Rock-5b PWM

[lurk101]

With

Linux rock-5b 5.10.72-rockchip-rk3588 #trunk.0102 SMP Sat Nov 5 07:56:18 UTC 2022 aarch64 GNU/Linux

I see only one PWM controller

pi@rock-5b:~$ ls /sys/class/pwm/pwmchip1/
device  export  npwm  power  subsystem  uevent  unexport
pi@rock-5b:~$ cat /sys/class/pwm/pwmchip1/npwm
1

How do I figure out its header pin assignment?

 

Is there a device tree overlay to expose all 4 PWM controllers?

Edited November 22, 2022 by lurk101
spelling

[lurk101]

Ok, looking at available overlays

pi@rock-5b:~$ ls /boot/dtb/rockchip/overlay/*pwm*
/boot/dtb/rockchip/overlay/rk3588-pwm12-m0.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm15-m3.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm13-m0.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm2-m1.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm13-m2.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm3-m1.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm14-m0.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm5-m2.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm14-m1.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm6-m2.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm15-m0.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm7-m3.dtbo
/boot/dtb/rockchip/overlay/rk3588-pwm15-m1.dtbo  /boot/dtb/rockchip/overlay/rk3588-pwm8-m0.dtbo

These seem to match the pin functions identified in the raxda rock-5b gpio pinout.

 

Looking at the armbianEnv file

pi@rock-5b:~$ cat /boot/armbianEnv.txt
verbosity=1
bootlogo=true
overlay_prefix=rockchip-rk3588
fdtfile=rockchip/rk3588-rock-5b.dtb
rootdev=UUID=e267943c-66ea-4d3c-b857-3a7208b48df4
rootfstype=ext4
usbstoragequirks=0x2537:0x1066:u,0x2537:0x1068:u

If the overlay prefix 'rockchip-rk3588' is a prefix to dtbo files named in overlays= statement then how is it possible to add these dtbo files as overlay.

 

Or, are these not compatible?

Edited November 23, 2022 by lurk101

[cocasema]

Here's what helped me with getting UARTs working. I haven't tried PWMs, but hope it should work for you as well.

 

sudo mkdir /boot/overlay-user/
sudo cp /boot/dtb-5.10.110-rockchip-rk3588/rockchip/overlay/rk3588-*.dtbo /boot/overlay-user/

 

And then add name(s) of the needed *.dtbo file(s) to the `/boot/armbianEnv.txt` and reboot.

 

...
user_overlays=rk3588-uart2-m0 rk3588-uart7-m2
...

 

[lurk101]

Oh! Thanks, but I've given up on Armbian for the Rock-5b. The Radxa image suits me fine and boots from NMVE.

[Efe Çetin]

Will be resolved with https://github.com/armbian/build/pull/4734

[lurk101]

In the mean time I had to rename the DTBO files from rock3588-....dtbo to rockchip-rk3588-....dtbo so that they could be used in arbianEnv.txt in the overlays= specification. Works fine for UART and PWM.

[lurk101]

@Efe Çetin How does you PR finally resolve the issue? Rename all the .dtbo files, or change the overlay-prefix?

 

BTW, the pd-max-voltage-12v.dtbo for forcing a PD supply negotiation to 12V instead of a default 20V also works well when renamed appropriately.