sdq: use symbolic names for pins and annotation classes

Eliminate magic numbers which are too hard to read and too easy to get
wrong during maintenance. Prefer symbolic identifiers instead for pins
and annotation classes.

diff --git a/decoders/sdq/pd.py b/decoders/sdq/pd.py
index c65faa8bc19ef96dfd2dfb04910223fbee476b70..d37458d0e05d06e27c977d92c39f0aa6180ded30 100644 (file)
--- a/decoders/sdq/pd.py
+++ b/decoders/sdq/pd.py
@@ -23,6 +23,12 @@ import sigrokdecode as srd
 class SamplerateError(Exception):
     pass
 
+class Pin:
+    SDQ, = range(1)
+
+class Ann:
+    BIT, BYTE, BREAK, = range(3)
+
 class Decoder(srd.Decoder):
     api_version = 3
     id = 'sdq'
@@ -45,9 +51,9 @@ class Decoder(srd.Decoder):
         ('break', 'Break'),
     )
     annotation_rows = (
-        ('bits', 'Bits', (0,)),
-        ('bytes', 'Bytes', (1,)),
-        ('breaks', 'Breaks', (2,)),
+        ('bits', 'Bits', (Ann.BIT,)),
+        ('bytes', 'Bytes', (Ann.BYTE,)),
+        ('breaks', 'Breaks', (Ann.BREAK,)),
     )
 
     def puts(self, data):
@@ -77,16 +83,16 @@ class Decoder(srd.Decoder):
 
     def handle_bit(self, bit):
         self.bits.append(bit)
-        self.putetu([0, ['Bit: %d' % bit, '%d' % bit]])
+        self.putetu([Ann.BIT, ['Bit: %d' % bit, '%d' % bit]])
 
         if len(self.bits) == 8:
             byte = bitpack(self.bits)
-            self.putbetu([1, ['Byte: %#04x' % byte, '%#04x' % byte]])
+            self.putbetu([Ann.BYTE, ['Byte: %#04x' % byte, '%#04x' % byte]])
             self.bits = []
             self.bytepos = 0
 
     def handle_break(self):
-        self.puts([2, ['Break', 'BR']])
+        self.puts([Ann.BREAK, ['Break', 'BR']])
         self.bits = []
         self.startsample = self.samplenum
         self.bytepos = 0
@@ -100,14 +106,14 @@ class Decoder(srd.Decoder):
         break_threshold = self.bit_width * 1.2
 
         # Wait until the line is high before inspecting input data.
-        sdq, = self.wait({0: 'h'})
+        sdq, = self.wait({Pin.SDQ: 'h'})
         while True:
             # Get the length of a low pulse (falling to rising edge).
-            sdq, = self.wait({0: 'f'})
+            sdq, = self.wait({Pin.SDQ: 'f'})
             self.startsample = self.samplenum
             if self.bytepos == 0:
                 self.bytepos = self.samplenum
-            sdq, = self.wait({0: 'r'})
+            sdq, = self.wait({Pin.SDQ: 'r'})
 
             # Check for 0 or 1 data bits, or the BREAK symbol.
             delta = self.samplenum - self.startsample