Unable to enable watchdog support from uboot side

Embedded Devices Linux
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1

I am using digi 6ul connect core chip(ccimx6uldcm). I want to enable watchdog from uboot so i can restart the system whenever the kernel panic happens and I can boot from dual boot partition in case of unable to boot due to bad image or some other issue.

for enabling the watchdog I enabled few config from ccimx6uldcm_defconfig file

CONFIG_WATCHDOG
CONFIG_WDT
CONFIG_WDT_MCA
CONFIG_MCA_WATCHDOG
CONFIG_WATCHDOG_TIMEOUT_MSECS

I modified the device tree ccimx6uldcm.dtsi file as below. Is there anything wrong with the device tree modification, because i can see build failures after adding below code. what is the right place to add the below code lines.

mca_cc6ul: mca-@7e {
watchdog {
compatible = “digi,mca-cc6ul-wdt”;
digi,timeout-sec = <15>;
digi,full-reset;
};
};

after doing this change still i can see the below msg on uboot console
U-Boot dub-2020.04-r5.2+g425dadfb02 (Jun 01 2022 - 09:34:33 +0000)

CPU: i.MX6UL rev1.2 528 MHz (running at 396 MHz)
CPU: Industrial temperature grade (-40C to 105C) at 63C
Reset cause: POR
I2C: ready
DRAM: 1 GiB
MCA: HW_VER=1 FW_VER=1.12
WDT: Not found!
PMIC: PFUZE3000 DEV_ID=0x30 REV_ID=0x11
NAND: 1024 MiB
MMC: FSL_SDHC: 0
In: serial
Out: serial
Err: serial
Model: Digi International ConnectCore 6UL DCM.
ConnectCore 6UL SOM variant 0x04: Industrial Ultralite 528MHz, 1GB NAND, 1GB DDR3, -40/+85C, Wireless, Bluetooth

still I m getting a “WDT: not found” msg, what are the things which I am doing wrong, or is there any way possible to enable the watchdog from the u-boot side. So I can restart the system in case of kernel panic

I can able to start watchdog after kernel launch, with the below command I can start
=>cat /dev/watchdog

2

U-Boot is running in non interrupt mode. There are (typically/basically) no IRQ handlers active in U-Boot mode.

When you trigger a watchdog, you would require to also trigger/schedule a task which would feed the watchdog or give it a bone, before the next watchdog timer has expired, as a sign of being alive.

This would require to schedule some kind of interrupt or background task in U-Boot. This is nothing which U-Boot is designed for. Typically you use U-Boot to inspect some hardware, program the final application firmware, debug some registers. However running a watchdog is somethings which belongs to an application → running Linux.

If you intend to use the watchdog in Linux, you will need to enable the MCA watchdog in Linux:
https://www.digi.com/resources/documentation/digidocs/embedded/dey/4.0/cc6ul/bsp_r_watchdog_mcadefault
https://www.digi.com/resources/documentation/digidocs/embedded/dey/4.0/cc6ul/bsp_r_mca-watchdog.html