CONFIG_ZYNQMP_FIRMWARE:
 
Firmware interface driver is used by different to
communicate with the firmware for various platform
management services.
Say yes to enable ZynqMP firmware interface driver.
In doubt, say N
 
Symbol: ZYNQMP_FIRMWARE [=y]
Type  : boolean
Prompt: Enable Xilinx Zynq MPSoC firmware interface
  Location:
    -> Firmware Drivers
      -> Zynq MPSoC Firmware Drivers
  Defined at drivers/firmware/xilinx/zynqmp/Kconfig:7
  Depends on: ARCH_ZYNQMP [=y]
  Selected by: ARCH_ZYNQMP [=y]

CONFIG_ZYNQMP_FIRMWARE_DEBUG:
 
Say yes to enable ZynqMP firmware interface debug APIs.
In doubt, say N
 
Symbol: ZYNQMP_FIRMWARE_DEBUG [=n]
Type  : boolean
Prompt: Enable Xilinx Zynq MPSoC firmware debug APIs
  Location:
    -> Firmware Drivers
      -> Zynq MPSoC Firmware Drivers
        -> Enable Xilinx Zynq MPSoC firmware interface (ZYNQMP_FIRMWARE [=y])
  Defined at drivers/firmware/xilinx/zynqmp/Kconfig:16
  Depends on: ARCH_ZYNQMP [=y] && ZYNQMP_FIRMWARE [=y] && DEBUG_FS [=y]

{
       compatible = "xlnx,zynqmp";
       #address-cells = <2>;
       #size-cells = <2>;
       firmware {
               zynqmp_firmware: zynqmp-firmware {
                       compatible = "xlnx,zynqmp-firmware";
                       method = "smc";
               };
       };
}

{
       compatible = "xlnx,versal";
       #address-cells = <2>;
       #size-cells = <2>;;
       firmware {
               versal_firmware: versal-firmware {
                        compatible = "xlnx,versal-firmware";
                        method = "smc";
       };
}

[    0.021138] zynqmp_plat_init Platform Management API v1.0

[    0.021146] zynqmp_plat_init Trustzone version v1.0

root@xilinx-zcu102-2018_1:~# ls /sys/kernel/debug/zynqmp-firmware/pm
root@xilinx-zcu102-2018_1:~# echo pm_get_api_version > /sys/kernel/debug/zynqmp-firmware/pm
root@xilinx-zcu102-2018_1:~# cat /sys/kernel/debug/zynqmp-firmware/pm
root@xilinx-zcu102-2018_1:~# PM-API Version = 1.0