Another PWM issue

I have recompiled Grinch 21.3.4 with modified tegra124-jetson_tk1-gpio-pm375-0000-c00-00.dtsi and tegra124-jetson_tk1-pinmux-pm375-0000-c00-00.dtsi as it is discribed here - http://elinux.org/Jetson/PWM. I’m trying to get something out of PWM0 under root:

echo 0 > /sys/class/pwm/pwmchip0/export
echo 10000000 > /sys/class/pwm/pwmchip0/pwm0/period
echo 5000000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle
echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable

but I get nothing out of gpio163 (pin 49 on J3A2). What I’m doing wrong?

Unfortunately the web link above shows an empty page, so I’m not sure what it described when you saw it.

Just as a checklist though, the compile should produce a “.dtb” version in kernel directory “arch/arm/boot/dts/” (tegra124-jetson_tk1-pm375-000-c00-00.dtb). I would then place a copy with a modified name in /boot, e.g., tegra124-jetson_tk1-pm375-000-c00-00_pwm.dtb, and name this in an alternate boot entry to /boot/extlinux/extlinux.conf. Have you placed the compiled alternate “.dtb” file in /boot and have you named it as the new FDT firmware file? If not, the firmware changes would not show up.

Dot at the end is part of punctuation not part of a link. http://elinux.org/Jetson/PWM .

I followed your instructions and this not help me either. Still nothing at the output of gpio163 (pin 49 on J3A2).

I don’t know if this is the issue, but I did notice a difference between what is on the wiki page versus the commands you posted here.

echo 10000000 > /sys/class/pwm/pwmchip0/pwm0/period
echo 1000000 > period

echo 5000000 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle
echo 500000 > duty_cycle

Both of the numbers are off by a factor of 10.