ZyXEL P-2812HNU-F1 FXS ports in Trunk

Hi,
is it possible to run this function on this device ? I compiled VPE image, with proper bootargs, configure asterisk and stil no "beep" on phone connected to phone ports...

In /target/linux/lantiq/files/arch/mips/boot/dts/lantiq/vr9_zyxel_p-2812hnu-fx.dtsi ->
bootargs = "console=ttyLTQ0,115200 mem=116M phym=128M vpe1_load_addr=0x87e00000 vpe1_mem=2M maxvpes=1 maxtcs=1 nosmp";

and in /target/linux/lantiq/config-5.4
CONFIG_MIPS_MT_SMP is not set

I think there is a problem with declaration of gpios for Lantiq XWAY SLIC120 int .dtsi file...

Ps. There is a EasyBox 904 with the same SLIC120 chip, and FXS ports working correctly.

Thank you for answer