Re: [PATCH v3 2/4] arm64: tegra: Add Tegra234 I2C devicetree nodes

From: Dmitry Osipenko
Date: Mon Jan 24 2022 - 11:48:53 EST


24.01.2022 14:18, Akhil R пишет:
> Add device tree nodes for Tegra234 I2C controllers
>
> Signed-off-by: Akhil R <akhilrajeev@xxxxxxxxxx>
> ---
> arch/arm64/boot/dts/nvidia/tegra234.dtsi | 121 +++++++++++++++++++++++++++++++
> 1 file changed, 121 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/nvidia/tegra234.dtsi b/arch/arm64/boot/dts/nvidia/tegra234.dtsi
> index 6b6f1580..c686827 100644
> --- a/arch/arm64/boot/dts/nvidia/tegra234.dtsi
> +++ b/arch/arm64/boot/dts/nvidia/tegra234.dtsi
> @@ -144,6 +144,96 @@
> status = "disabled";
> };
>
> + gen1_i2c: i2c@3160000 {
> + compatible = "nvidia,tegra194-i2c";
> + reg = <0x3160000 0x100>;
> + status = "disabled";
> + interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
> + clock-frequency = <400000>;
> + clocks = <&bpmp TEGRA234_CLK_I2C1
> + &bpmp TEGRA234_CLK_PLLP_OUT0>;
> + assigned-clocks = <&bpmp TEGRA234_CLK_I2C1>;
> + assigned-clock-parents = <&bpmp TEGRA234_CLK_PLLP_OUT0>;
> + clock-names = "div-clk", "parent";
> + resets = <&bpmp TEGRA234_RESET_I2C1>;
> + reset-names = "i2c";
> + };

The patchset looks okay to me, thank you. I've one question:

Could you please explain why the "PLLP" I2C timing configuration that is
specified in the "example" section of Tegra TRM isn't suitable for
T194/234? Why I2C Tegra kernel driver uses a different configuration?