[PATCH v8 1/2] mfd: devicetree: add bindings for Atmel Flexcom

[Cyrille Pitchen]

This patch documents the DT bindings for the Atmel Flexcom which will be
introduced by sama5d2x SoCs. These bindings will be used by the actual
Flexcom driver to be sent in another patch.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
---
 .../devicetree/bindings/mfd/atmel-flexcom.txt      | 68 ++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt

diff --git a/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
new file mode 100644
index 000000000000..588d527dbfa7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
@@ -0,0 +1,68 @@
+* Device tree bindings for Atmel Flexcom (Flexible Serial Communication Unit)
+
+The Atmel Flexcom is just a wrapper which embeds a SPI controller, an I2C
+controller and an USART. Only one function can be used at a time and is chosen
+at boot time according to the device tree.
+
+Required properties:
+- compatible:		Should be "atmel,sama5d2-flexcom"
+- reg:			Should be the pair (offset, size) for the Flexcom
+			dedicated I/O registers (without USART, TWI or SPI
+			registers).
+- clocks:		Should be the Flexcom peripheral clock from PMC.
+- #address-cells:	Should be <2>
+- #size-cells:		Should be <1>
+- ranges:		Should be a list of ranges.
+			One range per peripheral wrapped by the Flexcom. So each
+			range is a triplet (child_addr, parent_addr, size). The
+			first u32 of "child_addr" is the value to be set in the
+			Operating Mode bitfield of the Flexcom Mode Register.
+			Then "parent_addr" stores the base address of the
+			corresponding peripheral in the system memory. Finally,
+			"size" if the size of the memory region of this
+			peripheral.
+
+Required child:
+A single available child for the serial controller to enable.
+
+Required properties of this child:
+- reg:			Should be a pair (child_addr, size) with child_addr
+			matching one of the parent ranges.
+- clocks:		Should be the very same phandle as for the parent's one.
+
+Other properties remain unchanged. See documentation of the respective device:
+- ../serial/atmel-usart.txt
+- ../spi/spi_atmel.txt
+- ../i2c/i2c-at91.txt
+
+Example:
+
+flexcom at f8034000 {
+	compatible = "atmel,sama5d2-flexcom";
+	reg = <0xf8034000 0x200>;
+	clocks = <&flx0_clk>;
+	#address-cells = <2>;
+	#size-cells = <1>;
+	ranges = <1 0 0xf8034200 0x200		/* opmode 1: USART */
+		  2 0 0xf8034400 0x200		/* opmode 2: SPI */
+		  3 0 0xf8034600 0x200>;	/* opmode 3: I2C */
+
+	spi at 2,0 {
+		compatible = "atmel,at91rm9200-spi";
+		reg = <2 0 0x200>;
+		interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_flx0_default>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&flx0_clk>;
+		clock-names = "spi_clk";
+		atmel,fifo-size = <32>;
+
+		mtd_dataflash at 0 {
+			compatible = "atmel,at25f512b";
+			reg = <0>;
+			spi-max-frequency = <20000000>;
+		};
+	};
+};
-- 
1.8.2.2