How to set GPIO04(GPIO3_PCC.01) output low in the shutdown mode?

Autonomous Machines Jetson & Embedded Systems Jetson Xavier NX
1

Hi, I use shutdown new command to shutdown my Xavier NX SOM.
But I found that GPIO04(GPIO3_PCC.01) pin is always high in this state.
I want to control this pin output low in shutdown mode.
what should I do?

What’s more, I have set this pinmux to Drive 0.

--- a/bootloader/t186ref/BCT/tegra19x-mb1-pinmux-p3668-a01.cfg
+++ b/bootloader/t186ref/BCT/tegra19x-mb1-pinmux-p3668-a01.cfg
@@ -2,7 +2,7 @@
 ## Pinmux version 1.6
 ## Input pinmux file name: tegra19x-jetson_xavier_nx_module-pinmux.dtsi
 ## Input gpio file name: tegra19x-jetson_xavier_nx_module-gpio-default.dtsi
-## Generation date: 2023-05-20 10:04
+## Generation date: 2023-06-08 10:31
 ## PLEASE DO NOT EDIT THIS FILE
 ## This is autogenerated file using the script pinmux-dts2cfg.py
 ##
@@ -84,6 +84,10 @@ pinmux.0x0c2f1200 = 0x00000003; # CONFIG CC0
 pinmux.0x0c2f120c = 0x00000000; # CONTROL CC0
 pinmux.0x0c2f1210 = 0x00000000; # OUTPUT CC0
 pinmux.0x0c302048 = 0x00000000; # GPIO spi2_sck_pcc0
+pinmux.0x0c2f1220 = 0x00000003; # CONFIG CC1
+pinmux.0x0c2f122c = 0x00000000; # CONTROL CC1
+pinmux.0x0c2f1230 = 0x00000000; # OUTPUT CC1
+pinmux.0x0c302050 = 0x00000000; # GPIO spi2_miso_pcc1
 pinmux.0x0c2f1240 = 0x00000003; # CONFIG CC2
 pinmux.0x0c2f124c = 0x00000000; # CONTROL CC2
 pinmux.0x0c2f1250 = 0x00000000; # OUTPUT CC2
@@ -109,10 +113,6 @@ pinmux.0x02214e0c = 0x00000000; # CONTROL B0
 pinmux.0x02214e10 = 0x00000000; # OUTPUT B0
 pinmux.0x02446008 = 0x00000000; # GPIO cpu_pwr_req_0_pb0
 #### Pinmux for gpio-output-high pins ####
-pinmux.0x0c2f1220 = 0x00000003; # CONFIG CC1
-pinmux.0x0c2f122c = 0x00000000; # CONTROL CC1
-pinmux.0x0c2f1230 = 0x00000001; # OUTPUT CC1
-pinmux.0x0c302050 = 0x00000000; # GPIO spi2_miso_pcc1
 #### Pinmux for used pins ####
 pinmux.0x02431020 = 0x00000404; # aud_mclk_ps4: aud, pull-down, tristate-disable, input-disable, lpdr-disable

And my pinmux spread is :

image
image1464×262 8.11 KB

3

Hi Xzz,

Could you help to share the result of the following command on your board?

sudo busybox devmem 0x0c302050

Why you expect this pin (PCC.01) relating to shutdown commmand?
May I know what’s the use case for this pin?

4

Hi,kevinFFF,
I use this GPIO to enable/disable USB vbus-vcc, so I want it to be pulled down when the board shutdown, to make sure USB devices work well.

And the command result is here:

root@tegra-ubuntu:~# sudo busybox devmem 0x0c302050
0x00000002
5

You pinmux seems fine for this pin.

Could you help to share the result of the following command?

sudo cat /sys/kernel/debug/gpio|grep PCC.01
6

My L4T version is 32.7.3, so this command cannot run success.
And this is my result :

root@tegra-ubuntu:~# cat /sys/kernel/debug/gpio|grep 265
 gpio-265 (                    |init                ) out lo
7

Hi, KevinFFF,
It’s very strange.
I set the GPIO04 as output low in the system, and it does work.
However, after shutting down the system, the GPIO04 is pulled high. Why does this happen?
Additionally, I experienced the same situation when I changed to GPIO05.

8

Have you tried to update to latest R35.3.1 for Xavier NX?

Is there the pull-high resistor causing it pull-high after shutdown?

9

I have try it, but my driver report -517 error in 35.3.1.
And I have report it in another topic.

I disconnected all external circuits and only kept the source-side signal on the module， but the error happended again.

10

Could you help to answer this question?

11

Sorry for late, I dont nocite this topic has update.

As your doubt, I cut external circut, and the error is still exist…

12

It should not be pulled-high after shutdown the board.
Does the devkit also have the same behavior (GPIO04 pull-high after shutdown)?

14

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