> -----Original Message----- > From: Jonathan Cameron <jic23@xxxxxxxxxx> > Sent: Sunday, 10 October 2021 17:49 > To: Chindris, Mihail <Mihail.Chindris@xxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-iio@xxxxxxxxxxxxxxx; > lars@xxxxxxxxxx; Hennerich, Michael <Michael.Hennerich@xxxxxxxxxx>; > Sa, Nuno <Nuno.Sa@xxxxxxxxxx>; Bogdan, Dragos > <Dragos.Bogdan@xxxxxxxxxx>; alexandru.ardelean@xxxxxxxxxx; Mark > Brown <broonie@xxxxxxxxxx> > Subject: Re: [PATCH v2 1/2] dt-bindings: iio: dac: Add adi,ad3552r.yaml > > 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 > > +--- > > +$id: > > +https://urldefense.com/v3/__http://devicetree.org/schemas/iio/dac/adi > > > +,ad3552r.yaml*__;Iw!!A3Ni8CS0y2Y!pqvd1NyV8G8KXIcfAtV1erPpylxLUGXD > 1Tx5 > > +UoK2MMNNgQpv5RSyFb6NQDSL0sEuJOI$ > > +$schema: > > +https://urldefense.com/v3/__http://devicetree.org/meta- > schemas/core.y > > > +aml*__;Iw!!A3Ni8CS0y2Y!pqvd1NyV8G8KXIcfAtV1erPpylxLUGXD1Tx5UoK2 > MMNNgQ > > +pv5RSyFb6NQDSL3G5680U$ > > + > > +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. I tried with adi prefix but I get weird errors while running dt_binding_check for properties with adi prefix and with type:object Do you have any suggestion for this issues? > > + 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>; > > + }; > > + }; > > + }; > > +...
