unified udc code and automatic driver detection

1 files changed, 60 insertions, 0 deletions

diff --git a/kvmd/usb.py b/kvmd/usb.py
new file mode 100644
index 00000000..7bfc23ff
--- /dev/null
+++ b/kvmd/usb.py
@@ -0,0 +1,60 @@
+# ========================================================================== #
+#                                                                            #
+#    KVMD - The main Pi-KVM daemon.                                          #
+#                                                                            #
+#    Copyright (C) 2018-2021  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
+
+from typing import Tuple
+
+from .logging import get_logger
+
+from . import env
+
+
+# =====
+def find_udc(udc: str) -> Tuple[str, str]:
+    path = f"{env.SYSFS_PREFIX}/sys/class/udc"
+    candidates = sorted(os.listdir(path))
+    if not udc:
+        if len(candidates) == 0:
+            raise RuntimeError("Can't find any UDC")
+        udc = candidates[0]
+    elif udc not in candidates:
+        raise RuntimeError(f"Can't find selected UDC: {udc}")
+    driver = os.path.basename(os.readlink(os.path.join(path, udc, "device/driver")))
+    return (udc, driver)  # (fe980000.usb, dwc2)
+
+
+class UsbDeviceController:
+    def __init__(self, udc: str) -> None:
+        self.__udc = udc
+        self.__state_path = ""
+
+    def find(self) -> None:
+        udc = find_udc(self.__udc)[0]
+        self.__state_path = os.path.join(f"{env.SYSFS_PREFIX}/sys/class/udc", udc, "state")
+        get_logger().info("Using UDC %s", udc)
+
+    def can_operate(self) -> bool:
+        assert self.__state_path
+        with open(self.__state_path, "r") as state_file:
+            # https://www.maxlinear.com/Files/Documents/an213_033111.pdf
+            return (state_file.read().strip().lower() == "configured")