i2c.py: Fix typo resulting in a nonworking script.

[libsigrokdecode.git] / scripts / i2c.py

diff --git a/scripts/i2c.py b/scripts/i2c.py
index 6f9a160fa0cdee3054d5f7dc3cec778799b36268..f0e168849cca00d68b13356ab3de6b4e3cf38c45 100644 (file)
--- a/scripts/i2c.py
+++ b/scripts/i2c.py
@@ -65,35 +65,98 @@
 # TODO: Implement support for inverting SDA/SCL levels (0->1 and 1->0).
 # TODO: Implement support for detecting various bus errors.
 
-# TODO: Return two buffers, one with structured data for the GUI to parse
-#       and display, and one with human-readable ASCII output.
+#
+# I2C output format:
+#
+# The output consists of a (Python) list of I2C "packets", each of which
+# has an (implicit) index number (its index in the list).
+# Each packet consists of a Python dict with certain key/value pairs.
+#
+# TODO: Make this a list later instead of a dict?
+#
+# 'type': (string)
+#   - 'S' (START condition)
+#   - 'Sr' (Repeated START)
+#   - 'AR' (Address, read)
+#   - 'AW' (Address, write)
+#   - 'DR' (Data, read)
+#   - 'DW' (Data, write)
+#   - 'P' (STOP condition)
+# 'range': (tuple of 2 integers, the min/max samplenumber of this range)
+#   - (min, max)
+#   - min/max can also be identical.
+# 'data': (actual data as integer ???) TODO: This can be very variable...
+# 'ann': (string; additional annotations / comments)
+#
+# Example output:
+# [{'type': 'S',  'range': (150, 160), 'data': None, 'ann': 'Foobar'},
+#  {'type': 'AW', 'range': (200, 300), 'data': 0x50, 'ann': 'Slave 4'},
+#  {'type': 'DW', 'range': (310, 370), 'data': 0x00, 'ann': 'Init cmd'},
+#  {'type': 'AR', 'range': (500, 560), 'data': 0x50, 'ann': 'Get stat'},
+#  {'type': 'DR', 'range': (580, 640), 'data': 0xfe, 'ann': 'OK'},
+#  {'type': 'P',  'range': (650, 660), 'data': None, 'ann': None}]
+#
+# Possible other events:
+#   - Error event in case protocol looks broken:
+#     [{'type': 'ERROR', 'range': (min, max),
+#      'data': TODO, 'ann': 'This is not a Microchip 24XX64 EEPROM'},
+#     [{'type': 'ERROR', 'range': (min, max),
+#      'data': TODO, 'ann': 'TODO'},
+#   - TODO: Make list of possible errors accessible as metadata?
+#
+# TODO: I2C address of slaves.
+# TODO: Handle multiple different I2C devices on same bus
+#       -> we need to decode multiple protocols at the same time.
+# TODO: range: Always contiguous? Splitted ranges? Multiple per event?
+#
 
-def sigrokdecode_i2c(inbuf):
+#
+# I2C input format:
+#
+# signals:
+# [[id, channel, description], ...] # TODO
+#
+# Example:
+# {'id': 'SCL', 'ch': 5, 'desc': 'Serial clock line'}
+# {'id': 'SDA', 'ch': 7, 'desc': 'Serial data line'}
+# ...
+#
+# {'inbuf': [...],
+#  'signals': [{'SCL': }]}
+#
+
+def decode(inbuf):
        """I2C protocol decoder"""
 
+       # FIXME: Get the data in the correct format in the first place.
+       inbuf = [ord(x) for x in inbuf]
+
        # FIXME: This should be passed in as metadata, not hardcoded here.
-       signals = (2, 5)
-       channels = 8
+       metadata = {
+         'numchannels': 8,
+         'signals': {
+             'scl': {'ch': 5, 'name': 'SCL', 'desc': 'Serial clock line'},
+             'sda': {'ch': 7, 'name': 'SDA', 'desc': 'Serial data line'},
+           },
+       }
 
        o = wr = ack = d = ''
        bitcount = data = 0
        IDLE, START, ADDRESS, DATA = range(4)
        state = IDLE
 
-       # Get the bit number (and thus probe index) of the SCL/SDA signals.
-       scl_bit, sda_bit = signals
+       # Get the channel/probe number of the SCL/SDA signals.
+       scl_bit = metadata['signals']['scl']['ch']
+       sda_bit = metadata['signals']['sda']['ch']
 
        # Get SCL/SDA bit values (0/1 for low/high) of the first sample.
-       s = ord(inbuf[0])
+       s = inbuf[0]
        oldscl = (s & (1 << scl_bit)) >> scl_bit
        oldsda = (s & (1 << sda_bit)) >> sda_bit
 
        # Loop over all samples.
        # TODO: Handle LAs with more/less than 8 channels.
        for samplenum, s in enumerate(inbuf[1:]): # We skip the first byte...
- 
-               s = ord(s) # FIXME
-
                # Get SCL/SDA bit values (0/1 for low/high).
                scl = (s & (1 << scl_bit)) >> scl_bit
                sda = (s & (1 << sda_bit)) >> sda_bit
@@ -148,26 +211,23 @@ def sigrokdecode_i2c(inbuf):
 
        return o
 
-# This is just a draft.
-def sigrokdecode_register_i2c():
-       metadata = {
+def register():
+       return {
                'id': 'i2c',
                'name': 'I2C',
-               'description': 'Inter-Integrated Circuit (I2C) bus',
-               'function': 'sigrokdecode_i2c',
+               'desc': 'Inter-Integrated Circuit (I2C) bus',
                'inputformats': ['raw'],
                'signalnames':  {
                                'SCL': 'Serial clock line',
                                'SDA': 'Serial data line',
                                },
-               'ouputformats': ['i2c', 'ascii'],
+               'outputformats': ['i2c'],
        }
-       return metadata
 
 # Use psyco (if available) as it results in huge performance improvements.
 try:
        import psyco
-       psyco.bind(sigrokdecode_i2c)
+       psyco.bind(decode)
 except ImportError:
        pass