Jetson nano I2C pinmux

[854053437]

Hi,
I’m working on custom Nano board bsp and have a question about the I2C pinmux and device tree configuration.
In Xavier NX, there is a file in Jetson\r3531\hardware\nvidia\soc\t19x\kernel-dts\tegra194-soc\tegra194-soc-i2c.dtsi to describe the i2c node and its register such as

i2c0 = &gen1_i2c;
gen1_i2c: i2c@3160000 {
		#address-cells = <1>;
		#size-cells = <0>;
		iommus = <&smmu TEGRA_SID_GPCDMA_0>;
		dma-coherent;
		compatible = "nvidia,tegra194-i2c";
		reg = <0x0 0x3160000 0x0 0x100>;
		nvidia,hw-instance-id = <0x0>;
		interrupts = <0 TEGRA194_IRQ_I2C1 0x04>;
		scl-gpio = <&tegra_main_gpio TEGRA194_MAIN_GPIO(I, 3) 0>;
		sda-gpio = <&tegra_main_gpio TEGRA194_MAIN_GPIO(I, 4) 0>;
		status = "disabled";
		clock-frequency = <400000>;
		clocks = <&bpmp_clks TEGRA194_CLK_I2C1
			&bpmp_clks TEGRA194_CLK_PLLP_OUT0>;
		clock-names = "div-clk", "parent";
		resets = <&bpmp_resets TEGRA194_RESET_I2C1>;
		reset-names = "i2c";
		dmas = <&gpcdma 21>, <&gpcdma 21>;
		dma-names = "rx", "tx";
	};

and I can find the specific name of this I2C controller in the device tree by the corresponding name in the excel spreadsheet, thus achieving the configuration just like this

    i2c@3160000 {
        uih_rtc: uih_rtc@68 {
            compatible = "dallas,ds1340";
            reg = <0x68>;
        };
    };

But in nano, there is no such a file to connect the device tree and pinmux excel. And in the Product Design Guide file does not have this information either.
In my situation, I want to use these two I2C bus in pinmux excel

But in bsp file, there is only unclear I2C name and I really don’t know which bus corresponds to the I2C in excel.

aliases {
		i2c0 = &i2c1;
		i2c1 = &i2c2;
		i2c2 = &i2c3;
		i2c3 = &i2c4;
		i2c4 = &i2c5;
		i2c5 = &i2c6;
		i2c6 = &i2c7;
		spi0 = &spi0;
		spi1 = &spi1;
		spi2 = &spi2;
		spi3 = &spi3;
		qspi6 = &qspi6;
		serial0 = &uarta;
		serial1 = &uartb;
		serial2 = &uartc;
		serial3 = &uartd;
		rtc0 = "/i2c@7000d000/max77620@3c";
		rtc1 = "/rtc";
	};

Can you show me the relationship between i2c0-6 and GEN1_I2C?
Thanks

[854053437]

By the way, the name method in jetson is too complicated. There is three name in Xavier NX’s pinmux excel. If the dtb file do not have this information, I can not know the correct register in module.

i2c0 = &gen1_i2c;
gen1_i2c: i2c@3160000

I know I can use I2C-tools to detect the device but this is inconvenient before our custom board production

[ShaneCCC]

Suppose your are talking Orin Nano.
You can check the TRM and subtract 1 to map to software bus number.
For example GEN1 i2c is i2c0

a

[854053437]

Thanks for reply, but the object I talked about is just Nano not Orin Nano

[ShaneCCC]

Suppose Nano is the same. You can check TRM of TX1.

Thanks

[854053437]

there is no this information in TX1’s TRM

@ShaneCCC

[ShaneCCC]

You can check the pinmux file for example.
The function field of SFIO0 tell the I2C1 that’s HW name and subtract 1 to get software bus number.

[854053437]

but in nano’s pinmux, they are shown as, so which bus is this controller connected, I2C2 or i2c1?

@854053437

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[ShaneCCC]

THe GEN1 i2c is i2c bus 0.

Thanks

[854053437]

so it means Nano’s I2C GEN1、GEN2、GEN3 is i2C bus 0\1\2？

And the device tree node name is i2c@7000c000(i2c gen1)、i2c@7000c400(i2c gen2)、i2c@7000c500(i2c gen3)

Is that right?

[ShaneCCC]

Yes, that’s correct.

Thanks

[854053437]

ok，thank you！