Support for enabling SPI on Jetson Nano 2GB Kit

Hi, we are working on enabling the SPI on Jetson Nano 2GB developer kit. We have tested the SPI with jetson-io.py file and it is working fine.

We have added SPI patch (hdr40_pinmux) on dtsi file and tested with Jetson nano 4GB kit and eMMC based board, it is working fine. We have applied the same patch(hdr40_pinmux) and tested with 2GB kit but SPI is not working(loopback test).

We have compared custom-jetsonIO dtb and our SPI patch enabled DTB, it looks same. Can you please tell us, Is there anything I need to add for Jetson Nano 2GB kit?

Have a compare the REG for those two device.

sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi

sudo cat /sys/kernel/debug/tegra_gpio

Nano_2GB.txt (2.5 KB)
Nano_4GB.txt (4.7 KB)

Thanks for the quick reply @ShaneCCC. Attached the log files.

The configure looks the same with my configure on r32.7.1
My test result as below. BTW could you try jetson-io for Nano 2G to confirm it.

nvidia@nvidia-desktop:~$ sudo ./spidev_test -d /dev/spidev0.0 -g16 -zzz
using device: /dev/spidev0.0
setting spi mode for read,write
setting spi bpw
setting max speed for rd/wr
spi mode: 0
bits per word: 8 bytes per word: 1
max speed: 10000000 Hz (10000 KHz)
no. runs: 1
Using seed:0x62318d17
loop count = 0
using sequential pattern ....
transfer bytes [16]
0000: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
transfer: Return actual transfer length: 16
receive bytes [16]
0000: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
transfer: received packet size:16 len:16 stat:0
/dev/spidev0.0: TEST PASSED
====== Transfer stats ====
Transmit:
       total: 16B (0KiB 0MiB)
       total: 1P
       ioerr: 0B (0KiB 0MiB)
       ioerr: 0P
 Rate:
  wire total: -1B/s (0KB/s)
       total: -1B/s (0KB/s)
  wire total: -1P/s
       total: -1P/s
Receive:
       total: 16B (0KiB 0MiB)
       total: 1P
        good: 16B (0KiB 0MiB)
        good: 1P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.000570s

Hi @ShaneCCC, we have tested with jetson-io and it is working fine. We need to add the patch in Jetson nano 2GB dtsi file. Is there anything we have missed? Thanks in advance

I would suggest to unassemble the /boot/kernel_tegra210-p3448-0002-p3449-0000-b00-user-custom.dtb to compare with your to figure the root cause.

Confirm the dtb by /boot/extlinux/extlinux.conf

1 Like

Hi @ShaneCCC, We have compared both(user custom and our’s) the dtb and looks fine.
kernel_tegra210-p3448-0003-p3542-0000-user-custom.txt (3.2 KB)
tegra210-p3448-0003-p3542-0000.txt (3.3 KB)

Please check the attached files and share your comments on the same.

What’s the result from below command.

sudo cat /proc/device-tree/pinmux@700008d4/common/spi*/nvidia,function

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