How to change I2C clock rate dynamically in JP 6.0?

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

In Jetpack 5.0.2, I’m able to dynamically set the i2c clock rate using
“echo 100000 >> /sys/bus/i2c/devices/i2c-2/bus_clk_rate”.
But in Jetpack 6.0, I couldn’t do the same way.
So, how can I change the I2C clock rate dynamically in JP 6.0 without rebooting?

2

Hi @jp6_user, welcome to the NVIDIA developer forums.

We don’t have a specific category for Jetpack, but we do for specific Hardware SKUs. Can you share which Jetson you ae working on, then I will pass you on to the experts.

Thanks!

3

Hi @MarkusHoHo, I’m a new to these topics.
I’m using AGX Orin board (P3701-0000).

$ cat /proc/device-tree/model
NVIDIA Jetson AGX Orin Developer Kit

Please let me know if you need any more details.

4

Thanks!

If the Jetson experts need more information to help you, they will ask, no worries.

I think it might be as simple as some change of device directories between Jetpack versions or similar, but the Jetson team will know best.

8

Sorry for the late response.
Is this still an issue to support? Any result can be shared?

9

Hi @jp6_user!

I have not been able to find a way to directly set i2c clock without modify the device-tree and reboot. Maybe if you share more about the purpose to set i2c clock we could find a workaround.

We will be glad to help you!

Regards,

Oscar Fallas
Embedded SW Engineer at RidgeRun
Contact us: support@ridgerun.com
Developers wiki: https://developer.ridgerun.com
Website: https://www.ridgerun.com/

10

Hi @oscar.fallas,

I’m working with a device which supports multiple modes. When set in a particular mode, I need to transfer a bulk amount of data (either at 100KHz or 400KHz). Rest of the modes supports only100KHz.
Setting 100KHz in device tree works for me. But, if I can set it to 400KHz dynamically, I can transfer the bulk data faster and switch to other modes.

@kayccc, I compared the source codes of JP5 and JP6 and from my analysis, I believe that the attribute “bus_clk_rate” is not exposed. The commits which are responsible for it are not ported to JP6.

If you guys have any workaround with which we don’t need to update NVIDIA source code, please let me know.

11

Suppose you can try to migrate the change to JP6 by yourself for it.

Thanks

12

@ShaneCCC, is it possible that I can contribute/create pull request to your repo? If so, what’s the procedure?

14

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