пт, 18 лип. 2025 р. о 12:22 Mikko Perttunen <mperttu...@nvidia.com> пише:
>
> On Friday, July 18, 2025 6:15 PM Svyatoslav Ryhel wrote:
> > пт, 18 лип. 2025 р. о 12:01 Mikko Perttunen <mperttu...@nvidia.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 <clamo...@gmail.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@54080000 {
> > > >
> > > > status = "disabled";
> > > >
> > > > };
> > > >
> > > > + /* DSI MIPI calibration logic is a part of VI/CSI */
> > > > + mipi: mipi@54080220 {
> > > > + 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.
>
> We can consider different driver architectures to simplify things, but the
> device tree has to conform to hardware. The host1x bus has no 'mipi' device on
> it so we can't put one in the device tree.
>
I assume then placing mipi node as CSI or VI child would resolve your concern?
> >
> > > 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.
>
> We have to use the tegra20-vi node as that matches hardware, and each node can
> only be probed to one device, hence the issue.
>
> Great to see a CSI driver!
>
> Mikko
>
> >
> > > Thanks,
> > > Mikko
>
>
>
>
