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##
## This file is part of the sigrok 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, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
##
#
# TrekStor EBR30-a I2C demux protocol decoder
#
# Takes an I2C stream as input and outputs 3 different I2C streams, for the
# 3 different I2C devices on the TrekStor EBR30-a eBook reader (which are all
# physically connected to the same SCL/SDA lines).
#
# I2C slave addresses:
#
# - AXP199 battery management chip: 0x69/0x68 (8bit R/W), 0x34 (7bit)
# - H8563S RTC chip: 0xa3/0xa2 (8bit R/W), 0x51 (7bit)
# - Unknown accelerometer chip: 0x2b/0x2a (8bit R/W), 0x15 (7bit)
#
import sigrokdecode as srd
# I2C devices
AXP199 = 0
H8563S = 1
ACCEL = 2
class Decoder(srd.Decoder):
api_version = 1
id = 'ebr30a_i2c_demux'
name = 'EBR30-a I2C demux'
longname = 'TrekStor EBR30-a I2C demux'
desc = 'TODO.'
longdesc = 'TODO.'
license = 'gplv2+'
inputs = ['i2c']
outputs = ['i2c-axp199', 'i2c-h8563s', 'i2c-accel'] # TODO: type vs. inst.
probes = []
extra_probes = []
options = {}
annotations = []
def __init__(self, **kwargs):
self.packets = []
self.stream = -1
def start(self, metadata):
self.out_proto = []
self.out_proto.append(self.add(srd.OUTPUT_PROTO, 'i2c-axp199'))
self.out_proto.append(self.add(srd.OUTPUT_PROTO, 'i2c-h8563s'))
self.out_proto.append(self.add(srd.OUTPUT_PROTO, 'i2c-accel'))
# TODO: Annotations?
def report(self):
pass
# 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, ack_bit = data
# Add the I2C packet to our local cache.
self.packets += [[ss, es, data]]
if cmd in ('ADDRESS READ', 'ADDRESS WRITE'):
# print(hex(databyte))
if databyte == 0x34:
self.stream = AXP199
elif databyte == 0x51:
self.stream = H8563S
elif databyte == 0x15:
self.stream = ACCEL
else:
pass # TODO: Error?
# TODO: Can there be two ADDRESS READ/WRITE with two different
# slave addresses before any STOP occurs?
elif cmd == 'STOP':
if self.stream != -1:
# Send the whole chunk of I2C packets to the correct stream.
for p in self.packets:
# print(self.out_proto[self.stream], p)
self.put(p[0], p[1], self.out_proto[self.stream], p[2])
else:
print('Error: Could not determine correct stream!') # FIXME
self.packets = []
self.stream = -1
else:
pass # Do nothing, only add the I2C packet to our cache.
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