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

[Mike Looijmans <mike.looijmans@topic.nl>]

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@microchip.com/
> 
> 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@topic.nl>
>>
>> ---
>>
>>   .../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@topic.nl>
>> +
>> +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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