This patch adds the device tree binding documentation for the ad2s90 resolver-to-digital converter.
Signed-off-by: Matheus Tavares <matheus.bernard...@usp.br> --- .../bindings/iio/resolver/ad2s90.txt | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s90.txt diff --git a/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt new file mode 100644 index 000000000000..b42cc7752ffd --- /dev/null +++ b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt @@ -0,0 +1,26 @@ +Analog Devices AD2S90 Resolver-to-Digital Converter + +https://www.analog.com/en/products/ad2s90.html + +Required properties: + - compatible : should be "adi,ad2s90" + - reg : SPI chip select number for the device + - spi-max-frequency : set maximum clock frequency, must be 830000 + - spi-cpol and spi-cpha : must be defined to enable SPI mode 3 + +Note about max frequency: + Chip's max frequency, as specified in its datasheet, is 2Mhz. But a 600ns + delay is expected between the application of a logic LO to CS and the + application of SCLK, as also specified. And since the delay is not + implemented in the spi code, to satisfy it, SCLK's period should be at most + 2 * 600ns, so the max frequency should be 1 / (2 * 6e-7), which gives + roughly 830000Hz. + +Example: +resolver@0 { + compatible = "adi,ad2s90"; + reg = <0>; + spi-max-frequency = <830000>; + spi-cpol; + spi-cpha; +}; -- 2.18.0
