dt-bindings: aspeed-lpc: Document LPC Host Interface Controller

The LPC Host Interface Controller is part of a BMC SoC that is used for
communication with the host.
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/mfd/aspeed-lpc.txt

@@ -109,9 +109,50 @@ lpc: lpc@1e789000 {
 	};
 };
 
+BMC Node Children
+==================
+
+
 Host Node Children
 ==================
 
+LPC Host Interface Controller
+-------------------
+
+The LPC Host Interface Controller manages functions exposed to the host such as
+LPC firmware hub cycles, configuration of the LPC-to-AHB mapping, UART
+management and bus snoop configuration.
+
+Required properties:
+
+- compatible:	One of:
+		"aspeed,ast2400-lpc-ctrl";
+		"aspeed,ast2500-lpc-ctrl";
+
+- reg:		contains offset/length values of the host interface controller
+		memory regions
+
+- clocks:	contains a phandle to the syscon node describing the clocks.
+		There should then be one cell representing the clock to use
+
+- memory-region: A phandle to a reserved_memory region to be used for the LPC
+		to AHB mapping
+
+- flash:	A phandle to the SPI flash controller containing the flash to
+		be exposed over the LPC to AHB mapping
+
+Example:
+
+lpc-host@80 {
+	lpc_ctrl: lpc-ctrl@0 {
+		compatible = "aspeed,ast2500-lpc-ctrl";
+		reg = <0x0 0x80>;
+		clocks = <&syscon ASPEED_CLK_GATE_LCLK>;
+		memory-region = <&flash_memory>;
+		flash = <&spi>;
+	};
+};
+
 LPC Host Controller
 -------------------