onewire: placing protocol layers into separate directories

3 files changed, 281 insertions, 0 deletions

diff --git a/decoders/onewire_network/Makefile.am b/decoders/onewire_network/Makefile.am
new file mode 100644
index 0000000..17b3b04
--- /dev/null
+++ b/decoders/onewire_network/Makefile.am
@@ -0,0 +1,26 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## 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
+##
+
+pkgdatadir = $(DECODERS_DIR)/onewire
+
+dist_pkgdata_DATA = __init__.py onewire_link.py onewire_network.py
+
+CLEANFILES = *.pyc
+
diff --git a/decoders/onewire_network/__init__.py b/decoders/onewire_network/__init__.py
new file mode 100644
index 0000000..0a712ef
--- /dev/null
+++ b/decoders/onewire_network/__init__.py
@@ -0,0 +1,78 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## 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
+##
+
+'''
+1-Wire protocol decoder.
+
+The 1-Wire protocol enables bidirectional communication over a single wire (and
+ground) between a single master and one or multiple slaves. The protocol is
+layered, the provided parser decodes the next layers:
+- Link layer (reset, presence detection, reading/writing bits)
+- Network layer (skip, search, match device ROM addresses)
+The higher layers (transport, presentation) are not decoded, since they are
+mostly device specific and it would take a lot of code to interpret them.
+
+Sample rate:
+A high enough sample rate is required to properly detect all the elements of
+the protocol. A lower sample rate can be used if the master does not use
+overdrive communication speed. The next minimal values should be used:
+- overdrive     available:   2MHz minimum, 5MHz suggested
+- overdrive not available: 400kHz minimum, 1MHz suggested
+
+Probes:
+1-Wire requires a single signal, but some master implementations might have a
+separate signal use to deliver power to the bus during temperature conversion
+as an example. This power signal is currently not parsed.
+- owr (1-Wire bus)
+- pwr (1-Wire power)
+
+Options:
+1-Wire is an asynchronous protocol, so the decoder must know the sample rate.
+The timing for sampling bits, presence and reset is calculated by the decoder,
+but in case the user wishes to use different values, it is possible to
+configure the next timing values (number of sample rate periods):
+- overdrive              (if active the decoder will be prepared for overdrive)
+- cnt_normal_bit         (time for normal mode sample bit)
+- cnt_normal_presence    (time for normal mode sample presence)
+- cnt_normal_reset       (time for normal mode reset)
+- cnt_overdrive_bit      (time for overdrive mode sample bit)
+- cnt_overdrive_presence (time for overdrive mode sample presence)
+- cnt_overdrive_reset    (time for overdrive mode reset)
+This options should be configured only on very rare cases and the user should
+read the decoder source code to understand them correctly.
+
+Annotations:
+Annotations can be shown for each layer of the protocol separately:
+- link (the value of each transmitted bit is shown separately)
+- network (the ROM command, and address are shown)
+- transport (only transport layer byte transfers are shown)
+If link layer annotations are shown, possible issues with sample rate and sample
+timing are also shown.
+
+TODO:
+- add CRC checks for network layer
+- add transport layer code
+- review link layer code, to check for protocol correctness
+- define output protocol
+'''
+
+from .onewire_link    import *
+from .onewire_network import *
+
diff --git a/decoders/onewire_network/onewire_network.py b/decoders/onewire_network/onewire_network.py
new file mode 100644
index 0000000..836bce9
--- /dev/null
+++ b/decoders/onewire_network/onewire_network.py
@@ -0,0 +1,177 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2012 Iztok Jeras <iztok.jeras@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
+##
+
+# 1-Wire protocol decoder
+
+import sigrokdecode as srd
+
+# Annotation feed formats
+ANN_NETWORK   = 0
+ANN_TRANSPORT = 1
+
+# a dictionary of ROM commands and their names
+rom_command = {0x33: "READ ROM",
+               0x0f: "CONDITIONAL READ ROM",
+               0xcc: "SKIP ROM",
+               0x55: "MATCH ROM",
+               0xf0: "SEARCH ROM",
+               0xec: "CONDITIONAL SEARCH ROM",
+               0x3c: "OVERDRIVE SKIP ROM",
+               0x6d: "OVERDRIVE MATCH ROM"}
+
+class Decoder(srd.Decoder):
+    api_version = 1
+    id = 'onewire_network'
+    name = '1-Wire network layer'
+    longname = '1-Wire serial communication bus'
+    desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
+    license = 'gplv2+'
+    inputs = ['onewire_link']
+    outputs = ['onewire_network']
+    probes = []
+    optional_probes = []
+    options = {}
+    annotations = [
+        ['Network', 'Network layer events (device addressing)'],
+        ['Transport', 'Transport layer events'],
+    ]
+
+    def __init__(self, **kwargs):
+        # Event timing variables
+        self.net_beg = 0
+        self.net_end = 0
+        # Network layer variables
+        self.state   = 'COMMAND'
+        self.bit_cnt = 0
+        self.search  = "P"
+        self.data_p  = 0x0
+        self.data_n  = 0x0
+        self.data    = 0x0
+        self.net_rom = 0x0000000000000000
+
+    def start(self, metadata):
+        self.out_proto = self.add(srd.OUTPUT_PROTO, 'onewire_network')
+        self.out_ann   = self.add(srd.OUTPUT_ANN  , 'onewire_network')
+
+    def report(self):
+        pass
+
+    def decode(self, ss, es, data):
+        [code, val] = data
+
+        # State machine.
+        if (self.code == "RESET"):
+            self.state = "COMMAND"
+            self.search = "P"
+            self.bit_cnt = 0
+        elif (self.code == "BIT"):
+            if (self.state == "COMMAND"):
+                # Receiving and decoding a ROM command
+                if (self.onewire_collect(8, val)):
+                    self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK,
+                      ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, rom_command[self.data])]])
+                    if   (self.data == 0x33):  # READ ROM
+                        self.state = "GET ROM"
+                    elif (self.data == 0x0f):  # CONDITIONAL READ ROM
+                        self.state = "GET ROM"
+                    elif (self.data == 0xcc):  # SKIP ROM
+                        self.state = "TRANSPORT"
+                    elif (self.data == 0x55):  # MATCH ROM
+                        self.state = "GET ROM"
+                    elif (self.data == 0xf0):  # SEARCH ROM
+                        self.state = "SEARCH ROM"
+                    elif (self.data == 0xec):  # CONDITIONAL SEARCH ROM
+                        self.state = "SEARCH ROM"
+                    elif (self.data == 0x3c):  # OVERDRIVE SKIP ROM
+                        self.state = "TRANSPORT"
+                    elif (self.data == 0x69):  # OVERDRIVE MATCH ROM
+                        self.state = "GET ROM"
+            elif (self.state == "GET ROM"):
+                # A 64 bit device address is selected
+                # family code (1B) + serial number (6B) + CRC (1B)
+                if (self.onewire_collect(64, val)):
+                    self.net_rom = self.data & 0xffffffffffffffff
+                    self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
+                    self.state = "TRANSPORT"
+            elif (self.state == "SEARCH ROM"):
+                # A 64 bit device address is searched for
+                # family code (1B) + serial number (6B) + CRC (1B)
+                if (self.onewire_search(64)):
+                    self.net_rom = self.data & 0xffffffffffffffff
+                    self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK, ['ROM: 0x%016x' % self.net_rom]])
+                    self.state = "TRANSPORT"
+            elif (self.state == "TRANSPORT"):
+                # The transport layer is handled in byte sized units
+                if (self.onewire_collect(8, val)):
+                    self.put(self.net_beg, self.net_end, self.out_ann, [ANN_NETWORK  , ['TRANSPORT: 0x%02x' % self.data]])
+                    self.put(self.net_beg, self.net_end, self.out_ann, [ANN_TRANSPORT, ['TRANSPORT: 0x%02x' % self.data]])
+                    self.put(self.net_beg, self.net_end, self.out_proto, ['transfer', self.data])
+                    # TODO: Sending translort layer data to 1-Wire device models
+            else:
+                raise Exception('Invalid state: %s' % self.state)
+
+
+    # Link/Network layer data collector
+    def onewire_collect (self, length, val):
+        # Storing the sampe this sequence begins with
+        if (self.bit_cnt == 1):
+            self.net_beg = self.ss
+        self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+        self.bit_cnt  = self.bit_cnt + 1
+        # Storing the sampe this sequence ends with
+        # In case the full length of the sequence is received, return 1
+        if (self.bit_cnt == length):
+            self.net_end  = self.es
+            self.data = self.data & ((1<<length)-1)
+            self.bit_cnt  = 0
+            return (1)
+        else:
+            return (0)
+
+    # Link/Network layer search collector
+    def onewire_search (self, length):
+        # Storing the sampe this sequence begins with
+        if ((self.bit_cnt == 0) and (self.search == "P")):
+            self.net_beg = self.ss
+        # Master receives an original address bit
+        if   (self.search == "P"):
+          self.data_p = self.data_p & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+          self.search = "N"
+        # Master receives a complemented address bit
+        elif (self.search == "N"):
+          self.data_n = self.data_n & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+          self.search = "D"
+        # Master transmits an address bit
+        elif (self.search == "D"):
+          self.data   = self.data   & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+          self.search = "P"
+          self.bit_cnt    = self.bit_cnt + 1
+        # Storing the sampe this sequence ends with
+        # In case the full length of the sequence is received, return 1
+        if (self.bit_cnt == length):
+            self.net_end = self.es
+            self.data_p = self.data_p & ((1<<length)-1)
+            self.data_n = self.data_n & ((1<<length)-1)
+            self.data   = self.data   & ((1<<length)-1)
+            self.search = "P"
+            self.bit_cnt    = 0
+            return (1)
+        else:
+            return (0)