Add nRF24L01(+) protocol decoder.

1 files changed, 300 insertions, 0 deletions

diff --git a/decoders/nrf24l01/pd.py b/decoders/nrf24l01/pd.py
new file mode 100644
index 0000000..39a6808
--- /dev/null
+++ b/decoders/nrf24l01/pd.py
@@ -0,0 +1,300 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2014 Jens Steinhauser <jens.steinhauser@gmail.com>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, write to the Free Software
+## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+##
+
+import sigrokdecode as srd
+
+class MissingDataError(Exception):
+    pass
+
+regs = {
+#   addr: ('name',        size)
+    0x00: ('CONFIG',      1),
+    0x01: ('EN_AA',       1),
+    0x02: ('EN_RXADDR',   1),
+    0x03: ('SETUP_AW',    1),
+    0x04: ('SETUP_RETR',  1),
+    0x05: ('RF_CH',       1),
+    0x06: ('RF_SETUP',    1),
+    0x07: ('STATUS',      1),
+    0x08: ('OBSERVE_TX',  1),
+    0x09: ('RPD',         1),
+    0x0a: ('RX_ADDR_P0',  5),
+    0x0b: ('RX_ADDR_P1',  5),
+    0x0c: ('RX_ADDR_P2',  1),
+    0x0d: ('RX_ADDR_P3',  1),
+    0x0e: ('RX_ADDR_P4',  1),
+    0x0f: ('RX_ADDR_P5',  1),
+    0x10: ('TX_ADDR',     5),
+    0x11: ('RX_PW_P0',    1),
+    0x12: ('RX_PW_P1',    1),
+    0x13: ('RX_PW_P2',    1),
+    0x14: ('RX_PW_P3',    1),
+    0x15: ('RX_PW_P4',    1),
+    0x16: ('RX_PW_P5',    1),
+    0x17: ('FIFO_STATUS', 1),
+    0x1c: ('DYNPD',       1),
+    0x1d: ('FEATURE',     1)
+}
+
+class Decoder(srd.Decoder):
+    api_version = 2
+    id = 'nrf24l01'
+    name = 'NRF24L01(+)'
+    longname = 'Nordic Semiconductor nRF24L01/nRF24L01+'
+    desc = '2.4 GHz transceiver chip.'
+    license = 'gplv2+'
+    inputs = ['spi']
+    outputs = ['nrf24l01']
+    annotations = (
+        # sent from the host to the chip
+        ('cmd', 'Commands send to the device.'),
+        ('tx-data', 'Payload send to the device.'),
+
+        # returned by the chip
+        ('register', 'Registers read from the device.'),
+        ('rx-data', 'Payload read from the device.'),
+
+        ('warning', 'Warnings'),
+    )
+    ann_cmd = 0
+    ann_tx = 1
+    ann_reg = 2
+    ann_rx = 3
+    ann_warn = 4
+    annotation_rows = (
+        ('commands', 'Commands', (ann_cmd, ann_tx)),
+        ('responses', 'Responses', (ann_reg, ann_rx)),
+        ('warnings', 'Warnings', (ann_warn,)),
+    )
+
+    def __init__(self, **kwargs):
+        self.next()
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+
+    def warn(self, pos, msg):
+        '''Put a warning message 'msg' at 'pos'.'''
+        self.put(pos[0], pos[1], self.out_ann, [self.ann_warn, [msg]])
+
+    def putp(self, pos, ann, msg):
+        '''Put an annotation message 'msg' at 'pos'.'''
+        self.put(pos[0], pos[1], self.out_ann, [ann, [msg]])
+
+    def next(self):
+        '''Resets the decoder after a complete command was decoded.'''
+        # 'True' for the first byte after CS went low
+        self.first = True
+
+        # the current command, and the minimum and maximum number
+        # of data bytes to follow
+        self.cmd = None
+        self.min = 0
+        self.max = 0
+
+        # used to collect the bytes after the command byte
+        # (and the start/end sample number)
+        self.mb = []
+        self.mb_s = -1
+        self.mb_e = -1
+
+    def mosi_bytes(self):
+        '''Returns the collected MOSI bytes of a multi byte command.'''
+        return [b[0] for b in self.mb]
+
+    def miso_bytes(self):
+        '''Returns the collected MISO bytes of a multi byte command.'''
+        return [b[1] for b in self.mb]
+
+    def decode_command(self, pos, b):
+        '''Decodes the command byte 'b' at position 'pos' and prepares
+        the decoding of the following data bytes.'''
+        c = self.parse_command(b)
+        if c == None:
+            self.warn(pos, 'unknown command')
+            return
+
+        self.cmd, self.dat, self.min, self.max = c
+
+        if self.cmd in ('W_REGISTER', 'ACTIVATE'):
+            # don't output anything now, the command is merged with
+            # the data bytes following it
+            self.mb_s = pos[0]
+        else:
+            self.putp(pos, self.ann_cmd, self.format_command())
+
+    def format_command(self):
+        '''Returns the label for the current command.'''
+        if self.cmd == 'R_REGISTER':
+            reg = regs[self.dat][0] if self.dat in regs else 'unknown register'
+            return 'Cmd. R_REGISTER "{}"'.format(reg)
+        else:
+            return 'Cmd. {}'.format(self.cmd)
+
+    def parse_command(self, b):
+        '''Parses the command byte.
+
+        Returns a tuple consisting of:
+        - the name of the command
+        - additional data needed to dissect the following bytes
+        - minimum number of following bytes
+        - maximum number of following bytes
+        '''
+
+        if (b & 0xe0) in (0b00000000, 0b00100000):
+            c = 'R_REGISTER' if not (b & 0xe0) else 'W_REGISTER'
+            d = b & 0x1f
+            m = regs[d][1] if d in regs else 1
+            return (c, d, 1, m)
+        if b == 0b01010000:
+            # nRF24L01 only
+            return ('ACTIVATE', None, 1, 1)
+        if b == 0b01100001:
+            return ('R_RX_PAYLOAD', None, 1, 32)
+        if b == 0b01100000:
+            return ('R_RX_PL_WID', None, 1, 1)
+        if b == 0b10100000:
+            return ('W_TX_PAYLOAD', None, 1, 32)
+        if b == 0b10110000:
+            return ('W_TX_PAYLOAD_NOACK', None, 1, 32)
+        if (b & 0xf8) == 0b10101000:
+            return ('W_ACK_PAYLOAD', b & 0x07, 1, 32)
+        if b == 0b11100001:
+            return ('FLUSH_TX', None, 0, 0)
+        if b == 0b11100010:
+            return ('FLUSH_RX', None, 0, 0)
+        if b == 0b11100011:
+            return ('REUSE_TX_PL', None, 0, 0)
+        if b == 0b11111111:
+            return ('NOP', None, 0, 0)
+
+    def decode_register(self, pos, ann, regid, data):
+        '''Decodes a register.
+
+        pos   -- start and end sample numbers of the register
+        ann   -- is the annotation number that is used to output the register.
+        regid -- may be either an integer used as a key for the 'regs'
+                 dictionary, or a string directly containing a register name.'
+        data  -- is the register content.
+        '''
+
+        if type(regid) == int:
+            # get the name of the register
+            if regid not in regs:
+                self.warn(pos, 'unknown register')
+                return
+
+            name = regs[regid][0]
+        else:
+            name = regid
+
+        # multi byte register come LSByte first
+        data = reversed(data)
+
+        if self.cmd == 'W_REGISTER' and ann == self.ann_cmd:
+            # the 'W_REGISTER' command is merged with the following byte(s)
+            label = '{}: {}'.format(self.format_command(), name)
+        else:
+            label = 'Reg. {}'.format(name)
+
+        self.decode_mb_data(pos, ann, data, label)
+
+    def decode_mb_data(self, pos, ann, data, label, escape_all=True):
+        '''Decodes the data bytes 'data' of a multibyte command at position
+        'pos'. The decoded data is prefixed with 'label'. If 'excape_all' is
+        True, all data bytes are escaped as hex codes.'''
+
+        def escape(b):
+            c = chr(b)
+            if escape_all or not str.isprintable(c):
+                return '\\x{:02X}'.format(b)
+            return c
+
+        data = ''.join([escape(b) for b in data])
+        text = '{} = "{}"'.format(label, data)
+        self.putp(pos, ann, text)
+
+    def finish_command(self, pos):
+        '''Decodes the remaining data bytes at position 'pos'.'''
+
+        if self.cmd == 'R_REGISTER':
+            self.decode_register(pos, self.ann_reg,
+                                 self.dat, self.miso_bytes());
+        elif self.cmd == 'W_REGISTER':
+            self.decode_register(pos, self.ann_cmd,
+                                 self.dat, self.mosi_bytes());
+        elif self.cmd == 'R_RX_PAYLOAD':
+            self.decode_mb_data(pos, self.ann_rx,
+                                self.miso_bytes(), 'RX payload', False)
+        elif (self.cmd == 'W_TX_PAYLOAD' or
+              self.cmd == 'W_TX_PAYLOAD_NOACK'):
+            self.decode_mb_data(pos, self.ann_tx,
+                                self.mosi_bytes(), 'TX payload', False)
+        elif self.cmd == 'W_ACK_PAYLOAD':
+            lbl = 'ACK payload for pipe {}'.format(self.dat)
+            self.decode_mb_data(pos, self.ann_tx,
+                                self.mosi_bytes(), lbl, False)
+        elif self.cmd == 'R_RX_PL_WID':
+            msg = 'Payload width = {}'.format(self.mb[0][1])
+            self.putp(pos, self.ann_reg, msg)
+        elif self.cmd == 'ACTIVATE':
+            self.putp(pos, self.ann_cmd, self.format_command())
+            if self.mosi_bytes()[0] != 0x73:
+                self.warn(pos, 'wrong data for "ACTIVATE" command')
+
+    def decode(self, ss, es, data):
+        ptype, data1, data2 = data
+
+        if ptype == 'CS-CHANGE':
+            if data1 == 0 and data2 == 1:
+                # rising edge, the complete command is transmitted, process
+                # the bytes that were send after the command byte
+                if self.cmd:
+                    # check if we got the minimum number of data bytes
+                    # after the command byte
+                    if len(self.mb) < self.min:
+                        self.warn((ss, ss), 'missing data bytes')
+                    elif self.mb:
+                        self.finish_command((self.mb_s, self.mb_e))
+
+                self.next()
+        elif ptype == 'DATA':
+            mosi = data1
+            miso = data2
+            pos = (ss, es)
+
+            if miso == None or mosi == None:
+                raise MissingDataError('Both MISO and MOSI pins required.')
+
+            if self.first:
+                self.first = False
+                # first MOSI byte is always the command
+                self.decode_command(pos, mosi)
+                # first MISO byte is always the status register
+                self.decode_register(pos, self.ann_reg, 'STATUS', [miso])
+            else:
+                if not self.cmd or len(self.mb) >= self.max:
+                    self.warn(pos, 'excess byte')
+                else:
+                    # collect the bytes after the command byte
+                    if self.mb_s == -1:
+                        self.mb_s = ss
+                    self.mb_e = es
+                    self.mb.append((mosi, miso))