[libsigrokdecode.git] / decoders / i2cdemux / pd.py

##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##

import sigrokdecode as srd

class Decoder(srd.Decoder):
    api_version = 3
    id = 'i2cdemux'
    name = 'I²C demux'
    longname = 'I²C demultiplexer'
    desc = 'Demux I²C packets into per-slave-address streams.'
    license = 'gplv2+'
    inputs = ['i2c']
    outputs = [] # TODO: Only known at run-time.

    def __init__(self):
        self.packets = [] # Local cache of I²C packets
        self.slaves = [] # List of known slave addresses
        self.stream = -1 # Current output stream
        self.streamcount = 0 # Number of created output streams

    def start(self):
        self.out_python = []

    # Grab I²C packets into a local cache, until an I²C STOP condition
    # packet comes along. At some point before that STOP condition, there
    # will have been an ADDRESS READ or ADDRESS WRITE which contains the
    # I²C address of the slave that the master wants to talk to.
    # We use this slave address to figure out which output stream should
    # get the whole chunk of packets (from START to STOP).
    def decode(self, ss, es, data):

        cmd, databyte = data

        # Add the I²C packet to our local cache.
        self.packets.append([ss, es, data])

        if cmd in ('ADDRESS READ', 'ADDRESS WRITE'):
            if databyte in self.slaves:
                self.stream = self.slaves.index(databyte)
                return

            # We're never seen this slave, add a new stream.
            self.slaves.append(databyte)
            self.out_python.append(self.register(srd.OUTPUT_PYTHON,
                                   proto_id='i2c-%s' % hex(databyte)))
            self.stream = self.streamcount
            self.streamcount += 1
        elif cmd == 'STOP':
            if self.stream == -1:
                raise Exception('Invalid stream!') # FIXME?

            # Send the whole chunk of I²C packets to the correct stream.
            for p in self.packets:
                self.put(p[0], p[1], self.out_python[self.stream], p[2])

            self.packets = []
            self.stream = -1
        else:
            pass # Do nothing, only add the I²C packet to our cache.
Commit	Line	Data
	1	##
	2	## This file is part of the libsigrokdecode project.
	3	##
	4	## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
	5	##
	6	## This program is free software; you can redistribute it and/or modify
	7	## it under the terms of the GNU General Public License as published by
	8	## the Free Software Foundation; either version 2 of the License, or
	9	## (at your option) any later version.
	10	##
	11	## This program is distributed in the hope that it will be useful,
	12	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	## GNU General Public License for more details.
	15	##
	16	## You should have received a copy of the GNU General Public License
	17	## along with this program; if not, see <http://www.gnu.org/licenses/>.
	18	##
	19
	20	import sigrokdecode as srd
	21
	22	class Decoder(srd.Decoder):
	23	api_version = 3
	24	id = 'i2cdemux'
	25	name = 'I²C demux'
	26	longname = 'I²C demultiplexer'
	27	desc = 'Demux I²C packets into per-slave-address streams.'
	28	license = 'gplv2+'
	29	inputs = ['i2c']
	30	outputs = [] # TODO: Only known at run-time.
	31
	32	def __init__(self):
	33	self.packets = [] # Local cache of I²C packets
	34	self.slaves = [] # List of known slave addresses
	35	self.stream = -1 # Current output stream
	36	self.streamcount = 0 # Number of created output streams
	37
	38	def start(self):
	39	self.out_python = []
	40
	41	# Grab I²C packets into a local cache, until an I²C STOP condition
	42	# packet comes along. At some point before that STOP condition, there
	43	# will have been an ADDRESS READ or ADDRESS WRITE which contains the
	44	# I²C address of the slave that the master wants to talk to.
	45	# We use this slave address to figure out which output stream should
	46	# get the whole chunk of packets (from START to STOP).
	47	def decode(self, ss, es, data):
	48
	49	cmd, databyte = data
	50
	51	# Add the I²C packet to our local cache.
	52	self.packets.append([ss, es, data])
	53
	54	if cmd in ('ADDRESS READ', 'ADDRESS WRITE'):
	55	if databyte in self.slaves:
	56	self.stream = self.slaves.index(databyte)
	57	return
	58
	59	# We're never seen this slave, add a new stream.
	60	self.slaves.append(databyte)
	61	self.out_python.append(self.register(srd.OUTPUT_PYTHON,
	62	proto_id='i2c-%s' % hex(databyte)))
	63	self.stream = self.streamcount
	64	self.streamcount += 1
	65	elif cmd == 'STOP':
	66	if self.stream == -1:
	67	raise Exception('Invalid stream!') # FIXME?
	68
	69	# Send the whole chunk of I²C packets to the correct stream.
	70	for p in self.packets:
	71	self.put(p[0], p[1], self.out_python[self.stream], p[2])
	72
	73	self.packets = []
	74	self.stream = -1
	75	else:
	76	pass # Do nothing, only add the I²C packet to our cache.