console: Make baud an optional parameter

Make the baud rate an optional parameter to the console.py tool.  When
not present, it will default to 250000.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/Debugging.md

@@ -123,12 +123,15 @@ possible to manually send these MCU commands (functions marked with
 the DECL_COMMAND() macro in the Klipper source code). To do so, run:
 
 ```
-~/klippy-env/bin/python ./klippy/console.py /tmp/pseudoserial 250000
+~/klippy-env/bin/python ./klippy/console.py /tmp/pseudoserial
 ```
 
 See the "HELP" command within the tool for more information on its
 functionality.
 
+Some command-line options are available. For more information run:
+`~/klippy-env/bin/python ./klippy/console.py --help`
+
 Generating load graphs
 ======================
 

klippy/console.py

@@ -202,11 +202,18 @@ class KeyboardReader:
         self.data = kbdlines[-1]
 
 def main():
-    usage = "%prog [options] <serialdevice> <baud>"
+    usage = "%prog [options] <serialdevice>"
     opts = optparse.OptionParser(usage)
+    opts.add_option("-b", "--baud", type="int", dest="baud", help="baud rate")
     options, args = opts.parse_args()
-    serialport, baud = args
-    baud = int(baud)
+    if len(args) != 1:
+        opts.error("Incorrect number of arguments")
+    serialport = args[0]
+
+    baud = options.baud
+    if baud is None and not (serialport.startswith("/dev/rpmsg_")
+                             or serialport.startswith("/tmp/")):
+        baud = 250000
 
     logging.basicConfig(level=logging.DEBUG)
     r = reactor.Reactor()