both PWM channels are active, will dot digest your SW though.
this is for disabling HDMI audioand doesn't matter to PWM
EDIT:
as I have no idea what you're doing and how you're testing let me show you how I would
having the overlay loaded first check if the two PWM nodes got createdNow change to the folder for pwmchip0. As nothing has claimed them one will have to do this manuallyNow we have two PWM devices available.
Let's configure the first one and fire it up.as you can see PWM0 is active now, there is nothing for PWM1 so far.
Let's configure that as well and start it to.as my oszillocope is showing me two PWM's (one with 100kHz and another with 200kHz) I consider this as closed for me.
this is for disabling HDMI audio
Code:
dtoverlay=vc4-kms-v3d,noaudioEDIT:
as I have no idea what you're doing and how you're testing let me show you how I would
having the overlay loaded first check if the two PWM nodes got created
Code:
pi@cm4nanob:~ $ sudo cat /sys/kernel/debug/pwm0: platform/fe20c000.pwm, 2 PWM devices pwm-0 ((null) ): period: 0 ns duty: 0 ns polarity: normal pwm-1 ((null) ): period: 0 ns duty: 0 ns polarity: normalpi@cm4nanob:~ $ pinctrl get 12,1312: a0 pd | lo // GPIO12 = PWM0_013: a0 pd | lo // GPIO13 = PWM0_1Code:
pi@cm4nanob:~ $ cd /sys/class/pwmpi@cm4nanob:/sys/class/pwm $ cd pwmchip0Code:
pi@cm4nanob:/sys/class/pwm/pwmchip0 $ echo 0 > exportpi@cm4nanob:/sys/class/pwm/pwmchip0 $ echo 1 > exportpi@cm4nanob:/sys/class/pwm/pwmchip0 $ dirdeviceexportnpwm power pwm0 pwm1 subsystem uevent unexportLet's configure the first one and fire it up.
Code:
pi@cm4nanob:/sys/class/pwm/pwmchip0 $ cd pwm0pi@cm4nanob:/sys/class/pwm/pwmchip0/pwm0 $ echo 10000 > periodpi@cm4nanob:/sys/class/pwm/pwmchip0/pwm0 $ echo 6000 > duty_cyclepi@cm4nanob:/sys/class/pwm/pwmchip0/pwm0 $ echo 1 > enablepi@cm4nanob:/sys/class/pwm/pwmchip0/pwm0 $ sudo cat /sys/kernel/debug/pwm0: platform/fe20c000.pwm, 2 PWM devices pwm-0 (sysfs ): requested enabled period: 10000 ns duty: 6000 ns polarity: normal pwm-1 (sysfs ): requested period: 0 ns duty: 0 ns polarity: normalLet's configure that as well and start it to.
Code:
pi@cm4nanob:/sys/class/pwm/pwmchip0/pwm0 $ cd /sys/class/pwm/pwmchip0/pwm1pi@cm4nanob:/sys/class/pwm/pwmchip0/pwm1 $ echo 5000 > periodpi@cm4nanob:/sys/class/pwm/pwmchip0/pwm1 $ echo 3000 > duty_cyclepi@cm4nanob:/sys/class/pwm/pwmchip0/pwm1 $ echo 1 > enablepi@cm4nanob:/sys/class/pwm/pwmchip0/pwm1 $ sudo cat /sys/kernel/debug/pwm0: platform/fe20c000.pwm, 2 PWM devices pwm-0 (sysfs ): requested enabled period: 10000 ns duty: 6000 ns polarity: normal pwm-1 (sysfs ): requested enabled period: 5000 ns duty: 3000 ns polarity: normalStatistics: Posted by aBUGSworstnightmare — Tue Nov 11, 2025 6:00 am