powerpc: NAND: FSL UPM: document new bindings

This patch adds documentation for the new NAND FSL UPM bindings for:

 NAND: FSL-UPM: add multi chip support
 NAND: FSL-UPM: Add wait flags to support board/chip specific delays

It also documents the old binding for "chip-delay".
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Documentation/powerpc/dts-bindings/fsl/upm-nand.txt

@@ -5,9 +5,21 @@ Required properties:
 - reg : should specify localbus chip select and size used for the chip.
 - fsl,upm-addr-offset : UPM pattern offset for the address latch.
 - fsl,upm-cmd-offset : UPM pattern offset for the command latch.
-- gpios : may specify optional GPIO connected to the Ready-Not-Busy pin.
 
-Example:
+Optional properties:
+- fsl,upm-wait-flags : add chip-dependent short delays after running the
+	UPM pattern (0x1), after writing a data byte (0x2) or after
+	writing out a buffer (0x4).
+- fsl,upm-addr-line-cs-offsets : address offsets for multi-chip support.
+	The corresponding address lines are used to select the chip.
+- gpios : may specify optional GPIOs connected to the Ready-Not-Busy pins
+	(R/B#). For multi-chip devices, "n" GPIO definitions are required
+	according to the number of chips.
+- chip-delay : chip dependent delay for transfering data from array to
+	read registers (tR). Required if property "gpios" is not used
+	(R/B# pins not connected).
+
+Examples:
 
 upm@1,0 {
 	compatible = "fsl,upm-nand";
@@ -26,3 +38,26 @@ upm@1,0 {
 		};
 	};
 };
+
+upm@3,0 {
+	#address-cells = <0>;
+	#size-cells = <0>;
+	compatible = "tqc,tqm8548-upm-nand", "fsl,upm-nand";
+	reg = <3 0x0 0x800>;
+	fsl,upm-addr-offset = <0x10>;
+	fsl,upm-cmd-offset = <0x08>;
+	/* Multi-chip NAND device */
+	fsl,upm-addr-line-cs-offsets = <0x0 0x200>;
+	fsl,upm-wait-flags = <0x5>;
+	chip-delay = <25>; // in micro-seconds
+
+	nand@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		partition@0 {
+			    label = "fs";
+			    reg = <0x00000000 0x10000000>;
+		};
+	};
+};