[SOLVED] Unknown symbol devm_input_allocate_polled_device

I am trying to load kernel module on Raspberry Pi 4.

root@raspberrypi:/home/pi# uname -r 5.4.79-v7l+ root@raspberrypi:/home/pi# insmod i2c_rpi4_accel.ko insmod: ERROR: could not insert module i2c_rpi4_accel.ko: Unknown symbol in module

Trace (dmesg):

[ 85.132241] i2c_rpi4_accel: Unknown symbol devm_input_allocate_polled_device (err -2) [ 85.132328] i2c_rpi4_accel: Unknown symbol input_register_polled_device (err -2) [ 85.132398] i2c_rpi4_accel: Unknown symbol input_unregister_polled_device (err -2)

Kernel module contains these API calls. How to solve this problem? Probably something in the kernel configuration, but I don't know what parameter exactly to change.

Google search gives 2 links regarding INPUT_POLLDEV configuration parameter, this is what I have in the kernel tree directory:

alex@alex-21:~/linux_rpi4/linux$ cat .config | grep INPUT_POLLDEV
CONFIG_INPUT_POLLDEV=y

Kind of solution: Find file input-polldev.ko in Linux device tree and copy it to the board.

root@raspberrypi:/home/pi# ls i2c_rpi4_accel.ko input-polldev.ko root@raspberrypi:/home/pi# insmod input-polldev.ko root@raspberrypi:/home/pi# insmod i2c_rpi4_accel.ko