linux-kernel - Re: [PATCH v1 5/5] ARM: tegra: add MIPI calibration binding for Tegra20/Tegra30

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAPVz0n3W1yhrOsiYmYecxtPeYdZiK2_UY7vVc2tiYbYwfWPp7g@mail.gmail.com>
Date: Fri, 18 Jul 2025 12:15:23 +0300
From: Svyatoslav Ryhel <clamor95@...il.com>
To: Mikko Perttunen <mperttunen@...dia.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
	Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Thierry Reding <thierry.reding@...il.com>, Thierry Reding <treding@...dia.com>, 
	Jonathan Hunter <jonathanh@...dia.com>, Prashant Gaikwad <pgaikwad@...dia.com>, 
	Michael Turquette <mturquette@...libre.com>, Stephen Boyd <sboyd@...nel.org>, 
	Dmitry Osipenko <digetx@...il.com>, dri-devel@...ts.freedesktop.org, 
	devicetree@...r.kernel.org, linux-tegra@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org
Subject: Re: [PATCH v1 5/5] ARM: tegra: add MIPI calibration binding for Tegra20/Tegra30

пт, 18 лип. 2025 р. о 12:01 Mikko Perttunen <mperttunen@...dia.com> пише:
>
> On Thursday, July 17, 2025 11:21 PM Svyatoslav Ryhel wrote:
> > Add MIPI calibration device node for Tegra20 and Tegra30.
> >
> > Signed-off-by: Svyatoslav Ryhel <clamor95@...il.com>
> > ---
> >  arch/arm/boot/dts/nvidia/tegra20.dtsi | 14 ++++++++++++++
> >  arch/arm/boot/dts/nvidia/tegra30.dtsi | 18 ++++++++++++++++++
> >  2 files changed, 32 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/nvidia/tegra20.dtsi
> > b/arch/arm/boot/dts/nvidia/tegra20.dtsi index 92d422f83ea4..521261045cc8
> > 100644
> > --- a/arch/arm/boot/dts/nvidia/tegra20.dtsi
> > +++ b/arch/arm/boot/dts/nvidia/tegra20.dtsi
> > @@ -74,6 +74,16 @@ vi@...80000 {
> >                       status = "disabled";
> >               };
> >
> > +             /* DSI MIPI calibration logic is a part of VI/CSI */
> > +             mipi: mipi@...80220 {
> > +                     compatible = "nvidia,tegra20-mipi";
> > +                     reg = <0x54080220 0x100>;
> > +                     clocks = <&tegra_car TEGRA20_CLK_VI>,
> > +                              <&tegra_car TEGRA20_CLK_CSI>;
> > +                     clock-names = "vi", "csi";
> > +                     #nvidia,mipi-calibrate-cells = <1>;
> > +             };
> > +
>
> As you say in the comment, MIPI calibration on Tegra20/30 is part of VI/CSI.
> We can't add a "mipi" device here since such a device doesn't exist in the
> hardware hierarchy. We already have the VI device in the device tree, so we
> need to use that.

I understand your point, but embedding MIPI calibration logic into
VI/CSI driver will bring up another lever of unnecessary complexity
and excessive coding. While approach I have proposed preserves
separation between CSI and DSI and reuses already existing MIPI
calibration framework.

>
> A driver for tegra20-vi already exists in staging/drivers/media/tegra-video.
> We should aim not to break it. Perhaps bring it out of staging? (At least
> partially, but then why not the whole thing.)

It does not break VI/CSI, I have a WIP CSI implementation for
Tegra20/Tegra30 which I hope to submit soon.

>
> Thanks,
> Mikko
>
>
>
>