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nrf24l01: Check for CS# pin and only throw exceptions once.
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1##
2## This file is part of the libsigrokdecode project.
3##
4## Copyright (C) 2014 Jens Steinhauser <jens.steinhauser@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
21import sigrokdecode as srd
22
f04964c6 23class ChannelError(Exception):
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24 pass
25
26regs = {
27# addr: ('name', size)
28 0x00: ('CONFIG', 1),
29 0x01: ('EN_AA', 1),
30 0x02: ('EN_RXADDR', 1),
31 0x03: ('SETUP_AW', 1),
32 0x04: ('SETUP_RETR', 1),
33 0x05: ('RF_CH', 1),
34 0x06: ('RF_SETUP', 1),
35 0x07: ('STATUS', 1),
36 0x08: ('OBSERVE_TX', 1),
37 0x09: ('RPD', 1),
38 0x0a: ('RX_ADDR_P0', 5),
39 0x0b: ('RX_ADDR_P1', 5),
40 0x0c: ('RX_ADDR_P2', 1),
41 0x0d: ('RX_ADDR_P3', 1),
42 0x0e: ('RX_ADDR_P4', 1),
43 0x0f: ('RX_ADDR_P5', 1),
44 0x10: ('TX_ADDR', 5),
45 0x11: ('RX_PW_P0', 1),
46 0x12: ('RX_PW_P1', 1),
47 0x13: ('RX_PW_P2', 1),
48 0x14: ('RX_PW_P3', 1),
49 0x15: ('RX_PW_P4', 1),
50 0x16: ('RX_PW_P5', 1),
51 0x17: ('FIFO_STATUS', 1),
52 0x1c: ('DYNPD', 1),
35b380b1 53 0x1d: ('FEATURE', 1),
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54}
55
56class Decoder(srd.Decoder):
57 api_version = 2
58 id = 'nrf24l01'
35b380b1 59 name = 'nRF24L01(+)'
0e501c70 60 longname = 'Nordic Semiconductor nRF24L01/nRF24L01+'
35b380b1 61 desc = '2.4GHz transceiver chip.'
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62 license = 'gplv2+'
63 inputs = ['spi']
64 outputs = ['nrf24l01']
65 annotations = (
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66 # Sent from the host to the chip.
67 ('cmd', 'Commands sent to the device'),
68 ('tx-data', 'Payload sent to the device'),
0e501c70 69
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70 # Returned by the chip.
71 ('register', 'Registers read from the device'),
72 ('rx-data', 'Payload read from the device'),
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73
74 ('warning', 'Warnings'),
75 )
76 ann_cmd = 0
77 ann_tx = 1
78 ann_reg = 2
79 ann_rx = 3
80 ann_warn = 4
81 annotation_rows = (
82 ('commands', 'Commands', (ann_cmd, ann_tx)),
83 ('responses', 'Responses', (ann_reg, ann_rx)),
84 ('warnings', 'Warnings', (ann_warn,)),
85 )
86
87 def __init__(self, **kwargs):
88 self.next()
3cc4c4a9 89 self.requirements_met = True
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90
91 def start(self):
92 self.out_ann = self.register(srd.OUTPUT_ANN)
93
94 def warn(self, pos, msg):
95 '''Put a warning message 'msg' at 'pos'.'''
96 self.put(pos[0], pos[1], self.out_ann, [self.ann_warn, [msg]])
97
98 def putp(self, pos, ann, msg):
99 '''Put an annotation message 'msg' at 'pos'.'''
100 self.put(pos[0], pos[1], self.out_ann, [ann, [msg]])
101
102 def next(self):
103 '''Resets the decoder after a complete command was decoded.'''
35b380b1 104 # 'True' for the first byte after CS went low.
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105 self.first = True
106
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107 # The current command, and the minimum and maximum number
108 # of data bytes to follow.
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109 self.cmd = None
110 self.min = 0
111 self.max = 0
112
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113 # Used to collect the bytes after the command byte
114 # (and the start/end sample number).
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115 self.mb = []
116 self.mb_s = -1
117 self.mb_e = -1
118
119 def mosi_bytes(self):
120 '''Returns the collected MOSI bytes of a multi byte command.'''
121 return [b[0] for b in self.mb]
122
123 def miso_bytes(self):
124 '''Returns the collected MISO bytes of a multi byte command.'''
125 return [b[1] for b in self.mb]
126
127 def decode_command(self, pos, b):
128 '''Decodes the command byte 'b' at position 'pos' and prepares
129 the decoding of the following data bytes.'''
130 c = self.parse_command(b)
35b380b1 131 if c is None:
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132 self.warn(pos, 'unknown command')
133 return
134
135 self.cmd, self.dat, self.min, self.max = c
136
137 if self.cmd in ('W_REGISTER', 'ACTIVATE'):
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138 # Don't output anything now, the command is merged with
139 # the data bytes following it.
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140 self.mb_s = pos[0]
141 else:
142 self.putp(pos, self.ann_cmd, self.format_command())
143
144 def format_command(self):
145 '''Returns the label for the current command.'''
146 if self.cmd == 'R_REGISTER':
147 reg = regs[self.dat][0] if self.dat in regs else 'unknown register'
8aeedf9e 148 return 'Cmd R_REGISTER "{}"'.format(reg)
0e501c70 149 else:
8aeedf9e 150 return 'Cmd {}'.format(self.cmd)
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151
152 def parse_command(self, b):
153 '''Parses the command byte.
154
155 Returns a tuple consisting of:
156 - the name of the command
157 - additional data needed to dissect the following bytes
158 - minimum number of following bytes
159 - maximum number of following bytes
160 '''
161
162 if (b & 0xe0) in (0b00000000, 0b00100000):
163 c = 'R_REGISTER' if not (b & 0xe0) else 'W_REGISTER'
164 d = b & 0x1f
165 m = regs[d][1] if d in regs else 1
166 return (c, d, 1, m)
167 if b == 0b01010000:
168 # nRF24L01 only
169 return ('ACTIVATE', None, 1, 1)
170 if b == 0b01100001:
171 return ('R_RX_PAYLOAD', None, 1, 32)
172 if b == 0b01100000:
173 return ('R_RX_PL_WID', None, 1, 1)
174 if b == 0b10100000:
175 return ('W_TX_PAYLOAD', None, 1, 32)
176 if b == 0b10110000:
177 return ('W_TX_PAYLOAD_NOACK', None, 1, 32)
178 if (b & 0xf8) == 0b10101000:
179 return ('W_ACK_PAYLOAD', b & 0x07, 1, 32)
180 if b == 0b11100001:
181 return ('FLUSH_TX', None, 0, 0)
182 if b == 0b11100010:
183 return ('FLUSH_RX', None, 0, 0)
184 if b == 0b11100011:
185 return ('REUSE_TX_PL', None, 0, 0)
186 if b == 0b11111111:
187 return ('NOP', None, 0, 0)
188
189 def decode_register(self, pos, ann, regid, data):
190 '''Decodes a register.
191
192 pos -- start and end sample numbers of the register
193 ann -- is the annotation number that is used to output the register.
194 regid -- may be either an integer used as a key for the 'regs'
195 dictionary, or a string directly containing a register name.'
196 data -- is the register content.
197 '''
198
199 if type(regid) == int:
35b380b1 200 # Get the name of the register.
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201 if regid not in regs:
202 self.warn(pos, 'unknown register')
203 return
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204 name = regs[regid][0]
205 else:
206 name = regid
207
35b380b1 208 # Multi byte register come LSByte first.
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209 data = reversed(data)
210
211 if self.cmd == 'W_REGISTER' and ann == self.ann_cmd:
35b380b1 212 # The 'W_REGISTER' command is merged with the following byte(s).
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213 label = '{}: {}'.format(self.format_command(), name)
214 else:
8aeedf9e 215 label = 'Reg {}'.format(name)
0e501c70 216
8aeedf9e 217 self.decode_mb_data(pos, ann, data, label, True)
0e501c70 218
8aeedf9e 219 def decode_mb_data(self, pos, ann, data, label, always_hex):
0e501c70 220 '''Decodes the data bytes 'data' of a multibyte command at position
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221 'pos'. The decoded data is prefixed with 'label'. If 'always_hex' is
222 True, all bytes are decoded as hex codes, otherwise only non
223 printable characters are escaped.'''
224
225 if always_hex:
226 def escape(b):
227 return '{:02X}'.format(b)
228 else:
229 def escape(b):
230 c = chr(b)
231 if not str.isprintable(c):
232 return '\\x{:02X}'.format(b)
233 return c
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234
235 data = ''.join([escape(b) for b in data])
236 text = '{} = "{}"'.format(label, data)
237 self.putp(pos, ann, text)
238
239 def finish_command(self, pos):
240 '''Decodes the remaining data bytes at position 'pos'.'''
241
242 if self.cmd == 'R_REGISTER':
243 self.decode_register(pos, self.ann_reg,
35b380b1 244 self.dat, self.miso_bytes())
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245 elif self.cmd == 'W_REGISTER':
246 self.decode_register(pos, self.ann_cmd,
35b380b1 247 self.dat, self.mosi_bytes())
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248 elif self.cmd == 'R_RX_PAYLOAD':
249 self.decode_mb_data(pos, self.ann_rx,
250 self.miso_bytes(), 'RX payload', False)
251 elif (self.cmd == 'W_TX_PAYLOAD' or
252 self.cmd == 'W_TX_PAYLOAD_NOACK'):
253 self.decode_mb_data(pos, self.ann_tx,
254 self.mosi_bytes(), 'TX payload', False)
255 elif self.cmd == 'W_ACK_PAYLOAD':
256 lbl = 'ACK payload for pipe {}'.format(self.dat)
257 self.decode_mb_data(pos, self.ann_tx,
258 self.mosi_bytes(), lbl, False)
259 elif self.cmd == 'R_RX_PL_WID':
260 msg = 'Payload width = {}'.format(self.mb[0][1])
261 self.putp(pos, self.ann_reg, msg)
262 elif self.cmd == 'ACTIVATE':
263 self.putp(pos, self.ann_cmd, self.format_command())
264 if self.mosi_bytes()[0] != 0x73:
265 self.warn(pos, 'wrong data for "ACTIVATE" command')
266
267 def decode(self, ss, es, data):
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268 if not self.requirements_met:
269 return
270
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271 ptype, data1, data2 = data
272
273 if ptype == 'CS-CHANGE':
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274 if data1 == -1:
275 if data2 == -1:
276 self.requirements_met = False
277 raise ChannelError('CS# pin required.')
278
0e501c70 279 if data1 == 0 and data2 == 1:
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280 # Rising edge, the complete command is transmitted, process
281 # the bytes that were send after the command byte.
0e501c70 282 if self.cmd:
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283 # Check if we got the minimum number of data bytes
284 # after the command byte.
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285 if len(self.mb) < self.min:
286 self.warn((ss, ss), 'missing data bytes')
287 elif self.mb:
288 self.finish_command((self.mb_s, self.mb_e))
289
290 self.next()
291 elif ptype == 'DATA':
35b380b1 292 mosi, miso = data1, data2
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293 pos = (ss, es)
294
35b380b1 295 if miso is None or mosi is None:
3cc4c4a9 296 self.requirements_met = False
f04964c6 297 raise ChannelError('Both MISO and MOSI pins required.')
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298
299 if self.first:
300 self.first = False
35b380b1 301 # First MOSI byte is always the command.
0e501c70 302 self.decode_command(pos, mosi)
35b380b1 303 # First MISO byte is always the status register.
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304 self.decode_register(pos, self.ann_reg, 'STATUS', [miso])
305 else:
306 if not self.cmd or len(self.mb) >= self.max:
307 self.warn(pos, 'excess byte')
308 else:
35b380b1 309 # Collect the bytes after the command byte.
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310 if self.mb_s == -1:
311 self.mb_s = ss
312 self.mb_e = es
313 self.mb.append((mosi, miso))