edid: properly deal with leading I2C crud + small fixes

[libsigrokdecode.git] / decoders / edid / edid.py

diff --git a/decoders/edid/edid.py b/decoders/edid/edid.py
index b3ca128f5bcbbd2be20bb88655b3de31f68221e5..6d53bf1a609baac4d2d4b894d1e0ce99019bc37b 100644 (file)
--- a/decoders/edid/edid.py
+++ b/decoders/edid/edid.py
@@ -17,15 +17,9 @@
 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
 ##
 
-'''
-EDID 1.3 structure decoder.
-
-Details:
-https://en.wikipedia.org/wiki/Extended_display_identification_data
-'''
-
 # TODO:
 #    - EDID < 1.3
+#    - add short annotations
 #    - Signal level standard field in basic display parameters block
 #    - Additional color point descriptors
 #    - Additional standard timing descriptors
@@ -34,6 +28,7 @@ https://en.wikipedia.org/wiki/Extended_display_identification_data
 import sigrokdecode as srd
 import os
 
+
 EDID_HEADER = [0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00]
 OFF_VENDOR = 8
 OFF_VERSION = 18
@@ -45,7 +40,6 @@ OFF_DET_TIMING = 54
 OFF_NUM_EXT = 126
 OFF_CHECKSUM = 127
 
-
 # Pre-EDID established timing modes
 est_modes = [
     "720x400@70Hz",
@@ -79,6 +73,7 @@ xy_ratio = [
 ANN_FIELDS = 0
 ANN_SECTIONS = 1
 
+
 class Decoder(srd.Decoder):
     api_version = 1
     id = 'edid'
@@ -112,6 +107,8 @@ class Decoder(srd.Decoder):
         self.cnt += 1
         self.sn.append( [ss, es] )
         self.cache.append(data)
+        # debug
+#        self.put(ss, es, self.out_ann, [0, ["%d: [%.2x]" % (self.cnt, data)]])
 
         if self.state is None:
             # Wait for the EDID header
@@ -120,6 +117,7 @@ class Decoder(srd.Decoder):
                     # Throw away any garbage before the header
                     self.sn = self.sn[-8:]
                     self.cache = self.cache[-8:]
+                    self.cnt = 8
                     self.state = 'edid'
                     self.put(ss, es, self.out_ann, [0, ["EDID header"]])
         elif self.state == 'edid':
@@ -161,7 +159,7 @@ class Decoder(srd.Decoder):
         self.put(self.sn[start][0], self.sn[end][1], self.out_ann, [ANN_FIELDS, [annotation]])
 
     def lookup_pnpid(self, pnpid):
-        pnpid_file = os.path.dirname(__file__) + '/pnpids.txt'
+        pnpid_file = os.path.join(os.path.dirname(__file__), 'pnpids.txt')
         if os.path.exists(pnpid_file):
             for line in open(pnpid_file).readlines():
                 if line.find(pnpid + ';') == 0:
@@ -406,7 +404,7 @@ class Decoder(srd.Decoder):
                     + (posneg[sync2 & 0x01]) + ')'
         elif sync == 0x03:
             features += 'digital separate ('
-            features += 'Vsync polarity ' + (posneg[sync2 >> 1])
+            features += 'Vsync polarity ' + (posneg[(sync2 & 0x02) >> 1])
             features += ', Hsync polarity ' + (posneg[sync2 & 0x01])
             features += ')'
         features += ', '
@@ -461,7 +459,7 @@ class Decoder(srd.Decoder):
             if self.cache[i] != 0 and self.cache[i+1] != 0:
                 self.decode_detailed_timing(i)
             else:
-                if self.cache[i+2] == 0 or self.cache[i+4] == 0 or True:
+                if self.cache[i+2] == 0 or self.cache[i+4] == 0:
                     self.decode_descriptor(i)