MIPI CSI-2 controller (which controls the = D-PHY) > > > and the CSI controller: > > > - entity 1: sun6i-csi (1 pad, 1 link) > > > type Node subtype V4L flags 0 > > > device node name /dev/video0 > > > pad0: Sink > > > <- "sun6i-mipi-csi2":1 [ENABLED,IMMUTABLE] > > >=20 > > > - entity 5: sun6i-mipi-csi2 (2 pads, 2 links) > > > type V4L2 subdev subtype Unknown flags 0 > > > pad0: Sink > > > <- "ov5648 0-0036":0 [ENABLED,IMMUTABLE] > > > pad1: Source > > > -> "sun6i-csi":0 [ENABLED,IMMUTABLE] > > >=20 > > > - entity 8: ov5648 0-0036 (1 pad, 1 link) > > > type V4L2 subdev subtype Sensor flags 0 > > > device node name /dev/v4l-subdev0 > >=20 > > Question: I noticed is that sun6i-mipi-csi2 doesn't expose a node under= /dev/, but the sensor > > exposes it. Probably because it uses V4L2_SUBDEV_FL_HAS_DEVNODE and sun= 6i-csi() calls > > v4l2_device_register_subdev_nodes(). > >=20 > > I find this weird from a userspace pov, since usually we don't mix manu= al and auto propagation > > of the configs, so I started wondering if sun6i-csi driver should be ca= lling > > v4l2_device_register_subdev_nodes() in the first place. >=20 > I must admit that I didn't really pay attention to that, but since > sun6i-mipi-csi2 is basically a bridge driver, it doesn't make sense to ap= ply > manual configuration to it. It is actually designed to forward most subde= v ops > to its own subdev so configuring it manually would actually result in > configuring the sensor. >=20 > XXX Hum, I meant to add something here and then forgot. I'm pretty new to auto = vs manual propagation so I don't really have a clear opinion on this and wheth= er we should consider removing the sensor /dev node as well. I'm satisfied with the way things are currently, but it might be due to my own ignorance. Paul > > Also, sun6i-csi doesn't seem to be used by any board dts (it's declared= on the dtsi, but I > > didn't find any dts enabling it), so I wonder if it would be a bad thin= g if we update it. > > > > > pad0: Source > > > [fmt:SBGGR8_1X8/640x480@1/30 field:none colorspace:raw xfer:none yc= bcr:601 quantization:full-range] > > > -> "sun6i-mipi-csi2":0 [ENABLED,IMMUTABLE] > >=20 > > If I understand correctly, this is very similar to ipu3: > > sensor->bus->dma_engine > >=20 > > in the case of ipu3-cio2: > > sensor->ipu3-csi2->ipu3-cio2 > >=20 > > in this case: > > ov5648->sun6i-mipi-csi2->sun6i-csi >=20 > Yes this is the correct picture. >=20 > > On thing that is confusing me is the name csi2 with csi (that makes me = think of csi > > version one, which is not the case), I would rename it to sun6i-video (= or maybe > > it is just me who gets confused). >=20 > So the CSI name comes from the Allwinner litterature and implementation f= or that > controller. Since it supports parallel input on its own, it does in fact = support > parallel CSI. The DMA engine part alone from that controller is also used= for > MIPI CSI-2, so in this case the name looses its relevance. >=20 > > I know this driver is already upstream and not part of this series, but= on the other hand it > > doesn't seem to be used. >=20 > Personally I don't find a rename to be necessary and while I agree that > nothing would apparently prevent us from renaming it, I would prefer to k= eep > the naming in line with Allwinner's litterature. >=20 > > On another note, I always wonder if we should expose the bus in the top= ology, I'm not > > sure if it provides any useful API or information for userspace, and yo= u could have > > a cleaner code (maybe code could be under phy subsystem). But at the sa= me time, it > > seems this is a pattern on v4l2. > >=20 > > I'd like to hear what others think on the above. >=20 > My view on this is that we are dealing with two distinct controllers here, > one that acts as a DMA engine and one that acts as a bridge. As a result,= two > chained subdevs looks like the most appropriate representation to me. >=20 > Using the PHY subsystem would probably be abusing the framework since the > MIPI CSI-2 controller is not a PHY (and we do have a D-PHY driver for the= D-PHY > part that uses the PHY API already). >=20 > So tl;dr I don't agree that it would be cleaner. >=20 > Cheers, >=20 > Paul >=20 > > > Happy reviewing! > > >=20 > > > Paul Kocialkowski (14): > > > phy: Distinguish between Rx and Tx for MIPI D-PHY with submodes > > > phy: allwinner: phy-sun6i-mipi-dphy: Support D-PHY Rx mode for MIPI > > > CSI-2 > > > media: sun6i-csi: Support an optional dedicated memory pool > > > media: sun6i-csi: Fix the image storage bpp for 10/12-bit Bayer > > > formats > > > media: sun6i-csi: Only configure the interface data width for paral= lel > > > media: sun6i-csi: Support feeding from the MIPI CSI-2 controller > > > dt-bindings: media: i2c: Add A31 MIPI CSI-2 bindings documentation > > > media: sunxi: Add support for the A31 MIPI CSI-2 controller > > > ARM: dts: sun8i: v3s: Add CSI0 camera interface node > > > ARM: dts: sun8i: v3s: Add MIPI D-PHY and MIPI CSI-2 interface nodes > > > dt-bindings: media: i2c: Add A83T MIPI CSI-2 bindings documentation > > > media: sunxi: Add support for the A83T MIPI CSI-2 controller > > > ARM: dts: sun8i: a83t: Add MIPI CSI-2 controller node > > > media: sunxi: sun8i-a83t-mipi-csi2: Avoid using the (unsolicited) > > > interrupt > > >=20 > > > .../media/allwinner,sun6i-a31-mipi-csi2.yaml | 168 +++++ > > > .../media/allwinner,sun8i-a83t-mipi-csi2.yaml | 158 +++++ > > > arch/arm/boot/dts/sun8i-a83t.dtsi | 26 + > > > arch/arm/boot/dts/sun8i-v3s.dtsi | 62 ++ > > > drivers/media/platform/sunxi/Kconfig | 2 + > > > drivers/media/platform/sunxi/Makefile | 2 + > > > .../platform/sunxi/sun6i-csi/sun6i_csi.c | 54 +- > > > .../platform/sunxi/sun6i-csi/sun6i_csi.h | 20 +- > > > .../platform/sunxi/sun6i-mipi-csi2/Kconfig | 11 + > > > .../platform/sunxi/sun6i-mipi-csi2/Makefile | 4 + > > > .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.c | 635 +++++++++++++++++ > > > .../sunxi/sun6i-mipi-csi2/sun6i_mipi_csi2.h | 116 +++ > > > .../sunxi/sun8i-a83t-mipi-csi2/Kconfig | 11 + > > > .../sunxi/sun8i-a83t-mipi-csi2/Makefile | 4 + > > > .../sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.c | 92 +++ > > > .../sun8i-a83t-mipi-csi2/sun8i_a83t_dphy.h | 39 ++ > > > .../sun8i_a83t_mipi_csi2.c | 660 ++++++++++++++++= ++ > > > .../sun8i_a83t_mipi_csi2.h | 196 ++++++ > > > drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 164 ++++- > > > drivers/staging/media/rkisp1/rkisp1-isp.c | 3 +- > > > include/linux/phy/phy-mipi-dphy.h | 13 + > > > 21 files changed, 2408 insertions(+), 32 deletions(-) > > > create mode 100644 Documentation/devicetree/bindings/media/allwinner= ,sun6i-a31-mipi-csi2.yaml > > > create mode 100644 Documentation/devicetree/bindings/media/allwinner= ,sun8i-a83t-mipi-csi2.yaml > > > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/Kcon= fig > > > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/Make= file > > > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6= i_mipi_csi2.c > > > create mode 100644 drivers/media/platform/sunxi/sun6i-mipi-csi2/sun6= i_mipi_csi2.h > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /Kconfig > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /Makefile > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /sun8i_a83t_dphy.c > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /sun8i_a83t_dphy.h > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /sun8i_a83t_mipi_csi2.c > > > create mode 100644 drivers/media/platform/sunxi/sun8i-a83t-mipi-csi2= /sun8i_a83t_mipi_csi2.h > > >=20 >=20 > --=20 > Paul Kocialkowski, Bootlin > Embedded Linux and kernel engineering > https://bootlin.com --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --BXVAT5kNtrzKuDFl Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAl+ijSYACgkQ3cLmz3+f v9EP8gf/ep3ZT/jxOwRIeLC9QlQttVayezv2icEW1vWtW039XYjXl/Lz8Mkk/PIG KGhH3YVqbCxE2TH2LYpwn+RgVEDuUV/RW/lASfU8uHzKhe6hvZWGmL88qveAViPA E5h/lQtrItJluIkDgYv3ESNNG+R18HChsHVqzAcSgzvesrSnmW38XhWi1H68OBt9 NDsgIBIvObFX9aX6jzhCPigk7h8fhFjw//FxGQzCtU6BRX/7Rn4lMDmjMqdarZzV vORjKHaTfAbuS5sjuV6d4zXBRZhlJXsSTw3CssMtxeNEjgIxr2C63crhcqrkDixw RO/uBigt2IRNLEC8ssCrz/eowA7Zng== =yIar -----END PGP SIGNATURE----- --BXVAT5kNtrzKuDFl--