Why CAN_STB pin alwaws low?

Hello everyone, I need help.
Why is my TX2 (can0_stb) J26 Pin 3 always keep a low level?
It corresponds to gpio296. I have loaded the CAN module and it is still low.
I looked at /sys/kernel/debug/gpio and showed 296 out hi. Should it be high level?
what happened.

Thank you all

cat /sys/kernel/debug/gpio

GPIOs 256-319, platform/c2f0000.gpio, tegra-gpio-aon:
gpio-272 ( |temp_alert ) in hi
gpio-296 ( |gpio_can_stb ) out hi
gpio-297 ( |gpio_can_en ) out hi
gpio-302 ( |gpio_can_stb ) out hi
gpio-303 ( |gpio_can_en ) out hi
gpio-312 ( |Power ) in hi
gpio-313 ( |Volume Up ) in hi
gpio-314 ( |Volume Down ) in hi
gpio-315 ( |wifi-wake-ap ) in hi
gpio-316 ( |bt_host_wake ) in hi

It shows the gpio-296 is output at a high level,but I measure it with a voltmeter,and it`s a low level,

Hi dingjie,

Pin is low because Tegra is not driving this pin, it is disconnected. So, it will always show low.
Let me know if I can help you further.


Hi Shubhi

Can you tell me how to drive this pin?
I can drive CAN1_STBY (J26 pin13) similar to it,but CAN0_STBY (J26 pin3) is always low.


Hi dingjie,

You cannot drive this particular pin(CAN0_STBY) as the hardware connection itself is not there for this pin.
However,if you really want to use, you can try using any other pin in J26 which is not getting used(which is free to use) and add functionality of CAN0_STBY in device-tree to use it as STBY. I am not sure this will work or not as I have not tried it, but you can give it a try.


Hi Shubhi
I know that other pins can be used, but my board is already connected to CAN0_STBY of TX2.
I don`t want to chang my hardware.
Is CAN0_STBY from TX2 really unavailable?


Hi Dingjie,

Yes, CAN0_STBY is not available.