On Tue, May 14, 2024 at 2:23 AM Dumitru Ceclan via B4 Relay <devnull+dumitru.ceclan.analog.com@xxxxxxxxxx> wrote: > > From: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx> > > Add support for: AD4111, AD4112, AD4114, AD4115, AD4116. > > AD411x family ADCs support a VCOM pin, dedicated for single-ended usage. > AD4111/AD4112 support current channels, usage is implemented by > specifying channel reg values bigger than 15. > > Signed-off-by: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx> > --- > .../devicetree/bindings/iio/adc/adi,ad7173.yaml | 118 ++++++++++++++++++++- > 1 file changed, 117 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > index ea6cfcd0aff4..6cc3514f5ed8 100644 > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > @@ -19,7 +19,18 @@ description: | > primarily for measurement of signals close to DC but also delivers > outstanding performance with input bandwidths out to ~10kHz. > > + Analog Devices AD411x ADC's: > + The AD411X family encompasses a series of low power, low noise, 24-bit, > + sigma-delta analog-to-digital converters that offer a versatile range of > + specifications. They integrate an analog front end suitable for processing > + fully differential/single-ended and bipolar voltage inputs. > + > Datasheets for supported chips: > + https://www.analog.com/media/en/technical-documentation/data-sheets/AD4111.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/AD4112.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/AD4114.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/AD4115.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/AD4116.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-4.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf > @@ -31,6 +42,11 @@ description: | > properties: > compatible: > enum: > + - adi,ad4111 > + - adi,ad4112 > + - adi,ad4114 > + - adi,ad4115 > + - adi,ad4116 > - adi,ad7172-2 > - adi,ad7172-4 > - adi,ad7173-8 > @@ -129,6 +145,31 @@ patternProperties: > maximum: 15 > > diff-channels: > + description: | > + For using current channels specify select the current inputs > + and enable the adi,current-channel property. > + > + Family AD411x supports a dedicated VCOM voltage input. Did you mean VINCOM? Searching the datasheets for "VCOM" comes up empty. > + To select it set the second channel to 16. > + (VIN2, VCOM) -> diff-channels = <2 16> Jonathan mentioned this in v1 with regard to the current inputs, but it applies here too. There is a new proposed single-channel property [1] that would be preferred when an input is used as a single-ended or pseudo-differential input (i.e. with VINCOM or ADCIN15). [1]: https://lore.kernel.org/linux-iio/20240514120222.56488-5-alisa.roman@xxxxxxxxxx/ > + > + There are special values that can be selected besides the voltage > + analog inputs: > + 21: REF+ > + 22: REF− > + Supported only by AD7172-2, AD7172-4, AD7175-2, AD7175-8, AD7177-2: > + 19: ((AVDD1 − AVSS)/5)+ > + 20: ((AVDD1 − AVSS)/5)− > + Supported only by AD4111, AD4112: > + 12: IIN3+ > + 11: IIN3− > + 13: IIN2+ > + 10: IIN2− > + 14: IIN1+ > + 9: IIN1− > + 15: IIN0+ > + 8: IIN0− I just made a late reply on v1 where Jonathan suggested that the current inputs are differential with a similar comment to this: It doesn't seem to me like current inputs are differential if they are only measuring one current. They take 2 pins because you need a way for current to come in and go back out, but the datasheet calls them single-ended inputs. > + > items: > minimum: 0 > maximum: 31 > @@ -154,6 +195,23 @@ patternProperties: > - avdd > default: refout-avss > > + adi,current-channel: > + description: | > + Signal that the selected inputs are current channels. > + Only available on AD4111 and AD4112. > + type: boolean > + > + adi,channel-type: > + description: > + Used to differentiate between different channel types as the device > + register configurations are the same for all usage types. > + $ref: /schemas/types.yaml#/definitions/string > + enum: > + - single-ended > + - pseudo-differential > + - differential > + default: differential > + As suggested above, we should soon have diff-channels and single-channel to differentiate between (fully) differential and single-ended. Do we actually need to differentiate between single-ended and pseudo-differential though? I think the AD4116 datasheet is the only one that uses both of those terms. It gives the examples that for "single-ended" ADCIN15 would be connected to AVSS and for "pseudo-differential" ADCIN15 would be connected to REFOUT (AVSS + 2.5 V). So the only difference seems to be if the voltage on ADCIN15 is == 0V or != 0V. To make this like other pseudo-differential chips we have done recently, it seems to me like we should have an adcin15-supply property to describe the ADCIN15 input. Then we could use that property to determine single-ended vs. pseudo-differential (if there actually is a need for that) and we wouldn't need the adi,channel-type property. > required: > - reg > - diff-channels > @@ -166,7 +224,6 @@ allOf: > - $ref: /schemas/spi/spi-peripheral-props.yaml# > > # Only ad7172-4, ad7173-8 and ad7175-8 support vref2 > - # Other models have [0-3] channel registers > - if: > properties: > compatible: > @@ -187,6 +244,37 @@ allOf: > - vref > - refout-avss > - avdd > + > + - if: > + properties: > + compatible: > + contains: > + enum: > + - adi,ad4114 > + - adi,ad4115 > + - adi,ad4116 > + - adi,ad7173-8 > + - adi,ad7175-8 > + then: > + patternProperties: > + "^channel@[0-9a-f]$": > + properties: > + reg: > + maximum: 15 As discussed recently in the the very similar ad719x bindings [2], we may have been misunderstanding this limit so far. 15 is a bit artificially low since input pins can be used more than once in different "channels". But that is really an issues with the existing bindings, not just this patch. [2]: https://lore.kernel.org/linux-iio/20240511122955.2372f56e@jic23-huawei/ > + > + - if: > + properties: > + compatible: > + contains: > + enum: > + - adi,ad7172-2 > + - adi,ad7175-2 > + - adi,ad7176-2 > + - adi,ad7177-2 > + then: > + patternProperties: > + "^channel@[0-9a-f]$": > + properties: > reg: > maximum: 3 > > @@ -210,6 +298,34 @@ allOf: > required: > - adi,reference-select > > + - if: > + properties: > + compatible: > + contains: > + enum: > + - adi,ad4111 > + - adi,ad4112 > + - adi,ad4114 > + - adi,ad4115 > + - adi,ad4116 > + then: > + properties: > + avdd2-supply: false > + > + - if: > + properties: > + compatible: > + not: > + contains: > + enum: > + - adi,ad4111 > + - adi,ad4112 > + then: > + patternProperties: > + "^channel@[0-9a-f]$": > + properties: > + adi,current-channel: false > + > - if: > anyOf: > - required: [clock-names] > > -- > 2.43.0 > >
