Add a wrapper around pySerial to monkey patch support for custom baud…

…rates

This is only useful if the pyserial version installed is lower than 2.7
since that doesn't support custom baudrates such as 250000.

printrun/printcore.py

@@ -17,7 +17,7 @@
 
 __version__ = "2015.03.10"
 
-from serial import Serial, SerialException, PARITY_ODD, PARITY_NONE
+from serialWrapper import Serial, SerialException, PARITY_ODD, PARITY_NONE
 from select import error as SelectError
 import threading
 from Queue import Queue, Empty as QueueEmpty

printrun/serialWrapper.py

@@ -0,0 +1,41 @@
+# Serial wrapper around pyserial that adds support for custom baudrates (250000)
+# on linux, when pyserial is < 2.7
+
+__copyright__ = "Copyright (C) 2015 Aleph Objects - Released under terms of the AGPLv3 License"
+
+from serial import *
+import os
+
+if os.name == 'posix':
+	import serial.serialposix
+
+	if not hasattr(serial.serialposix, "TCGETS2") and \
+	   hasattr(serial.serialposix, "set_special_baudrate"):
+		# Detected pyserial < 2.7 which doesn't support custom baudrates
+		# Replacing set_special_baudrate with updated function from pyserial 2.7
+
+		TCGETS2 = 0x802C542A
+		TCSETS2 = 0x402C542B
+		BOTHER = 0o010000
+
+		def set_special_baudrate(port, baudrate):
+			# right size is 44 on x86_64, allow for some growth
+			import array
+			buf = array.array('i', [0] * 64)
+
+			try:
+				# get serial_struct
+				FCNTL.ioctl(port.fd, TCGETS2, buf)
+				# set custom speed
+				buf[2] &= ~TERMIOS.CBAUD
+				buf[2] |= BOTHER
+				buf[9] = buf[10] = baudrate
+
+				# set serial_struct
+				res = FCNTL.ioctl(port.fd, TCSETS2, buf)
+			except IOError, e:
+				raise ValueError('Failed to set custom baud rate (%s): %s' % (baudrate, e))
+
+		# We need to change the function inside the serialposix module otherwise, it won't
+		# be called by the code within that module
+		serial.serialposix.set_special_baudrate = set_special_baudrate