gpio: Add Nuvoton NCT6694 GPIO support

This driver supports GPIO and IRQ functionality for NCT6694 MFD
device based on USB interface.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Ming Yu <a0282524688@gmail.com>
Link: https://lore.kernel.org/r/20250912091952.1169369-3-a0282524688@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: m1ng1109

MAINTAINERS

@@ -18085,6 +18085,7 @@ F:	include/uapi/linux/nubus.h
 NUVOTON NCT6694 MFD DRIVER
 M:	Ming Yu <tmyu0@nuvoton.com>
 S:	Supported
+F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/mfd/nct6694.c
 F:	include/linux/mfd/nct6694.h
 

drivers/gpio/Kconfig

@@ -1522,6 +1522,18 @@ config GPIO_MAX77759
 	  This driver can also be built as a module. If so, the module will be
 	  called gpio-max77759.
 
+config GPIO_NCT6694
+	tristate "Nuvoton NCT6694 GPIO controller support"
+	depends on MFD_NCT6694
+	select GENERIC_IRQ_CHIP
+	select GPIOLIB_IRQCHIP
+	help
+	  This driver supports 8 GPIO pins per bank that can all be interrupt
+	  sources.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called gpio-nct6694.
+
 config GPIO_PALMAS
 	tristate "TI PALMAS series PMICs GPIO"
 	depends on MFD_PALMAS

drivers/gpio/Makefile

@@ -128,6 +128,7 @@ obj-$(CONFIG_GPIO_MT7621)		+= gpio-mt7621.o
 obj-$(CONFIG_GPIO_MVEBU)		+= gpio-mvebu.o
 obj-$(CONFIG_GPIO_MXC)			+= gpio-mxc.o
 obj-$(CONFIG_GPIO_MXS)			+= gpio-mxs.o
+obj-$(CONFIG_GPIO_NCT6694)		+= gpio-nct6694.o
 obj-$(CONFIG_GPIO_NOMADIK)		+= gpio-nomadik.o
 obj-$(CONFIG_GPIO_NPCM_SGPIO)		+= gpio-npcm-sgpio.o
 obj-$(CONFIG_GPIO_OCTEON)		+= gpio-octeon.o