hid relay driver

PKGBUILD

@@ -50,6 +50,7 @@ depends=(
 	python-pam
 	python-pillow
 	python-xlib
+	python-hidapi
 	freetype2
 	v4l-utils
 	nginx-mainline

kvmd/plugins/ugpio/hidrelay.py

@@ -0,0 +1,168 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018  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 asyncio
+import contextlib
+
+from typing import Dict
+from typing import Optional
+
+import hid
+
+from ...logging import get_logger
+
+from ... import aiotools
+
+from ...yamlconf import Option
+
+from ...validators.basic import valid_float_f01
+
+from ...validators.os import valid_abs_path
+
+from . import GpioDriverOfflineError
+from . import BaseUserGpioDriver
+
+
+# =====
+class Plugin(BaseUserGpioDriver):
+    # http://vusb.wikidot.com/project:driver-less-usb-relays-hid-interface
+    # https://github.com/trezor/cython-hidapi/blob/6057d41b5a2552a70ff7117a9d19fc21bf863867/chid.pxd
+
+    def __init__(  # pylint: disable=super-init-not-called
+        self,
+        instance_name: str,
+        notifier: aiotools.AioNotifier,
+
+        device_path: str,
+        state_poll: float,
+    ) -> None:
+
+        super().__init__(instance_name, notifier)
+
+        self.__device_path = device_path
+        self.__state_poll = state_poll
+
+        self.__device: Optional[hid.device] = None
+        self.__stop = False
+
+        self.__initials: Dict[int, Optional[bool]] = {}
+
+    @classmethod
+    def get_plugin_options(cls) -> Dict:
+        return {
+            "device":     Option("", type=valid_abs_path, unpack_as="device_path"),
+            "state_poll": Option(5.0, type=valid_float_f01),
+        }
+
+    def register_input(self, pin: int) -> None:
+        _ = pin
+
+    def register_output(self, pin: int, initial: Optional[bool]) -> None:
+        self.__initials[pin] = initial
+
+    def prepare(self) -> None:
+        logger = get_logger(0)
+        logger.info("Initializing %s ...", self)
+        try:
+            for (pid, state) in self.__initials.items():
+                if state is not None:
+                    self.write(pid, state)
+        except Exception:
+            logger.exception("Can't perform first initialization of %s", self)
+
+    async def run(self) -> None:
+        prev_raw = -1
+        while True:
+            try:
+                raw = self.__read_raw()
+            except Exception:
+                raw = -1
+            if raw != prev_raw:
+                await self._notifier.notify()
+                prev_raw = raw
+            await asyncio.sleep(self.__state_poll)
+
+    def cleanup(self) -> None:
+        self.__close_device()
+        self.__stop = True
+
+    def read(self, pin: int) -> bool:
+        if self.__check_pin(pin):
+            try:
+                return bool(self.__read_raw() & (1 << pin))
+            except Exception:
+                raise GpioDriverOfflineError(self) from None
+        return False
+
+    def write(self, pin: int, state: bool) -> None:
+        if self.__check_pin(pin):
+            try:
+                with self.__ensure_device("writing") as device:
+                    report = [(0xFF if state else 0xFD), pin + 1]  # Pin numeration starts from 0
+                    result = device.send_feature_report(report)
+                    if result < 0:
+                        raise RuntimeError(f"Retval of send_feature_report() < 0: {result}")
+            except Exception:
+                raise GpioDriverOfflineError(self) from None
+
+    # =====
+
+    def __check_pin(self, pin: int) -> bool:
+        ok = (0 <= pin <= 7)
+        if not ok:
+            get_logger(0).warning("Unsupported pin for %s: %d", self, pin)
+        return ok
+
+    def __read_raw(self) -> int:
+        with self.__ensure_device("reading") as device:
+            return device.get_feature_report(1, 8)[7]
+
+    @contextlib.contextmanager
+    def __ensure_device(self, context: str) -> hid.device:
+        assert not self.__stop
+        if self.__device is None:
+            device = hid.device()
+            device.open_path(self.__device_path.encode("utf-8"))
+            device.set_nonblocking(True)
+            self.__device = device
+            get_logger(0).info("Opened %s while %s", self, context)
+        try:
+            yield self.__device
+        except Exception as err:
+            get_logger(0).error("Error occured on %s while %s: %s: %s",
+                                self, context, type(err).__name__, err)
+            self.__close_device()
+            raise
+
+    def __close_device(self) -> None:
+        if self.__device:
+            try:
+                self.__device.close()
+            except Exception:
+                pass
+            self.__device = None
+            get_logger(0).info("Closed %s", self)
+
+    def __str__(self) -> str:
+        return f"HidRelay({self._instance_name}, {self.__device_path})"
+
+    __repr__ = __str__

testenv/Dockerfile

@@ -19,6 +19,7 @@ RUN pacman -Syu --noconfirm \
 		python-dbus \
 		python-psutil \
 		python-mako \
+		python-hidapi \
 		nginx-mainline \
 		socat \
 		eslint \