refactoring

kvmd/plugins/hid/ch9329/chip.py

@@ -0,0 +1,67 @@
+# ========================================================================== #
+#                                                                            #
+#    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 serial
+
+
+# =====
+class ChipResponseError(Exception):
+    pass
+
+
+# =====
+class Chip:
+    def __init__(self, device_path: str, speed: int, read_timeout: float) -> None:
+        self.__tty = serial.Serial(device_path, speed, timeout=read_timeout)
+        self.__device_path = device_path
+
+    def xfer(self, cmd: list[int]) -> int:
+        self.__send(cmd)
+        return self.__recv()
+
+    def __send(self, cmd: list[int]) -> None:
+        # RESET = [0x00,0x0F,0x00]
+        # GET_INFO = [0x00,0x01,0x00]
+        if len(cmd) == 0:
+            cmd = [0x00, 0x01, 0x00]
+        cmd = [0x57, 0xAB, *cmd, self.__make_checksum(cmd)]
+        self.__tty.write(serial.to_bytes(cmd))
+
+    def __recv(self) -> int:
+        data = self.__tty.read(5)
+        if len(data) < 5:
+            raise ChipResponseError("Too short response, HID might be disconnected")
+
+        if data and data[4]:
+            data += self.__tty.read(data[4] + 1)
+
+        if self.__make_checksum(data[:-1]) != data[-1]:
+            raise ChipResponseError("Invalid response checksum")
+
+        if data[4] == 1 and data[5] != 0:
+            raise ChipResponseError(f"Response error code = {data[5]!r}")
+
+        # led_byte (info) response
+        return (data[7] if data[3] == 0x81 else -1)
+
+    def __make_checksum(self, cmd: (list[int] | bytes)) -> int:
+        return (sum(cmd) % 256)