R/G/B/X LEDs using stock Ubuntu 24.04

SteveInAU

Hi all,

I'm trying to figure out how to enable control of the additional LEDs next to the ethernet port on the UP4000.

I'm trying to not install any specific UP board kernel to make this happen - as these will likely be deployed and required to be supported by us for 5-8 years - likely beyond the timeframe of supported software released by UP....

Is there a way to enable certain GPIOs directly to allow this to work?

I notice at the moment, I can see:

# ls -l /sys/class/leds
total 0
lrwxrwxrwx 1 root root 0 May  8 06:20 enp2s0-0::lan -> ../../devices/pci0000:00/0000:00:13.1/0000:02:00.0/net/enp2s0/enp2s0-0::lan
lrwxrwxrwx 1 root root 0 May  8 06:20 enp2s0-1::lan -> ../../devices/pci0000:00/0000:00:13.1/0000:02:00.0/net/enp2s0/enp2s0-1::lan
lrwxrwxrwx 1 root root 0 May  8 06:20 enp2s0-2::lan -> ../../devices/pci0000:00/0000:00:13.1/0000:02:00.0/net/enp2s0/enp2s0-2::lan

... and it does look like at least some of the GPIO control is available with the stock Ubuntu 24.04 kernel:

# ls -l /sys/class/gpio/
total 0
--w------- 1 root root 4096 May  9 06:21 export
lrwxrwxrwx 1 root root    0 May  8 06:20 gpiochip512 -> ../../devices/platform/INT3452:00/gpio/gpiochip512
lrwxrwxrwx 1 root root    0 May  8 06:20 gpiochip590 -> ../../devices/platform/INT3452:01/gpio/gpiochip590
lrwxrwxrwx 1 root root    0 May  8 06:20 gpiochip667 -> ../../devices/platform/INT3452:02/gpio/gpiochip667
lrwxrwxrwx 1 root root    0 May  8 06:20 gpiochip714 -> ../../devices/platform/INT3452:03/gpio/gpiochip714
--w------- 1 root root 4096 May  9 06:21 unexport

Right now, I'm only looking to get basic ON / OFF support working - but it would likely be good to register them as normal LEDs to allow some of the effects to work...

HarryChiu

Hi @SteveInAU

Please install the Pinctrl, and refer to the link.
https://github.com/up-division/pinctrl-upboard

https://github.com/up-board/up-community/wiki/How-to-use-the-peripherals-on-40-Pin-Header

Best Regards,
Harry Chiu

HarryChiu

Hi @SteveInAU

The Pinctrl driver can only control Y/R/G leds.
If you want to control the blue led, can control it via GPIO, number is 585.

Best Regards,
Harry Chiu

smallkitties

Hello Harry Chiu,

The directions at https://github.com/up-division/pinctrl-upboard are no longer correct.

The Pinctrl driver does not allow access to the leds. If we follow:
https://github.com/up-board/up-community/wiki/How-to-use-the-peripherals-on-40-Pin-Header

$ ls -l /sys/class/leds
clearly shows that a 'upboard' folder was not created and thus not possible to perform:
$ echo 1 > /sys/class/leds/upboard:green:/brightness

Also, exporting 585 and changing the value does nothing.

Furthermore, exporting GPIOs only seems to work with Rpi GPIO numbering. For example, with respect to physical pin 19:
$ echo 422 > /sys/class/gpio/export <=== Fails
$ echo 10 > /sys/class/gpio/export <=== Works

My UP4000 build uses: Ubuntu 24.04, 6.11.0-28-generic, dkms installed, and Pinctrl driver installed

HarryChiu

Hi @smallkitties

After installing pinctrl, will gpiochip0 appear under /sys/class/gpio/??

Best Regards,
Harry Chiu