pinctrl: add Intel BayTrail GPIO/pinctrl support

Add support for gpio on Intel BayTrail platforms. BayTrail supports 3 banks
of gpios called SCORE, NCORE ans SUS with 102, 28 and 44 gpio pins.
Supports gpio interrupts and ACPI gpio events

Pins may be muxed to alternate function instead of gpio by firmware.
This driver does not touch the pin muxing and expect firmare
to set pin muxing and pullup/down properties properly.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/Kconfig

@@ -58,6 +58,18 @@ config PINCTRL_AT91
 	help
 	  Say Y here to enable the at91 pinctrl driver
 
+config PINCTRL_BAYTRAIL
+	bool "Intel Baytrail GPIO pin control"
+	depends on GPIOLIB && ACPI && X86
+        select IRQ_DOMAIN
+	help
+	  driver for memory mapped GPIO functionality on Intel Baytrail
+	  platforms. Supports 3 banks with 102, 28 and 44 gpios.
+	  Most pins are usually muxed to some other functionality by firmware,
+	  so only a small amount is available for gpio use.
+
+	  Requires ACPI device enumeration code to set up a platform device.
+
 config PINCTRL_BCM2835
 	bool
 	select PINMUX

drivers/pinctrl/Makefile

@@ -16,6 +16,7 @@ obj-$(CONFIG_PINCTRL_AB9540)	+= pinctrl-ab9540.o
 obj-$(CONFIG_PINCTRL_AB8505)	+= pinctrl-ab8505.o
 obj-$(CONFIG_PINCTRL_AT91)	+= pinctrl-at91.o
 obj-$(CONFIG_PINCTRL_BCM2835)	+= pinctrl-bcm2835.o
+obj-$(CONFIG_PINCTRL_BAYTRAIL)	+= pinctrl-baytrail.o
 obj-$(CONFIG_PINCTRL_IMX)	+= pinctrl-imx.o
 obj-$(CONFIG_PINCTRL_IMX35)	+= pinctrl-imx35.o
 obj-$(CONFIG_PINCTRL_IMX51)	+= pinctrl-imx51.o