[PATCH 2/3] dt-bindings: iio: adc: add bindings for mcp3911

[Marcus Folkesson <marcus.folkesson@gmail.com>]

MCP3911 is a dual channel Analog Front End (AFE) containing two
synchronous sampling delta-sigma Analog-to-Digital Converters (ADC).

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Kent Gustavsson <kent@minoris.se>
---
 .../devicetree/bindings/iio/adc/mcp3911.txt        | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/mcp3911.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/mcp3911.txt b/Documentation/devicetree/bindings/iio/adc/mcp3911.txt
new file mode 100644
index 000000000000..e233ee94ad96
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/mcp3911.txt
@@ -0,0 +1,33 @@
+* Microchip MCP3911 Dual channel analog front end (ADC)
+
+Required properties:
+ - compatible: Should be "microchip,mcp3911"
+ - reg: SPI chip select number for the device
+
+Recommended properties:
+ - spi-max-frequency: Definition as per
+	 Documentation/devicetree/bindings/spi/spi-bus.txt.
+	 Max frequency for this chip is 20MHz.
+
+Optional properties:
+ - device-addr: Device address when multiple MCP3911 chips are present on the
+	same SPI bus. Valid values are 0-3. Defaults to 0.
+ - external-clock: Use external clock instead of crystal oscillator.
+ - external-vref: Use external voltage reference
+ - vref-supply:	Phandle to the external reference voltage supply. (only valid in combination with `external-vref`)
+ - ch0-width: width for channel0. Valid widths are 16 and 24bits.
+ - ch1-width: width for channel1. Valid widths are 16 and 24bits.
+
+
+Example:
+adc@0 {
+	compatible = "microchip,mcp3911";
+	reg = <0>;
+	spi-max-frequency = <20000000>;
+	device-addr = <0>;
+	ch0-width = <16>;
+	ch1-width = <24>;
+	external-clock;
+	external-vref;
+	vref-supply = <&vref_reg>;
+};
-- 
2.11.0.rc2