dt-bindings:iio:proximity: Add sx9324 binding

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>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220101203817.290512-5-gwendal@chromium.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/proximity/semtech,sx9324.yaml

+# 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
+
+
+  semtech,ph01-resolution:
+    $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,ph23-resolution:
+    $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:
+    $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,ph01-proxraw-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 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,ph23-proxraw-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 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,ph01-resolution = <256>;
+        semtech,ph23-resolution = <256>;
+        semtech,startup-sensor = <1>;
+        semtech,ph01-proxraw-strength = <2>;
+        semtech,ph23-proxraw-strength = <2>;
+        semtech,avg-pos-strength = <64>;
+      };
+    };