Implement PawnIO detection and fix ioperm permissions

Author: Steve-Tech

cros_ec_python/devices/lpc.py

@@ -116,8 +116,8 @@ def ec_init(self) -> None:
 
         # Request I/O permissions
         if (
-            (res := self.portio.ioperm(EC_LPC_ADDR_HOST_DATA, EC_MEMMAP_SIZE, True))
-            or (res := self.portio.ioperm(EC_LPC_ADDR_HOST_CMD, EC_MEMMAP_SIZE, True))
+            (res := self.portio.ioperm(EC_LPC_ADDR_HOST_DATA, 1, True))
+            or (res := self.portio.ioperm(EC_LPC_ADDR_HOST_CMD, 1, True))
             or (
                 res := self.portio.ioperm(
                     EC_LPC_ADDR_HOST_PACKET, EC_LPC_HOST_PACKET_SIZE, True
@@ -283,6 +283,7 @@ def ec_command_v3(
         for i in range(len(request)):
             csum += request[i]
 
+        # Write checksum field so the entire packet sums to 0
         request[1] = (-csum) & 0xFF
 
         # Copy header
@@ -301,7 +302,7 @@ def ec_command_v3(
 
         # Read back response and start checksum
         csum = 0
-        data_out = bytearray(1 + 1 + 2 + 2 + 2)
+        data_out = bytearray(struct.calcsize("BBHHH"))
         for i in range(len(data_out)):
             data_out[i] = self.portio.inb(EC_LPC_ADDR_HOST_PACKET + i)
             csum += data_out[i]

cros_ec_python/devices/pawnio.py

@@ -1,6 +1,7 @@
 import struct
 import warnings
 import ctypes
+import os
 from ctypes import wintypes
 from ctypes import util as ctypes_util
 
@@ -103,8 +104,12 @@ def _pawnio_close(self):
 
     @staticmethod
     def detect() -> bool:
-        # TODO
-        return True
+        """
+        Detect if the PawnIO driver is installed.
+        """
+        return bool(ctypes_util.find_library("PawnIOLib.dll")) or os.path.exists(
+            "C:\\Program Files\\PawnIO\\PawnIOLib.dll"
+        )
 
     def ec_init(self) -> None:
         self._pawnio_open()