No /dev/spidev and Unknown symbols warnings in 'dmesg'

[quyphamdev]

After I installed the driver, I don't see any /dev/spidev and I got these warnings in 'dmesg':
[11212.412026] spi_ch341_usb: Unknown symbol spi_unregister_device (err 0)
[11212.412046] spi_ch341_usb: Unknown symbol spi_finalize_current_transfer (err 0)
[11212.412075] spi_ch341_usb: Unknown symbol spi_unregister_controller (err 0)
[11212.412098] spi_ch341_usb: Unknown symbol __spi_alloc_controller (err 0)
[11212.412116] spi_ch341_usb: Unknown symbol spi_register_controller (err 0)

There were errors when compiling the driver. There was no definition of at least a function in spi.h. So I replaced it with another spi.h file. Then the compilation went through.
How can I fix this ?
I am on CentOS 7 (3.10.0-1127.19.1.el7.x86_64). I am using this board https://www.amazon.com/dp/B082KQ75QM/ref=cm_sw_em_r_mt_dp_-3cNFb8VTDVM3?_encoding=UTF8&psc=1

Thanks

[UncleGrumpy]

The error is because the header you supplied had the needed definition, but that is not the header compiled into the kernel so the kernel had no idea what to do with it. The problem will be fixed if pull request #20 is approved. I have verified that it will work :)