Support for 8188eu?

The firmware is available (rtl8188eu-firmware) but there are no drivers available to support it on OpenWrt's repos.
8188eu was supported with the rtl8xxxu driver on 17.01 but after this commit the patches that made 8188eu work were dropped.
Any hints I could follow to make it work ?

The driver is not ready yet for everyday use. When I used it, only STA working with low speed.
The vendor-provided driver uses the old api - WEXT, which is not supported by the system.
You can build the legacy driver, but then you have to manually configure hostapd and wpa_supplicant.

I assume you are referring to the driver in staging ( Do you happen to have the Makefile/Patches you used to build it ? That would be really helpful.

Yep, I'm told about staging drivers. Its use wext api, not nl80211.

I have an RTL8188EUS based USB Wifi dongle and want to make it work on Openwrt 21.x. The adaptor works fine on Ubuntu Linux but does not work in OpenWRT due to lack of drivers. Is there any way to make it work? Will above block of code related to RTL8188 make it work if I add it in file?

that block of "code" is 7 years old.

what kernel is your ubuntu using ?
and what version of openwrt/kernel do you have in your openwrt device ?

I am using Ubuntu 20.04 update to latest linux kernel 5.13. It worked out of the box on that.
The openwrt device is using latest OpenWRT 21.02.1.
I am familiar with overall development process of OpenWRT and I have written several applications on OpenWRT. But I am not much familiar with OpenWRT device drivers and how to make them work. If I get pointers, I can try to make it work.

Try the snapshots, I think the kernel's 5.10, it might be new(er) enough to get the 8188 supported.

I am able to get the driver compiled but the Luci Network-> Wireless link does not get displayed.

kernel module is present

> root@OpenWrt:/lib/firmware/rtlwifi# lsmod
> 8188eu                694899  0

wlan0 entry also get ceated

root@OpenWrt:/# ip addr
8: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 7c:c2:c6:1e:a0:02 brd ff:ff:ff:ff:ff:ff

dmesg shows following:

[  794.256268] usb 1-1: new high-speed USB device number 3 using xhci-mtk
[  794.438037] Chip Version Info: CHIP_8188E_Normal_Chip_TSMC_D_CUT_1T1R_RomVer(0)
[  794.468402] EEPROM ID = 0x8129

What could be wrong with the driver? How to get OpenWRT to recognise it fully?

Ask Realtek.
Rule of thumb is however it is garbage, and ppl should stay away.

What's the intended use?

Want to use it as Wifi Client. The problem as of now is that radio0 device itself is not getting created.

try adding a new interface.

it should have been detected, but who knows.