otgbind pseudo-gpio plugin

1 files changed, 119 insertions, 0 deletions

diff --git a/kvmd/plugins/ugpio/otgbind.py b/kvmd/plugins/ugpio/otgbind.py
new file mode 100644
index 00000000..5b5291fa
--- /dev/null
+++ b/kvmd/plugins/ugpio/otgbind.py
@@ -0,0 +1,119 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <[email protected]>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+# ========================================================================== #
+
+
+import os
+import asyncio
+
+from typing import Optional
+
+from ...logging import get_logger
+
+from ...inotify import InotifyMask
+from ...inotify import Inotify
+
+from ... import env
+from ... import aiotools
+
+from . import BaseUserGpioDriver
+
+
+# =====
+class Plugin(BaseUserGpioDriver):
+    def __init__(
+        self,
+        instance_name: str,
+        notifier: aiotools.AioNotifier,
+
+        udc: str,  # XXX: Not from options, see /kvmd/apps/kvmd/__init__.py for details
+    ) -> None:
+
+        super().__init__(instance_name, notifier)
+
+        self.__udc = udc
+
+    def register_input(self, pin: int, debounce: float) -> None:
+        _ = pin
+        _ = debounce
+
+    def register_output(self, pin: int, initial: Optional[bool]) -> None:
+        _ = pin
+        _ = initial
+
+    def prepare(self) -> None:
+        candidates = sorted(os.listdir(f"{env.SYSFS_PREFIX}/sys/class/udc"))
+        if not self.__udc:
+            if len(candidates) == 0:
+                raise RuntimeError("Can't find any UDC")
+            self.__udc = candidates[0]
+        elif self.__udc not in candidates:
+            raise RuntimeError(f"Can't find selected UDC: {self.__udc}")
+        get_logger().info("Using UDC %s", self.__udc)
+
+    async def run(self) -> None:
+        logger = get_logger(0)
+        while True:
+            try:
+                while True:
+                    await self._notifier.notify()
+                    if os.path.isdir(self.__get_driver_path()):
+                        break
+                    await asyncio.sleep(5)
+
+                with Inotify() as inotify:
+                    inotify.watch(self.__get_driver_path(), InotifyMask.ALL_MODIFY_EVENTS)
+                    await self._notifier.notify()
+                    while True:
+                        need_restart = False
+                        need_notify = False
+                        for event in (await inotify.get_series(timeout=1)):
+                            need_notify = True
+                            if event.mask & (InotifyMask.DELETE_SELF | InotifyMask.MOVE_SELF | InotifyMask.UNMOUNT):
+                                logger.warning("Got fatal inotify event: %s; reinitializing OTG-bind ...", event)
+                                need_restart = True
+                                break
+                        if need_restart:
+                            break
+                        if need_notify:
+                            await self._notifier.notify()
+            except Exception:
+                logger.exception("Unexpected OTG-bind watcher error")
+
+    def cleanup(self) -> None:
+        pass
+
+    def read(self, pin: int) -> bool:
+        _ = pin
+        return os.path.islink(self.__get_driver_path(self.__udc))
+
+    def write(self, pin: int, state: bool) -> None:
+        _ = pin
+        with open(self.__get_driver_path("bind" if state else "unbind"), "w") as ctl_file:
+            ctl_file.write(f"{self.__udc}\n")
+
+    def __get_driver_path(self, name: str="") -> str:
+        path = f"{env.SYSFS_PREFIX}/sys/bus/platform/drivers/dwc2"
+        return (os.path.join(path, name) if name else path)
+
+    def __str__(self) -> str:
+        return f"GPIO({self._instance_name})"
+
+    __repr__ = __str__