Re: [PATCH v4 4/5] dt-bindings: iio: adc: ad7949: add per channel reference
From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-07-31 15:00:11
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linux-iio, lkml
On Tue, 27 Jul 2021 19:29:05 -0400 Liam Beguin [off-list ref] wrote:
From: Liam Beguin <redacted> Add bindings documentation describing per channel reference voltage selection. This adds the adi,internal-ref-microvolt property, and child nodes for each channel. This is required to properly configure the ADC sample request based on which reference source should be used for the calculation. Signed-off-by: Liam Beguin <redacted>
I'm fine with this, but as it's a bit unusual, definitely want to give a little more time for Rob and others to take a look. Jonathan
quoted hunk ↗ jump to hunk
--- .../bindings/iio/adc/adi,ad7949.yaml | 69 +++++++++++++++++-- 1 file changed, 65 insertions(+), 4 deletions(-)diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml index 9b56bd4d5510..893f72b8081e 100644 --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7949.yaml@@ -26,19 +26,63 @@ properties: reg: maxItems: 1 + vrefin-supply: + description: + Buffered ADC reference voltage supply. + vref-supply: description: - ADC reference voltage supply + Unbuffered ADC reference voltage supply. spi-max-frequency: true - "#io-channel-cells": + '#io-channel-cells': const: 1 + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + required: - compatible - reg - - vref-supply + +patternProperties: + '^channel@([0-7])$': + type: object + description: | + Represents the external channels which are connected to the ADC. + + properties: + reg: + description: | + The channel number. + Up to 4 channels, numbered from 0 to 3 for adi,ad7682. + Up to 8 channels, numbered from 0 to 7 for adi,ad7689 and adi,ad7949. + items: + minimum: 0 + maximum: 7 + + adi,internal-ref-microvolt: + description: | + Internal reference voltage selection in microvolts. + + If no internal reference is specified, the channel will default to the + external reference defined by vrefin-supply (or vref-supply). + vrefin-supply will take precedence over vref-supply if both are defined. + + If no supplies are defined, the reference selection will default to + 4096mV internal reference. + + enum: [2500000, 4096000] + default: 4096000 + + required: + - reg + + additionalProperties: false additionalProperties: false@@ -49,9 +93,26 @@ examples: #size-cells = <0>; adc@0 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "adi,ad7949"; reg = <0>; - vref-supply = <&vdd_supply>; + vrefin-supply = <&vdd_supply>; + + channel@0 { + adi,internal-ref-microvolt = <4096000>; + reg = <0>; + }; + + channel@1 { + adi,internal-ref-microvolt = <2500000>; + reg = <1>; + }; + + channel@2 { + reg = <2>; + }; }; }; ...