Need help on clock-names, mclk properties of the camera node clocked by an external clock generator?

Robotics & Edge Computing Jetson Systems Jetson Orin Nano
,
1

Dear experts,

Currently, I am using a Versaclock5 clock generator in order to provide clock sources to multiple camera sensors with different frequencies (and higher than the default frequency provided by the default MCLK pins of the MIPI-CSI2 camera interfaces).

The clock generator node is as below :

i2c@c240000 {
    vc5: clock-generator@6a {
        compatible = "idt,5p49v5925";
        reg = <0x6a>;
        #clock-cells = <1>;
        clocks = <&ref25>;
        clock-names = "xin";

        /*
        * ASSIGNED CLOCKS CONFIGURATION
        * Here we select OUT1 (index 1) and OUT2 (index 2) to be configured at boot
        */
        assigned-clocks = <&vc5 1>, <&vc5 2>;
        assigned-clock-rates = <37125000>, <74250000>; /* OUT1 = 37.125 MHz, OUT2 = 74.25 MHz */

        /* Electrical characteristics for individual outputs */
        OUT1 {
            idt,mode = <VC5_CMOS>;
            idt,voltage-microvolt = <1800000>;
            idt,slew-percent = <85>;
        };

        OUT2 {
            idt,mode = <VC5_CMOS>;
            idt,voltage-microvolt = <1800000>;
            idt,slew-percent = <85>;
        };
    };
};

How should I replace the default clock-names, mclk properties of the camera node(s) (which is/are the clock consumer(s)) in this case, please ?

			imx296_a@1a {
				status = "okay";
#				clocks = <&bpmp_clks TEGRA234_CLK_EXTPERIPH1>, <&bpmp_clks TEGRA234_CLK_EXTPERIPH1>;
#				clock-names = "extperiph1", "pllp_grtba";
#				mclk = "extperiph1";
#				clock-frequency = <27000000>; // Max. freq supported by the Jetson, ignored if an on-module oscillator is used.

				clocks = <&vc5 1>;
				clock-names = "mclk"; // or "inck" depending on camera driver
				clock-frequency = <37125000>;

				reset-gpios = <&tegra_main_gpio CAM0_PWDN GPIO_ACTIVE_HIGH>;
 			};

Knowing that I set the the clock-names as above (and omitting the mclk property as I haven’t known what to put), I got below error :

[   12.562879] imx296 9-001a: unable to get clock mclk
[   12.562882] imx296 9-001a: unable to power get
[   12.562884] imx296 9-001a: tegra camera driver registration failed

Thanks in advance and best regards,

Khang

Khang

3

hello khang.l4es,

clock-names is a consumer-local lookup name; it does not need to be the VersaClock output name.
mclk is NVIDIA’s property telling the camera driver which lookup name to pass to devm_clk_get() API.

please refer to developer guide, Device Properties for the mclk property description.
let me re-cap as below..

The maximum frequency for extperiph1 is 37.09 MHz. If you need a frequency greater than 37.09 MHz, use an external clock source. Other input clocks, extperiph2, extperiph3, and extperiph4 are limited to 24 MHz.
mclk* need not be set if the sensor is using the clock source provided by the camera module.