srd: onewire_network: Cosmetics, simplifications, doc fixes.

2 files changed, 140 insertions, 119 deletions

diff --git a/decoders/onewire_network/__init__.py b/decoders/onewire_network/__init__.py
index 9b6e510..25b3f5d 100644
--- a/decoders/onewire_network/__init__.py
+++ b/decoders/onewire_network/__init__.py
@@ -19,35 +19,44 @@
 ##
 
 '''
-1-Wire protocol decoder.
+1-Wire protocol decoder (network layer).
 
-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.
-- Link layer (reset, presence detection, reading/writing bits)
-- Network layer (skip/search/match device ROM addresses)
-- Transport layer (transport data between 1-Wire master and device)
+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:
 
-Network layer
+ - Link layer (reset, presence detection, reading/writing bits)
+ - Network layer (skip/search/match device ROM addresses)
+ - Transport layer (transport data between 1-Wire master and device)
+
+Network layer:
+
+Protocol output format:
+TODO.
 
 Annotations:
-The next link layer annotations are shown:
-- RESET/PRESENCE True/False
-  The event is marked from the signal negative edge to the end of the reset
-  high period. It is also reported if there are any devices attached to the
-  bus.
-The next network layer annotations are shown:
-- ROM COMMAND val name
-  The requested ROM command is displayed as an 8bit HEX value and by name.
-- ROM val
-  The 64bit value of the addressed device is displayed:
-  family code (1B) + serial number (6B) + CRC (1B)
-- DATA val
-  Data intended for the transport layer is displayed as an 8bit HEX value.
+
+The following link layer annotations are shown:
+
+ - RESET/PRESENCE True/False
+   The event is marked from the signal negative edge to the end of the reset
+   high period. It is also reported if there are any devices attached to the
+   bus.
+
+The following network layer annotations are shown:
+
+ - ROM command <val> <name>
+   The requested ROM command is displayed as an 8bit hex value and by name.
+ - ROM <val>
+   The 64bit value of the addressed device is displayed:
+   Family code (1 byte) + serial number (6 bytes) + CRC (1 byte)
+ - Data <val>
+   Data intended for the transport layer is displayed as an 8bit hex value.
 
 TODO:
-- add CRC checks, to see if there were communication errors on the wire
-- add reporting original/complement address values from the search algorithm
+ - Add CRC checks, to see if there were communication errors on the wire.
+ - Add reporting original/complement address values from the search algorithm.
 '''
 
 from .onewire_network import *
+
diff --git a/decoders/onewire_network/onewire_network.py b/decoders/onewire_network/onewire_network.py
index 9e641fd..a4f6f4a 100644
--- a/decoders/onewire_network/onewire_network.py
+++ b/decoders/onewire_network/onewire_network.py
@@ -18,27 +18,27 @@
 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 ##
 
-# 1-Wire protocol decoder
+# 1-Wire protocol decoder (network layer)
 
 import sigrokdecode as srd
 
-# a dictionary of ROM commands and their names, next state
+# Dictionary of ROM commands and their names, next state.
 command = {
-    0x33: ["READ ROM"              , "GET ROM"   ], 
-    0x0f: ["CONDITIONAL READ ROM"  , "GET ROM"   ],
-    0xcc: ["SKIP ROM"              , "TRANSPORT" ],
-    0x55: ["MATCH ROM"             , "GET ROM"   ],
-    0xf0: ["SEARCH ROM"            , "SEARCH ROM"],
-    0xec: ["CONDITIONAL SEARCH ROM", "SEARCH ROM"],
-    0x3c: ["OVERDRIVE SKIP ROM"    , "TRANSPORT" ],
-    0x6d: ["OVERDRIVE MATCH ROM"   , "GET ROM"   ]
+    0x33: ['READ ROM'              , 'GET ROM'   ],
+    0x0f: ['CONDITIONAL READ ROM'  , 'GET ROM'   ],
+    0xcc: ['SKIP ROM'              , 'TRANSPORT' ],
+    0x55: ['MATCH ROM'             , 'GET ROM'   ],
+    0xf0: ['SEARCH ROM'            , 'SEARCH ROM'],
+    0xec: ['CONDITIONAL SEARCH ROM', 'SEARCH ROM'],
+    0x3c: ['OVERDRIVE SKIP ROM'    , 'TRANSPORT' ],
+    0x6d: ['OVERDRIVE MATCH ROM'   , 'GET ROM'   ],
 }
 
 class Decoder(srd.Decoder):
     api_version = 1
     id = 'onewire_network'
     name = '1-Wire network layer'
-    longname = '1-Wire serial communication bus'
+    longname = '1-Wire serial communication bus (network layer)'
     desc = 'Bidirectional, half-duplex, asynchronous serial bus.'
     license = 'gplv2+'
     inputs = ['onewire_link']
@@ -55,116 +55,128 @@ class Decoder(srd.Decoder):
         self.net_beg = 0
         self.net_end = 0
         # Network layer variables
-        self.state   = 'COMMAND'
+        self.state = 'COMMAND'
         self.bit_cnt = 0
-        self.search  = "P"
-        self.data_p  = 0x0
-        self.data_n  = 0x0
-        self.data    = 0x0
+        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')
+        self.out_ann = self.add(srd.OUTPUT_ANN, 'onewire_network')
 
     def report(self):
         pass
 
+    def putx(self, data):
+        # Helper function for most annotations.
+        self.put(self.net_beg, self.net_end, self.out_ann, data)
+
+    def puty(self, data):
+        # Helper function for most protocol packets.
+        self.put(self.net_beg, self.net_end, self.out_proto, data)
+
     def decode(self, ss, es, data):
-        [code, val] = data
+        code, val = data
 
         # State machine.
-        if (code == "RESET/PRESENCE"):
-            self.search = "P"
+        if code == 'RESET/PRESENCE':
+            self.search = 'P'
             self.bit_cnt = 0
-            self.put(ss, es, self.out_ann, [0, ['RESET/PRESENCE: %s' % ('True' if val else 'False')]])
+            self.put(ss, es, self.out_ann,
+                     [0, ['RESET/PRESENCE: %s' % ('True' if val else 'False')]])
             self.put(ss, es, self.out_proto, ['RESET/PRESENCE', val])
-            self.state = "COMMAND"
-        elif (code == "BIT"):
-            if (self.state == "COMMAND"):
-                # Receiving and decoding a ROM command
-                if (self.onewire_collect(8, val, ss, es)):
-                    if (self.data in command):
-                        self.put(self.net_beg, self.net_end, self.out_ann, [0,
-                          ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, command[self.data][0])]])
+            self.state = 'COMMAND'
+        elif code == 'BIT':
+            if self.state == 'COMMAND':
+                # Receiving and decoding a ROM command.
+                if self.onewire_collect(8, val, ss, es):
+                    if self.data in command:
+                        self.putx([0, ['ROM COMMAND: 0x%02x \'%s\''
+                                  % (self.data, command[self.data][0])]])
                         self.state = command[self.data][1]
                     else:
-                        self.put(self.net_beg, self.net_end, self.out_ann, [0,
-                          ['ROM COMMAND: 0x%02x \'%s\'' % (self.data, 'UNRECOGNIZED')]])
-                        self.state = "COMMAND ERROR"
-            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, ss, es)):
+                        self.putx([0, ['ROM COMMAND: 0x%02x \'%s\''
+                                  % (self.data, 'UNRECOGNIZED')]])
+                        self.state = 'COMMAND ERROR'
+            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, ss, es):
                     self.net_rom = self.data & 0xffffffffffffffff
-                    self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM: 0x%016x' % self.net_rom]])
-                    self.put(self.net_beg, self.net_end, self.out_proto, ['ROM', 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, val, ss, es)):
+                    self.putx([0, ['ROM: 0x%016x' % self.net_rom]])
+                    self.puty(['ROM', 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, val, ss, es):
                     self.net_rom = self.data & 0xffffffffffffffff
-                    self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM: 0x%016x' % self.net_rom]])
-                    self.put(self.net_beg, self.net_end, self.out_proto, ['ROM', 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, ss, es)):
-                    self.put(self.net_beg, self.net_end, self.out_ann, [0, ['DATA: 0x%02x' % self.data]])
-                    self.put(self.net_beg, self.net_end, self.out_proto, ['DATA', self.data])
-            elif (self.state == "COMMAND ERROR"):
-                # Since the command is not recognized, print raw data
-                if (self.onewire_collect(8, val, ss, es)):
-                    self.put(self.net_beg, self.net_end, self.out_ann, [0, ['ROM ERROR DATA: 0x%02x' % self.data]])
+                    self.putx([0, ['ROM: 0x%016x' % self.net_rom]])
+                    self.puty(['ROM', 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, ss, es):
+                    self.putx([0, ['DATA: 0x%02x' % self.data]])
+                    self.puty(['DATA', self.data])
+            elif self.state == 'COMMAND ERROR':
+                # Since the command is not recognized, print raw data.
+                if self.onewire_collect(8, val, ss, es):
+                    self.putx([0, ['ROM ERROR DATA: 0x%02x' % self.data]])
             else:
                 raise Exception('Invalid state: %s' % self.state)
 
-
-    # Link/Network layer data collector
-    def onewire_collect (self, length, val, ss, es):
-        # Storing the sampe this sequence begins with
-        if (self.bit_cnt == 1):
+    # Link/Network layer data collector.
+    def onewire_collect(self, length, val, ss, es):
+        # Storing the sample this sequence begins with.
+        if self.bit_cnt == 1:
             self.net_beg = 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  = es
-            self.data = self.data & ((1<<length)-1)
-            self.bit_cnt  = 0
-            return (1)
+        self.bit_cnt += 1
+        # Storing the sample this sequence ends with.
+        # In case the full length of the sequence is received, return 1.
+        if self.bit_cnt == length:
+            self.net_end = es
+            self.data = self.data & ((1 << length) - 1)
+            self.bit_cnt = 0
+            return 1
         else:
-            return (0)
+            return 0
 
-    # Link/Network layer search collector
-    def onewire_search (self, length, val, ss, es):
-        # Storing the sampe this sequence begins with
-        if ((self.bit_cnt == 0) and (self.search == "P")):
+    # Link/Network layer search collector.
+    def onewire_search(self, length, val, ss, es):
+        # Storing the sample this sequence begins with.
+        if (self.bit_cnt == 0) and (self.search == 'P'):
             self.net_beg = 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):
+
+        if self.search == 'P':
+            # Master receives an original address bit.
+            self.data_p = self.data_p & ~(1 << self.bit_cnt) | \
+                          (val << self.bit_cnt)
+            self.search = 'N'
+        elif self.search == 'N':
+            # Master receives a complemented address bit.
+            self.data_n = self.data_n & ~(1 << self.bit_cnt) | \
+                          (val << self.bit_cnt)
+            self.search = 'D'
+        elif self.search == 'D':
+            # Master transmits an address bit.
+            self.data = self.data & ~(1 << self.bit_cnt) | (val << self.bit_cnt)
+            self.search = 'P'
+            self.bit_cnt += 1
+
+        # Storing the sample this sequence ends with.
+        # In case the full length of the sequence is received, return 1.
+        if self.bit_cnt == length:
             self.net_end = 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)
+            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)
+            return 0