dt-bindings: leds: add pca955x

This adds the devicetree bindings for the PCA955x I2C LED blinkers.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

Documentation/devicetree/bindings/leds/leds-pca955x.txt

+* NXP - pca955x LED driver
+
+The PCA955x family of chips are I2C LED blinkers whose pins not used
+to control LEDs can be used as general purpose I/Os. The GPIO pins can
+be input or output, and output pins can also be pulse-width controlled.
+
+Required properties:
+- compatible : should be one of :
+	"nxp,pca9550"
+	"nxp,pca9551"
+	"nxp,pca9552"
+	"nxp,pca9553"
+- #address-cells: must be 1
+- #size-cells: must be 0
+- reg: I2C slave address. depends on the model.
+
+Optional properties:
+- gpio-controller: allows pins to be used as GPIOs.
+- #gpio-cells: must be 2.
+- gpio-line-names: define the names of the GPIO lines
+
+LED sub-node properties:
+- reg : number of LED line.
+		from 0 to  1 for the pca9550
+		from 0 to  7 for the pca9551
+		from 0 to 15 for the pca9552
+		from 0 to  3 for the pca9553
+- type: (optional) either
+	PCA9532_TYPE_NONE
+	PCA9532_TYPE_LED
+	PCA9532_TYPE_GPIO
+	see dt-bindings/leds/leds-pca955x.h (default to LED)
+- label : (optional)
+	see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger : (optional)
+	see Documentation/devicetree/bindings/leds/common.txt
+
+Examples:
+
+pca9552: pca9552@60 {
+	compatible = "nxp,pca9552";
+	#address-cells = <1>;
+        #size-cells = <0>;
+	reg = <0x60>;
+
+	gpio-controller;
+	#gpio-cells = <2>;
+	gpio-line-names = "GPIO12", "GPIO13", "GPIO14", "GPIO15";
+
+	gpio@12 {
+		reg = <12>;
+		type = <PCA955X_TYPE_GPIO>;
+	};
+	gpio@13 {
+		reg = <13>;
+		type = <PCA955X_TYPE_GPIO>;
+	};
+	gpio@14 {
+		reg = <14>;
+		type = <PCA955X_TYPE_GPIO>;
+	};
+	gpio@15 {
+		reg = <15>;
+		type = <PCA955X_TYPE_GPIO>;
+	};
+
+	led@0 {
+		label = "red:power";
+		linux,default-trigger = "default-on";
+		reg = <0>;
+		type = <PCA955X_TYPE_LED>;
+	};
+	led@1 {
+		label = "green:power";
+		reg = <1>;
+		type = <PCA955X_TYPE_LED>;
+	};
+	led@2 {
+		label = "pca9552:yellow";
+		reg = <2>;
+		type = <PCA955X_TYPE_LED>;
+	};
+	led@3 {
+		label = "pca9552:white";
+		reg = <3>;
+		type = <PCA955X_TYPE_LED>;
+	};
+};