modify: DI 输入监听

aibox_sophon_adapter/diwatch/devicetree.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""从设备树复算 gpio-in-N 对应的全局 GPIO 号。"""
+
+from pathlib import Path
+
+from .config import DEVICETREE_BASE
+
+
+def _read_be32(path: Path, offset: int = 0):
+    try:
+        data = path.read_bytes()
+    except OSError:
+        return None
+    if len(data) < offset + 4:
+        return None
+    return int.from_bytes(data[offset:offset + 4], "big")
+
+
+def derive_gpio(n: int, base_dir: str = DEVICETREE_BASE):
+    """从设备树复算 IN<n> 的全局 GPIO 号。
+
+    返回 (gpio_num, label, pin) 或 None。
+    """
+    base = Path(base_dir)
+    f = base / f"gpio-in-{n}" / "control-gpios"
+    if not f.exists():
+        return None
+
+    try:
+        data = f.read_bytes()
+    except OSError:
+        return None
+    if len(data) < 8:
+        return None
+
+    ph = int.from_bytes(data[0:4], "big")
+    pin = int.from_bytes(data[4:8], "big")
+
+    # phandle -> gpio-controller 节点
+    ctrl = None
+    for c in base.glob("gpio@*/gpio-controller@*"):
+        cph = _read_be32(c / "phandle")
+        if cph == ph:
+            ctrl = c
+            break
+    if ctrl is None:
+        return None
+
+    bank = ctrl.parent.name
+    if bank.startswith("gpio@"):
+        bank = bank[len("gpio@"):]
+    label = f"{bank}.gpio"
+
+    # label -> gpiochip base
+    gpio_class = Path("/sys/class/gpio")
+    if not gpio_class.exists():
+        return None
+    for g in gpio_class.glob("gpiochip*"):
+        try:
+            if (g / "label").read_text().strip() == label:
+                chip_base = int((g / "base").read_text().strip())
+                return chip_base + pin, label, pin
+        except (OSError, ValueError):
+            continue
+    return None