parallel: Enforce that at least one pin must be provided.

[libsigrokdecode.git] / decoders / parallel / pd.py

diff --git a/decoders/parallel/pd.py b/decoders/parallel/pd.py
index 330d5142facb20c579257f23293076abd4a66eeb..cafaefc071b4904718c84ab5e589bb695d005ea5 100644 (file)
--- a/decoders/parallel/pd.py
+++ b/decoders/parallel/pd.py
@@ -54,15 +54,18 @@ Packet:
    word <worditemcount> is 7, and so on.
 '''
 
-def probe_list(num_probes):
+def channel_list(num_channels):
     l = [{'id': 'clk', 'name': 'CLK', 'desc': 'Clock line'}]
-    for i in range(num_probes):
+    for i in range(num_channels):
         d = {'id': 'd%d' % i, 'name': 'D%d' % i, 'desc': 'Data line %d' % i}
         l.append(d)
     return tuple(l)
 
+class ChannelError(Exception):
+    pass
+
 class Decoder(srd.Decoder):
-    api_version = 1
+    api_version = 2
     id = 'parallel'
     name = 'Parallel'
     longname = 'Parallel sync bus'
@@ -70,7 +73,7 @@ class Decoder(srd.Decoder):
     license = 'gplv2+'
     inputs = ['logic']
     outputs = ['parallel']
-    optional_probes = probe_list(8)
+    optional_channels = channel_list(8)
     options = (
         {'id': 'clock_edge', 'desc': 'Clock edge to sample on',
             'default': 'rising', 'values': ('rising', 'falling')},
@@ -92,7 +95,6 @@ class Decoder(srd.Decoder):
         self.oldpins = None
         self.ss_item = self.es_item = None
         self.first = True
-        self.state = 'IDLE'
 
     def start(self):
         self.out_python = self.register(srd.OUTPUT_PYTHON)
@@ -123,7 +125,7 @@ class Decoder(srd.Decoder):
         self.items.append(item)
         self.itemcount += 1
 
-        if self.first == True:
+        if self.first:
             # Save the start sample and item for later (no output yet).
             self.ss_item = self.samplenum
             self.first = False
@@ -181,12 +183,10 @@ class Decoder(srd.Decoder):
                 continue
             self.oldpins = pins
 
-            # State machine.
-            if self.state == 'IDLE':
-                if pins[0] not in (0, 1):
-                    self.handle_bits(pins[1:])
-                else:
-                    self.find_clk_edge(pins[0], pins[1:])
-            else:
-                raise Exception('Invalid state: %s' % self.state)
+            if sum(1 for p in pins if p in (0, 1)) == 0:
+                raise ChannelError('At least one channel has to be supplied.')
 
+            if pins[0] not in (0, 1):
+                self.handle_bits(pins[1:])
+            else:
+                self.find_clk_edge(pins[0], pins[1:])