How to choose the clock

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

I choose GPIO01 as the mclk of the camera, may I ask how to fill in the equipment information of this part?
`{
clocks = <&tegra_car TEGRA186_CLK_EXTPERIPH1>;
clock-names = extperiph1;
mclk = extperiph1;

}`

3

What’s GPIO01?
Suppose you can change to another clock source like

                                imx219_d@10 {
                                        clocks = <&tegra_car TEGRA186_CLK_EXTPERIPH2>;
                                        clock-names = "extperiph2";
                                        mclk = "extperiph2";
                                        reset-gpios = <&tca6408_21 3 GPIO_ACTIVE_HIGH>;
4

These are some pins that I saw in the manual that can output the clock. At present, my hardware uses GPIO01 to do the camera clock. Whether to configure the device tree. I don’t know how to adapt GPIO01

7.2 Clock Buffer and XTAL
 There are up to four clock outputs from the Jetson module: 
• CAM0_MCLK
• CAM1_MCLK
• GPIO01 (MCLK #2)
• GPIO11 (MCLK #3)
7

Please refer to TX2 OEM DG for the CAM_MCLK option. There are three MCLKs as below:

mclk
mclk810×176 26.2 KB

8

How do I choose TX2NX?

9

Please find out in the Jetson TX2 NX Product Design Guide in DLC.

10

In tx2nx, I want to use gpio01 to provide mclk for csi4. I have found that GPIO01 can be used as EXTPERIPH3_CLK in Jetson_TX2_NX_pinmux_config_1.05.xlsm, and then I configured the following in the device tree. However, you cannot output a clock signal on GPIO01. What else do I need to configure?

		i2c_0:i2c@0 {
			imx415_cam0: rbpcv2_imx415_a@10 {
				compatible = "nvidia,imx415";
				clocks = <&tegra_car TEGRA186_CLK_EXTPERIPH3>;
				clock-names = "extperiph3";
				mclk = "extperiph3";

GPIO01
GPIO011433×378 13.2 KB

12

May need pinmux configure for extperiph3 like below.

{
					nvidia,pins = "gpio_cam2_pn1";
 					nvidia,function = "extperiph3";
 					nvidia,pin-group = "extperiph3_clk";
 					nvidia,pull = <TEGRA_PIN_PULL_UP>;
 					nvidia,tristate = <TEGRA_PIN_DISABLE>;
 					nvidia,enable-input = <TEGRA_PIN_DISABLE>;
 					nvidia,lpdr = <TEGRA_PIN_DISABLE>;
 				};
13

I have configured under tegra186-p3636-0001-p3509-0000-a01.dts, but there is still no clock signal output:

#include "common/tegra186-p3636-0001-common.dtsi"
#include "common/tegra186-p3509-0000-cvb.dtsi"
#include "common/tegra186-p3509-0000-a00-fixed-regulator.dtsi"
#include "common/tegra186-p3636-0001-a00-prod.dtsi"
#include "common/tegra186-camera-lanai-rbpcv2-imx415.dtsi"

/* plugin manager */
#include "common/tegra186-super-module-e2614-p3509-0000-a00.dtsi"

/ {
	compatible = "nvidia,p3509-0000+p3636-0001", "nvidia,tegra186";

	nvidia,dtsfilename = __FILE__;
	nvidia,boardids = "3636:0001:A0";
	nvidia,proc-boardid = "3636:0001:A0";
	nvidia,fastboot-usb-vid = <0x0955>;
	nvidia,fastboot-usb-pid = <0xee16>;

	chosen {
		board-has-eeprom;
		bootargs ="console=ttyS0,115200";
		stdout-path = &uarta;
		nvidia,tegra-joint_xpu_rail;
	};
	pinmux@70000868 {
		pinctrl-names = "default";
		pinctrl-0 = <&pinmux_default>;

		pinmux_default: pinmux@0 {
				hdr40-pin29 {
					nvidia,pins = "gpio_cam2_pn1";
					nvidia,function = "extperiph3";
					nvidia,pin-group = "extperiph3_clk";
					nvidia,pull = <TEGRA_PIN_PULL_UP>;
					nvidia,tristate = <TEGRA_PIN_DISABLE>;
					nvidia,enable-input = <TEGRA_PIN_DISABLE>;
					nvidia,lpdr = <TEGRA_PIN_DISABLE>;
				};
		};
	};```
14

Please dump the device tree to confirm.

dtc -I fs -O dts -o extracted_proc.dts /proc/device-tree
16

The dump contains the following information

pinmux@70000868 {
                pinctrl-0 = <0xd1>;
                pinctrl-names = "default";

                pinmux@0 {
                        phandle = <0xd1>;
                        linux,phandle = <0xd1>;

                        hdr40-pin29 {
                                nvidia,enable-input = <0x0>;
                                nvidia,pins = "gpio_cam2_pn1";
                                nvidia,lpdr = <0x0>;
                                nvidia,tristate = <0x0>;
                                nvidia,function = "extperiph3";
                                nvidia,pin-group = "extperiph3_clk";
                                nvidia,pull = <0x2>;
                        };
                };
        };