otgconf gpio plugin

kvmd/plugins/ugpio/otgconf.py

@@ -0,0 +1,140 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main PiKVM daemon.                                           #
+#                                                                            #
+#    Copyright (C) 2018-2022  Maxim Devaev <mdevaev@gmail.com>               #
+#                                                                            #
+#    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 Callable
+from typing import Any
+
+from ...logging import get_logger
+
+from ...inotify import InotifyMask
+from ...inotify import Inotify
+
+from ... import aiotools
+from ... import usb
+
+from ...yamlconf import Section
+
+from ...validators.basic import valid_stripped_string_not_empty
+
+from . import BaseUserGpioDriver
+
+
+# =====
+class Plugin(BaseUserGpioDriver):
+    def __init__(
+        self,
+        instance_name: str,
+        notifier: aiotools.AioNotifier,
+
+        otg_config: Section,  # XXX: Not from options, see /kvmd/apps/kvmd/__init__.py for details
+    ) -> None:
+
+        super().__init__(instance_name, notifier)
+
+        self.__udc: str = otg_config.udc
+        self.__init_delay: float = otg_config.init_delay
+
+        gadget: str = otg_config.gadget
+        self.__udc_path = usb.get_gadget_path(gadget, usb.G_UDC)
+        self.__functions_path = usb.get_gadget_path(gadget, usb.G_FUNCTIONS)
+        self.__profile_path = usb.get_gadget_path(gadget, usb.G_PROFILE)
+
+        self.__lock = asyncio.Lock()
+
+    @classmethod
+    def get_pin_validator(cls) -> Callable[[Any], Any]:
+        return valid_stripped_string_not_empty
+
+    def prepare(self) -> None:
+        self.__udc = usb.find_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.isfile(self.__udc_path):
+                        break
+                    await asyncio.sleep(5)
+
+                with Inotify() as inotify:
+                    inotify.watch(os.path.dirname(self.__udc_path), InotifyMask.ALL_MODIFY_EVENTS)
+                    inotify.watch(self.__profile_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")
+                await asyncio.sleep(1)
+
+    async def read(self, pin: str) -> bool:
+        if pin == "udc":
+            return self.__is_udc_enabled()
+        return os.path.exists(os.path.join(self.__profile_path, pin))
+
+    async def write(self, pin: str, state: bool) -> None:
+        async with self.__lock:
+            if pin == "udc":
+                self.__set_udc_enabled(state)
+            else:
+                if self.__is_udc_enabled():
+                    self.__set_udc_enabled(False)
+                try:
+                    if state:
+                        os.symlink(
+                            os.path.join(self.__functions_path, pin),
+                            os.path.join(self.__profile_path, pin),
+                        )
+                    else:
+                        os.unlink(os.path.join(self.__profile_path, pin))
+                finally:
+                    await asyncio.sleep(self.__init_delay)
+                    self.__set_udc_enabled(True)
+
+    def __set_udc_enabled(self, enabled: bool) -> None:
+        with open(self.__udc_path, "w") as udc_file:
+            udc_file.write(self.__udc if enabled else "\n")
+
+    def __is_udc_enabled(self) -> bool:
+        with open(self.__udc_path) as udc_file:
+            return bool(udc_file.read().strip())
+
+    def __str__(self) -> str:
+        return f"GPIO({self._instance_name})"
+
+    __repr__ = __str__