add support for decode spi dual/quad

mfont-bz17 · mfont-bz17 · commit f4435ab93a7e · 2023-04-11T15:47:26.000+02:00
diff --git a/spi_dual_quad/__init__.py b/spi_dual_quad/__init__.py
@@ -0,0 +1,30 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2023 Marc Font Freixa <mfont@bz17.dev>
+##
+## 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, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+The SPI Dual/Quad (Serial Peripheral Interface) protocol decoder supports synchronous
+SPI(-like) protocols with a clock line, a SIO0, SIO1, SIO2, SIO3 lines for data
+transfer in two directions, and an optional CS# pin.
+
+If CS# is supplied, data is only decoded when CS# is asserted (clock
+transitions where CS# is not asserted are ignored). If CS# is not supplied,
+data is decoded on every clock transition (depending on SPI mode).
+'''
+
+from .pd import Decoder
diff --git a/spi_dual_quad/pd.py b/spi_dual_quad/pd.py
@@ -0,0 +1,356 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2023 Marc Font Freixa <mfont@bz17.dev>
+##
+## 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, see <http://www.gnu.org/licenses/>.
+##
+
+import sigrokdecode as srd
+from collections import namedtuple
+
+Data = namedtuple('Data', ['ss', 'es', 'val'])
+
+'''
+OUTPUT_PYTHON format:
+
+Packet:
+[<ptype>, <data1>, <data2>]
+
+<ptype>:
+ - 'DATA': <data1> contains the spi data.
+   The data is _usually_ 8 bits (but can also be fewer or more bits).
+   Both data items are Python numbers (not strings), or None if the respective
+   channel was not supplied.
+ - 'BITS': <data1>/<data2> contain a list of bit values in this sio0/sio1/sio2/sio3 data
+   item, and for each of those also their respective start-/endsample numbers.
+ - 'CS-CHANGE': <data1> is the old CS# pin value, <data2> is the new value.
+   Both data items are Python numbers (0/1), not strings. At the beginning of
+   the decoding a packet is generated with <data1> = None and <data2> being the
+   initial state of the CS# pin or None if the chip select pin is not supplied.
+ - 'TRANSFER': <data1> contain a list of Data() namedtuples for each
+   byte transferred during this block of CS# asserted time. Each Data() has
+   fields ss, es, and val.
+
+Examples:
+ ['CS-CHANGE', None, 1]
+ ['CS-CHANGE', 1, 0]
+ ['DATA', 0xff]
+ ['BITS', [[1, 80, 82], [1, 83, 84], [1, 85, 86], [1, 87, 88],
+           [1, 89, 90], [1, 91, 92], [1, 93, 94], [1, 95, 96]],
+          [[0, 80, 82], [1, 83, 84], [0, 85, 86], [1, 87, 88],
+           [1, 89, 90], [1, 91, 92], [0, 93, 94], [0, 95, 96]]]
+ ['DATA', 0x65]
+ ['DATA', 0xa8]
+ ['DATA', 0x55]
+ ['CS-CHANGE', 0, 1]
+ ['TRANSFER', [Data(ss=80, es=96, val=0xff), ...]]
+'''
+
+# Key: (CPOL, CPHA). Value: SPI mode.
+# Clock polarity (CPOL) = 0/1: Clock is low/high when inactive.
+# Clock phase (CPHA) = 0/1: Data is valid on the leading/trailing clock edge.
+spi_mode = {
+    (0, 0): 0, # Mode 0
+    (0, 1): 1, # Mode 1
+    (1, 0): 2, # Mode 2
+    (1, 1): 3, # Mode 3
+}
+
+ann_spi_data, ann_spi_sio0, ann_spi_sio1, ann_spi_sio2, ann_spi_sio3, ann_spi_other, ann_spi_xfer = range(7)
+
+class ChannelError(Exception):
+    pass
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'spi-dual-quad'
+    name = 'SPI Dual/Quad'
+    longname = 'Dual/Quad Serial Peripheral Interface'
+    desc = 'Full-duplex, synchronous, serial bus.'
+    license = 'gplv2+'
+    inputs = ['logic']
+    outputs = ['spi']
+    tags = ['Embedded/industrial']
+    channels = (
+        {'id': 'clk', 'name': 'CLK', 'desc': 'Clock'},
+        {'id': 'sio0', 'name': 'SIO0', 'desc': 'SPI Input/Output 0'},
+        {'id': 'sio1', 'name': 'SIO1', 'desc': 'SPI Input/Output 1'},
+    )
+    optional_channels = (
+        {'id': 'sio2', 'name': 'SIO2', 'desc': 'SPI Input/Output 2'},
+        {'id': 'sio3', 'name': 'SIO3', 'desc': 'SPI Input/Output 3'},
+        {'id': 'cs', 'name': 'CS#', 'desc': 'Chip-select'},
+    )
+    options = (
+        {'id': 'cs_polarity', 'desc': 'CS# polarity', 'default': 'active-low',
+            'values': ('active-low', 'active-high')},
+        {'id': 'cpol', 'desc': 'Clock polarity', 'default': 0,
+            'values': (0, 1)},
+        {'id': 'cpha', 'desc': 'Clock phase', 'default': 0,
+            'values': (0, 1)},
+        {'id': 'bitorder', 'desc': 'Bit order',
+            'default': 'msb-first', 'values': ('msb-first', 'lsb-first')},
+        {'id': 'wordsize', 'desc': 'Word size', 'default': 8},
+    )
+    annotations = (
+        ('spi-data', 'SPI data'),
+        ('sio0-bit', 'SIO0 bit'),
+        ('sio1-bit', 'SIO1 bit'),
+        ('sio2-bit', 'SIO2 bit'),
+        ('sio3-bit', 'SIO3 bit'),
+        ('warning', 'Warning'),
+        ('spi-transfer', 'SPI transfer'),
+    )
+    annotation_rows = (
+        ('sio0-bits', 'SIO0 bits', (ann_spi_sio0,)),
+        ('sio1-bits', 'SIO1 bits', (ann_spi_sio1,)),
+        ('sio2-bits', 'SIO2 bits', (ann_spi_sio2,)),
+        ('sio3-bits', 'SIO3 bits', (ann_spi_sio3,)),
+        ('spi-data-vals', 'SPI data', (ann_spi_data,)),
+        ('spi-transfers', 'SPI transfers', (ann_spi_xfer,)),
+        ('other', 'Other', (ann_spi_other,)),
+    )
+    binary = (
+        ('spi-data', 'SPI Data'),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.samplerate = None
+        self.bitcount = 0
+        self.spidata = 0
+        self.sio0bits = []
+        self.sio1bits = []
+        self.sio2bits = []
+        self.sio3bits = []
+        self.spibytes = []
+        self.ss_block = -1
+        self.ss_transfer = -1
+        self.cs_was_deasserted = False
+        self.have_cs = None
+        self.is_quad = None
+
+    def start(self):
+        self.out_python = self.register(srd.OUTPUT_PYTHON)
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+        self.out_binary = self.register(srd.OUTPUT_BINARY)
+        self.out_bitrate = self.register(srd.OUTPUT_META,
+                meta=(int, 'Bitrate', 'Bitrate during transfers'))
+        self.bw = (self.options['wordsize'] + 7) // 8
+
+    def metadata(self, key, value):
+       if key == srd.SRD_CONF_SAMPLERATE:
+            self.samplerate = value
+
+    def putw(self, data):
+        self.put(self.ss_block, self.samplenum, self.out_ann, data)
+
+    def putdata(self):
+        # Pass sio0/sio1/sio2/sio3 bits and then data to the next PD up the stack.
+        data = self.spidata
+        sio0_bits = self.sio0bits
+        sio1_bits = self.sio1bits
+        sio2_bits = self.sio2bits
+        sio3_bits = self.sio3bits
+
+        ss, es = self.sio0bits[-1][1], self.sio0bits[0][2]
+        bdata = data.to_bytes(self.bw, byteorder='big')
+        self.put(ss, es, self.out_binary, [0, bdata])
+        if self.is_quad:
+            self.put(ss, es, self.out_python, ['BITS', sio3_bits, sio2_bits, sio1_bits, sio0_bits])
+        else:
+            self.put(ss, es, self.out_python, ['BITS', sio1_bits, sio0_bits])
+        self.put(ss, es, self.out_python, ['DATA', data])
+
+        self.spibytes.append(Data(ss=ss, es=es, val=data))
+
+        # Bit annotations.
+        for bit in self.sio0bits:
+            self.put(bit[1], bit[2], self.out_ann, [ann_spi_sio0, ['%d' % bit[0]]])
+        for bit in self.sio1bits:
+            self.put(bit[1], bit[2], self.out_ann, [ann_spi_sio1, ['%d' % bit[0]]])
+
+        if self.is_quad:
+            for bit in self.sio2bits:
+                self.put(bit[1], bit[2], self.out_ann, [ann_spi_sio2, ['%d' % bit[0]]])
+            for bit in self.sio3bits:
+                self.put(bit[1], bit[2], self.out_ann, [ann_spi_sio3, ['%d' % bit[0]]])
+
+        # Dataword annotations.
+        self.put(ss, es, self.out_ann, [ann_spi_data, ['%02X' % self.spidata]])
+
+    def reset_decoder_state(self):
+        self.spidata = 0
+        self.sio0bits = []
+        self.sio1bits = []
+        self.sio2bits = []
+        self.sio3bits = []
+        self.bitcount = 0
+
+    def cs_asserted(self, cs):
+        active_low = (self.options['cs_polarity'] == 'active-low')
+        return (cs == 0) if active_low else (cs == 1)
+
+    def handle_bit(self, sio0, sio1, sio2, sio3, clk, cs):
+        # If this is the first bit of a dataword, save its sample number.
+        if self.bitcount == 0:
+            self.ss_block = self.samplenum
+            self.cs_was_deasserted = \
+                not self.cs_asserted(cs) if self.have_cs else False
+
+        ws = self.options['wordsize']
+        bo = self.options['bitorder']
+
+        if self.is_quad:
+            # Quad SPI SIO0 bits 4,0
+            # Quad SPI SIO1 bits 5,1
+            # Quad SPI SIO2 bits 6,2
+            # Quad SPI SIO3 bits 7,3
+            if bo == 'msb-first':
+                self.spidata |= sio3 << (ws - 1 - self.bitcount)
+                self.spidata |= sio2 << (ws - 1 - self.bitcount - 1)
+                self.spidata |= sio1 << (ws - 1 - self.bitcount - 2)
+                self.spidata |= sio0 << (ws - 1 - self.bitcount - 3)
+            else:
+                self.spidata |= sio3 << self.bitcount
+                self.spidata |= sio2 << (self.bitcount + 1)
+                self.spidata |= sio1 << (self.bitcount + 2)
+                self.spidata |= sio0 << (self.bitcount + 3)
+        else:
+            # Dual SPI SIO0 bits 6,4,2,0
+            # Dual SPI SIO1 bits 7,5,3,1
+            if bo == 'msb-first':
+                self.spidata |= sio1 << (ws - 1 - self.bitcount)
+                self.spidata |= sio0 << (ws - 1 - self.bitcount - 1)
+            else:
+                self.spidata |= sio1 << self.bitcount
+                self.spidata |= sio0 << (self.bitcount + 1)
+
+        # Guesstimate the endsample for this bit (can be overridden below).
+        es = self.samplenum
+        if self.bitcount > 0:
+            es += self.samplenum - self.sio0bits[0][1]
+
+        self.sio0bits.insert(0, [sio0, self.samplenum, es])
+        self.sio1bits.insert(0, [sio1, self.samplenum, es])
+        if self.is_quad:
+            self.sio2bits.insert(0, [sio2, self.samplenum, es])
+            self.sio3bits.insert(0, [sio3, self.samplenum, es])
+
+        if self.bitcount > 0:
+            self.sio0bits[1][2] = self.samplenum
+            self.sio1bits[1][2] = self.samplenum
+            if self.is_quad:
+                self.sio2bits[1][2] = self.samplenum
+                self.sio3bits[1][2] = self.samplenum
+
+        if self.is_quad:
+            self.bitcount += 4
+        else:
+            self.bitcount += 2
+
+        # Continue to receive if not enough bits were received, yet.
+        if self.bitcount != ws:
+            return
+
+        self.putdata()
+
+        # Meta bitrate.
+        if self.samplerate:
+            elapsed = 1 / float(self.samplerate)
+            elapsed *= (self.samplenum - self.ss_block + 1)
+            bitrate = int(1 / elapsed * ws)
+            self.put(self.ss_block, self.samplenum, self.out_bitrate, bitrate)
+
+        if self.have_cs and self.cs_was_deasserted:
+            self.putw([ann_spi_other, ['CS# was deasserted during this data word!']])
+
+        self.reset_decoder_state()
+
+    def find_clk_edge(self, sio0, sio1, sio2, sio3, clk, cs, first):
+        if self.have_cs and (first or self.matched[self.have_cs]):
+            # Send all CS# pin value changes.
+            oldcs = None if first else 1 - cs
+            self.put(self.samplenum, self.samplenum, self.out_python,
+                     ['CS-CHANGE', oldcs, cs])
+
+            if self.cs_asserted(cs):
+                self.ss_transfer = self.samplenum
+                self.spibytes = []
+            elif self.ss_transfer != -1:
+                self.put(self.ss_transfer, self.samplenum, self.out_ann,
+                    [ann_spi_xfer, [' '.join(format(x.val, '02X') for x in self.spibytes)]])
+                self.put(self.ss_transfer, self.samplenum, self.out_python,
+                    ['TRANSFER', self.spibytes])
+
+            # Reset decoder state when CS# changes (and the CS# pin is used).
+            self.reset_decoder_state()
+
+        # We only care about samples if CS# is asserted.
+        if self.have_cs and not self.cs_asserted(cs):
+            return
+
+        # Ignore sample if the clock pin hasn't changed.
+        if first or not self.matched[0]:
+            return
+
+        # Sample data on rising/falling clock edge (depends on mode).
+        mode = spi_mode[self.options['cpol'], self.options['cpha']]
+        if mode == 0 and clk == 0:   # Sample on rising clock edge
+            return
+        elif mode == 1 and clk == 1: # Sample on falling clock edge
+            return
+        elif mode == 2 and clk == 1: # Sample on falling clock edge
+            return
+        elif mode == 3 and clk == 0: # Sample on rising clock edge
+            return
+
+        # Found the correct clock edge, now get the SPI bit(s).
+        self.handle_bit(sio0, sio1, sio2, sio3, clk, cs)
+
+    def decode(self):
+        # The CLK input is mandatory. SIO0 and SIO1 are mandatory for Dual SPI.
+        if not self.has_channel(0) and not self.has_channel(1) and not self.has_channel(2):
+            raise ChannelError('For Dual SPI SIO0 and SIO1 are pins required.')
+        # The CLK input is mandatory. SIO3 and SIO4 are mandatory for Quad SPI.
+        if (self.has_channel(3) and not self.has_channel(4)) or (self.has_channel(4) and not self.has_channel(3)):
+            raise ChannelError('For Quad SPI SIO2 and SIO3 are pins required.')
+
+        # Mark that SPI is Quad
+        self.is_quad = self.has_channel(3) and self.has_channel(4)
+        self.have_cs = self.has_channel(5)
+        if not self.have_cs:
+            self.put(0, 0, self.out_python, ['CS-CHANGE', None, None])
+
+        # We want all CLK changes. We want all CS changes if CS is used.
+        # Map 'have_cs' from boolean to an integer index. This simplifies
+        # evaluation in other locations.
+        wait_cond = [{0: 'e'}]
+        if self.have_cs:
+            self.have_cs = len(wait_cond)
+            wait_cond.append({5: 'e'})
+
+        # "Pixel compatibility" with the v2 implementation. Grab and
+        # process the very first sample before checking for edges. The
+        # previous implementation did this by seeding old values with
+        # None, which led to an immediate "change" in comparison.
+        (clk, sio0, sio1, sio2, sio3, cs) = self.wait({})
+        self.find_clk_edge(sio0, sio1, sio2, sio3, clk, cs, True)
+
+        while True:
+            (clk, sio0, sio1, sio2, sio3, cs) = self.wait(wait_cond)
+            self.find_clk_edge(sio0, sio1, sio2, sio3, clk, cs, False)
