On Fri, 8 Oct 2021 12:39:08 +0000 Mihail Chindris <mihail.chindris@xxxxxxxxxx> wrote: > Add documentation for ad3552r > > Signed-off-by: Mihail Chindris <mihail.chindris@xxxxxxxxxx> Hi Mihael, A few comments inline. Thanks, Jonathan > --- > .../bindings/iio/dac/adi,ad3552r.yaml | 199 ++++++++++++++++++ > 1 file changed, 199 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml > > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml > new file mode 100644 > index 000000000000..1086e935d330 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad3552r.yaml > @@ -0,0 +1,199 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +# Copyright 2020 Analog Devices Inc. > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/iio/dac/adi,ad3552r.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Analog Devices AD2552R DAC device driver > + > +maintainers: > + - Mihail Chindris <mihail.chindris@xxxxxxxxxx> > + > +description: | > + Bindings for the Analog Devices AD3552R DAC device. Datasheet can be Extra space before DAC, and doesn't mention the other supported part. One option to avoid a never ending list is "and similar." > + found here: > + https://www.analog.com/media/en/technical-documentation/data-sheets/ad3552r.pdf Good to have datasheet for the other part as well as I don't think this is a shared datasheet? > + > +properties: > + compatible: > + enum: > + - adi,ad3552r > + - adi,ad3542r Alphabetical order preferred. > + > + reg: > + maxItems: 1 > + > + spi-max-frequency: > + maximum: 30000000 > + > + reset-gpios: > + maxItems: 1 > + > + ldac-gpios: > + description: | > + If a LDAC gpio is specified it will generate a LDAC pulse each time the > + trigger handler sends data to the chip. Trigger handler is a linux concept. You need to write this more generically. Something like. "LDAC pin is used as a hardware trigger to update a set of DACs." > + maxItems: 1 > + > + vref-supply: > + description: > + The regulator to use as an external reference. If it does not exists the > + internal reference will be used. External reference must be 2.5V > + > + adi,vref-out-en: > + description: Vref I/O driven by internal vref to 2.5V. If not set, Vref pin > + will be floating. > + type: boolean > + > + adi,sdo-drive-strength: > + description: | > + Configure SDIO0 and SDIO1 strength levels: > + - 0: low SDO drive strength. > + - 1: medium low SDO drive strength. > + - 2: medium high SDO drive strength. > + - 3: high SDO drive strength > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2, 3] > + > +patternProperties: > + "^channel@([0-1])$": > + type: object > + description: Configurations of the DAC Channels > + properties: > + reg: > + description: Channel number > + enum: [0, 1] > + > + custom-output-range-config: Not a generic property so I think this needs an adi prefix. > + type: object > + description: Configuration of custom range when > + adi,output-range-microvolt is not present. > + The formulas for calculation the output voltages are > + Vout_fs = 2.5 + [(GainN + Offset/1024) * 2.5 * Rfbx * 1.03] > + Vout_zs = 2.5 - [(GainP + Offset/1024) * 2.5 * Rfbx * 1.03] > + properties: > + adi,gain-offset: > + description: Gain offset used in the above formula > + $ref: /schemas/types.yaml#/definitions/int32 > + maximum: 511 > + minimum: -511 > + adi,gain-scaling-p: > + description: | > + Scaling p: > + 0: 1.0 > + 1: 0.5 > + 2: 0.25 > + 3: 0.125 Given this is just a mapping to a simple set of values, could we just have the values or express it as 1/(2^GainP) in the equation above and call it adi,gain-scalling-inv-log2 or something like that? If we can avoid a mapping table that is always a nice to have > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2, 3] > + adi,gain-scaling-n: > + description: | > + Scaling p: > + 0: 1.0 > + 1: 0.5 > + 2: 0.25 > + 3: 0.125 > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [0, 1, 2, 3] > + adi,rfb-ohms: > + description: Feedback Resistor > + required: > + - adi,gain-offset > + - adi,gain-sacling-p > + - adi,gain-sacling-n > + - adi,rfb-ohms > + required: > + - reg > + > + oneOf: > + # If adi,output-range is missing, custom-output-range-config must be used adi,output-range-microvolt is missing... > + - required: > + - adi,output-range-microvolt > + - required: > + - custom-output-range-config > + > +allOf: > + - if: > + properties: > + compatible: > + contains: > + const: adi,ad3542r > + then: > + patternProperties: > + "^channel@([0-1])$": > + type: object > + properties: > + adi,output-range-microvolt: > + description: | > + Voltage output range of the channel as <minimum, maximum> > + Required connections: > + Rfb1x for: 0 to 2.5 V; 0 to 3V; 0 to 5 V; > + Rfb2x for: 0 to 10 V; 2.5 to 7.5V; -5 to 5 V; > + oneOf: > + - items: > + - const: 0 > + - enum: [2500000, 3000000, 5000000, 10000000] > + - items: > + - const: -2500000 > + - const: 7500000 > + - items: > + - const: -5000000 > + - const: 5000000 > + required: > + - adi,output-range-microvolt > + - if: > + properties: > + compatible: > + contains: > + const: adi,ad3552r > + then: > + patternProperties: > + "^channel@([0-1])$": > + type: object > + properties: > + adi,output-range-microvolt: | > + Voltage output range of the channel as <minimum, maximum> > + Required connections: > + Rfb1x for: 0 to 2.5 V; 0 to 5 V; > + Rfb2x for: 0 to 10 V; -5 to 5 V; > + Rfb4x for: -10 to 10V > + oneOf: > + - items: > + - const: 0 > + - enum: [2500000, 5000000, 10000000] > + - items: > + - const: -5000000 > + - const: 5000000 > + - items: > + - const: -10000000 > + - const: 10000000 > + > +required: > + - compatible > + - reg > + - spi-max-frequency > + > +additionalProperties: false > + > +examples: > + - | > + ad3552r { > + compatible = "adi,ad3552r"; > + reg = <0>; > + spi-max-frequency = <20000000>; > + channel@0 { > + reg = <0>; > + adi,output-range-microvolt = <0 10000000>; > + }; > + channel@1 { > + reg = <1>; > + custom-output-range-config { > + adi,gain-offset = <5>; > + adi,gain-scaling-p = <1>; > + adi,gain-scaling-n = <2>; > + adi,rfb-ohms = <1>; > + }; > + }; > + }; > +...
