dt-bindings: gpio: Convert Unisoc EIC controller binding to yaml

Convert the Unisoc EIC controller binding to DT schema format.
Update the maxItems of 'reg' property, since the current gpio-eic-sprd
driver supports 3 reg items. Also removed a few similar examples.

Signed-off-by: Chunyan Zhang <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>

Author: Chunyan Zhang

Documentation/devicetree/bindings/gpio/gpio-eic-sprd.txt

@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2022 Unisoc Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/sprd,gpio-eic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Unisoc EIC controller
+
+maintainers:
+  - Orson Zhai <[email protected]>
+  - Baolin Wang <[email protected]>
+  - Chunyan Zhang <[email protected]>
+
+description: |
+  The EIC is the abbreviation of external interrupt controller, which can
+  be used only in input mode. The Spreadtrum platform has 2 EIC controllers,
+  one is in digital chip, and another one is in PMIC. The digital chip EIC
+  controller contains 4 sub-modules, i.e. EIC-debounce, EIC-latch, EIC-async and
+  EIC-sync. But the PMIC EIC controller contains only one EIC-debounce sub-
+  module.
+
+  The EIC-debounce sub-module provides up to 8 source input signal
+  connections. A debounce mechanism is used to capture the input signals'
+  stable status (millisecond resolution) and a single-trigger mechanism
+  is introduced into this sub-module to enhance the input event detection
+  reliability. In addition, this sub-module's clock can be shut off
+  automatically to reduce power dissipation. Moreover the debounce range
+  is from 1ms to 4s with a step size of 1ms. The input signal will be
+  ignored if it is asserted for less than 1 ms.
+
+  The EIC-latch sub-module is used to latch some special power down signals
+  and generate interrupts, since the EIC-latch does not depend on the APB
+  clock to capture signals.
+
+  The EIC-async sub-module uses a 32kHz clock to capture the short signals
+  (microsecond resolution) to generate interrupts by level or edge trigger.
+
+  The EIC-sync is similar with GPIO's input function, which is a synchronized
+  signal input register. It can generate interrupts by level or edge trigger
+  when detecting input signals.
+
+properties:
+  compatible:
+    enum:
+      - sprd,sc9860-eic-debounce
+      - sprd,sc9860-eic-latch
+      - sprd,sc9860-eic-async
+      - sprd,sc9860-eic-sync
+      - sprd,sc2731-eic
+
+  reg:
+    minItems: 1
+    maxItems: 3
+    description:
+      EIC controller can support maximum 3 banks which has its own
+      address base.
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+  interrupts:
+    maxItems: 1
+    description:
+      The interrupt shared by all GPIO lines for this controller.
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+  - interrupt-controller
+  - "#interrupt-cells"
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        eic_debounce: gpio@40210000 {
+            compatible = "sprd,sc9860-eic-debounce";
+            reg = <0 0x40210000 0 0x80>;
+            gpio-controller;
+            #gpio-cells = <2>;
+            interrupt-controller;
+            #interrupt-cells = <2>;
+            interrupts = <GIC_SPI 52 IRQ_TYPE_LEVEL_HIGH>;
+        };
+    };
+...