Realtek USB card reader

modulename: rtsx_usb.ko

configname: CONFIG_MISC_RTSX_USB

Linux Kernel Configuration
└─>Device Drivers
└─>Misc devices
└─>Realtek USB card reader
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Select this option to get support for Realtek USB 2.0 card readers
including RTS5129, RTS5139, RTS5179 and RTS5170.
Realtek card reader supports access to many types of memory cards,
such as Memory Stick Pro, Secure Digital and MultiMediaCard.

source code:
selects
CONFIG_MFD_CORE

depends
CONFIG_USB