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| -rw-r--r-- | Documentation/devicetree/bindings/iio/afe/current-sense-shunt.txt | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.txt b/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.txt new file mode 100644 index 000000000..0f67108a0 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/afe/current-sense-shunt.txt @@ -0,0 +1,41 @@ +Current Sense Shunt +=================== + +When an io-channel measures the voltage over a current sense shunt, +the interesting measurement is almost always the current through the +shunt, not the voltage over it. This binding describes such a current +sense circuit. + +Required properties: +- compatible : "current-sense-shunt" +- io-channels : Channel node of a voltage io-channel. +- shunt-resistor-micro-ohms : The shunt resistance in microohms. + +Example: +The system current is measured by measuring the voltage over a +3.3 ohms shunt resistor. + +sysi { + compatible = "current-sense-shunt"; + io-channels = <&tiadc 0>; + + /* Divide the voltage by 3300000/1000000 (or 3.3) for the current. */ + shunt-resistor-micro-ohms = <3300000>; +}; + +&i2c { + tiadc: adc@48 { + compatible = "ti,ads1015"; + reg = <0x48>; + #io-channel-cells = <1>; + + #address-cells = <1>; + #size-cells = <0>; + + channel@0 { /* IN0,IN1 differential */ + reg = <0>; + ti,gain = <1>; + ti,datarate = <4>; + }; + }; +}; |