X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=decoders%2Fi2c.py;h=e63ab8525454eb48ae10a2b244e01bb0862aa4b1;hb=876f83fd3396ce581e700741e58414c2f4f6277e;hp=60558c5a76eeb34e4b8a08c0ba14a5de997992f2;hpb=94d43b37bd34263f5ed9f7135aac5fe7413c7f07;p=libsigrokdecode.git diff --git a/decoders/i2c.py b/decoders/i2c.py index 60558c5..e63ab85 100644 --- a/decoders/i2c.py +++ b/decoders/i2c.py @@ -22,7 +22,6 @@ # I2C protocol decoder # -# # The Inter-Integrated Circuit (I2C) bus is a bidirectional, multi-master # bus using two signals (SCL = serial clock line, SDA = serial data line). # @@ -69,48 +68,47 @@ # TODO: Handle multiple different I2C devices on same bus # -> we need to decode multiple protocols at the same time. -# -# I2C protocol output format: -# -# The protocol output consists of a (Python) list of I2C "packets", each of -# which is of the form -# -# [ _i2c_command_, _data_, _ack_bit_ ] -# -# _i2c_command_ is one of: -# - 'START' (START condition) -# - 'START_REPEAT' (Repeated START) -# - 'ADDRESS_READ' (Address, read) -# - 'ADDRESS_WRITE' (Address, write) -# - 'DATA_READ' (Data, read) -# - 'DATA_WRITE' (Data, write) -# - 'STOP' (STOP condition) -# -# _data_ is the data or address byte associated with the ADDRESS_* and DATA_* -# command. For START, START_REPEAT and STOP, this is None. -# -# _ack_bit_ is either 'ACK' or 'NACK', but may also be None. -# -# +""" +I2C protocol output format: + +The protocol output consists of a (Python) list of I2C "packets", each of +which is of the form + + [ _i2c_command_, _data_, _ack_bit_ ] -import sigrokdecode +_i2c_command_ is one of: + - 'START' (START condition) + - 'START_REPEAT' (Repeated START) + - 'ADDRESS_READ' (Address, read) + - 'ADDRESS_WRITE' (Address, write) + - 'DATA_READ' (Data, read) + - 'DATA_WRITE' (Data, write) + - 'STOP' (STOP condition) -# annotation feed formats +_data_ is the data or address byte associated with the ADDRESS_* and DATA_* +command. For START, START_REPEAT and STOP, this is None. + +_ack_bit_ is either 'ACK' or 'NACK', but may also be None. +""" + +import sigrokdecode as srd + +# Annotation feed formats ANN_SHIFTED = 0 ANN_SHIFTED_SHORT = 1 ANN_RAW = 2 -# values are verbose and short annotation, respectively +# Values are verbose and short annotation, respectively. protocol = { - 'START': ['START', 'S'], - 'START_REPEAT': ['START REPEAT', 'Sr'], - 'STOP': ['STOP', 'P'], - 'ACK': ['ACK', 'A'], - 'NACK': ['NACK', 'N'], - 'ADDRESS_READ': ['ADDRESS READ', 'AR'], - 'ADDRESS_WRITE': ['ADDRESS WRITE','AW'], - 'DATA_READ': ['DATA READ', 'DR'], - 'DATA_WRITE': ['DATA WRITE', 'DW'], + 'START': ['START', 'S'], + 'START REPEAT': ['START REPEAT', 'Sr'], + 'STOP': ['STOP', 'P'], + 'ACK': ['ACK', 'A'], + 'NACK': ['NACK', 'N'], + 'ADDRESS READ': ['ADDRESS READ', 'AR'], + 'ADDRESS WRITE': ['ADDRESS WRITE', 'AW'], + 'DATA READ': ['DATA READ', 'DR'], + 'DATA WRITE': ['DATA WRITE', 'DW'], } # States @@ -118,11 +116,10 @@ FIND_START = 0 FIND_ADDRESS = 1 FIND_DATA = 2 - -class Decoder(sigrokdecode.Decoder): +class Decoder(srd.Decoder): id = 'i2c' name = 'I2C' - longname = 'Inter-Integrated Circuit (I2C) bus' + longname = 'Inter-Integrated Circuit' desc = 'I2C is a two-wire, multi-master, serial bus.' longdesc = '...' author = 'Uwe Hermann' @@ -135,22 +132,20 @@ class Decoder(sigrokdecode.Decoder): {'id': 'sda', 'name': 'SDA', 'desc': 'Serial data line'}, ] options = { - 'address-space': ['Address space (in bits)', 7], + 'addressing': ['Slave addressing (in bits)', 7], # 7 or 10 } - annotation = [ + annotations = [ # ANN_SHIFTED - ["7-bit shifted hex", - "Read/Write bit shifted out from the 8-bit i2c slave address"], + ['7-bit shifted hex', + 'Read/write bit shifted out from the 8-bit I2C slave address'], # ANN_SHIFTED_SHORT - ["7-bit shifted hex (short)", - "Read/Write bit shifted out from the 8-bit i2c slave address"], + ['7-bit shifted hex (short)', + 'Read/write bit shifted out from the 8-bit I2C slave address'], # ANN_RAW - ["Raw hex", "Unaltered raw data"] + ['Raw hex', 'Unaltered raw data'], ] def __init__(self, **kwargs): - self.out_proto = None - self.out_ann = None self.samplecnt = 0 self.bitcount = 0 self.databyte = 0 @@ -161,39 +156,40 @@ class Decoder(sigrokdecode.Decoder): self.oldscl = None self.oldsda = None + # Set protocol decoder option defaults. + self.addressing = Decoder.options['addressing'][1] + def start(self, metadata): - self.out_proto = self.add(sigrokdecode.SRD_OUTPUT_PROTO, 'i2c') - self.out_ann = self.add(sigrokdecode.SRD_OUTPUT_ANN, 'i2c') + self.out_proto = self.add(srd.OUTPUT_PROTO, 'i2c') + self.out_ann = self.add(srd.OUTPUT_ANN, 'i2c') def report(self): pass def is_start_condition(self, scl, sda): - """START condition (S): SDA = falling, SCL = high""" + # START condition (S): SDA = falling, SCL = high if (self.oldsda == 1 and sda == 0) and scl == 1: return True return False def is_data_bit(self, scl, sda): - """Data sampling of receiver: SCL = rising""" + # Data sampling of receiver: SCL = rising if self.oldscl == 0 and scl == 1: return True return False def is_stop_condition(self, scl, sda): - """STOP condition (P): SDA = rising, SCL = high""" + # STOP condition (P): SDA = rising, SCL = high if (self.oldsda == 0 and sda == 1) and scl == 1: return True return False def found_start(self, scl, sda): - if self.is_repeat_start == 1: - cmd = 'START_REPEAT' - else: - cmd = 'START' - self.put(self.out_proto, [ cmd, None, None ]) - self.put(self.out_ann, [ ANN_SHIFTED, [protocol[cmd][0]] ]) - self.put(self.out_ann, [ ANN_SHIFTED_SHORT, [protocol[cmd][1]] ]) + cmd = 'START REPEAT' if (self.is_repeat_start == 1) else 'START' + + self.put(self.out_proto, [cmd, None, None]) + self.put(self.out_ann, [ANN_SHIFTED, [protocol[cmd][0]]]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, [protocol[cmd][1]]]) self.state = FIND_ADDRESS self.bitcount = self.databyte = 0 @@ -201,10 +197,10 @@ class Decoder(sigrokdecode.Decoder): self.wr = -1 def found_address_or_data(self, scl, sda): - """Gather 8 bits of data plus the ACK/NACK bit.""" + # Gather 8 bits of data plus the ACK/NACK bit. if self.startsample == -1: - # TODO: should be samplenum, as received from the feed + # TODO: Should be samplenum, as received from the feed. self.startsample = self.samplecnt self.bitcount += 1 @@ -214,21 +210,18 @@ class Decoder(sigrokdecode.Decoder): # Return if we haven't collected all 8 + 1 bits, yet. if self.bitcount != 9: - return [] + return - # send raw output annotation before we start shifting out - # read/write and ack/nack bits - self.put(self.out_ann, [ANN_RAW, ["0x%.2x" % self.databyte]]) + # Send raw output annotation before we start shifting out + # read/write and ack/nack bits. + self.put(self.out_ann, [ANN_RAW, ['0x%.2x' % self.databyte]]) # We received 8 address/data bits and the ACK/NACK bit. self.databyte >>= 1 # Shift out unwanted ACK/NACK bit here. if self.state == FIND_ADDRESS: # The READ/WRITE bit is only in address bytes, not data bytes. - if self.databyte & 1: - self.wr = 0 - else: - self.wr = 1 + self.wr = 0 if (self.databyte & 1) else 1 d = self.databyte >> 1 elif self.state == FIND_DATA: d = self.databyte @@ -236,32 +229,23 @@ class Decoder(sigrokdecode.Decoder): # TODO: Error? pass - # last bit that came in was the ACK/NACK bit (1 = NACK) - if sda == 1: - ack_bit = 'NACK' - else: - ack_bit = 'ACK' + # Last bit that came in was the ACK/NACK bit (1 = NACK). + ack_bit = 'NACK' if (sda == 1) else 'ACK' - # TODO: Simplify. if self.state == FIND_ADDRESS and self.wr == 1: - cmd = 'ADDRESS_WRITE' + cmd = 'ADDRESS WRITE' elif self.state == FIND_ADDRESS and self.wr == 0: - cmd = 'ADDRESS_READ' + cmd = 'ADDRESS READ' elif self.state == FIND_DATA and self.wr == 1: - cmd = 'DATA_WRITE' + cmd = 'DATA WRITE' elif self.state == FIND_DATA and self.wr == 0: - cmd = 'DATA_READ' - self.put(self.out_proto, [ cmd, d, ack_bit ] ) - self.put(self.out_ann, [ANN_SHIFTED, [ - "%s" % protocol[cmd][0], - "0x%02x" % d, - "%s" % protocol[ack_bit][0]] - ] ) - self.put(self.out_ann, [ANN_SHIFTED_SHORT, [ - "%s" % protocol[cmd][1], - "0x%02x" % d, - "%s" % protocol[ack_bit][1]] - ] ) + cmd = 'DATA READ' + + self.put(self.out_proto, [cmd, d, ack_bit]) + self.put(self.out_ann, [ANN_SHIFTED, + [protocol[cmd][0], '0x%02x' % d, protocol[ack_bit][0]]]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, + [protocol[cmd][1], '0x%02x' % d, protocol[ack_bit][1]]]) self.bitcount = self.databyte = 0 self.startsample = -1 @@ -274,20 +258,20 @@ class Decoder(sigrokdecode.Decoder): pass def found_stop(self, scl, sda): - self.put(self.out_proto, [ 'STOP', None, None ]) - self.put(self.out_ann, [ ANN_SHIFTED, [protocol['STOP'][0]] ]) - self.put(self.out_ann, [ ANN_SHIFTED_SHORT, [protocol['STOP'][1]] ]) + self.put(self.out_proto, ['STOP', None, None]) + self.put(self.out_ann, [ANN_SHIFTED, [protocol['STOP'][0]]]) + self.put(self.out_ann, [ANN_SHIFTED_SHORT, [protocol['STOP'][1]]]) self.state = FIND_START self.is_repeat_start = 0 self.wr = -1 def put(self, output_id, data): - # inject sample range into the call up to sigrok - # TODO: 0-0 sample range for now + # Inject sample range into the call up to sigrok. + # TODO: 0-0 sample range for now. super(Decoder, self).put(0, 0, output_id, data) - def decode(self, timeoffset, duration, data): + def decode(self, ss, es, data): for samplenum, (scl, sda) in data: self.samplecnt += 1