X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=decoders%2Fi2c%2Fpd.py;h=60e9c452cd711524de5d0561f4d4d86e4d9700d4;hb=a929afa618be52072786b51f1b9ea7be03edcd49;hp=2500ae4cc6e036a7620a1dd5e2c0c830a3b05af7;hpb=d94ff143ef7725388299ef9bd3be7ebc60e0dd2e;p=libsigrokdecode.git

diff --git a/decoders/i2c/pd.py b/decoders/i2c/pd.py
index 2500ae4..60e9c45 100644
--- a/decoders/i2c/pd.py
+++ b/decoders/i2c/pd.py
@@ -21,17 +21,35 @@
 # I2C protocol decoder
 
 # TODO: Look into arbitration, collision detection, clock synchronisation, etc.
-# TODO: Handle clock stretching.
-# TODO: Handle combined messages / repeated START.
-# TODO: Implement support for 7bit and 10bit slave addresses.
+# TODO: Implement support for 10bit slave addresses.
 # TODO: Implement support for inverting SDA/SCL levels (0->1 and 1->0).
 # TODO: Implement support for detecting various bus errors.
-# TODO: I2C address of slaves.
-# TODO: Handle multiple different I2C devices on same bus
-#       -> we need to decode multiple protocols at the same time.
 
 import sigrokdecode as srd
 
+'''
+Protocol output format:
+
+I2C packet:
+[<cmd>, <data>]
+
+<cmd> is one of:
+ - 'START' (START condition)
+ - 'START REPEAT' (Repeated START condition)
+ - 'ADDRESS READ' (Slave address, read)
+ - 'ADDRESS WRITE' (Slave address, write)
+ - 'DATA READ' (Data, read)
+ - 'DATA WRITE' (Data, write)
+ - 'STOP' (STOP condition)
+ - 'ACK' (ACK bit)
+ - 'NACK' (NACK bit)
+
+<data> is the data or address byte associated with the 'ADDRESS*' and 'DATA*'
+command. Slave addresses do not include bit 0 (the READ/WRITE indication bit).
+For example, a slave address field could be 0x51 (instead of 0xa2).
+For 'START', 'START REPEAT', 'STOP', 'ACK', and 'NACK' <data> is None.
+'''
+
 # CMD: [annotation-type-index, long annotation, short annotation]
 proto = {
     'START':           [0, 'Start',         'S'],
@@ -60,7 +78,6 @@ class Decoder(srd.Decoder):
     ]
     optional_probes = []
     options = {
-        'addressing': ['Slave addressing (in bits)', 7], # 7 or 10
         'address_format': ['Displayed slave address format', 'shifted'],
     }
     annotations = [
@@ -75,8 +92,15 @@ class Decoder(srd.Decoder):
         ['Data write', 'Data write'],
         ['Warnings', 'Human-readable warnings'],
     ]
+    binary = (
+        'Address read',
+        'Address write',
+        'Data read',
+        'Data write',
+    )
 
     def __init__(self, **kwargs):
+        self.samplerate = None
         self.startsample = -1
         self.samplenum = None
         self.bitcount = 0
@@ -87,13 +111,19 @@ class Decoder(srd.Decoder):
         self.oldscl = 1
         self.oldsda = 1
         self.oldpins = [1, 1]
+        self.pdu_start = None
+        self.pdu_bits = 0
 
-    def start(self, metadata):
-        self.out_proto = self.add(srd.OUTPUT_PROTO, 'i2c')
-        self.out_ann = self.add(srd.OUTPUT_ANN, 'i2c')
+    def metadata(self, key, value):
+        if key == srd.SRD_CONF_SAMPLERATE:
+            self.samplerate = value
 
-    def report(self):
-        pass
+    def start(self):
+        self.out_proto = self.register(srd.OUTPUT_PYTHON)
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+        self.out_binary = self.add(srd.OUTPUT_BINARY)
+        self.out_bitrate = self.register(srd.OUTPUT_META,
+                meta=(int, 'Bitrate', 'Bitrate from Start bit to Stop bit'))
 
     def putx(self, data):
         self.put(self.startsample, self.samplenum, self.out_ann, data)
@@ -101,6 +131,9 @@ class Decoder(srd.Decoder):
     def putp(self, data):
         self.put(self.startsample, self.samplenum, self.out_proto, data)
 
+    def putb(self, data):
+        self.put(self.startsample, self.samplenum, self.out_binary, data)
+
     def is_start_condition(self, scl, sda):
         # START condition (S): SDA = falling, SCL = high
         if (self.oldsda == 1 and sda == 0) and scl == 1:
@@ -121,6 +154,8 @@ class Decoder(srd.Decoder):
 
     def found_start(self, scl, sda):
         self.startsample = self.samplenum
+        self.pdu_start = self.samplenum
+        self.pdu_bits = 0
         cmd = 'START REPEAT' if (self.is_repeat_start == 1) else 'START'
         self.putp([cmd, None])
         self.putx([proto[cmd][0], proto[cmd][1:]])
@@ -153,18 +188,24 @@ class Decoder(srd.Decoder):
             if self.options['address_format'] == 'shifted':
                 d = d >> 1
 
+        bin_class = -1
         if self.state == 'FIND ADDRESS' and self.wr == 1:
             cmd = 'ADDRESS WRITE'
+            bin_class = 1
         elif self.state == 'FIND ADDRESS' and self.wr == 0:
             cmd = 'ADDRESS READ'
+            bin_class = 0
         elif self.state == 'FIND DATA' and self.wr == 1:
             cmd = 'DATA WRITE'
+            bin_class = 3
         elif self.state == 'FIND DATA' and self.wr == 0:
             cmd = 'DATA READ'
+            bin_class = 2
 
         self.putp([cmd, d])
         self.putx([proto[cmd][0], ['%s: %02X' % (proto[cmd][1], d),
                   '%s: %02X' % (proto[cmd][2], d), '%02X' % d]])
+        self.putb((bin_class, bytes([d])))
 
         # Done with this packet.
         self.startsample = -1
@@ -181,6 +222,11 @@ class Decoder(srd.Decoder):
         self.state = 'FIND DATA'
 
     def found_stop(self, scl, sda):
+        # Meta bitrate
+        elapsed = 1 / float(self.samplerate) * (self.samplenum - self.pdu_start + 1)
+        bitrate = int(1 / elapsed * self.pdu_bits)
+        self.put(self.startsample, self.samplenum, self.out_bitrate, bitrate)
+
         self.startsample = self.samplenum
         cmd = 'STOP'
         self.putp([cmd, None])
@@ -190,6 +236,8 @@ class Decoder(srd.Decoder):
         self.wr = -1
 
     def decode(self, ss, es, data):
+        if self.samplerate is None:
+            raise Exception("Cannot decode without samplerate.")
         for (self.samplenum, pins) in data:
 
             # Ignore identical samples early on (for performance reasons).
@@ -197,6 +245,8 @@ class Decoder(srd.Decoder):
                 continue
             self.oldpins, (scl, sda) = pins, pins
 
+            self.pdu_bits += 1
+
             # TODO: Wait until the bus is idle (SDA = SCL = 1) first?
 
             # State machine.