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

[Mikko Perttunen <mperttunen@nvidia.com>]

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@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.

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.)

Thanks,
Mikko