gpio: Add support for Intel LJCA USB GPIO driver

This patch implements the GPIO function of Intel USB-I2C/GPIO/SPI adapter
device named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA
GPIO module with specific protocol through interfaces exported by LJCA USB
driver.
Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230225140118.2037220-3-xiang.ye@intel.com

drivers/gpio/Kconfig

@@ -1253,6 +1253,18 @@ config GPIO_KEMPLD
 	  This driver can also be built as a module. If so, the module will be
 	  called gpio-kempld.
 
+config GPIO_LJCA
+	tristate "INTEL La Jolla Cove Adapter GPIO support"
+	depends on MFD_LJCA
+	select GPIOLIB_IRQCHIP
+	default MFD_LJCA
+	help
+	  Select this option to enable GPIO driver for the INTEL
+	  La Jolla Cove Adapter (LJCA) board.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gpio-ljca.
+
 config GPIO_LP3943
 	tristate "TI/National Semiconductor LP3943 GPIO expander"
 	depends on MFD_LP3943

drivers/gpio/Makefile

@@ -77,6 +77,7 @@ obj-$(CONFIG_GPIO_IXP4XX)		+= gpio-ixp4xx.o
 obj-$(CONFIG_GPIO_JANZ_TTL)		+= gpio-janz-ttl.o
 obj-$(CONFIG_GPIO_KEMPLD)		+= gpio-kempld.o
 obj-$(CONFIG_GPIO_LATCH)		+= gpio-latch.o
+obj-$(CONFIG_GPIO_LJCA) 		+= gpio-ljca.o
 obj-$(CONFIG_GPIO_LOGICVC)		+= gpio-logicvc.o
 obj-$(CONFIG_GPIO_LOONGSON1)		+= gpio-loongson1.o
 obj-$(CONFIG_GPIO_LOONGSON)		+= gpio-loongson.o