Fan-control for Penta-Sata Tower

History

extension was developed for Penta-Sata-Towers with rockpi4 running LibreELEC. Original driver from radxa uses propietary port of pigpio, which I could not port it to LE. Furthermore LibreELEC (LE) does not provide a real shell, but uses busybox. Busybox does not contain support for arrays in shellscripts, nor does it support any real scripting language.

Therefore I had to write some python scripts, that work with the tools provided by LE.

Note: uses legacy sysfs - but sysfs works with current linux-kernels if enabled.

One remaining problem is, that dtb overlays don't work for rockpi4 on LE. Using overlays break boot process.

When the driver was ready and running, I found out, that it has no dependencies, so that it may run on any linux system.

That's the good news.

The bad news: any linux has its own dtb-handling - each of them (of cause) incompatible with others.

Preparation

• debian/ubuntu

  uses /boot/hw_intfc.conf to configure hardware modules. Search for lines like:

  • intfc:pwm0=on/off
  • intfc:pwm1=on/off If both values are set to on you're fine. If not, change them to on.

• armbian

  uses overlays at /boot/dtb/rockchip/overlay, but does not provide an overlay for pwm modules. Provided overlay was written by PetrozPL compile it with:

  dts -O dtb -o rockchip-pwm-gpio.dtbo -b -0 -@ rockchip-pwm-gpio.dts
  

  • copy it to /boot/dtb/rockchip/overlay
  • Enable that overlay by changing /boot/armbianEnv.txt
  • Look for a line like: overlay_prefix=rockchip
  • Add a line after that line: overlays=pwm-gpio

• libreELEC

  LE does not support dtb-overlays, nor does it support configurable hardware modules. So you have to patch the original dtb file:

  1. copy existing dtb from /flash to some place where you have space and write permission. Could be on LE, but does not need to (scp is your friend)

  2. decompile dtb into source with this command (my dtb is rk3399-rock-pi-4a.dtb): dtc -I dtb -O dts -o rk3399-rock-pi-4a.dts rk3399-rock-pi-4a.dtb

  3. load dts file in your favorite editor and search for "pwm@ff42" and you'll find several matching sections like this:

     pwm@ff420000 {
          compatible = "rockchip,rk3399-pwm\0rockchip,rk3288-pwm";
          reg = < 0x00 0xff420000 0x00 0x10 >;
          #pwm-cells = < 0x03 >;
          pinctrl-names = "default";
          pinctrl-0 = < 0x85 >;
          clocks = < 0x76 0x1e >;
          clock-names = "pwm";
          status = "disabled";
          phandle = < 0xf6 >;
          };
  
     pwm@ff420010 {
          compatible = "rockchip,rk3399-pwm\0rockchip,rk3288-pwm";
          reg = < 0x00 0xff420010 0x00 0x10 >;
          #pwm-cells = < 0x03 >;
          pinctrl-names = "default";
          pinctrl-0 = < 0x86 >;
          clocks = < 0x76 0x1e >;
          clock-names = "pwm";
          status = "disabled";
          phandle = < 0xf7 >;
          };
  

  4. replace line status = "disabled" with line status = "okay"

  5. save file and exit editor

  6. copy file back to LE - to a writable directory

  7. compile dts file (on your LE) into dtb with this command:

  dtc -O dtb -o rk3399-rock-pi-4a.dtb -b O -@ rk3399-rock-pi-4a.dts
  

  8. copy compiled binary to /flash overwriting the original dtb file

• slackware

  slackware does not have overlay support, so try to follow instructions from LE Instead of /flash use /boot

  Note: changes at dtb require reboot to become active

Installation

• after preparing system run sudo make install

• Beside fan-control, this package provides support for the top-panel button. Three states are recognized:

  • click - default is toggle control between temperature based control and fan running at fullspeed
  • double-click - default reboots the system
  • (long) pressed - default shutdown to poweroff

Customization

• if you like to change temperature-based fan-speed or change the button functions look at /etc/rockpi-sata.conf

Update

• fanctl has been modified to be able to use TempLogger to reduce system load, if system runs conky.arcs too.

Have fun