[PATCH 2/2] dt-bindings: iio: adc: Add DT docs for AD7292

[PATCH 2/2] dt-bindings: iio: adc: Add DT docs for AD7292

[Marcelo Schmitt]

Add a device tree binding doc for AD7292 monitor and control system.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
---
 .../bindings/iio/adc/adi,ad7292.yaml          | 71 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 72 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
new file mode 100644
index 000000000000..16be9ea4194d
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD7292 10-Bit Monitor and Control System
+
+maintainers:
+  - Marcelo Schmitt <marcelo.schmitt1@gmail.com>
+
+description: |
+  Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs,
+  Temperature Sensor, and GPIOs
+
+  Specifications about the part can be found at:
+    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7292
+
+  reg:
+    maxItems: 1
+
+  vref-supply:
+    description: |
+      The regulator supply for ADC and DAC reference voltage.
+    maxItems: 1
+
+  spi-cpha:
+    description: |
+      See Documentation/devicetree/bindings/spi/spi-controller.yaml
+    maxItems: 1
+
+  diff-channels:
+    description: |
+      Empty property to tell whether VIN0 and VIN1 shall work as differential
+      inputs.
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    spi0 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ad7292: ad7292@0 {
+        compatible = "adi,ad7292";
+        reg = <0>;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        spi-max-frequency = <25000000>;
+        vref-supply = <&adc_vref>;
+        spi-cpha;
+        diff-channels;
+      };
+    }
diff --git a/MAINTAINERS b/MAINTAINERS
index e78317a5f4f1..5941cfc0d6f7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -819,6 +819,7 @@ L:	linux-iio@vger.kernel.org
 W:	http://ez.analog.com/community/linux-device-drivers
 S:	Supported
 F:	drivers/iio/adc/ad7292.c
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
 
 ANALOG DEVICES INC AD7606 DRIVER
 M:	Stefan Popa <stefan.popa@analog.com>
-- 
2.23.0

Re: [PATCH 2/2] dt-bindings: iio: adc: Add DT docs for AD7292

[Jonathan Cameron]

On Sun, 13 Oct 2019 11:13:47 -0300
Marcelo Schmitt <marcelo.schmitt1@gmail.com> wrote:

> Add a device tree binding doc for AD7292 monitor and control system.
> 
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
> ---
>  .../bindings/iio/adc/adi,ad7292.yaml          | 71 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 72 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> new file mode 100644
> index 000000000000..16be9ea4194d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD7292 10-Bit Monitor and Control System
> +
> +maintainers:
> +  - Marcelo Schmitt <marcelo.schmitt1@gmail.com>
> +
> +description: |
> +  Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs,
> +  Temperature Sensor, and GPIOs
> +
> +  Specifications about the part can be found at:
> +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad7292
> +
> +  reg:
> +    maxItems: 1
> +
> +  vref-supply:
> +    description: |
> +      The regulator supply for ADC and DAC reference voltage.
> +    maxItems: 1
> +
> +  spi-cpha:
> +    description: |
> +      See Documentation/devicetree/bindings/spi/spi-controller.yaml
> +    maxItems: 1
> +
> +  diff-channels:
> +    description: |
> +      Empty property to tell whether VIN0 and VIN1 shall work as differential
> +      inputs.
> +    maxItems: 1

This looks like a nice general interface, but really isn't as it only applies
to the first two channels.

Can you use the standard channel defintions
Documentation/devicetree/bindings/iio/adc.txt
to specify this?

It may seem overly complex, but it has the benefit of being generic.

Would be something like:

channel@0 {
	diff-channels = < 0 1 >
};
channel@2 {
};
vs all the channels being present, none set as diff.

Thanks,

Jonathan

> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +required:
> +  - compatible
> +  - reg
> +
> +examples:
> +  - |
> +    spi0 {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      ad7292: ad7292@0 {
> +        compatible = "adi,ad7292";
> +        reg = <0>;
> +
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        spi-max-frequency = <25000000>;
> +        vref-supply = <&adc_vref>;
> +        spi-cpha;
> +        diff-channels;
> +      };
> +    }
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e78317a5f4f1..5941cfc0d6f7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -819,6 +819,7 @@ L:	linux-iio@vger.kernel.org
>  W:	http://ez.analog.com/community/linux-device-drivers
>  S:	Supported
>  F:	drivers/iio/adc/ad7292.c
> +F:	Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
>  
>  ANALOG DEVICES INC AD7606 DRIVER
>  M:	Stefan Popa <stefan.popa@analog.com>