x86: gpio: add pinctrl support from the device tree

Every pin can be configured now from the device tree. A dt-bindings
has been added to describe the different property available.

Change-Id: I1668886062655f83700d0e7bbbe3ad09b19ee975
Signed-off-by: Gabriel Huau <contact@huau-gabriel.fr>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/device-tree-bindings/gpio/intel,x86-pinctrl.txt b/doc/device-tree-bindings/gpio/intel,x86-pinctrl.txt
new file mode 100644
index 0000000..45ab1af
--- /dev/null
+++ b/doc/device-tree-bindings/gpio/intel,x86-pinctrl.txt
@@ -0,0 +1,31 @@
+Intel x86 PINCTRL/GPIO controller
+
+Pin-muxing on x86 can be described with a node for the PINCTRL master
+node and a set of child nodes for each pin on the SoC.
+
+The PINCTRL master node requires the following properties:
+- compatible : "intel,x86-pinctrl"
+
+Pin nodes must be children of the pinctrl master node and can
+contain the following properties:
+- pad-offset        - (required) offset in the IOBASE for the pin to configured.
+- gpio-offset       - (required) offset in the GPIOBASE for the pin to configured and
+					also the bit shift in this register.
+- mode-gpio			- (optional) standalone property to force the pin into GPIO mode.
+- mode-func			- (optional) function number to assign to the pin. if 'mode-gpio'
+					is set, this property will be ignored.
+in case of 'mode-gpio' property set:
+- output-value		- (optional) this set the default output value of the GPIO.
+- direction         - (optional) this set the direction of the gpio.
+- pull-str          - (optional) this set the pull strength of the pin.
+- pull-assign       - (optional) this set the pull assignement (up/down) of the pin.
+
+Example:
+
+pin_usb_host_en0@0 {
+    gpio-offset = <0x80 8>;
+    pad-offset = <0x260>;
+    mode-gpio;
+    output-value = <1>;
+    direction = <PIN_OUTPUT>;
+};