[PATCH v3 09/11] dt-bindings: input: Document hid-over-spi DT schema

[Jingyuan Liang <jingyliang@chromium.org>]

Documentation describes the required and optional properties for
implementing Device Tree for a Microsoft G6 Touch Digitizer that
supports HID over SPI Protocol 1.0 specification.

The properties are common to HID over SPI.

Signed-off-by: Dmitry Antipov <dmanti@microsoft.com>
Signed-off-by: Jarrett Schultz <jaschultz@microsoft.com>
Signed-off-by: Jingyuan Liang <jingyliang@chromium.org>
---
 .../devicetree/bindings/input/hid-over-spi.yaml    | 126 +++++++++++++++++++++
 1 file changed, 126 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/hid-over-spi.yaml b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
new file mode 100644
index 000000000000..d1b0a2e26c32
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/hid-over-spi.yaml
@@ -0,0 +1,126 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/hid-over-spi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: HID over SPI Devices
+
+maintainers:
+  - Benjamin Tissoires <benjamin.tissoires@redhat.com>
+  - Jiri Kosina <jkosina@suse.cz>
+
+description: |+
+  HID over SPI provides support for various Human Interface Devices over the
+  SPI bus. These devices can be for example touchpads, keyboards, touch screens
+  or sensors.
+
+  The specification has been written by Microsoft and is currently available
+  here: https://www.microsoft.com/en-us/download/details.aspx?id=103325
+
+  If this binding is used, the kernel module spi-hid will handle the
+  communication with the device and the generic hid core layer will handle the
+  protocol.
+
+allOf:
+  - $ref: /schemas/input/touchscreen/touchscreen.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - microsoft,g6-touch-digitizer
+          - const: hid-over-spi
+      - description: Just "hid-over-spi" alone is allowed, but not recommended.
+        const: hid-over-spi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+    description:
+      GPIO specifier for the digitizer's reset pin (active low). The line must
+      be flagged with GPIO_ACTIVE_LOW.
+
+  vdd-supply:
+    description:
+      Regulator for the VDD supply voltage.
+
+  input-report-header-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+      A value to be included in the Read Approval packet, listing an address of
+      the input report header to be put on the SPI bus. This address has 24
+      bits.
+
+  input-report-body-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+      A value to be included in the Read Approval packet, listing an address of
+      the input report body to be put on the SPI bus. This address has 24 bits.
+
+  output-report-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 0xffffff
+    description:
+      A value to be included in the Output Report sent by the host, listing an
+      address where the output report on the SPI bus is to be written to. This
+      address has 24 bits.
+
+  read-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      Value to be used in Read Approval packets. 1 byte.
+
+  write-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint8
+    description:
+      Value to be used in Write Approval packets. 1 byte.
+
+required:
+  - compatible
+  - interrupts
+  - reset-gpios
+  - vdd-supply
+  - input-report-header-address
+  - input-report-body-address
+  - output-report-address
+  - read-opcode
+  - write-opcode
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      hid@0 {
+        compatible = "microsoft,g6-touch-digitizer", "hid-over-spi";
+        reg = <0x0>;
+        interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
+        reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
+        vdd-supply = <&pm8350c_l3>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&ts_d6_int_bias>;
+        input-report-header-address = <0x1000>;
+        input-report-body-address = <0x1004>;
+        output-report-address = <0x2000>;
+        read-opcode = /bits/ 8 <0x0b>;
+        write-opcode = /bits/ 8 <0x02>;
+      };
+    };

-- 
2.53.0.1185.g05d4b7b318-goog