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6eb87578 | 1 | ## |
50bd5d25 | 2 | ## This file is part of the libsigrokdecode project. |
6eb87578 GM |
3 | ## |
4 | ## Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz> | |
12549f11 | 5 | ## Copyright (C) 2012-2014 Uwe Hermann <uwe@hermann-uwe.de> |
6eb87578 GM |
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 2 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, write to the Free Software | |
19 | ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | ## | |
ad2dc0de | 21 | |
677d597b | 22 | import sigrokdecode as srd |
67e847fd | 23 | |
0702e0cf | 24 | ''' |
c515eed7 | 25 | OUTPUT_PYTHON format: |
0702e0cf UH |
26 | |
27 | SPI packet: | |
28 | [<cmd>, <data1>, <data2>] | |
29 | ||
30 | Commands: | |
31 | - 'DATA': <data1> contains the MISO data, <data2> contains the MOSI data. | |
32 | The data is _usually_ 8 bits (but can also be fewer or more bits). | |
12549f11 UH |
33 | Both data items are Python numbers (not strings), or None if the respective |
34 | probe was not supplied. | |
cddd11bc UH |
35 | - 'BITS': <data1>/<data2> contain a list of bit values in this MISO/MOSI data |
36 | item, and for each of those also their respective start-/endsample numbers. | |
0702e0cf UH |
37 | - 'CS CHANGE': <data1> is the old CS# pin value, <data2> is the new value. |
38 | Both data items are Python numbers (0/1), not strings. | |
39 | ||
40 | Examples: | |
41 | ['CS-CHANGE', 1, 0] | |
42 | ['DATA', 0xff, 0x3a] | |
cddd11bc UH |
43 | ['BITS', [[1, 80, 82], [1, 83, 84], [1, 85, 86], [1, 87, 88], |
44 | [1, 89, 90], [1, 91, 92], [1, 93, 94], [1, 95, 96]], | |
d78e0beb UH |
45 | [[0, 80, 82], [1, 83, 84], [0, 85, 86], [1, 87, 88], |
46 | [1, 89, 90], [1, 91, 92], [0, 93, 94], [0, 95, 96]]] | |
0702e0cf | 47 | ['DATA', 0x65, 0x00] |
12549f11 UH |
48 | ['DATA', 0xa8, None] |
49 | ['DATA', None, 0x55] | |
0702e0cf UH |
50 | ['CS-CHANGE', 0, 1] |
51 | ''' | |
52 | ||
8a7ce2a3 | 53 | # Key: (CPOL, CPHA). Value: SPI mode. |
94bbdb9a UH |
54 | # Clock polarity (CPOL) = 0/1: Clock is low/high when inactive. |
55 | # Clock phase (CPHA) = 0/1: Data is valid on the leading/trailing clock edge. | |
c94c8c91 UH |
56 | spi_mode = { |
57 | (0, 0): 0, # Mode 0 | |
58 | (0, 1): 1, # Mode 1 | |
59 | (1, 0): 2, # Mode 2 | |
60 | (1, 1): 3, # Mode 3 | |
61 | } | |
62 | ||
677d597b | 63 | class Decoder(srd.Decoder): |
a2c2afd9 | 64 | api_version = 1 |
67e847fd | 65 | id = 'spi' |
2b7d0e2b | 66 | name = 'SPI' |
3d3da57d | 67 | longname = 'Serial Peripheral Interface' |
a465436e | 68 | desc = 'Full-duplex, synchronous, serial bus.' |
6eb87578 GM |
69 | license = 'gplv2+' |
70 | inputs = ['logic'] | |
71 | outputs = ['spi'] | |
6b5b91d2 | 72 | probes = [ |
49e8a4d6 | 73 | {'id': 'clk', 'name': 'CLK', 'desc': 'Clock'}, |
6b5b91d2 | 74 | ] |
efa64173 | 75 | optional_probes = [ |
49e8a4d6 UH |
76 | {'id': 'miso', 'name': 'MISO', 'desc': 'Master in, slave out'}, |
77 | {'id': 'mosi', 'name': 'MOSI', 'desc': 'Master out, slave in'}, | |
78 | {'id': 'cs', 'name': 'CS#', 'desc': 'Chip-select'}, | |
efa64173 | 79 | ] |
238b4080 | 80 | options = { |
94bbdb9a UH |
81 | 'cs_polarity': ['CS# polarity', 'active-low'], |
82 | 'cpol': ['Clock polarity', 0], | |
83 | 'cpha': ['Clock phase', 0], | |
84 | 'bitorder': ['Bit order within the SPI data', 'msb-first'], | |
c94c8c91 | 85 | 'wordsize': ['Word size of SPI data', 8], # 1-64? |
3eda7779 | 86 | 'format': ['Data format', 'hex'], |
238b4080 | 87 | } |
b1bb5eed | 88 | annotations = [ |
cddd11bc UH |
89 | ['miso-data', 'MISO data'], |
90 | ['mosi-data', 'MOSI data'], | |
91 | ['miso-bits', 'MISO bits'], | |
92 | ['mosi-bits', 'MOSI bits'], | |
9f2f42c0 | 93 | ['warnings', 'Human-readable warnings'], |
b1bb5eed | 94 | ] |
06b52ebb | 95 | annotation_rows = ( |
cddd11bc UH |
96 | ('miso-data', 'MISO data', (0,)), |
97 | ('miso-bits', 'MISO bits', (2,)), | |
98 | ('mosi-data', 'MOSI data', (1,)), | |
99 | ('mosi-bits', 'MOSI bits', (3,)), | |
100 | ('other', 'Other', (4,)), | |
06b52ebb | 101 | ) |
6eb87578 | 102 | |
3643fc3f | 103 | def __init__(self): |
8a3c8792 | 104 | self.samplerate = None |
bcd14870 | 105 | self.oldclk = 1 |
a10bfc48 | 106 | self.bitcount = 0 |
bbc100f7 | 107 | self.misodata = self.mosidata = 0 |
cddd11bc | 108 | self.misobits = [] |
bbc100f7 | 109 | self.mosibits = [] |
ec0afe27 | 110 | self.startsample = -1 |
d6bace96 | 111 | self.samplenum = -1 |
bb08f4b3 | 112 | self.cs_was_deasserted = False |
3e3c0330 | 113 | self.oldcs = -1 |
2fcd7c22 | 114 | self.oldpins = None |
bbc100f7 | 115 | self.have_cs = self.have_miso = self.have_mosi = None |
191ec8c5 | 116 | self.state = 'IDLE' |
6eb87578 | 117 | |
8a3c8792 BV |
118 | def metadata(self, key, value): |
119 | if key == srd.SRD_CONF_SAMPLERATE: | |
120 | self.samplerate = value | |
121 | ||
8915b346 | 122 | def start(self): |
c515eed7 | 123 | self.out_python = self.register(srd.OUTPUT_PYTHON) |
be465111 | 124 | self.out_ann = self.register(srd.OUTPUT_ANN) |
8a3c8792 BV |
125 | self.out_bitrate = self.register(srd.OUTPUT_META, |
126 | meta=(int, 'Bitrate', 'Bitrate during transfers')) | |
3643fc3f | 127 | |
ec0afe27 UH |
128 | def putw(self, data): |
129 | self.put(self.startsample, self.samplenum, self.out_ann, data) | |
130 | ||
bbc100f7 UH |
131 | def putdata(self): |
132 | # Pass MISO and MOSI bits and then data to the next PD up the stack. | |
133 | so = self.misodata if self.have_miso else None | |
134 | si = self.mosidata if self.have_mosi else None | |
135 | so_bits = self.misobits if self.have_miso else None | |
136 | si_bits = self.mosibits if self.have_mosi else None | |
7c09dbb2 UH |
137 | |
138 | if self.have_miso: | |
139 | ss, es = self.misobits[-1][1], self.misobits[0][2] | |
140 | if self.have_mosi: | |
141 | ss, es = self.mosibits[-1][1], self.mosibits[0][2] | |
142 | ||
143 | self.put(ss, es, self.out_python, ['BITS', si_bits, so_bits]) | |
144 | self.put(ss, es, self.out_python, ['DATA', si, so]) | |
cddd11bc | 145 | |
bbc100f7 UH |
146 | # Bit annotations. |
147 | if self.have_miso: | |
148 | for bit in self.misobits: | |
149 | self.put(bit[1], bit[2], self.out_ann, [2, ['%d' % bit[0]]]) | |
150 | if self.have_mosi: | |
151 | for bit in self.mosibits: | |
152 | self.put(bit[1], bit[2], self.out_ann, [3, ['%d' % bit[0]]]) | |
153 | ||
154 | # Dataword annotations. | |
155 | if self.have_miso: | |
808c6e74 | 156 | self.put(ss, es, self.out_ann, [0, ['%02X' % self.misodata]]) |
bbc100f7 | 157 | if self.have_mosi: |
808c6e74 | 158 | self.put(ss, es, self.out_ann, [1, ['%02X' % self.mosidata]]) |
cddd11bc | 159 | |
d482a2d3 UH |
160 | def reset_decoder_state(self): |
161 | self.misodata = 0 if self.have_miso else None | |
162 | self.mosidata = 0 if self.have_mosi else None | |
163 | self.misobits = [] if self.have_miso else None | |
164 | self.mosibits = [] if self.have_mosi else None | |
165 | self.bitcount = 0 | |
166 | ||
bcd14870 | 167 | def handle_bit(self, miso, mosi, clk, cs): |
cddd11bc | 168 | # If this is the first bit of a dataword, save its sample number. |
191ec8c5 UH |
169 | if self.bitcount == 0: |
170 | self.startsample = self.samplenum | |
bb08f4b3 | 171 | self.cs_was_deasserted = False |
efa64173 UH |
172 | if self.have_cs: |
173 | active_low = (self.options['cs_polarity'] == 'active-low') | |
bb08f4b3 | 174 | deasserted = (cs == 1) if active_low else (cs == 0) |
efa64173 | 175 | if deasserted: |
bb08f4b3 | 176 | self.cs_was_deasserted = True |
2fcd7c22 | 177 | |
191ec8c5 | 178 | ws = self.options['wordsize'] |
d6bace96 | 179 | |
bbc100f7 UH |
180 | # Receive MISO bit into our shift register. |
181 | if self.have_miso: | |
182 | if self.options['bitorder'] == 'msb-first': | |
183 | self.misodata |= miso << (ws - 1 - self.bitcount) | |
184 | else: | |
185 | self.misodata |= miso << self.bitcount | |
186 | ||
191ec8c5 | 187 | # Receive MOSI bit into our shift register. |
12549f11 UH |
188 | if self.have_mosi: |
189 | if self.options['bitorder'] == 'msb-first': | |
190 | self.mosidata |= mosi << (ws - 1 - self.bitcount) | |
191 | else: | |
192 | self.mosidata |= mosi << self.bitcount | |
3e3c0330 | 193 | |
808c6e74 | 194 | # Guesstimate the endsample for this bit (can be overridden below). |
bbc100f7 UH |
195 | es = self.samplenum |
196 | if self.bitcount > 0: | |
8e8096e8 UH |
197 | if self.have_miso: |
198 | es += self.samplenum - self.misobits[0][1] | |
199 | elif self.have_mosi: | |
200 | es += self.samplenum - self.mosibits[0][1] | |
c94c8c91 | 201 | |
cddd11bc | 202 | if self.have_miso: |
d78e0beb | 203 | self.misobits.insert(0, [miso, self.samplenum, es]) |
cddd11bc | 204 | if self.have_mosi: |
d78e0beb | 205 | self.mosibits.insert(0, [mosi, self.samplenum, es]) |
bbc100f7 UH |
206 | |
207 | if self.bitcount > 0 and self.have_miso: | |
d78e0beb | 208 | self.misobits[1][2] = self.samplenum |
bbc100f7 | 209 | if self.bitcount > 0 and self.have_mosi: |
d78e0beb | 210 | self.mosibits[1][2] = self.samplenum |
cddd11bc | 211 | |
191ec8c5 | 212 | self.bitcount += 1 |
1ea831e9 | 213 | |
191ec8c5 UH |
214 | # Continue to receive if not enough bits were received, yet. |
215 | if self.bitcount != ws: | |
216 | return | |
b1bb5eed | 217 | |
bbc100f7 | 218 | self.putdata() |
12549f11 UH |
219 | |
220 | # Meta bitrate. | |
bbc100f7 UH |
221 | elapsed = 1 / float(self.samplerate) |
222 | elapsed *= (self.samplenum - self.startsample + 1) | |
8a3c8792 BV |
223 | bitrate = int(1 / elapsed * self.options['wordsize']) |
224 | self.put(self.startsample, self.samplenum, self.out_bitrate, bitrate) | |
225 | ||
bb08f4b3 | 226 | if self.have_cs and self.cs_was_deasserted: |
cddd11bc | 227 | self.putw([4, ['CS# was deasserted during this data word!']]) |
191ec8c5 | 228 | |
d482a2d3 | 229 | self.reset_decoder_state() |
191ec8c5 | 230 | |
bcd14870 | 231 | def find_clk_edge(self, miso, mosi, clk, cs): |
efa64173 | 232 | if self.have_cs and self.oldcs != cs: |
191ec8c5 | 233 | # Send all CS# pin value changes. |
c515eed7 | 234 | self.put(self.samplenum, self.samplenum, self.out_python, |
191ec8c5 UH |
235 | ['CS-CHANGE', self.oldcs, cs]) |
236 | self.oldcs = cs | |
efa64173 | 237 | # Reset decoder state when CS# changes (and the CS# pin is used). |
d482a2d3 | 238 | self.reset_decoder_state() |
191ec8c5 UH |
239 | |
240 | # Ignore sample if the clock pin hasn't changed. | |
bcd14870 | 241 | if clk == self.oldclk: |
191ec8c5 | 242 | return |
b1bb5eed | 243 | |
bcd14870 | 244 | self.oldclk = clk |
b1bb5eed | 245 | |
191ec8c5 UH |
246 | # Sample data on rising/falling clock edge (depends on mode). |
247 | mode = spi_mode[self.options['cpol'], self.options['cpha']] | |
bcd14870 | 248 | if mode == 0 and clk == 0: # Sample on rising clock edge |
191ec8c5 | 249 | return |
bcd14870 | 250 | elif mode == 1 and clk == 1: # Sample on falling clock edge |
191ec8c5 | 251 | return |
bcd14870 | 252 | elif mode == 2 and clk == 1: # Sample on falling clock edge |
191ec8c5 | 253 | return |
bcd14870 | 254 | elif mode == 3 and clk == 0: # Sample on rising clock edge |
191ec8c5 UH |
255 | return |
256 | ||
257 | # Found the correct clock edge, now get the SPI bit(s). | |
bcd14870 | 258 | self.handle_bit(miso, mosi, clk, cs) |
191ec8c5 UH |
259 | |
260 | def decode(self, ss, es, data): | |
8a3c8792 BV |
261 | if self.samplerate is None: |
262 | raise Exception("Cannot decode without samplerate.") | |
12549f11 | 263 | # Either MISO or MOSI can be omitted (but not both). CS# is optional. |
191ec8c5 | 264 | for (self.samplenum, pins) in data: |
01329e88 | 265 | |
191ec8c5 UH |
266 | # Ignore identical samples early on (for performance reasons). |
267 | if self.oldpins == pins: | |
268 | continue | |
bcd14870 | 269 | self.oldpins, (clk, miso, mosi, cs) = pins, pins |
12549f11 UH |
270 | self.have_miso = (miso in (0, 1)) |
271 | self.have_mosi = (mosi in (0, 1)) | |
efa64173 | 272 | self.have_cs = (cs in (0, 1)) |
b1bb5eed | 273 | |
9ed11500 UH |
274 | # Either MISO or MOSI (but not both) can be omitted. |
275 | if not (self.have_miso or self.have_mosi): | |
276 | raise Exception('Either MISO or MOSI (or both) pins required.') | |
277 | ||
191ec8c5 UH |
278 | # State machine. |
279 | if self.state == 'IDLE': | |
bcd14870 | 280 | self.find_clk_edge(miso, mosi, clk, cs) |
191ec8c5 UH |
281 | else: |
282 | raise Exception('Invalid state: %s' % self.state) | |
ad2dc0de | 283 |