dt-bindings: Add bindings for Azoteq IQS620A/621/622/624/625

This patch adds device tree bindings for the Azoteq IQS620A, IQS621,
IQS622, IQS624 and IQS625 multi-function sensors.

A total of three bindings are presented (one MFD and two child nodes);
they are submitted as a single patch because the child node bindings
have no meaning in the absence of the MFD binding.
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/input/iqs62x-keys.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/iqs62x-keys.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Azoteq IQS620A/621/622/624/625 Keys and Switches
+
+maintainers:
+  - Jeff LaBundy <jeff@labundy.com>
+
+description: |
+  The Azoteq IQS620A, IQS621, IQS622, IQS624 and IQS625 multi-function sensors
+  feature a variety of self-capacitive, mutual-inductive and Hall-effect sens-
+  ing capabilities that can facilitate a variety of contactless key and switch
+  applications.
+
+  These functions are collectively represented by a "keys" child node from the
+  parent MFD driver. See Documentation/devicetree/bindings/mfd/iqs62x.yaml for
+  further details and examples. Sensor hardware configuration (self-capacitive
+  vs. mutual-inductive, etc.) is selected based on the device's firmware.
+
+properties:
+  compatible:
+    enum:
+      - azoteq,iqs620a-keys
+      - azoteq,iqs621-keys
+      - azoteq,iqs622-keys
+      - azoteq,iqs624-keys
+      - azoteq,iqs625-keys
+
+  linux,keycodes:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+      - minItems: 1
+        maxItems: 16
+    description: |
+      Specifies the numeric keycodes associated with each available touch or
+      proximity event according to the following table. An 'x' indicates the
+      event is supported for a given device. Specify 0 for unused events.
+
+      -------------------------------------------------------------------------
+      | #  | Event              | IQS620A | IQS621 | IQS622 | IQS624 | IQS625 |
+      -------------------------------------------------------------------------
+      | 0  | CH0 Touch          |    x    |    x   |    x   |    x   |    x   |
+      |    | Antenna 1 Touch*   |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 1  | CH0 Proximity      |    x    |    x   |    x   |    x   |    x   |
+      |    | Antenna 1 Prox.*   |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 2  | CH1 Touch          |    x    |    x   |    x   |    x   |    x   |
+      |    | Ant. 1 Deep Touch* |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 3  | CH1 Proximity      |    x    |    x   |    x   |    x   |    x   |
+      -------------------------------------------------------------------------
+      | 4  | CH2 Touch          |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 5  | CH2 Proximity      |    x    |        |        |        |        |
+      |    | Antenna 2 Prox.*   |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 6  | Metal (+) Touch**  |    x    |    x   |        |        |        |
+      |    | Ant. 2 Deep Touch* |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 7  | Metal (+) Prox.**  |    x    |    x   |        |        |        |
+      |    | Antenna 2 Touch*   |    x    |        |        |        |        |
+      -------------------------------------------------------------------------
+      | 8  | Metal (-) Touch**  |    x    |    x   |        |        |        |
+      -------------------------------------------------------------------------
+      | 9  | Metal (-) Prox.**  |    x    |    x   |        |        |        |
+      -------------------------------------------------------------------------
+      | 10 | SAR Active***      |    x    |        |    x   |        |        |
+      -------------------------------------------------------------------------
+      | 11 | SAR Quick Rel.***  |    x    |        |    x   |        |        |
+      -------------------------------------------------------------------------
+      | 12 | SAR Movement***    |    x    |        |    x   |        |        |
+      -------------------------------------------------------------------------
+      | 13 | SAR Filter Halt*** |    x    |        |    x   |        |        |
+      -------------------------------------------------------------------------
+      | 14 | Wheel Up           |         |        |        |    x   |        |
+      -------------------------------------------------------------------------
+      | 15 | Wheel Down         |         |        |        |    x   |        |
+      -------------------------------------------------------------------------
+      *   Two-channel SAR. Replaces CH0-2 plus metal touch and proximity events
+          if enabled via firmware.
+      **  "+" and "-" refer to the polarity of a channel's delta (LTA - counts),
+          where "LTA" is defined as the channel's long-term average.
+      *** One-channel SAR. Replaces CH0-2 touch and proximity events if enabled
+          via firmware.
+
+patternProperties:
+  "^hall-switch-(north|south)$":
+    type: object
+    description:
+      Represents north/south-field Hall-effect sensor touch or proximity
+      events. Note that north/south-field orientation is reversed on the
+      IQS620AXzCSR device due to its flip-chip package.
+
+    properties:
+      linux,code:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Numeric switch code associated with the event.
+
+      azoteq,use-prox:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          If present, specifies that Hall-effect sensor reporting should
+          use the device's wide-range proximity threshold instead of its
+          close-range touch threshold (default).
+
+    required:
+      - linux,code
+
+    additionalProperties: false
+
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - azoteq,iqs624-keys
+          - azoteq,iqs625-keys
+then:
+  patternProperties:
+    "^hall-switch-(north|south)$": false
+
+required:
+  - compatible
+  - linux,keycodes
+
+additionalProperties: false
+
+...

Documentation/devicetree/bindings/mfd/iqs62x.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/iqs62x.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Azoteq IQS620A/621/622/624/625 Multi-Function Sensors
+
+maintainers:
+  - Jeff LaBundy <jeff@labundy.com>
+
+description: |
+  The Azoteq IQS620A, IQS621, IQS622, IQS624 and IQS625 multi-function sensors
+  integrate multiple sensing technologies in a single package.
+
+  Link to datasheets: https://www.azoteq.com/
+
+properties:
+  compatible:
+    enum:
+      - azoteq,iqs620a
+      - azoteq,iqs621
+      - azoteq,iqs622
+      - azoteq,iqs624
+      - azoteq,iqs625
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  firmware-name:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      Specifies the name of the calibration and configuration file selected by
+      the driver. If this property is omitted, the name is chosen based on the
+      device name with ".bin" as the extension (e.g. iqs620a.bin for IQS620A).
+
+  keys:
+    $ref: ../input/iqs62x-keys.yaml
+
+  pwm:
+    $ref: ../pwm/iqs620a-pwm.yaml
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    /*
+     * Dual capacitive buttons with proximity-activated function, unipolar lid
+     * switch and panel-mounted LED.
+     */
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            iqs620a@44 {
+                    compatible = "azoteq,iqs620a";
+                    reg = <0x44>;
+                    interrupt-parent = <&gpio>;
+                    interrupts = <17 IRQ_TYPE_LEVEL_LOW>;
+
+                    keys {
+                            compatible = "azoteq,iqs620a-keys";
+
+                            linux,keycodes = <KEY_SELECT>,
+                                             <KEY_MENU>,
+                                             <KEY_OK>,
+                                             <KEY_MENU>;
+
+                            hall-switch-south {
+                                    linux,code = <SW_LID>;
+                                    azoteq,use-prox;
+                            };
+                    };
+
+                    iqs620a_pwm: pwm {
+                            compatible = "azoteq,iqs620a-pwm";
+                            #pwm-cells = <2>;
+                    };
+            };
+    };
+
+    pwmleds {
+            compatible = "pwm-leds";
+
+            panel {
+                    pwms = <&iqs620a_pwm 0 1000000>;
+                    max-brightness = <255>;
+            };
+    };
+
+  - |
+    /* Single inductive button with bipolar dock/tablet-mode switch. */
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            iqs620a@44 {
+                    compatible = "azoteq,iqs620a";
+                    reg = <0x44>;
+                    interrupt-parent = <&gpio>;
+                    interrupts = <17 IRQ_TYPE_LEVEL_LOW>;
+
+                    firmware-name = "iqs620a_coil.bin";
+
+                    keys {
+                            compatible = "azoteq,iqs620a-keys";
+
+                            linux,keycodes = <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <KEY_MUTE>;
+
+                            hall-switch-north {
+                                    linux,code = <SW_DOCK>;
+                            };
+
+                            hall-switch-south {
+                                    linux,code = <SW_TABLET_MODE>;
+                            };
+                    };
+            };
+    };
+
+  - |
+    /* Dual capacitive buttons with volume knob. */
+    #include <dt-bindings/input/input.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            iqs624@44 {
+                    compatible = "azoteq,iqs624";
+                    reg = <0x44>;
+                    interrupt-parent = <&gpio>;
+                    interrupts = <17 IRQ_TYPE_LEVEL_LOW>;
+
+                    keys {
+                            compatible = "azoteq,iqs624-keys";
+
+                            linux,keycodes = <BTN_0>,
+                                             <0>,
+                                             <BTN_1>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <0>,
+                                             <KEY_VOLUMEUP>,
+                                             <KEY_VOLUMEDOWN>;
+                    };
+            };
+    };
+
+...

Documentation/devicetree/bindings/pwm/iqs620a-pwm.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/iqs620a-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Azoteq IQS620A PWM Generator
+
+maintainers:
+  - Jeff LaBundy <jeff@labundy.com>
+
+description: |
+  The Azoteq IQS620A multi-function sensor generates a fixed-frequency PWM
+  output represented by a "pwm" child node from the parent MFD driver. See
+  Documentation/devicetree/bindings/mfd/iqs62x.yaml for further details as
+  well as an example.
+
+properties:
+  compatible:
+    enum:
+      - azoteq,iqs620a-pwm
+
+  "#pwm-cells":
+    const: 2
+
+required:
+  - compatible
+  - "#pwm-cells"
+
+additionalProperties: false
+
+...