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61c2bd36 | 1 | ## |
50bd5d25 | 2 | ## This file is part of the libsigrokdecode project. |
61c2bd36 BV |
3 | ## |
4 | ## Copyright (C) 2012 Bert Vermeulen <bert@biot.com> | |
48eee789 | 5 | ## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de> |
61c2bd36 BV |
6 | ## |
7 | ## This program is free software; you can redistribute it and/or modify | |
8 | ## it under the terms of the GNU General Public License as published by | |
9 | ## the Free Software Foundation; either version 3 of the License, or | |
10 | ## (at your option) any later version. | |
11 | ## | |
12 | ## This program is distributed in the hope that it will be useful, | |
13 | ## but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ## GNU General Public License for more details. | |
16 | ## | |
17 | ## You should have received a copy of the GNU General Public License | |
18 | ## along with this program; if not, see <http://www.gnu.org/licenses/>. | |
19 | ## | |
20 | ||
48eee789 UH |
21 | # TODO: Support for filtering out multiple slave/direction pairs? |
22 | ||
156509ca | 23 | import sigrokdecode as srd |
61c2bd36 BV |
24 | |
25 | class Decoder(srd.Decoder): | |
b197383c | 26 | api_version = 3 |
61c2bd36 | 27 | id = 'i2cfilter' |
bbe6d87f JH |
28 | name = 'I²C filter' |
29 | longname = 'I²C filter' | |
30 | desc = 'Filter out addresses/directions in an I²C stream.' | |
61c2bd36 BV |
31 | license = 'gplv3+' |
32 | inputs = ['i2c'] | |
48eee789 | 33 | outputs = ['i2c'] |
d6d8a8a4 | 34 | tags = ['Util'] |
84c1c0b5 BV |
35 | options = ( |
36 | {'id': 'address', 'desc': 'Address to filter out of the I²C stream', | |
37 | 'default': 0}, | |
38 | {'id': 'direction', 'desc': 'Direction to filter', 'default': 'both', | |
39 | 'values': ('read', 'write', 'both')} | |
40 | ) | |
61c2bd36 | 41 | |
92b7b49f | 42 | def __init__(self): |
10aeb8ea GS |
43 | self.reset() |
44 | ||
45 | def reset(self): | |
48eee789 UH |
46 | self.curslave = -1 |
47 | self.curdirection = None | |
bbe6d87f | 48 | self.packets = [] # Local cache of I²C packets |
61c2bd36 | 49 | |
8915b346 | 50 | def start(self): |
c515eed7 | 51 | self.out_python = self.register(srd.OUTPUT_PYTHON, proto_id='i2c') |
48eee789 UH |
52 | if self.options['address'] not in range(0, 127 + 1): |
53 | raise Exception('Invalid slave (must be 0..127).') | |
61c2bd36 | 54 | |
bbe6d87f | 55 | # Grab I²C packets into a local cache, until an I²C STOP condition |
48eee789 UH |
56 | # packet comes along. At some point before that STOP condition, there |
57 | # will have been an ADDRESS READ or ADDRESS WRITE which contains the | |
bbe6d87f | 58 | # I²C address of the slave that the master wants to talk to. |
48eee789 UH |
59 | # If that slave shall be filtered, output the cache (all packets from |
60 | # START to STOP) as proto 'i2c', otherwise drop it. | |
61c2bd36 | 61 | def decode(self, ss, es, data): |
61c2bd36 | 62 | |
48eee789 UH |
63 | cmd, databyte = data |
64 | ||
bbe6d87f | 65 | # Add the I²C packet to our local cache. |
48eee789 | 66 | self.packets.append([ss, es, data]) |
61c2bd36 | 67 | |
48eee789 UH |
68 | if cmd in ('ADDRESS READ', 'ADDRESS WRITE'): |
69 | self.curslave = databyte | |
70 | self.curdirection = cmd[8:].lower() | |
71 | elif cmd in ('STOP', 'START REPEAT'): | |
72 | # If this chunk was not for the correct slave, drop it. | |
73 | if self.options['address'] == 0: | |
74 | pass | |
75 | elif self.curslave != self.options['address']: | |
76 | self.packets = [] | |
61c2bd36 | 77 | return |
48eee789 UH |
78 | |
79 | # If this chunk was not in the right direction, drop it. | |
80 | if self.options['direction'] == 'both': | |
81 | pass | |
82 | elif self.options['direction'] != self.curdirection: | |
83 | self.packets = [] | |
61c2bd36 | 84 | return |
48eee789 UH |
85 | |
86 | # TODO: START->STOP chunks with both read and write (Repeat START) | |
bbe6d87f | 87 | # Otherwise, send out the whole chunk of I²C packets. |
48eee789 | 88 | for p in self.packets: |
c515eed7 | 89 | self.put(p[0], p[1], self.out_python, p[2]) |
48eee789 UH |
90 | |
91 | self.packets = [] | |
61c2bd36 | 92 | else: |
bbe6d87f | 93 | pass # Do nothing, only add the I²C packet to our cache. |