88 lines
2.8 KiB
YAML
88 lines
2.8 KiB
YAML
# SPDX-License-Identifier: GPL-2.0
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/iio/adc/adc.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: IIO Common Properties for ADC Channels
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maintainers:
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- Jonathan Cameron <jic23@kernel.org>
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description:
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A few properties are defined in a common way ADC channels.
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properties:
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$nodename:
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pattern: "^channel(@[0-9a-f]+)?$"
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description:
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A channel index should match reg.
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reg:
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maxItems: 1
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label:
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description: Unique name to identify which channel this is.
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bipolar:
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$ref: /schemas/types.yaml#/definitions/flag
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description: If provided, the channel is to be used in bipolar mode.
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diff-channels:
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$ref: /schemas/types.yaml#/definitions/uint32-array
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maxItems: 2
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minItems: 2
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description:
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Many ADCs have dual Muxes to allow different input pins to be routed
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to both the positive and negative inputs of a differential ADC.
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The first value specifies the positive input pin, the second
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specifies the negative input pin.
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There are also some ADCs, where the differential channel has dedicated
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positive and negative inputs which can be used to measure differential
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voltage levels. For those setups, this property can be configured with
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the 'reg' property for both inputs (i.e. diff-channels = <reg reg>).
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single-channel:
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$ref: /schemas/types.yaml#/definitions/uint32
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description:
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When devices combine single-ended and differential channels, allow the
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channel for a single element to be specified, independent of reg (as for
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differential channels). If this and diff-channels are not present reg
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shall be used instead.
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common-mode-channel:
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$ref: /schemas/types.yaml#/definitions/uint32
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description:
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Some ADCs have differential input pins that can be used to measure
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single-ended or pseudo-differential inputs. This property can be used
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in addition to single-channel to signal software that this channel is
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not differential but still specify two inputs.
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The input pair is specified by setting single-channel to the positive
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input pin and common-mode-channel to the negative pin.
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settling-time-us:
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description:
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Time between enabling the channel and first stable readings.
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oversampling-ratio:
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$ref: /schemas/types.yaml#/definitions/uint32
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description:
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Oversampling is used as replacement of or addition to the low-pass filter.
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In some cases, the desired filtering characteristics are a function the
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device design and can interact with other characteristics such as
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settling time.
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anyOf:
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- oneOf:
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- required:
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- reg
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- diff-channels
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- required:
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- reg
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- single-channel
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- required:
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- reg
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additionalProperties: true
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