Re: [PATCH 1/2] dt-bindings: iio: adc: Add microchip MCP3561/2/4R devices

[Mike Looijmans]

On 23-05-2023 18:00, Conor Dooley wrote:
> On Tue, May 23, 2023 at 02:43:53PM +0200, Mike Looijmans wrote:
> > The MCP3564R is a 24-bit ADC with 8 multiplexed inputs. The MCP3561R is
> > the same device with 2 inputs, the MCP3562R has 4 inputs. The device
> > contains one ADC and a multiplexer to select the inputs to the ADC.
>
> My favourite - nothing for a while & then two come along almost at once!
> https://lore.kernel.org/all/20230519160145.44208-2-marius.cristea@xxxxxxxxxxxxx/
>
> Would you mind, since he seems to have sent it first, reviewing his
> series?

Oh, damn. Want to, just have to figure out how I can reply to mails that I 
never got (had delivery turned off for linux-iio). Tips welcome (just send to 
me personally...)


I see lots of similarities, but also some differences. The main being that I 
aimed at being able to add buffer support (continuous sampling, IRQ driven).


Also spotted a minor bug in Marius' driver, so yeah, I definitely want to 
comment...



> Cheers,
> Conor.
>
> > Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
> >
> > ---
> >
> >   .../bindings/iio/adc/microchip,mcp356xr.yaml  | 84 +++++++++++++++++++
> >   1 file changed, 84 insertions(+)
> >   create mode 100644 Documentation/devicetree/bindings/iio/adc/microchip,mcp356xr.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,mcp356xr.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,mcp356xr.yaml
> > new file mode 100644
> > index 000000000000..4aef166894c8
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/microchip,mcp356xr.yaml
> > @@ -0,0 +1,84 @@
> > +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
> > +# Copyright 2023 Topic Embedded Systems
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/adc/microchip,mcp356xr.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Microchip MCP3561R/MCP3562R/MCP3564R ADC
> > +
> > +maintainers:
> > +  - Mike Looijmans <mike.looijmans@xxxxxxxx>
> > +
> > +description: |
> > +  Bindings for the Microchip MCP356xR 8-channel ADC devices. Datasheet and info
> > +  can be found at: https://www.microchip.com/en-us/product/MCP3564R
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - microchip,mcp3561r
> > +      - microchip,mcp3562r
> > +      - microchip,mcp3564r
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  spi-max-frequency:
> > +    maximum: 20000000
> > +
> > +  clocks:
> > +    description:
> > +      Phandle and clock identifier for external sampling clock.
> > +      If not specified, the internal crystal oscillator will be used.
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    description: IRQ line of the ADC
> > +    maxItems: 1
> > +
> > +  drive-open-drain:
> > +    description:
> > +      Whether to drive the IRQ signal as push-pull (default) or open-drain. Note
> > +      that the device requires this pin to become "high", otherwise it will stop
> > +      converting.
> > +    type: boolean
> > +
> > +  microchip,device-addr:
> > +    description: Device address when multiple chips are present on the same bus.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    enum: [0, 1, 2, 3]
> > +    default: 1
> > +
> > +  vref-supply:
> > +    description:
> > +      Phandle to the external reference voltage supply.
> > +      If not specified, the internal voltage reference (2.4V) will be used.
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +
> > +allOf:
> > +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    spi {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      adc@0 {
> > +        compatible = "microchip,mcp3564r";
> > +        reg = <0>;
> > +        interrupt-parent = <&gpio5>;
> > +        interrupts = <15 2>;
> > +        spi-max-frequency = <20000000>;
> > +        microchip,device-addr = <1>;
> > +        vref-supply = <&vref_reg>;
> > +        clocks = <&xtal>;
> > +      };
> > +    };
> > --
> > 2.17.1

--
Mike Looijmans
System Expert

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