RE: [PATCH v1 1/2] bindings: iio: adc: Add StarFive JHB100 SARADC

[Xingyu Wu]

On 2026/5/19 00:24, Conor Dooley wrote:
> 
> On Mon, May 18, 2026 at 04:18:51PM +0800, Xingyu Wu wrote:
> > Add the new documentation of SAR-ADC for the StarFive JHB100 SoC.
> >
> > Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> > ---
> >  .../iio/adc/starfive,jhb100-saradc.yaml       | 62 +++++++++++++++++++
> >  1 file changed, 62 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/iio/adc/starfive,jhb100-saradc.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/iio/adc/starfive,jhb100-saradc.yam
> > l
> > b/Documentation/devicetree/bindings/iio/adc/starfive,jhb100-saradc.yam
> > l
> > new file mode 100644
> > index 000000000000..ba8e19b72ad7
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/starfive,jhb100-saradc
> > +++ .yaml
> > @@ -0,0 +1,62 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id:
> > +http://devicetree.org/schemas/iio/adc/starfive,jhb100-saradc.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Successive Approximation Register (SAR) A/D converter for the
> > +StarFive JHB100 SoC
> > +
> > +maintainers:
> > +  - Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
> > +
> > +properties:
> > +  compatible:
> > +    const: starfive,jhb100-saradc
> > +
> > +  reg:
> > +    maxItem: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  resets:
> > +    maxItems: 2
> > +
> > +  "#io-channel-cells":
> > +    const: 1
> > +
> > +  upper-bound-mv:
> > +    description: The upper bound voltage value of the monitor.
> > +    $ref: /schemas/types.yaml#/definitions/uint16
> > +
> > +  lower-bound-mv:
> > +    description: The lower bound voltage value of the monitor.
> > +    $ref: /schemas/types.yaml#/definitions/uint16
> > +
> > +  scan-freq:
> > +    description: Number of the scan cycle interval.
> > +    $ref: /schemas/types.yaml#/definitions/uint16
> 
> Can you explain why any of these three properties are something that should be in
> the devicetree rather than software controlled?

My intention is to be able to obtain the initial values from the devicetree during probe and preset them.
Do I need to drop them and just set them through sysfs?

> 
> How are the bounds calculated?

The measurement range of this ADC hardware is from 0 to 1800 mV. This set value cannot exceed it. This explanation will be added later.

Best regards,
Xingyu Wu