Cannot detect any signal from CAM0_MCLK by oscilloscope

[kingkong]

Platform: P3668 + P3509
OS: Jetpack 4.6.1
I have a custom camera board without crystal.
Because I still cannot get i2c ack from my camera, I find out the problem is mclk not working.

I try to add the device setting below into imx219, and add the clock implement in imx219 driver, beacuse there is a crystal in rpi camera:
clocks = <&bpmp_clks TEGRA194_CLK_EXTPERIPH1>,
<&bpmp_clks TEGRA194_CLK_PLLP_OUT0>;
clock-names = “extperiph1”, “pllp_grtba”;
mclk = “extperiph1”;
clock-frequency = <24000000>;

And I check the enable count in /sys/kernel/debug/clk/clk_summary.
Streaming:
extperiph1 1 1 24000000 24000000 0 0
Without streaming:
extperiph1 0 0 24000000 24000000 0 0

When streaming, I cannot detect any signal from CAM0_MCLK by oscilloscope.
Any help is very thankful.

[JerryChang]

hello kingkong,

it’s baseboard camera clock, and the maximum frequency for extperiph1 is 24-MHz.

may I know what’s the failure messages from kernel side,
could you please also review the port bindings? thanks

[kingkong]

hello JerryChang,

There is no error message about clock setting, only no ack from i2c.
I connected our camera board at CAM0(J9) yesterday.
And now I just try to connect CAM1(J1), I can find the mclk at CAM1 connector.
Does this mean the CAM0_MCLK in CAM0 hardware is broken? How to verify it?
But IMX219 can work at CAM0.

[JerryChang]

hello kingkong,

no ack from i2c usually caused by regulator settings.
since this is your own camera driver bring-up. had you modify device tree to enable regulator settings?

[kingkong]

hello JerryChang,

My camera can work at CAM1 connector, but not work at CAM0, because the CAM0_MCLK is no signal.
The device setting is same at CAM0 and CAM1.

[JerryChang]

hello kingkong,

had you update device tree? there’s default device tree settings to define the configurations.

[kingkong]

hello JerryChang,

Yes, I check the device tree is mine.

[JerryChang]

hello kingkong,

it usually regulator settings cause the failure. please share your device tree for reference, thanks

[kingkong]

hello JerryChang,

But my problem is mclk not work. Is this caused by regulator?

[JerryChang]

hello kingkong,

it might be, please start with checking regulator settings.

[kingkong]

Could you suggest how to check it?

[JerryChang]

hello kingkong,

please review your schematic, you should have corresponding device tree settings to assign them, especially, 3.3v, 1.8v, 1.2v…etc.

BTW,
had you also check Jetson Xavier NX Camera Design Guide,
you should have MUX to direct CAM_I2C correctly.
thanks

[kingkong]

hello JerryChang,

As I know MCLK and MUX is independent, please correct me.

[JerryChang]

they’re independent, but it should power-on then providing the clock.