projects / libsigrokdecode.git / blame
| Commit | Line | Data |
|---|---|---|
| d567790b UH |
1 | ## |
| 2 | ## This file is part of the sigrok project. | |
| 3 | ## | |
| 4 | ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de> | |
| 5 | ## | |
| 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. | |
| 10 | ## | |
| 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. | |
| 15 | ## | |
| 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 | |
| 19 | ## | |
| 20 | ||
| 21 | # | |
| 22 | # Generic I2C demultiplexing protocol decoder | |
| 23 | # | |
| 24 | # Takes an I2C stream as input and outputs multiple I2C streams, each stream | |
| 25 | # containing only I2C packets for one specific I2C slave. | |
| 26 | # | |
| 27 | ||
| 28 | import sigrokdecode as srd | |
| 29 | ||
| 30 | class Decoder(srd.Decoder): | |
| 31 | api_version = 1 | |
| 32 | id = 'i2cdemux' | |
| 33 | name = 'I2C demux' | |
| 34 | longname = 'Generic I2C demultiplexer' | |
| 35 | desc = 'TODO.' | |
| 36 | longdesc = 'TODO.' | |
| 37 | license = 'gplv2+' | |
| 38 | inputs = ['i2c'] | |
| 39 | outputs = [] # TODO: Only known at run-time. | |
| 40 | probes = [] | |
| 41 | options = {} | |
| 42 | annotations = [] | |
| 43 | ||
| 44 | def __init__(self, **kwargs): | |
| 45 | self.packets = [] # Local cache of I2C packets | |
| 46 | self.slaves = [] # List of known slave addresses | |
| 47 | self.stream = -1 # Current output stream | |
| 48 | self.streamcount = 0 # Number of created output streams | |
| 49 | ||
| 50 | def start(self, metadata): | |
| 51 | self.out_proto = [] | |
| 52 | ||
| 53 | def report(self): | |
| 54 | pass | |
| 55 | ||
| 56 | # Grab I2C packets into a local cache, until an I2C STOP condition | |
| 57 | # packet comes along. At some point before that STOP condition, there | |
| 58 | # will have been an ADDRESS READ or ADDRESS WRITE which contains the | |
| 59 | # I2C address of the slave that the master wants to talk to. | |
| 60 | # We use this slave address to figure out which output stream should | |
| 61 | # get the whole chunk of packets (from START to STOP). | |
| 62 | def decode(self, ss, es, data): | |
| 63 | ||
| 64 | cmd, databyte, ack = data | |
| 65 | ||
| 66 | # Add the I2C packet to our local cache. | |
| 67 | self.packets += [[ss, es, data]] | |
| 68 | ||
| 69 | if cmd in ('ADDRESS READ', 'ADDRESS WRITE'): | |
| 70 | if databyte in self.slaves: | |
| 71 | self.stream = self.slaves.index(databyte) | |
| 72 | return | |
| 73 | ||
| 74 | # We're never seen this slave, add a new stream. | |
| 75 | self.slaves += [databyte] | |
| 76 | self.out_proto += [self.add(srd.OUTPUT_PROTO, | |
| 77 | 'i2c-%s' % hex(databyte))] | |
| 78 | self.stream = self.streamcount | |
| 79 | self.streamcount += 1 | |
| 80 | elif cmd == 'STOP': | |
| 81 | if self.stream == -1: | |
| 82 | raise Exception('Invalid stream!') # FIXME? | |
| 83 | ||
| 84 | # Send the whole chunk of I2C packets to the correct stream. | |
| 85 | for p in self.packets: | |
| 86 | self.put(p[0], p[1], self.out_proto[self.stream], p[2]) | |
| 87 | ||
| 88 | self.packets = [] | |
| 89 | self.stream = -1 | |
| 90 |