| Message ID | 20181124002312.6923-5-matheus.bernardino@usp.br (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | staging:iio:ad2s90: Add dt support and move out of staging | expand |
On Fri, 23 Nov 2018 22:23:09 -0200, Matheus Tavares wrote: > This patch adds the device tree binding documentation for the ad2s90 > resolver-to-digital converter. > > Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> > --- > Changes in v3: > - Added reference to spi-bus documentation after spi properties, as > suggested by Alexandru Ardelean. > > Changes in v2: > - Rewritten 'spi-cpol and spi-cpha' item to say that the device can > work in either mode (0,0) or (1,1) and explain how they should be > specified in DT. > > .../bindings/iio/resolver/ad2s90.txt | 31 +++++++++++++++++++ > 1 file changed, 31 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s90.txt > Reviewed-by: Rob Herring <robh@kernel.org>
On Mon, 26 Nov 2018 19:52:27 -0600 Rob Herring <robh@kernel.org> wrote: > On Fri, 23 Nov 2018 22:23:09 -0200, Matheus Tavares wrote: > > This patch adds the device tree binding documentation for the ad2s90 > > resolver-to-digital converter. > > > > Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> > > --- > > Changes in v3: > > - Added reference to spi-bus documentation after spi properties, as > > suggested by Alexandru Ardelean. > > > > Changes in v2: > > - Rewritten 'spi-cpol and spi-cpha' item to say that the device can > > work in either mode (0,0) or (1,1) and explain how they should be > > specified in DT. > > > > .../bindings/iio/resolver/ad2s90.txt | 31 +++++++++++++++++++ > > 1 file changed, 31 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s90.txt > > > > Reviewed-by: Rob Herring <robh@kernel.org> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan
diff --git a/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt new file mode 100644 index 000000000000..477d41fa6467 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/resolver/ad2s90.txt @@ -0,0 +1,31 @@ +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: + Either SPI mode (0,0) or (1,1) must be used, so specify none or both of + spi-cpha, spi-cpol. + +See for more details: + Documentation/devicetree/bindings/spi/spi-bus.txt + +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; +};
This patch adds the device tree binding documentation for the ad2s90 resolver-to-digital converter. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> --- Changes in v3: - Added reference to spi-bus documentation after spi properties, as suggested by Alexandru Ardelean. Changes in v2: - Rewritten 'spi-cpol and spi-cpha' item to say that the device can work in either mode (0,0) or (1,1) and explain how they should be specified in DT. .../bindings/iio/resolver/ad2s90.txt | 31 +++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s90.txt