gpio: Add GPIO support for the ACCES 104-DIO-48E

The ACCES 104-DIO-48E device provides 48 lines digital I/O via two
Programmable Peripheral Interface (PPI) chips of type 82C55. Bit C3 at
each 24-bit Group can be used as an external interrupt, triggered by a
rising edge.

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 dio_48e_base module parameter. The interrupt line number for the
device may be configured via the dio_48e_irq module parameter.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b5337f2..5e31748 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -487,6 +487,15 @@
 menu "Port-mapped I/O GPIO drivers"
 	depends on X86 # Unconditional I/O space access
 
+config GPIO_104_DIO_48E
+	tristate "ACCES 104-DIO-48E GPIO support"
+	select GPIOLIB_IRQCHIP
+	help
+	  Enables GPIO support for the ACCES 104-DIO-48E family. The base port
+	  address for the device may be configured via the dio_48e_base module
+	  parameter. The interrupt line number for the device may be configured
+	  via the dio_48e_irq module parameter.
+
 config GPIO_104_IDIO_16
 	tristate "ACCES 104-IDIO-16 GPIO support"
 	select GPIOLIB_IRQCHIP