gpio: Add GPIO support for the WinSystems WS16C48

The WinSystems WS16C48 device provides 48 lines of digital I/O. In
addition, the first 24 lines may be used for interrupt-handled edge
detection; rising edge detection and falling edge detection are
supported.

This driver provides GPIO and IRQ support for these 48 channels of
digital I/O. The base port address for the device may be configured via
the ws16c48_base module parameter. The interrupt line number for the
device may be configured via the ws16c48_irq module parameter.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

MAINTAINERS

@@ -11871,6 +11871,12 @@ M:	David Härdeman <david@hardeman.nu>
 S:	Maintained
 F:	drivers/media/rc/winbond-cir.c
 
+WINSYSTEMS WS16C48 GPIO DRIVER
+M:	William Breathitt Gray <vilhelm.gray@gmail.com>
+L:	linux-gpio@vger.kernel.org
+S:	Maintained
+F:	drivers/gpio/gpio-ws16c48.c
+
 WIMAX STACK
 M:	Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 M:	linux-wimax@intel.com

drivers/gpio/Kconfig

@@ -570,6 +570,15 @@ config GPIO_TS5500
 	  blocks of the TS-5500: DIO1, DIO2 and the LCD port, and the TS-5600
 	  LCD port.
 
+config GPIO_WS16C48
+	tristate "WinSystems WS16C48 GPIO support"
+	select GPIOLIB_IRQCHIP
+	help
+	  Enables GPIO support for the WinSystems WS16C48. The base port address
+	  for the device may be configured via the ws16c48_base module
+	  parameter. The interrupt line number for the device may be configured
+	  via the ws16c48_irq module parameter.
+
 endmenu
 
 menu "I2C GPIO expanders"

drivers/gpio/Makefile

@@ -111,6 +111,7 @@ obj-$(CONFIG_GPIO_VX855)	+= gpio-vx855.o
 obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
 obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
 obj-$(CONFIG_GPIO_WM8994)	+= gpio-wm8994.o
+obj-$(CONFIG_GPIO_WS16C48)	+= gpio-ws16c48.o
 obj-$(CONFIG_GPIO_XGENE)	+= gpio-xgene.o
 obj-$(CONFIG_GPIO_XGENE_SB)	+= gpio-xgene-sb.o
 obj-$(CONFIG_GPIO_XILINX)	+= gpio-xilinx.o