[PATCH v4 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: Boris Brezillon <boris.brezillon at free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
---
 .../devicetree/bindings/mfd/atmel-flexcom.txt      | 58 ++++++++++++++++++++++
 1 file changed, 58 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 0000000..38f0e43
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
@@ -0,0 +1,58 @@
+* 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: "atmel,sama5d2-flexcom"
+- reg: shall be the offset/length value for Flexcom dedicated I/O registers
+  (without USART, TWI or SPI registers).
+- clocks: shall be the Flexcom peripheral clock from PMC.
+- #address-cells: should be <1>
+- #size-cells: should be <1>
+- ranges: one range for the full I/O register region (including USART, TWI and
+  SPI registers)
+- atmel,flexcom-mode: shall be a string among { "spi", "usart", "i2c", "twi" }.
+  "i2c" and "twi" are synonymous.
+
+Required child:
+a child device of type matching the "atmel,flexcom-mode" property.
+The reg property of this child should be:
+- <0x200 0x200> for USART
+- <0x400 0x200> for SPI
+- <0x600 0x200> for I2C
+The phandle provided by the clocks property of the child is the same as one for
+the Flexcom parent.
+Other properties remain unchanged. See documentation of the respective device.
+
+Example:
+
+flx0: flexcom at f8034000 {
+	compatible = "atmel,sama5d2-flexcom";
+	reg = <0xf8034000 0x200>;
+	clocks = <&flx0_clk>;
+	#address-cells = <1>;
+	#size-cells = <1>;
+	ranges = <0x0 0xf8034000 0x800>;
+	atmel,flexcom-mode = "spi";
+
+	spi at f8034400 {
+		compatible = "atmel,at91rm9200-spi";
+		reg = <0x400 0x200>;
+		interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_flx0_ioset1>;
+		#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