Say yes here to enable the Broadcom iProc GPIO driver.

The Broadcom iProc based SoCs- Cygnus, NS2, NSP and Stingray, use
same GPIO Controller IP hence this driver could be used for all.

The Broadcom Cygnus SoC has 3 GPIO controllers including the ASIU
GPIO controller (ASIU), the chipCommonG GPIO controller (CCM), and
the always-ON GPIO controller (CRMU/AON). All 3 GPIO controllers are
supported by this driver.

The Broadcom NSP has two GPIO controllers including the ChipcommonA
GPIO, the ChipcommonB GPIO. Later controller is supported by this
driver.

The Broadcom NS2 has two GPIO controller including the CRMU GPIO,
the ChipcommonG GPIO. Both controllers are supported by this driver.

The Broadcom Stingray GPIO controllers are supported by this driver.

All above SoCs GPIO controllers support basic PINCONF functions such
as bias pull up, pull down, and drive strength configurations, when
these pins are muxed to GPIO.

It provides the framework where pins from the individual GPIO can be
individually muxed to GPIO function, through interaction with the
SoCs IOMUX controller. This features could be used only on SoCs which
support individual pin muxing.

source code:

drivers/pinctrl/bcm/pinctrl-iproc-gpio.c