STMicroelectronics STMFX GPIO expander pinctrl driver

modulename: pinctrl-stmfx.ko

configname: CONFIG_PINCTRL_STMFX

Linux Kernel Configuration
└─>Device Drivers
└─>Pin controllers
└─>STMicroelectronics STMFX GPIO expander pinctrl driver
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Driver for STMicroelectronics Multi-Function eXpander (STMFX)
GPIO expander.
This provides a GPIO interface supporting inputs and outputs,
and configuring push-pull, open-drain, and can also be used as
interrupt-controller.

source code: