[RFC PATCH 4/6] dt-bindings: input: describe the Romulus13 QSPI touchpad

[fQwQf]

Describe the fixed-address HID-over-SPI touchpad on Surface Laptop 7
13.8-inch, with quad address/data transfers, an active-low reset and a 5
V supply.

Signed-off-by: Jizhou Tong <fqwqf@xxxxxxxxx>
---
 .../input/microsoft,romulus13-touchpad.yaml   | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/microsoft,romulus13-touchpad.yaml

diff --git a/Documentation/devicetree/bindings/input/microsoft,romulus13-touchpad.yaml b/Documentation/devicetree/bindings/input/microsoft,romulus13-touchpad.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..88e4664c56e7fb1c3f9f5949a3ded2f9d7070604
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/microsoft,romulus13-touchpad.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/microsoft,romulus13-touchpad.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microsoft Surface Laptop 7 13.8-inch QSPI touchpad
+
+maintainers:
+  - Jizhou Tong <fqwqf@xxxxxxxxx>
+
+description:
+  The touchpad on the 13.8-inch Surface Laptop 7 uses the HID SPI v3
+  protocol over a quad SPI connection. Its supply and board reset states
+  must be controlled during initialization and recovery.
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: microsoft,romulus13-touchpad
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vdd-supply:
+    description: Touchpad 5 V supply.
+
+  spi-max-frequency:
+    maximum: 20000000
+
+  spi-rx-bus-width:
+    items:
+      - const: 4
+
+  spi-tx-bus-width:
+    items:
+      - const: 4
+
+  reset-gpios:
+    maxItems: 1
+    description: Active-low touchpad reset.
+
+  pinctrl-0: true
+
+  pinctrl-names:
+    items:
+      - const: default
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - vdd-supply
+  - spi-rx-bus-width
+  - spi-tx-bus-width
+  - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        touchpad@0 {
+            compatible = "microsoft,romulus13-touchpad";
+            reg = <0>;
+            spi-max-frequency = <20000000>;
+            spi-rx-bus-width = <4>;
+            spi-tx-bus-width = <4>;
+            interrupts-extended = <&tlmm 3 IRQ_TYPE_LEVEL_LOW>;
+            vdd-supply = <&vreg_ts_5p0>;
+            reset-gpios = <&tlmm 120 GPIO_ACTIVE_LOW>;
+            pinctrl-0 = <&touchpad_reset>;
+            pinctrl-names = "default";
+        };
+    };