Xavier NX RTC Module Shutoff Request

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
1

Hello,

I was wondering if someone would be able to help. I have seen several other people attempt this with success in forum topics. It follows from this link below (basically before FLASHING, I update 2 files mentioned in the link, then FLASH a Jetson Xavier NX to shutoff the Back Battery Charger for the RTC battery):

I have made the requested changes in (for Xavier CPUs):

tegra194-mb1-bct-pmic-p2888-0001-a04-E-0-p2822-0000.cfg
→ pmic.system.block[2].commands[1].0x04.0x01 = 0x00;

And,

tegra186-mb1-bct-pmic-p3636-0001-a00.cfg
–>pmic.generic.1.block[0].count = 2;
–>pmic.generic.1.block[0].commands[1].0x04.0x01 = 0x00;

But, when flashing is finished, the Backup Battery Module is still at 3.0 Volts. What would I be missing in this case to shutoff this module?

Thanks for the help!
Ryan

3

Sorry for the late response, have you managed to get issue resolved or still need the support? Thanks

4

I have tried the mentioned changes in the .cfg files many times with no luck, the RTC battery charge module is still at 3.00 Volts.

Yes, we are still looking for guidance.

5

How did you flash the file?

6

We use the script right from the NVIDIA Toolkit:

nvsdkmanager_flash.sh --storage nvme0n1p1 (we are using an SSD)

Before this command is ran, I changed the .cfg file in tegra194-mb1-bct-pmic-p2888-0001-a04-E-0-p2822-0000.cfg with:

tegra194-mb1-bct-pmic-p2888-0001-a04-E-0-p2822-0000.cfg
→ pmic.system.block[2].commands[1].0x04.0x01 = 0x00;

I even took from the T186 example and added pmic.system.block[2].count = 2; above the commands incase that was the issue.

Both times a no go. I know I am probably doing something wrong…any insight?

Ryan

7

Hi,

Please try to run with flash.sh directly. Use emmc case first. Share the flash log.

8

Here is one from yesterday…

flash_3-6_0_20230307-133411.log (63.1 KB)

9

Hi,

I don’t need this one. I need the flash log from flash.sh. Not initrd flash log.

10

Sorry it has taken some time to generate this.

flash.log (435.9 KB)

11

Hi,

P2888 is for jetson AGX xaiver… You are using xaiver NX…

12

OK, I looked in the log file and found that the Xavier NX is P3668. From this I went and located the file:

tegra194-mb1-bct-pmic-p3668-0001-a00.cfg (only file under P3668 for PMIC)

From Coin Cell Battery charging disable - #3 by TheBenjamin

The solution had said for T194, insert the following command:

pmic.system.block[2].commands[1].0x04.0x01 = 0x0;

I did the above and did notice during the FLASH process from a typo that I did have the right file now. Unfortunately, after a few test flashes, modifying and adding the above line did not work. I am still reading a 3.00 Volt potential.

Any ideas what I would be missing? Thanks,
Ryan

13

Which path did you modify this file?

14

/<home_directory>/Linux_for_Tegra/bootloader/t186ref/BCT/tegra194-mb1-bct-pmic-p3668-0001-a00.cfg

15

Did you remember to remove the copy under <home_directory>/Linux_for_Tegra/bootloader/?

16

I just did that, flashed again, confirmed the new file under /bootloader/ had added commands during FLASH and after it was completed, it is still at 3.00 Volts.

17

What is the result if you run this command after entering kernel?

i2cset -f -y 4 0x03c 0x04 0x08

and

i2cset -f -y 4 0x03c 0x04 0x00

19

Circuit is now shutoff. With both commands.

After a reboot though, the settings do not persist and the circuit is back on.

20

Ok, so does this meet your request ? I mean this “circuit is shutdown” behavior is what you want?

21

Yes, thank you for your help.

Ryan

22

Please remove the whole “backup-battery {” property from below device tree and it shall give you a permanently shutdown in kernel.

hardware/nvidia/platform/t19x/jakku/kernel-dts/common/tegra194-spmic-p3668.dtsi