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1 | ## | |
2 | ## This file is part of the sigrok project. | |
3 | ## | |
4 | ## Copyright (C) 2012 Iztok Jeras <iztok.jeras@gmail.com> | |
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 | # 1-Wire protocol decoder | |
22 | ||
23 | import sigrokdecode as srd | |
24 | ||
25 | # Annotation feed formats | |
26 | ANN_NETWORK = 0 | |
27 | ANN_TRANSPORT = 1 | |
28 | ||
29 | # a dictionary of ROM commands and their names | |
30 | rom_command = {0x33: "READ ROM", | |
31 | 0x0f: "CONDITIONAL READ ROM", | |
32 | 0xcc: "SKIP ROM", | |
33 | 0x55: "MATCH ROM", | |
34 | 0xf0: "SEARCH ROM", | |
35 | 0xec: "CONDITIONAL SEARCH ROM", | |
36 | 0x3c: "OVERDRIVE SKIP ROM", | |
37 | 0x6d: "OVERDRIVE MATCH ROM"} | |
38 | ||
39 | class Decoder(srd.Decoder): | |
40 | api_version = 1 | |
41 | id = 'onewire_network' | |
42 | name = '1-Wire network layer' | |
43 | longname = '1-Wire serial communication bus' | |
44 | desc = 'Bidirectional, half-duplex, asynchronous serial bus.' | |
45 | license = 'gplv2+' | |
46 | inputs = ['onewire_link'] | |
47 | outputs = ['onewire_network'] | |
48 | probes = [] | |
49 | optional_probes = [] | |
50 | options = {} | |
51 | annotations = [ | |
52 | ['Network', 'Network layer events (device addressing)'], | |
53 | ['Transport', 'Transport layer events'], | |
54 | ] | |
55 | ||
56 | def __init__(self, **kwargs): | |
57 | # Event timing variables | |
58 | self.net_beg = 0 | |
59 | self.net_end = 0 | |
60 | # Network layer variables | |
61 | self.state = 'COMMAND' | |
62 | self.bit_cnt = 0 | |
63 | self.search = "P" | |
64 | self.data_p = 0x0 | |
65 | self.data_n = 0x0 | |
66 | self.data = 0x0 | |
67 | self.net_rom = 0x0000000000000000 | |
68 | ||
69 | def start(self, metadata): | |
70 | self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network') | |
71 | self.out_ann = self.add(srd.OUTPUT_ANN , 'onewire_network') | |
72 | ||
73 | def report(self): | |
74 | pass | |
75 | ||
76 | def decode(self, ss, es, data): | |
77 | [code, val] = data | |
78 | ||
79 | # State machine. | |
80 | if (code == "RESET/PRESENCE"): | |
81 | self.state = "COMMAND" | |
82 | self.search = "P" | |
83 | self.bit_cnt = 0 | |
84 | elif (code == "BIT"): | |
85 | if (self.state == "COMMAND"): | |
86 | # Receiving and decoding a ROM command | |
87 | if (self.onewire_collect(8, val, ss, es)): | |
88 | self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, | |
89 | ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, rom_command[self.data])]]) | |
90 | if (self.data == 0x33): # READ ROM | |
91 | self.state = "GET ROM" | |
92 | elif (self.data == 0x0f): # CONDITIONAL READ ROM | |
93 | self.state = "GET ROM" | |
94 | elif (self.data == 0xcc): # SKIP ROM | |
95 | self.state = "TRANSPORT" | |
96 | elif (self.data == 0x55): # MATCH ROM | |
97 | self.state = "GET ROM" | |
98 | elif (self.data == 0xf0): # SEARCH ROM | |
99 | self.state = "SEARCH ROM" | |
100 | elif (self.data == 0xec): # CONDITIONAL SEARCH ROM | |
101 | self.state = "SEARCH ROM" | |
102 | elif (self.data == 0x3c): # OVERDRIVE SKIP ROM | |
103 | self.state = "TRANSPORT" | |
104 | elif (self.data == 0x69): # OVERDRIVE MATCH ROM | |
105 | self.state = "GET ROM" | |
106 | elif (self.state == "GET ROM"): | |
107 | # A 64 bit device address is selected | |
108 | # family code (1B) + serial number (6B) + CRC (1B) | |
109 | if (self.onewire_collect(64, val, ss, es)): | |
110 | self.net_rom = self.data & 0xffffffffffffffff | |
111 | self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]]) | |
112 | self.state = "TRANSPORT" | |
113 | elif (self.state == "SEARCH ROM"): | |
114 | # A 64 bit device address is searched for | |
115 | # family code (1B) + serial number (6B) + CRC (1B) | |
116 | if (self.onewire_search(64, val, ss, es)): | |
117 | self.net_rom = self.data & 0xffffffffffffffff | |
118 | self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]]) | |
119 | self.state = "TRANSPORT" | |
120 | elif (self.state == "TRANSPORT"): | |
121 | # The transport layer is handled in byte sized units | |
122 | if (self.onewire_collect(8, val, ss, es)): | |
123 | self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK , ['TRANSPORT: 0x%02x' % self.data]]) | |
124 | self.put(self.net_beg, self.net_end, self.out_ann, [ANN_TRANSPORT, ['TRANSPORT: 0x%02x' % self.data]]) | |
125 | self.put(self.net_beg, self.net_end, self.out_proto, ['transfer', self.data]) | |
126 | # TODO: Sending translort layer data to 1-Wire device models | |
127 | else: | |
128 | raise Exception('Invalid state: %s' % self.state) | |
129 | ||
130 | ||
131 | # Link/Network layer data collector | |
132 | def onewire_collect (self, length, val, ss, es): | |
133 | # Storing the sampe this sequence begins with | |
134 | if (self.bit_cnt == 1): | |
135 | self.net_beg = ss | |
136 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
137 | self.bit_cnt = self.bit_cnt + 1 | |
138 | # Storing the sampe this sequence ends with | |
139 | # In case the full length of the sequence is received, return 1 | |
140 | if (self.bit_cnt == length): | |
141 | self.net_end = es | |
142 | self.data = self.data & ((1<<length)-1) | |
143 | self.bit_cnt = 0 | |
144 | return (1) | |
145 | else: | |
146 | return (0) | |
147 | ||
148 | # Link/Network layer search collector | |
149 | def onewire_search (self, length, val, ss, es): | |
150 | # Storing the sampe this sequence begins with | |
151 | if ((self.bit_cnt == 0) and (self.search == "P")): | |
152 | self.net_beg = ss | |
153 | # Master receives an original address bit | |
154 | if (self.search == "P"): | |
155 | self.data_p = self.data_p & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
156 | self.search = "N" | |
157 | # Master receives a complemented address bit | |
158 | elif (self.search == "N"): | |
159 | self.data_n = self.data_n & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
160 | self.search = "D" | |
161 | # Master transmits an address bit | |
162 | elif (self.search == "D"): | |
163 | self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt) | |
164 | self.search = "P" | |
165 | self.bit_cnt = self.bit_cnt + 1 | |
166 | # Storing the sampe this sequence ends with | |
167 | # In case the full length of the sequence is received, return 1 | |
168 | if (self.bit_cnt == length): | |
169 | self.net_end = es | |
170 | self.data_p = self.data_p & ((1<<length)-1) | |
171 | self.data_n = self.data_n & ((1<<length)-1) | |
172 | self.data = self.data & ((1<<length)-1) | |
173 | self.search = "P" | |
174 | self.bit_cnt = 0 | |
175 | return (1) | |
176 | else: | |
177 | return (0) |