Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
From:   Alexander Stein <alexander.stein@ew.tq-group.com>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        Paul Elder <paul.elder@ideasonboard.com>,
        kieran.bingham@ideasonboard.com, tomi.valkeinen@ideasonboard.com,
        umang.jain@ideasonboard.com, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Tim Harvey <tharvey@gateworks.com>,
        Philippe Schenker <philippe.schenker@toradex.com>,
        Marek Vasut <marex@denx.de>,
        Gregor Herburger <gregor.herburger@ew.tq-group.com>,
        Marcel Ziswiler <marcel.ziswiler@toradex.com>,
        open list <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 2/2] arm64: dts: imx8mp: Add overlays for ISP instances
Date:   Thu, 30 Nov 2023 10:51:22 +0100
Message-ID: <5734628.DvuYhMxLoT@steina-w>
Organization: TQ-Systems GmbH
In-Reply-To: <20231129151637.GG24293@pendragon.ideasonboard.com>
References: <20231129093113.255161-1-paul.elder@ideasonboard.com> <7122934.GXAFRqVoOG@steina-w> <20231129151637.GG24293@pendragon.ideasonboard.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="iso-8859-1"
Precedence: bulk

Hi Laurent,

Am Mittwoch, 29. November 2023, 16:16:37 CET schrieb Laurent Pinchart:
> Hi Alexander,
>=20
> On Wed, Nov 29, 2023 at 11:20:07AM +0100, Alexander Stein wrote:
> > Am Mittwoch, 29. November 2023, 10:31:13 CET schrieb Paul Elder:
> > > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >=20
> > > Add two overlay to enable each ISP instance. The ISP is wired directly
> > > to the CSIS for now, bypassing the ISI completely.
> >=20
> > I'm not sure if this is worth adding in a separate overlay.
>=20
> The trouble is that, at this point, selection between the ISP and the
> ISI can only be performed through DT :-S That's why this is implemented
> as an overlay.

I feel a better place would be the overlay which actually adds the sensor.=
=20
This knows best whether ISI or ISP should be used.

> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
> > > ---
> > >=20
> > >  arch/arm64/boot/dts/freescale/Makefile        |  2 ++
> > >  .../arm64/boot/dts/freescale/imx8mp-isp1.dtso | 36 +++++++++++++++++=
++
> > >  .../arm64/boot/dts/freescale/imx8mp-isp2.dtso | 36 +++++++++++++++++=
++
> > >  3 files changed, 74 insertions(+)
> > >  create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-isp1.dtso
> > >  create mode 100644 arch/arm64/boot/dts/freescale/imx8mp-isp2.dtso
> > >=20
> > > diff --git a/arch/arm64/boot/dts/freescale/Makefile
> > > b/arch/arm64/boot/dts/freescale/Makefile index
> > > 300049037eb0..f97dfac11189
> > > 100644
> > > --- a/arch/arm64/boot/dts/freescale/Makefile
> > > +++ b/arch/arm64/boot/dts/freescale/Makefile
> > > @@ -113,6 +113,8 @@ dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-dhcom-pdk2.dtb
> > >=20
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-dhcom-pdk3.dtb
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-evk.dtb
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-icore-mx8mp-edimm2.2.dtb
> > >=20
> > > +dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-isp1.dtbo
> > > +dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-isp2.dtbo
> > >=20
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-msc-sm2s-ep1.dtb
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-phyboard-pollux-rdk.dtb
> > >  dtb-$(CONFIG_ARCH_MXC) +=3D imx8mp-tqma8mpql-mba8mpxl.dtb
> > >=20
> > > diff --git a/arch/arm64/boot/dts/freescale/imx8mp-isp1.dtso
> > > b/arch/arm64/boot/dts/freescale/imx8mp-isp1.dtso new file mode 100644
> > > index 000000000000..cf394ed224ab
> > > --- /dev/null
> > > +++ b/arch/arm64/boot/dts/freescale/imx8mp-isp1.dtso
> > > @@ -0,0 +1,36 @@
> > > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> > > +/*
> > > + * Copyright 2022 Ideas on Board Oy
> > > + */
> > > +
> > > +/dts-v1/;
> > > +/plugin/;
> > > +
> > > +#include <dt-bindings/media/video-interfaces.h>
> > > +
> > > +&isi_0 {
> > > +	status =3D "disabled";
> >=20
> > ISI is disabled by default. What is your intention here?
>=20
> It could be enabled by an overlay for a camera module. Ideally we want
> to be able to enable both the ISI and ISP at runtime, but that's not
> possible yet and will require a very large amount of work.

Again IMHO this is part of sensor setup, in a very specific overlay. To put=
 it=20
into different words: I barely see the gain of this small overlay.

Runtime switching would require a combined media controller including both =
ISI=20
and ISP, no?

Best regards,
Alexander

> > > +
> > > +	ports {
> > > +		port@0 {
> > > +			/delete-node/ endpoint;
> >=20
> > This doesn't work in overlays. See [1]. Otherwise the OF graph connecti=
ons
> > look fine to me. I'm using the same in my local overlay.
>=20
> Interesting, I wasn't aware of that. Maybe we should fix it :-)
>=20
> > [1]
> > https://lore.kernel.org/all/CAMuHMdWu4KZbBkvEofUV2wuA1g2S=3DXHHM3RUN1cN=
rcZB
> > khsPZA@mail.gmail.com/>=20
> > > +		};
> > > +	};
> > > +};
> > > +
> > > +&isp_0 {
> > > +	status =3D "okay";
> > > +
> > > +	ports {
> > > +		port@1 {
> > > +			isp0_in: endpoint {
> > > +				bus-type =3D <MEDIA_BUS_TYPE_PARALLEL>;
> > > +				remote-endpoint =3D <&mipi_csi_0_out>;
> > > +			};
> > > +		};
> > > +	};
> > > +};
> > > +
> > > +&mipi_csi_0_out {
> > > +	remote-endpoint =3D <&isp0_in>;
> > > +};
> > > diff --git a/arch/arm64/boot/dts/freescale/imx8mp-isp2.dtso
> > > b/arch/arm64/boot/dts/freescale/imx8mp-isp2.dtso new file mode 100644
> > > index 000000000000..14e2e7b2617f
> > > --- /dev/null
> > > +++ b/arch/arm64/boot/dts/freescale/imx8mp-isp2.dtso
> > > @@ -0,0 +1,36 @@
> > > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> > > +/*
> > > + * Copyright 2022 Ideas on Board Oy
> > > + */
> > > +
> > > +/dts-v1/;
> > > +/plugin/;
> > > +
> > > +#include <dt-bindings/media/video-interfaces.h>
> > > +
> > > +&isi_0 {
> > > +	status =3D "disabled";
> > > +
> > > +	ports {
> > > +		port@1 {
> > > +			/delete-node/ endpoint;
> > > +		};
> > > +	};
> > > +};
> > > +
> > > +&isp_1 {
> > > +	status =3D "okay";
> > > +
> > > +	ports {
> > > +		port@1 {
> > > +			isp1_in: endpoint {
> > > +				bus-type =3D <MEDIA_BUS_TYPE_PARALLEL>;
> > > +				remote-endpoint =3D <&mipi_csi_1_out>;
> > > +			};
> > > +		};
> > > +	};
> > > +};
> > > +
> > > +&mipi_csi_1_out {
> > > +	remote-endpoint =3D <&isp1_in>;
> > > +};


=2D-=20
TQ-Systems GmbH | M=FChlstra=DFe 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht M=FCnchen, HRB 105018
Gesch=E4ftsf=FChrer: Detlef Schneider, R=FCdiger Stahl, Stefan Schneider
http://www.tq-group.com/