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, write to the Free Software
18 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 import sigrokdecode as srd
23 class Decoder(srd.Decoder):
27 longname = 'I²C demultiplexer'
28 desc = 'Demux I²C packets into per-slave-address streams.'
31 outputs = [] # TODO: Only known at run-time.
37 def __init__(self, **kwargs):
38 self.packets = [] # Local cache of I²C packets
39 self.slaves = [] # List of known slave addresses
40 self.stream = -1 # Current output stream
41 self.streamcount = 0 # Number of created output streams
46 # Grab I²C packets into a local cache, until an I²C STOP condition
47 # packet comes along. At some point before that STOP condition, there
48 # will have been an ADDRESS READ or ADDRESS WRITE which contains the
49 # I²C address of the slave that the master wants to talk to.
50 # We use this slave address to figure out which output stream should
51 # get the whole chunk of packets (from START to STOP).
52 def decode(self, ss, es, data):
56 # Add the I²C packet to our local cache.
57 self.packets.append([ss, es, data])
59 if cmd in ('ADDRESS READ', 'ADDRESS WRITE'):
60 if databyte in self.slaves:
61 self.stream = self.slaves.index(databyte)
64 # We're never seen this slave, add a new stream.
65 self.slaves.append(databyte)
66 self.out_proto.append(self.register(srd.OUTPUT_PYTHON,
67 proto_id='i2c-%s' % hex(databyte)))
68 self.stream = self.streamcount
72 raise Exception('Invalid stream!') # FIXME?
74 # Send the whole chunk of I²C packets to the correct stream.
75 for p in self.packets:
76 self.put(p[0], p[1], self.out_proto[self.stream], p[2])
81 pass # Do nothing, only add the I²C packet to our cache.