On Thu, 21 Sep 2023 09:43:42 -0500 David Lechner <dlechner@xxxxxxxxxxxx> wrote: > This adds new DeviceTree bindings for the Analog Devices, Inc. AD2S1210 > resolver-to-digital converter. > > Co-developed-by: Apelete Seketeli <aseketeli@xxxxxxxxxxxx> > Signed-off-by: Apelete Seketeli <aseketeli@xxxxxxxxxxxx> > Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx> We've become more fussy about it recently but for new bindings at least, we want to include all power supplies and mark them as required. A few other trivial things inline, Jonathan > --- > > v2 changes: > * Add Co-developed-by: > * Remove extraneous quotes on strings > * Remove extraneous pipe on some multi-line descriptions > > .../bindings/iio/resolver/adi,ad2s1210.yaml | 150 ++++++++++++++++++ > 1 file changed, 150 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/resolver/adi,ad2s1210.yaml > > diff --git a/Documentation/devicetree/bindings/iio/resolver/adi,ad2s1210.yaml b/Documentation/devicetree/bindings/iio/resolver/adi,ad2s1210.yaml > new file mode 100644 > index 000000000000..f55c9652cfb7 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/resolver/adi,ad2s1210.yaml > @@ -0,0 +1,150 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/iio/resolver/adi,ad2s1210.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Analog Devices AD2S1210 Resolver-to-Digital Converter > + > +maintainers: > + - Michael Hennerich <michael.hennerich@xxxxxxxxxx> > + > +description: | > + The AD2S1210 is a complete 10-bit to 16-bit resolution tracking > + resolver-to-digital converter, integrating an on-board programmable > + sinusoidal oscillator that provides sine wave excitation for > + resolvers. > + > + The AD2S1210 allows the user to read the angular position or the > + angular velocity data directly from the parallel outputs or through > + the serial interface. > + > + A1 A0 Result Should say what A0 and A1 are. It's down below but seems odd that it is here for RES0 and RES1 but not the A1 and A0 signals. > + 0 0 Normal mode - position output > + 0 1 Normal mode - velocity output > + 1 0 Reserved > + 1 1 Configuration mode > + > + In normal mode, the resolution of the digital output is selected using > + the RES0 and RES1 input pins. In configuration mode, the resolution is > + selected by setting the RES0 and RES1 bits in the control register. > + > + RES1 RES0 Resolution (Bits) > + 0 0 10 > + 0 1 12 > + 1 0 14 > + 1 1 16 > + > + Note on SPI connections: The CS line on the AD2S1210 should hard-wired to > + logic low and the WR/FSYNC line on the AD2S1210 should be connected to the > + SPI CSn output of the SPI controller. That is impressively random ;) Good to call it out. > + > + Datasheet: > + https://www.analog.com/media/en/technical-documentation/data-sheets/ad2s1210.pdf > + > +properties: > + compatible: > + const: adi,ad2s1210 > + > + reg: > + maxItems: 1 > + > + spi-max-frequency: > + maximum: 25000000 > + > + spi-cpha: true > + > + clocks: > + maxItems: 1 > + description: External oscillator clock (CLKIN). > + > + reset-gpios: > + description: > + GPIO connected to the /RESET pin. As the line needs to be low for the > + reset to be active, it should be configured as GPIO_ACTIVE_LOW. > + maxItems: 1 > + > + sample-gpios: > + description: > + GPIO connected to the /SAMPLE pin. As the line needs to be low to trigger > + a sample, it should be configured as GPIO_ACTIVE_LOW. > + maxItems: 1 > + > + mode-gpios: > + description: > + GPIO lines connected to the A0 and A1 pins. These pins select the data > + transfer mode. > + minItems: 2 > + maxItems: 2 > + > + resolution-gpios: > + description: > + GPIO lines connected to the RES0 and RES1 pins. These pins select the > + resolution of the digital output. If omitted, it is assumed that the > + RES0 and RES1 pins are hard-wired to match the assigned-resolution-bits > + property. > + minItems: 2 > + maxItems: 2 > + > + fault-gpios: > + description: > + GPIO lines connected to the LOT and DOS pins. These pins combined indicate > + the type of fault present, if any. As these pins a pulled low to indicate > + a fault condition, they should be configured as GPIO_ACTIVE_LOW. What if someone is being odd and connected only 1 of them? It's annoying how often people run out of pins and do things like this. > + minItems: 2 > + maxItems: 2 > + > + adi,fixed-mode: > + description: > + This is used to indicate the selected mode if A0 and A1 are hard-wired > + instead of connected to GPIOS (i.e. mode-gpios is omitted). > + $ref: /schemas/types.yaml#/definitions/string > + enum: [config, velocity, position] > + > + assigned-resolution-bits: > + description: > + Resolution of the digital output required by the application. This > + determines the precision of the angle and/or the maximum speed that can > + be measured. If resolution-gpios is omitted, it is assumed that RES0 and > + RES1 are hard-wired to match this value. > + enum: [10, 12, 14, 16] Good description as this was non obvious. > + > +required: > + - compatible > + - reg > + - spi-cpha > + - clocks > + - sample-gpios > + - assigned-resolution-bits > + > +oneOf: > + - required: > + - mode-gpios > + - required: > + - adi,fixed-mode I think this allows for both. It's fiddlier to exclude that but would be a nice to have perhaps rather than relying on text above that says 'don't do it'. > + > +allOf: > + - $ref: /schemas/spi/spi-peripheral-props.yaml# > + > +unevaluatedProperties: false > + > +examples: > + - | > + #include <dt-bindings/gpio/gpio.h> > + > + spi { > + #address-cells = <1>; > + #size-cells = <0>; > + > + resolver@0 { > + compatible = "adi,ad2s1210"; > + reg = <0>; > + spi-max-frequency = <20000000>; > + spi-cpha; > + clocks = <&ext_osc>; > + sample-gpios = <&gpio0 90 GPIO_ACTIVE_LOW>; > + mode-gpios = <&gpio0 86 0>, <&gpio0 87 0>; > + resolution-gpios = <&gpio0 88 0>, <&gpio0 89 0>; > + assigned-resolution-bits = <16>; > + }; > + };
