They are included in the staging tree at https://git.kernel.org/cgit/linux/kernel/git/gregkh/staging.git/ and they are NOT supported by linux-wireless developers or mailing list. Instead ask for support in http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel . Maintainers are Greg Kroah-Hartman <email@example.com> and Larry Finger <Larry.Finger@lwfinger.net>.
If you get an unsupported device, you can donate it to the driver maintainer. For more info ask Larry Finger <Larry.Finger@lwfinger.net>.
The firmware for those devices can be downloaded from: https://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmware.git
See this page for a list of devices that based on the rtl819x chip.