On Sat, 2020-03-21 at 21:35 +0200, Alexandru Lazar wrote: > Hi Jonathan, > > > Please consider also adding the vdd-supply. > > It's not really required, but if you don't add it from the start > > chances are high that at some point someone else will need to > > add it. > > Sorry if I'm missing something obvious here -- what vdd-supply is > that? Are you thinking of the regulator used for the ADC's reference > voltage? That's already there (vref-supply). > > Or did you mean I should add a definition for the regulator output used > for the device's Vdd input (i.e. the positive supply voltage)? Needless > to say, I'm happy to add it if you think it's a good idea. It's just I > don't think I've seen it in other drivers (except maybe ad7192?) -- so I > figured I'd ask before sending a botched v5. > Yep. Jonathan refers to Vdd input/pin [on the chip] which is different from Vref [REF pin]. Not all drivers define Vdd. Some call it AVdd. You can check via: git grep -i vdd | cut -d: -f1 | sort | uniq -c in the drivers/iio folder It's an idea to add it, and that can give control to the driver to power-up the ADC, by defining a regulator [vdd-supply] in the device-tree. Maybe it could be interesting to move this to the IIO core as an option-flag. [But that's another discussion] > Best regards, > Alex > > > One trivial thing inline. Otherwise looks good to me. > > > > > --- > > > .../bindings/iio/adc/maxim,max1241.yaml | 61 +++++++++++++++++++ > > > 1 file changed, 61 insertions(+) > > > create mode 100644 > > > Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > > > > > diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > > b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > > new file mode 100644 > > > index 000000000000..de41d422ce3b > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml > > > @@ -0,0 +1,61 @@ > > > +# SPDX-License-Identifier: GPL-2.0 > > > +# Copyright 2020 Ioan-Alexandru Lazar > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Maxim MAX1241 12-bit, single-channel analog to digital converter > > > + > > > +maintainers: > > > + - Ioan-Alexandru Lazar <alazar@xxxxxxxxxxxxx> > > > + > > > +description: | > > > + Bindings for the max1241 12-bit, single-channel ADC device. This > > > + driver supports voltage reading and can optionally be configured for > > > > Driver shouldn't be mentioned in the binding. It's a description of the > > hardware only. > > > > > + power-down mode operation. The datasheet can be found at: > > > + https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf > > > + > > > +properties: > > > + compatible: > > > + enum: > > > + - maxim,max1241 > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + vref-supply: > > > + description: > > > + Device tree identifier of the regulator that provides the external > > > + reference voltage. > > > + maxItems: 1 > > > + > > > + shdn-gpios: > > > + description: > > > + GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If > > > + specified, the /SHDN pin will be asserted between conversions, > > > + thus enabling power-down mode. > > > + maxItems: 1 > > > + > > > +required: > > > + - compatible > > > + - reg > > > + - vref-supply > > > + > > > +examples: > > > + - | > > > + #include <dt-bindings/gpio/gpio.h> > > > + spi0 { > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + adc@0 { > > > + compatible = "maxim,max1241"; > > > + reg = <0>; > > > + vref-supply = <&vdd_3v3_reg>; > > > + spi-max-frequency = <1000000>; > > > + shdn-gpios = <&gpio 26 1>; > > > + }; > > > + }; > > > + > > > +
