devices: add basic core device serial comms driver

artiq/devices/corecom_serial.py

@@ -0,0 +1,35 @@
+import os
+import struct
+import termios
+
+class CoreCom:
+	def __init__(self, dev="/dev/ttyUSB1", baud=115200):
+		self._fd = os.open(dev, os.O_RDWR | os.O_NOCTTY)
+		self.port = os.fdopen(self._fd, "r+b", buffering=0)
+		iflag, oflag, cflag, lflag, ispeed, ospeed, cc = \
+				termios.tcgetattr(self._fd)
+		iflag = termios.IGNBRK | termios.IGNPAR
+		oflag = 0
+		cflag |= termios.CLOCAL | termios.CREAD | termios.CS8
+		lflag = 0
+		ispeed = ospeed = getattr(termios, "B"+str(baud))
+		cc[termios.VMIN] = 1
+		cc[termios.VTIME] = 0
+		termios.tcsetattr(self._fd, termios.TCSANOW, [
+			iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
+		termios.tcdrain(self._fd)
+		termios.tcflush(self._fd, termios.TCOFLUSH)
+		termios.tcflush(self._fd, termios.TCIFLUSH)
+
+	def close(self):
+		self.port.close()
+
+	def __enter__(self):
+		return self
+
+	def __exit__(self, type, value, traceback):
+		self.close()
+
+	def run(self, kcode):
+		self.port.write(struct.pack(">LL", 0x5a5a5a5a, len(kcode)))
+		self.port.write(kcode)