[PATCH v7 1/3] dt-bindings: counter: add gpio-counter binding

[Wadim Mueller <wafgo01@gmail.com>]

Add a binding for a generic GPIO-based counter. Two GPIOs (signal-a,
signal-b) drive two Counts; optional index GPIOs load a preset. The
counter function (quadrature, pulse-direction, increase/decrease) is
selected at runtime via the counter sysfs interface.

Signed-off-by: Wadim Mueller <wafgo01@gmail.com>
---
v7:
  - index-gpios split into seperate index1-gpios/index2-gpios, so
    Count 2 can have an index line without a dummy entry for Count 1
  - dropped Conors Ack since the binding changed
---
 .../bindings/counter/gpio-counter.yaml        | 60 +++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/counter/gpio-counter.yaml

diff --git a/Documentation/devicetree/bindings/counter/gpio-counter.yaml b/Documentation/devicetree/bindings/counter/gpio-counter.yaml
new file mode 100644
index 000000000000..782cb177ed0b
--- /dev/null
+++ b/Documentation/devicetree/bindings/counter/gpio-counter.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/counter/gpio-counter.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO-based Counter
+
+maintainers:
+  - Wadim Mueller <wafgo01@gmail.com>
+
+description: |
+  GPIO-based software counter with two Counts:
+    * Count 1: A + B. Quadrature X1/X2/X4, pulse-direction, inc/dec.
+    * Count 2: B. Inc / dec.
+  The function is selected at runtime via the counter sysfs ABI. Each
+  Count has an optional Index (Z) that loads its preset on rising edge.
+
+properties:
+  compatible:
+    const: gpio-counter
+
+  signal-a-gpios:
+    maxItems: 1
+    description: Signal A (phase A; pulse input in pulse-direction/inc/dec).
+
+  signal-b-gpios:
+    maxItems: 1
+    description:
+      Signal B (phase B; direction in pulse-direction; pulse input for
+      Count 2).
+
+  index1-gpios:
+    maxItems: 1
+    description: Optional Index (Z) input for Count 1.
+
+  index2-gpios:
+    maxItems: 1
+    description: Optional Index (Z) input for Count 2.
+
+required:
+  - compatible
+  - signal-a-gpios
+  - signal-b-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    counter {
+        compatible = "gpio-counter";
+        signal-a-gpios = <&gpio0 10 GPIO_ACTIVE_LOW>;
+        signal-b-gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
+        index1-gpios = <&gpio0 12 GPIO_ACTIVE_LOW>;
+        index2-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+    };
+
+...
-- 
2.43.0