GPIO PWM not work.

hello,

I want to use GPIO Pin18. And I can run simple_out.py, It works fine.

but simple_pwm.py not work.

Besides,these code bollow not work too.

cd /sys/class/pwm/pwmchip2
echo 0 > export
cd pwm0
echo 20000 > period
echo 10000 > duty_cycle
echo 1 > enable


cd /sys/devices/32c0000.pwm/pwm/pwmchip2
echo 0 > export
cd pwm0
echo 2600000 > period
echo 2400000 > duty_cycle
echo 1 > enable

Here is pwm info.

nvidia@nvidia-desktop:~$ sudo cat /sys/kernel/debug/pwm
platform/39c0000.tachometer, 1 PWM device
pwm-0 (generic_pwm_tachomet): requested period: 0 ns duty: 0 ns polarity: normal

platform/32f0000.pwm, 1 PWM device
pwm-0 (sysfs ): requested period: 0 ns duty: 0 ns polarity: normal

platform/32c0000.pwm, 1 PWM device
pwm-0 ((null) ): period: 10000000 ns duty: 5000000 ns polarity: normal

platform/c340000.pwm, 1 PWM device
pwm-0 (pwm-fan ): requested enabled period: 45334 ns duty: 0 ns polarity: normal

platform/3280000.pwm, 1 PWM device
pwm-0 (sysfs ): requested enabled period: 20000 ns duty: 10000 ns polarity: normal

hello afhel,

may I know which pin you would like to configure as PWM?
also, is there kernel failures about configuring duty cycle via sysnode?
thanks

Hi

Thank you for reply, I just want one PWM, 13/15/18, any one of them.

My hardware is Jetson AGX XAVIER DEVELOPMENT KIT. System version is R32. How can I check kernel failures?

nvidia@nvidia-desktop:~$ head -n 1 /etc/nv_tegra_release

R32 (release), REVISION: 2.3, GCID: 17644089, BOARD: t186ref, EABI: aarch64, DATE: Tue Nov 5 21:48:17 UTC 2019

hello afhel,

just for confirmation, you means these pin-13 (PWM01), pin-15 (GPIO27_PWM2), pin-18 (GPIO35_PWM3) of Xavier J30 GPIO.

taking pin-13 (PWM01) as an example, its default settings is GPIO.
please access pinmux spreadsheets from download center, and you should have configurations with that.
you should also check Pinmux and GPIO Configuration for documentation of configurations.
thanks