2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
6 ## This program is free software; you can redistribute it and/or modify
7 ## it under the terms of the GNU General Public License as published by
8 ## the Free Software Foundation; either version 2 of the License, or
9 ## (at your option) any later version.
11 ## This program is distributed in the hope that it will be useful,
12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 ## GNU General Public License for more details.
16 ## You should have received a copy of the GNU General Public License
17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
20 import sigrokdecode as srd
22 class Decoder(srd.Decoder):
26 longname = 'I²C demultiplexer'
27 desc = 'Demux I²C packets into per-slave-address streams.'
30 outputs = [] # TODO: Only known at run-time.
36 self.packets = [] # Local cache of I²C packets
37 self.slaves = [] # List of known slave addresses
38 self.stream = -1 # Current output stream
39 self.streamcount = 0 # Number of created output streams
44 # Grab I²C packets into a local cache, until an I²C STOP condition
45 # packet comes along. At some point before that STOP condition, there
46 # will have been an ADDRESS READ or ADDRESS WRITE which contains the
47 # I²C address of the slave that the master wants to talk to.
48 # We use this slave address to figure out which output stream should
49 # get the whole chunk of packets (from START to STOP).
50 def decode(self, ss, es, data):
54 # Add the I²C packet to our local cache.
55 self.packets.append([ss, es, data])
57 if cmd in ('ADDRESS READ', 'ADDRESS WRITE'):
58 if databyte in self.slaves:
59 self.stream = self.slaves.index(databyte)
62 # We're never seen this slave, add a new stream.
63 self.slaves.append(databyte)
64 self.out_python.append(self.register(srd.OUTPUT_PYTHON,
65 proto_id='i2c-%s' % hex(databyte)))
66 self.stream = self.streamcount
70 raise Exception('Invalid stream!') # FIXME?
72 # Send the whole chunk of I²C packets to the correct stream.
73 for p in self.packets:
74 self.put(p[0], p[1], self.out_python[self.stream], p[2])
79 pass # Do nothing, only add the I²C packet to our cache.