diff options
author | Peter Rosin <peda@axentia.se> | 2018-04-23 23:08:06 +0200 |
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committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2018-04-28 17:59:32 +0100 |
commit | 1351b50cc4b8abcab128febf3a27d01af44697b3 (patch) | |
tree | 3acb5a84be4e3285edad3ecf772668253d14f71a /Documentation/devicetree/bindings/iio | |
parent | 5cb0789de1fe3b8be2d0ab9a78451a48ae07e74c (diff) |
dt-bindings: iio: afe: add binding for current-sense-shunt
An ADC is often used to measure other quantities indirectly. This
binding describe one cases, a current through a shunt resistor
measured by the voltage over it.
Signed-off-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'Documentation/devicetree/bindings/iio')
-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 000000000000..8e7b3e408a52 --- /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 mesaurement 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>; + }; + }; +}; |