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Diffstat (limited to 'decoders/ddc.py')
-rw-r--r-- | decoders/ddc.py | 74 |
1 files changed, 0 insertions, 74 deletions
diff --git a/decoders/ddc.py b/decoders/ddc.py deleted file mode 100644 index f839093..0000000 --- a/decoders/ddc.py +++ /dev/null @@ -1,74 +0,0 @@ -## -## This file is part of the sigrok project. -## -## Copyright (C) 2012 Bert Vermeulen <bert@biot.com> -## -## 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 3 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, If not, see <http://www.gnu.org/licenses/>. -## - -''' -This decoder extracts a DDC stream from an I2C session between a computer -and a display device. The stream is output as plain bytes. - -Details: -https://en.wikipedia.org/wiki/Display_Data_Channel -''' - -import sigrokdecode as srd - -class Decoder(srd.Decoder): - id = 'ddc' - name = 'DDC' - longname = 'Display Data Channel' - desc = 'A protocol for communication between computers and displays.' - longdesc = '' - license = 'gplv3+' - inputs = ['i2c'] - outputs = ['ddc'] - probes = [] - options = {} - annotations = [ - ['Byte stream', 'DDC byte stream as read from display.'], - ] - - def __init__(self, **kwargs): - self.state = None - - def start(self, metadata): - self.out_ann = self.add(srd.OUTPUT_ANN, 'ddc') - - def decode(self, ss, es, data): - try: - cmd, data, ack_bit = data - except Exception as e: - raise Exception('malformed I2C input: %s' % str(e)) from e - - if self.state is None: - # Wait for the DDC session to start. - if cmd in ('START', 'START REPEAT'): - self.state = 'start' - elif self.state == 'start': - if cmd == 'ADDRESS READ' and data == 80: - # 80 is the I2C slave address of a connected display, - # so this marks the start of the DDC data transfer. - self.state = 'transfer' - elif cmd == 'STOP': - # Got back to the idle state. - self.state = None - elif self.state == 'transfer': - if cmd == 'DATA READ': - # There shouldn't be anything but data reads on this - # address, so ignore everything else. - self.put(ss, es, self.out_ann, [0, ['0x%.2x' % data]]) - |