[Q] How can I use P9 14 as PWM?

echo “am33x-pwm” > …slots
echo “pwm-test-P9_14” > …slots
(yes, I’m not rewrite those file names correctly here)

Above does not make PWM work for P9_14 pin. Though there are period_ns and duty_ns, if I
echo “1” > run
nothing happens. If I do this on P8_13, it works. Why does this not work for me?

Ah, I’m using 3.8.13 kernel on BeagleBone Black

what are the contents of /sys/class/pwm

Thank you for your help.

pwmchip0 and pwmchip1 2 files are there.

Weird thing is that after echo “pwm-test-P9…” and echo “pwm-test-P8…”, though there are pwm-test-P9_14 and
pwm-test-P8_13, and contents of the directores are same, only P8_13 does show result in oscilloscope but
P9_14 does not show result.

Check pinmux

cat < /sys/kernel/debug/pwm

and post it here.

cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins
and post it here.

Thanks, first cat /sys/kernel/debug/pwm