Re: [PATCH v4 4/5] dt-bindings: iio: Add sx9324 binding

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 20 Nov 2021 02:15:00 -0800
Gwendal Grignou <gwendal@chromium.org> wrote:

> Similar to SX9310, add biddings to setup sx9324 hardware properties.
> SX9324 is a little different, introduce 4 phases to be configured in 2
> pairs over 3 antennas.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>

No devicetree list or RobH in the to list so this won't get the review
from them that it needs.  Fix that for v5.

A few suggestions inline about consistency of property naming.
I don't have particularly strong views on that though so could be persuaded
what you have is better perhaps...

> ---
> Changes in v4:
> - Use const instead of single enum
> - Specify ph0-pin better
> - Recopy type information for phX-pin
> - Fix cut and paste errors.
> 
> Changes in v3:
> - Remove duplicate information.
> - Use intervals instead of enum.
> - Fix filter description.
> 
> Changes in v2:
> - Fix interrupt documentation wording.
> 
>  .../iio/proximity/semtech,sx9324.yaml         | 161 ++++++++++++++++++
>  1 file changed, 161 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/proximity/semtech,sx9324.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/proximity/semtech,sx9324.yaml b/Documentation/devicetree/bindings/iio/proximity/semtech,sx9324.yaml
> new file mode 100644
> index 00000000000000..70e4736fb1cc9a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/proximity/semtech,sx9324.yaml
> @@ -0,0 +1,161 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/proximity/semtech,sx9324.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Semtech's SX9324 capacitive proximity sensor
> +
> +maintainers:
> +  - Gwendal Grignou <gwendal@chromium.org>
> +  - Daniel Campello <campello@chromium.org>
> +
> +description: |
> +  Semtech's SX9324 proximity sensor.
> +
> +properties:
> +  compatible:
> +    const: semtech,sx9324
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    description:
> +      Generated by device to announce preceding read request has finished
> +      and data is available or that a close/far proximity event has happened.
> +    maxItems: 1
> +
> +  vdd-supply:
> +    description: Main power supply
> +
> +  svdd-supply:
> +    description: Host interface power supply
> +
> +  "#io-channel-cells":
> +    const: 1
> +
> +  semtech,ph0-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description: |
> +      Array of 3 entries. Index represent the id of the CS pin.
> +      Value indicates how each CS pin is used during phase 0.
> +      Each of the 3 pins have the following value -
> +      0 : unused (high impedance)
> +      1 : measured input
> +      2 : dynamic shield
> +      3 : grounded.
> +      For instance, CS0 measured, CS1 shield and CS2 ground is [1, 2, 3]
> +    items:
> +      enum: [ 0, 1, 2, 3 ]
> +    minItems: 3
> +    maxItems: 3
> +
> +  semtech,ph1-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description: Same as ph0-pin for phase 1.
> +    items:
> +      enum: [ 0, 1, 2, 3 ]
> +    minItems: 3
> +    maxItems: 3
> +
> +  semtech,ph2-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description: Same as ph0-pin for phase 2.
> +    items:
> +      enum: [ 0, 1, 2, 3 ]
> +    minItems: 3
> +    maxItems: 3
> +
> +  semtech,ph3-pin:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description: Same as ph0-pin for phase 3.
> +    items:
> +      enum: [ 0, 1, 2, 3 ]
> +    minItems: 3
> +    maxItems: 3
> +

One blank line only

> +
> +  semtech,resolution01:
Given phX naming above, maybe this should be

     semtech,ph01-resolution

etc for consistency?  Rob may have a better idea for what would be consistent
with other dt bindings here.

> +    $ref: /schemas/types.yaml#definitions/uint32
> +    enum: [8, 16, 32, 64, 128, 256, 512, 1024]
> +    description:
> +      Capacitance measurement resolution. For phase 0 and 1.
> +      Higher the number, higher the resolution.
> +    default: 128
> +
> +  semtech,resolution23:
> +    $ref: /schemas/types.yaml#definitions/uint32
> +    enum: [8, 16, 32, 64, 128, 256, 512, 1024]
> +    description:
> +      Capacitance measurement resolution. For phase 2 and 3
> +    default: 128
> +
> +  semtech,startup-sensor:

Perhaps include ph in the name to make it clear this is setting the initial
phase as per the descriptions above.

> +    $ref: /schemas/types.yaml#definitions/uint32
> +    enum: [0, 1, 2, 3]
> +    default: 0
> +    description: |
> +      Phase used for start-up proximity detection.
> +      It is used when we enable a phase to remove static offset and measure
> +      only capacitance changes introduced by the user.
> +
> +  semtech,proxraw-strength01:
> +    $ref: /schemas/types.yaml#definitions/uint32
> +    min: 0
> +    max: 7
> +    default: 1
> +    description:
> +      PROXRAW filter strength for phase 0 and 1. A value of 0 represents off,
> +      and other values represent 1-1/2^N.
> +
> +  semtech,proxraw-strength23:
> +    $ref: /schemas/types.yaml#definitions/uint32
> +    min: 0
> +    max: 7
> +    default: 1
> +    description:
> +      Same as proxraw-strength01, for phase 2 and 3.
> +
> +  semtech,avg-pos-strength:
> +    $ref: /schemas/types.yaml#definitions/uint32
> +    enum: [0, 16, 64, 128, 256, 512, 1024, 4294967295]
> +    default: 16
> +    description: |
> +      Average positive filter strength. A value of 0 represents off and
> +      UINT_MAX (4294967295) represents infinite. Other values
> +      represent 1-1/N.
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#io-channel-cells"
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      proximity@28 {
> +        compatible = "semtech,sx9324";
> +        reg = <0x28>;
> +        interrupt-parent = <&pio>;
> +        interrupts = <5 IRQ_TYPE_LEVEL_LOW 5>;
> +        vdd-supply = <&pp3300_a>;
> +        svdd-supply = <&pp1800_prox>;
> +        #io-channel-cells = <1>;
> +        semtech,ph0-pin = <1, 2, 3>;
> +        semtech,ph1-pin = <3, 2, 1>;
> +        semtech,ph2-pin = <1, 2, 3>;
> +        semtech,ph3-pin = <3, 2, 1>;
> +        semtech,resolution01 = 2;
> +        semtech,resolution23 = 2;
> +        semtech,startup-sensor = <1>;
> +        semtech,proxraw-strength01 = <2>;
> +        semtech,proxraw-strength23 = <2>;
> +        semtech,avg-pos-strength = <64>;
> +      };
> +    };