Master-Slave Communication Between Two Jetson Nano over SPI

[prasad.suralkar]

Hii @ShaneCCC ,

$./spidev_test -D /dev/spidev1.0 -g8 -zz
using device: /dev/spidev1.0
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:0x5f673610
loop count = 0 
using sequential pattern ....
transfer bytes [8]
0000: 00 01 02 03 04 05 06 07 
transfer ioctl error: -1
/dev/spidev1.0: TEST FAILED !!!!! (status:-1)

Thank you.

[ShaneCCC]

Your PINs configure looks like incorrect. You can try devmem2 to write it like my REG dump and run the spidev_test command to verify.

@prasad.suralkar

Bank: 1 Reg: 0x70003064 Val: 0x00006004 -> spi2_mosi_pb4
Bank: 1 Reg: 0x70003068 Val: 0x00006044 -> spi2_miso_pb5
Bank: 1 Reg: 0x7000306c Val: 0x00006044 -> spi2_sck_pb6
Bank: 1 Reg: 0x70003070 Val: 0x0000600a -> spi2_cs0_pb7
Bank: 1 Reg: 0x70003074 Val: 0x00006015 -> spi2_cs1_pdd0

[prasad.suralkar]

Hii @ShaneCCC ,
I have edited pinmux but the result is same,

Pinmux settings

$ cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi
Bank: 1 Reg: 0x70003050 Val: 0x0000e004 -> spi1_mosi_pc0
Bank: 1 Reg: 0x70003054 Val: 0x0000e044 -> spi1_miso_pc1
Bank: 1 Reg: 0x70003058 Val: 0x0000e004 -> spi1_sck_pc2
Bank: 1 Reg: 0x7000305c Val: 0x0000e009 -> spi1_cs0_pc3
Bank: 1 Reg: 0x70003060 Val: 0x0000e015 -> spi1_cs1_pc4
Bank: 1 Reg: 0x70003064 Val: 0x00006044 -> spi2_mosi_pb4
Bank: 1 Reg: 0x70003068 Val: 0x00006044 -> spi2_miso_pb5
Bank: 1 Reg: 0x7000306c Val: 0x00006044 -> spi2_sck_pb6
Bank: 1 Reg: 0x70003070 Val: 0x00006044 -> spi2_cs0_pb7
Bank: 1 Reg: 0x70003074 Val: 0x00006044 -> spi2_cs1_pdd0
Bank: 1 Reg: 0x70003078 Val: 0x0000e015 -> spi4_mosi_pc7
Bank: 1 Reg: 0x7000307c Val: 0x0000e015 -> spi4_miso_pd0
Bank: 1 Reg: 0x70003080 Val: 0x0000e015 -> spi4_sck_pc5
Bank: 1 Reg: 0x70003084 Val: 0x0000e015 -> spi4_cs0_pc6
Bank: 1 Reg: 0x70003088 Val: 0x00002040 -> qspi_sck_pee0
Bank: 1 Reg: 0x7000308c Val: 0x00002000 -> qspi_cs_n_pee1
Bank: 1 Reg: 0x70003090 Val: 0x00002040 -> qspi_io0_pee2
Bank: 1 Reg: 0x70003094 Val: 0x00002040 -> qspi_io1_pee3
Bank: 1 Reg: 0x70003098 Val: 0x00002040 -> qspi_io2_pee4
Bank: 1 Reg: 0x7000309c Val: 0x00002040 -> qspi_io3_pee5
Bank: 0 Reg: 0x70000b70 Val: 0x00000001 -> drive_qspi_comp_control
Bank: 0 Reg: 0x70000b78 Val: 0x00000001 -> drive_qspi_lpbk_control
Bank: 0 Reg: 0x70000a78 Val: 0x00808000 -> drive_qspi_comp

Loopback test on slave: -

./spidev_test -D /dev/spidev1.0 -g8 -zzz
using device: /dev/spidev1.0
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:0x5f67792e
loop count = 0 
using sequential pattern ....
transfer bytes [8]
0000: 00 01 02 03 04 05 06 07 
transfer ioctl error: -1
/dev/spidev1.0: TEST FAILED !!!!! (status:-1)
====== Transfer stats ====
Transmit:
       total: 18446744073709551615B (18014398509481983KiB 17592186044415MiB)
       total: 1P 
       ioerr: 8B (0KiB 0MiB)
       ioerr: 1P
 Rate:
  wire total: -1B/s (0KB/s)
       total: -1B/s (0KB/s)
  wire total: -1P/s
       total: -1P/s
Receive:
       total: 0B (0KiB 0MiB)
       total: 0P 
        good: 0B (0KiB 0MiB)
        good: 0P
       ioerr: 1P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.046195s

Kernel debug logs :

[ +21.272636] spidev spi1.0: setup 8 bpw, ~cpol, ~cpha, 33000000Hz
[  +0.000031] spidev spi1.0: setup mode 0, 8 bits/w, 33000000 Hz max --> 0
[  +0.000004] spidev spi1.0: spi mode 0
[  +0.000019] spidev spi1.0: setup 8 bpw, ~cpol, ~cpha, 33000000Hz
[  +0.000017] spidev spi1.0: setup mode 0, 8 bits/w, 33000000 Hz max --> 0
[  +0.000004] spidev spi1.0: 8 bits per word
[  +0.000016] spidev spi1.0: setup 8 bpw, ~cpol, ~cpha, 10000000Hz
[  +0.000016] spidev spi1.0: setup mode 0, 8 bits/w, 10000000 Hz max --> 0
[  +0.000132] spi-tegra124-slave 7000d600.spi: RxTx len:8 bpw:8 0us 10000000Hz
[  +0.000005] spi-tegra124-slave 7000d600.spi: Tx is not supported in mode 0
[  +0.017342] spi-tegra124-slave 7000d600.spi: spi can not start transfer, err -22
[  +0.014932] spi_master spi1: failed to transfer one message from queue

Thank you.

[ShaneCCC]

Did you short pin 37/22 for loopback test?

[prasad.suralkar]

Hii @ShaneCCC ,
yes

Thank you.

[prasad.suralkar]

Hii @ShaneCCC ,
Thank you for your support.
Loopback test does not work on slave, it gives error but the master slave communication worked fine but I just want to ask that

@ShaneCCC

Bank: 1 Reg: 0x70003064 Val: 0x00006044 -> spi2_mosi_pb4
Bank: 1 Reg: 0x70003068 Val: 0x00006044 -> spi2_miso_pb5
Bank: 1 Reg: 0x7000306c Val: 0x00006044 -> spi2_sck_pb6
Bank: 1 Reg: 0x70003070 Val: 0x00006044 -> spi2_cs0_pb7
Bank: 1 Reg: 0x70003074 Val: 0x00006044 -> spi2_cs1_pdd0

1. Why only this pinmux(provided by you) setting is worked and not other ?

2. Master and slave communicate with each other in transmit only(-t) and receive only(-r) mode, when use normal command(without -t/-r) slave does not wait for master, slave gives error & test fails. is there any command by using that we can test duplex communication on master and slave?

Thank You.

[prasad.suralkar]

Hii @ShaneCCC ,
I have couple of questions,

1. I have done the pinmux setting according to technical guide provided by NVIDIA for jetson nano, but spidev_test passes only when we set pinmux settings according to your pinmux, I dont understand why is that happens.
2. How we can send our data like patternfile example

To transfer all bytes from user defined pattern file,
spidev_test -D/dev/spidev0.0 -s18000000 -f/path/to/patternfile

using spidev_test. I have created a file with dummy data but it fails when we run command

./spidev_test -D/dev/spidev1.0 -s20000 -fpatternfile -zzz
using device: /dev/spidev1.0
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: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f674756
loop count = 0 
Using user defined pattern from patternfile file ....
transfer ioctl error: -1
/dev/spidev1.0: TEST FAILED !!!!! (status:-1)
====== Transfer stats ====
Transmit:
       total: 18446744073709551615B (18014398509481983KiB 17592186044415MiB)
       total: 1P 
       ioerr: 0B (0KiB 0MiB)
       ioerr: 1P
 Rate:
  wire total: -1B/s (0KB/s)
       total: -1B/s (0KB/s)
  wire total: -1P/s
       total: -1P/s
Receive:
       total: 0B (0KiB 0MiB)
       total: 0P 
        good: 0B (0KiB 0MiB)
        good: 0P
       ioerr: 1P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.126969s

but same file gives test passed on Master and test failed on slave
here are results :-

1. ON MASTER

$ ./spidev_test -D/dev/spidev1.0 -s20000 -fpatternfile1 -zzz -t
Disabling receive
using device: /dev/spidev1.0
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: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f6748a4
loop count = 0 
Using user defined pattern from patternfile1 file ....
/dev/spidev1.0: TEST PASSED 
====== Transfer stats ====
Transmit:
       total: 0B (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

  Total time: 0.000321s

$./spidev_test -D/dev/spidev1.0 -s20000 -fpatternfile1 -zzz -r
Disabling transmit
using device: /dev/spidev1.0
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: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f674804
loop count = 0 
transfer: Return actual transfer length: 0
/dev/spidev1.0: TEST PASSED 
====== Transfer stats ====
Receive:
       total: 0B (0KiB 0MiB)
       total: 0P 
        good: 0B (0KiB 0MiB)
        good: 0P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.000277s

2. ON SLAVE :

$./spidev_test -D/dev/spidev1.0 -s20000 -fpatternfile1 -H -O -zzz -t
Disabling receive
using device: /dev/spidev1.0
setting spi mode for read,write
setting spi bpw
setting max speed for rd/wr
spi mode: 3
bits per word: 8 bytes per word: 1
max speed: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f674898
loop count = 0 
Using user defined pattern from patternfile1 file ....
transfer ioctl error: -1
/dev/spidev1.0: TEST FAILED !!!!! (status:-1)
====== Transfer stats ====
Transmit:
       total: 18446744073709551615B (18014398509481983KiB 17592186044415MiB)
       total: 1P 
       ioerr: 0B (0KiB 0MiB)
       ioerr: 1P
 Rate:
  wire total: -1B/s (0KB/s)
       total: -1B/s (0KB/s)
  wire total: -1P/s
       total: -1P/s

  Total time: 0.034047s

$./spidev_test -D/dev/spidev1.0 -s20000 -fpatternfile1 -zzz -r
Disabling transmit
using device: /dev/spidev1.0
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: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f674889
loop count = 0 
^Ctransfer ioctl error: -1
/dev/spidev1.0: TEST FAILED !!!!! (status:-1)
====== Transfer stats ====
Receive:
       total: 0B (0KiB 0MiB)
       total: 0P 
        good: 0B (0KiB 0MiB)
        good: 0P
       ioerr: 1P
     dataerr: 0P
 Rate:
        good: 0B/s (0KB/s)
        good: 0P/s
 packet drop: -1/10000

  Total time: 1.418285s

3. This full duplex test is not giving fix results sometimes it gives error sometimes it successfully completed, what to do in this case ?

$./spidev_test -D/dev/spidev1.0 -n1 -s20000 -g12 -p4 -H -zzz
using device: /dev/spidev1.0
setting spi mode for read,write
setting spi bpw
setting max speed for rd/wr
spi mode: 1
bits per word: 8 bytes per word: 1
max speed: 20000 Hz (20 KHz)
no. runs: 1
Using seed:0x5f675340
loop count = 0 
Using rand() buffer 
Using crc check 
transfer packet bytes [12]
0000: FE EE CA AB FF FF FF FF 00 00 00 00 
transfer: Return actual transfer length: 12
receive packet bytes [12]
0000: FE EE CA AB FF FF FF FF 00 00 00 00 
transfer: received packet size:12 len:0 stat:0
/dev/spidev1.0: TEST PASSED 
====== Transfer stats ====
Transmit:
       total: 12B (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: 12B (0KiB 0MiB)
       total: 1P 
        good: 12B (0KiB 0MiB)
        good: 1P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: -1B/s (0KB/s)
        good: -1P/s
 packet drop: -1/10000

  Total time: 0.934475s

slave only transmits at mode 1 and mode 3 so above test fails in SPI mode 3 and sometimes it works in mode 3 and fails in mode 1, it always gives unpredictable output What should I do ?

4. can you please tell me is there Buffer Overwrite occur in SPI ?

Thank You.

[csena]

I have 2 Jetson Nano devices. I want these Jetson Nano devices to communicate with SPI. I want one of the Jetson Nano devices to be in master mode and the other device (Jetson Nano) in slave mode. I tried the solutions you suggested but I couldn’t get any results. I guess the data answers apply to Jetson Xavier. Do the same solutions apply to the Jetson Nano ? Can I get information about this topic?

[ShaneCCC]

I will try on Nano by spi@0 as master and spi@1 as slave later.

[ShaneCCC]

Below is my test result. SPI@0 as slave SPI@1 as master.
The version is r32.6.1
nvidia@nvidia-desktop:~$ cat /etc/nv_tegra_release

R32 (release), REVISION: 6.1, GCID: 27863751, BOARD: t210ref, EABI: aarch64, DATE: Mon Jul 26 19:20:30 UTC 2021

Attached my test dtb here for reference.
nano-spi-slave.dtb (233.6 KB)

The connection is 18 ↔ 24, 16 ↔ 26, 21<->22, 19 ↔ 37, 13 ↔ 23

Master

nvidia@nvidia-desktop:~$ ./spidev_test -D /dev/spidev1.0 -g 512 -s 11000000 -t -p0 -n1 -zzz
using device: /dev/spidev1.0
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: 11000000 Hz (11000 KHz)
no. runs: 1
Using seed:0x6165510a
loop count = 0
using sequential pattern ....
transfer bytes [512]
0000: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
0010: 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
0020: 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
0030: 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
0040: 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
0050: 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F
0060: 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F
0070: 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F
0080: 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F
0090: 90 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F
00A0: A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF
00B0: B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF
00C0: C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF
00D0: D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF
00E0: E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF
00F0: F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE 00
0100: 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10
0110: 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20
0120: 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30
0130: 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40
0140: 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50
0150: 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60
0160: 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70
0170: 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F 80
0180: 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F 90
0190: 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F A0
01A0: A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF B0
01B0: B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF C0
01C0: C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF D0
01D0: D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF E0
01E0: E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF F0
01F0: F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE 00 01
/dev/spidev1.0: TEST PASSED
====== Transfer stats ====
Transmit:
       total: 512B (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

  Total time: 0.002629s

Slave

nvidia@nvidia-desktop:~$ ./spidev_test -D /dev/spidev0.0 -g 512 -s 11000000 -r -p0 -n1 -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: 11000000 Hz (11000 KHz)
no. runs: 1
Using seed:0x61655102
loop count = 0
transfer: Return actual transfer length: 512
receive bytes [512]
0000: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
0010: 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
0020: 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
0030: 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
0040: 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
0050: 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F
0060: 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F
0070: 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F
0080: 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F
0090: 90 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F
00A0: A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF
00B0: B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF
00C0: C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF
00D0: D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF
00E0: E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF
00F0: F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE 00
0100: 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10
0110: 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20
0120: 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30
0130: 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40
0140: 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50
0150: 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60
0160: 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70
0170: 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F 80
0180: 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F 90
0190: 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F A0
01A0: A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF B0
01B0: B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF C0
01C0: C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF D0
01D0: D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF E0
01E0: E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF F0
01F0: F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE 00 01
transfer: received packet size:512 len:512 stat:0
/dev/spidev0.0: TEST PASSED
====== Transfer stats ====
Receive:
       total: 512B (0KiB 0MiB)
       total: 1P
        good: 512B (0KiB 0MiB)
        good: 1P
       ioerr: 0P
     dataerr: 0P
 Rate:
        good: 61B/s (0KB/s)
        good: 0P/s
 packet drop: -1/10000

  Total time: 8.353936s

[csena]

Thank you for your answer. The spidev_test test didn’t work for me. Which test are you using?
The test I use: linux/spidev_test.c at master · torvalds/linux · GitHub

[ShaneCCC]

Try this

How to set to spi slave mode

This’s build by my tree. Remove the .txt and change it as executable file. spidev_test.txt (69.1 KB)

[prasad.suralkar]

Hii @csena ,
Does your SPI worked, is spidev_test ran successful.

Thank You.

[csena]

spidev_test seems to be running on the master device. But it doesn’t work on the slave device. What should I do?

[prasad.suralkar]

Hii @csena ,
do device tree setup as shown in the

How to set to spi slave mode

Hello I want to run spi test by connecting spi1 and spi3 of jetson xavier nx board. Before connecting spi1-spi3, I connected spi1’s MOSI-MISO (spi3’s MOSI-MISO) and tested with the spidev_test.c example to confirm that tx rx works well for both spi1 and spi3. (Currently jetson xavier nx board has jetpack4.4 version installed.) Here I have some questions. How to set the master mode and slave mode when connecting spi1 and spi3? (Should I update pinmux? or https://www.jetsonhacks.com/2020/0…

then change pinmux settings as shown using devmem2

Master-Slave Communication Between Two Jetson Nano over SPI

Did you configure those PINs by jetson-io? Confirm below command. sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi nvidia@nvidia-desktop:~$ sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi [sudo] password for nvidia: Bank: 1 Reg: 0x70003050 Val: 0x0000e044 -> spi1_mosi_pc0 Bank: 1 Reg: 0x70003054 Val: 0x0000e044 -> spi1_miso_pc1 Bank: 1 Reg: 0x70003058 Val: 0x0000e044 -> spi1_sck_pc2 Bank: 1 Reg: 0x7000305c Val: 0x0000e048 -> spi1_cs0_pc3 Bank: 1 Reg: 0x70003060 Val: 0x000…

and then try running spidev_test on slave 1st and then on master.
use this command on master as well as on slave
./spidev_test -D/dev/spidev1.0 -n1 -s20000 -H -g12 -p4 -zzz

use -H and -O options to set SPI mode just be sure that only on mode 1 & 3 slave can transmit as well as receive the message in mode 0 and 2 slave can only receive message.

Thank You.

[ShaneCCC]

You can using my dtb to confirm device tree configure.