Thor ,38.4,carried board t5000, pwm can not outpout waves

Robotics & Edge Computing Jetson Systems Jetson Thor
1

I encountered a problem: PWM2 cannot output waveform，PWM3 can output waves，the config is the same .Is there any difference between PWM2 and PWM3？My PWM2 configuration is as follows:

root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1# echo 0 > export
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1#
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1#
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1#
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1# ls
device export npwm power pwm0 subsystem uevent unexport
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1# cd pwm0
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# ls
capture duty_cycle enable period polarity power uevent
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# echo 20000 > period
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# echo 10000 > duty_cycle
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# echo 1 > enable
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0#
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0#
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# ls
capture duty_cycle enable period polarity power uevent
root@tegra-ubuntu:/sys/devices/platform/bus@0/810c5e0000.pwm/pwm/pwmchip1/pwm0# cd /sys/kernel/debug/bpmp/debug/clk/pwm2
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2#
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2#
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2# ls
dvfs flags hidden max_rate mrqcount parent pto_counter refcount vdd_core
dvfs_table fmon hz_off min_rate mrq_rate_locked possible_parents rate state
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2# cat parent
osc
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2# cat rate
27000000
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2#
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2#
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2#
root@tegra-ubuntu:/sys/kernel/debug/bpmp/debug/clk/pwm2# cat /sys/kernel/debug/pwm
0: platform/c6a0000.pwm, 1 PWM device
pwm-0 (pwm-fan ): requested enabled period: 40000 ns duty: 37490 ns polarity: normal usage_power

1: platform/810c5e0000.pwm, 1 PWM device
pwm-0 (sysfs ): requested enabled period: 20000 ns duty: 10000 ns polarity: normal

2: platform/810c5f0000.pwm, 1 PWM device
pwm-0 ((null) ): period: 0 ns duty: 0 ns polarity: normal

3: platform/810c620000.pwm, 1 PWM device
pwm-0 ((null) ): period: 0 ns duty: 0 ns polarity: normal

4: platform/810c5c0000.tachometer, 1 PWM device
pwm-0 ((null) ): period: 0 ns duty: 0 ns polarity: normal

3

I followed along and applied all of your commands to 810c5f0000.pwm because my Thor doesn’t have your 810c5e0000.pwm. I got similar results as below.

echo /sys/devices/platform/bus@0/*.pwm

/sys/devices/platform/bus@0/810c5f0000.pwm
/sys/devices/platform/bus@0/810c620000.pwm 
/sys/devices/platform/bus@0/c6a0000.pwm

What does this ls show on your Thor?

ls /sys/devices/platform/bus@0/*.pwm/pwm/pwmchip*/

/sys/devices/platform/bus@0/810c5f0000.pwm/pwm/pwmchip1/:
device  export  npwm  power  pwm0  subsystem  uevent  unexport

/sys/devices/platform/bus@0/810c620000.pwm/pwm/pwmchip2/:
device  export  npwm  power  subsystem  uevent  unexport

/sys/devices/platform/bus@0/c6a0000.pwm/pwm/pwmchip0/:
device  export  npwm  power  subsystem  uevent  unexport

cat /sys/kernel/debug/pwm

0: platform/c6a0000.pwm, 1 PWM device
 pwm-0   (pwm-fan             ): requested enabled period: 40000 ns duty: 12079 ns polarity: normal usage_power

1: platform/810c5f0000.pwm, 1 PWM device
 pwm-0   (sysfs               ): requested enabled period: 20000 ns duty: 10000 ns polarity: normal

2: platform/810c620000.pwm, 1 PWM device
 pwm-0   ((null)              ): period: 0 ns duty: 0 ns polarity: normal

3: platform/810c5c0000.tachometer, 1 PWM device
 pwm-0   ((null)              ): period: 0 ns duty: 0 ns polarity: normal
4

i know ，The pwm2 pinmux is configured as a GPIO

6

Hi asdfqq55,

Are you using the devkit or custom board for Thor?

pwm2(GPIO27, PF.07): pwm@810c5e0000
pwm3(GPIO34, PG.00): pwm@810c5f0000

Have you configured the pinmux before use?
If so, could you share the pinmux configuration for PWM2 and PWM3 in your case?

Have you tried other period and duty cycle?