dt-bindings: iio: accel: Document ADXL345 accelerometer binding

Add the device tree binding documentation for the ADXL345 3-axis digital
accelerometer.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/devicetree/bindings/iio/accel/adxl345.txt b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
new file mode 100644 (file)
index 0000000..e7111b0
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+++ b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
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+Analog Devices ADXL345 3-Axis, +/-(2g/4g/8g/16g) Digital Accelerometer
+
+http://www.analog.com/en/products/mems/accelerometers/adxl345.html
+
+Required properties:
+ - compatible : should be "adi,adxl345"
+ - reg : the I2C address or SPI chip select number of the sensor
+
+Required properties for SPI bus usage:
+ - spi-max-frequency : set maximum clock frequency, must be 5000000
+ - spi-cpol and spi-cpha : must be defined for adxl345 to enable SPI mode 3
+
+Optional properties:
+ - interrupt-parent : phandle to the parent interrupt controller as documented
+   in Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+ - interrupts: interrupt mapping for IRQ as documented in
+   Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+Example for a I2C device node:
+
+       accelerometer@2a {
+               compatible = "adi,adxl345";
+               reg = <0x53>;
+               interrupt-parent = <&gpio1>;
+               interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+       };
+
+Example for a SPI device node:
+
+       accelerometer@0 {
+               compatible = "adi,adxl345";
+               reg = <0>;
+               spi-max-frequency = <5000000>;
+               spi-cpol;
+               spi-cpha;
+               interrupt-parent = <&gpio1>;
+               interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+       };