From: Uwe Hermann Date: Tue, 19 Jun 2012 15:29:18 +0000 (+0200) Subject: srd: Split USB decoder in two PDs (which stack). X-Git-Tag: libsigrokdecode-0.1.1~76 X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=2dc6d41c64a8235308e61b4f9b509c7fecb2b502;p=libsigrokdecode.git srd: Split USB decoder in two PDs (which stack). The 'usb_signalling' decoder just decodes symbols from D+/D- levels, handles bit stuffing and outputs the symbols and (potential) packets. The 'usb_protocol' decoder takes that output and tried to parse USB packets from it (SOF, SETUP, IN, OUT, DATA0, and so on). This is the base decoder on top of which various others will stack later on. The two new PDs are work in progress, so we still keep the old 'usb' PD around for a little while, until the two new ones are fully working and well-tested. --- diff --git a/configure.ac b/configure.ac index be2946e..ec1a14f 100644 --- a/configure.ac +++ b/configure.ac @@ -168,6 +168,8 @@ AC_CONFIG_FILES([Makefile decoders/uart/Makefile decoders/uart_dump/Makefile decoders/usb/Makefile + decoders/usb_signalling/Makefile + decoders/usb_protocol/Makefile ]) AC_OUTPUT diff --git a/decoders/Makefile.am b/decoders/Makefile.am index 60cd853..65a0580 100644 --- a/decoders/Makefile.am +++ b/decoders/Makefile.am @@ -39,5 +39,7 @@ SUBDIRS = \ transitioncounter \ uart \ uart_dump \ - usb + usb \ + usb_signalling \ + usb_protocol diff --git a/decoders/usb/usb.py b/decoders/usb/usb.py index 529868e..c5b6a2e 100644 --- a/decoders/usb/usb.py +++ b/decoders/usb/usb.py @@ -166,12 +166,12 @@ class Decoder(srd.Decoder): if sym == self.sym: continue - if self.scount == 1: - # We ignore single sample width "pulses", i.e., symbol changes - # (D+/D- line changes). I sometimes get these with the OLS. - self.sym = sym - self.scount = 0 - continue + # if self.scount == 1: + # # We ignore single sample width "pulses", i.e., symbol changes + # # (D+/D- line changes). I sometimes get these with the OLS. + # self.sym = sym + # self.scount = 0 + # continue # How many bits since the last transition? if self.packet != '' or self.sym != 'J': diff --git a/decoders/usb_protocol/Makefile.am b/decoders/usb_protocol/Makefile.am new file mode 100644 index 0000000..599092b --- /dev/null +++ b/decoders/usb_protocol/Makefile.am @@ -0,0 +1,26 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +pkgdatadir = $(DECODERS_DIR)/usb_protocol + +dist_pkgdata_DATA = __init__.py usb_protocol.py + +CLEANFILES = *.pyc + diff --git a/decoders/usb_protocol/__init__.py b/decoders/usb_protocol/__init__.py new file mode 100644 index 0000000..a19304e --- /dev/null +++ b/decoders/usb_protocol/__init__.py @@ -0,0 +1,47 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +''' +USB (low-speed and full-speed) protocol decoder. + +Protocol layer (USB spec, chapter 8): + +Bit/byte ordering: Bits are sent onto the bus LSB-first. Multibyte fields +are transmitted in little-endian order (i.e., LSB to MSB). + +SYNC field: All packets begin with a SYNC field (8 bits). + +Packet field format: Packets start with an SOP (Start Of Packet) delimiter +that is part of the SYNC field, and end with an EOP (End Of Packet). + +PID: A PID (packet identifier) follows the SYNC field of every packet. A PID +consists of a 4-bit packet type field, and a 4 bit check field. +The check field is the one's complement of the packet type field. + +Protocol output format: +TODO + +Details: +https://en.wikipedia.org/wiki/USB +http://www.usb.org/developers/docs/ +''' + +from .usb_protocol import * + diff --git a/decoders/usb_protocol/usb_protocol.py b/decoders/usb_protocol/usb_protocol.py new file mode 100644 index 0000000..b1cd33b --- /dev/null +++ b/decoders/usb_protocol/usb_protocol.py @@ -0,0 +1,137 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2011 Gareth McMullin +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +# USB (low-speed and full-speed) protocol decoder + +import sigrokdecode as srd + +# Packet IDs (PIDs). +# The first 4 bits are the 'packet type' field, the last 4 bits are the +# 'check field' (each bit in the check field must be the inverse of the resp. +# bit in the 'packet type' field; if not, that's a 'PID error'). +# For the 4-bit strings, the left-most '1' or '0' is the LSB, i.e. it's sent +# to the bus first. +pids = { + # Tokens + '10000111': ['OUT', 'Address & EP number in host-to-function transaction'], + '10010110': ['IN', 'Address & EP number in function-to-host transaction'], + '10100101': ['SOF', 'Start-Of-Frame marker & frame number'], + '10110100': ['SETUP', 'Address & EP number in host-to-function transaction for SETUP to a control pipe'], + + # Data + # Note: DATA2 and MDATA are HS-only. + '11000011': ['DATA0', 'Data packet PID even'], + '11010010': ['DATA1', 'Data packet PID odd'], + '11100001': ['DATA2', 'Data packet PID HS, high bandwidth isosynchronous transaction in a microframe'], + '11110000': ['MDATA', 'Data packet PID HS for split and high-bandwidth isosynchronous transactions'], + + # Handshake + '01001011': ['ACK', 'Receiver accepts error-free packet'], + '01011010': ['NAK', 'Receiver cannot accept or transmitter cannot send'], + '01111000': ['STALL', 'EP halted or control pipe request unsupported'], + '01101001': ['NYET', 'No response yet from receiver'], + + # Special + '00111100': ['PRE', 'Host-issued preamble; enables downstream bus traffic to low-speed devices'], + '00111100': ['ERR', 'Split transaction error handshake'], + '00011110': ['SPLIT', 'HS split transaction token'], + '00101101': ['PING', 'HS flow control probe for a bulk/control EP'], + '00001111': ['Reserved', 'Reserved PID'], +} + +def bitstr_to_num(bitstr): + if not bitstr: + return 0 + l = list(bitstr) + l.reverse() + return int(''.join(l), 2) + +def packet_decode(packet): + sync = packet[:8] + pid = packet[8:16] + pid = pids.get(pid, (pid, ''))[0] + + # Remove CRC. + if pid in ('OUT', 'IN', 'SOF', 'SETUP'): + data = packet[16:-5] + if pid == 'SOF': + data = str(bitstr_to_num(data)) + else: + dev = bitstr_to_num(data[:7]) + ep = bitstr_to_num(data[7:]) + data = 'DEV %d EP %d' % (dev, ep) + elif pid in ('DATA0', 'DATA1'): + data = packet[16:-16] + tmp = '' + while data: + tmp += '%02x ' % bitstr_to_num(data[:8]) + data = data[8:] + data = tmp + else: + data = packet[16:] + + # The SYNC pattern for low-speed/full-speed is KJKJKJKK (0001). + if sync != '00000001': + return 'SYNC INVALID: %s' % sync + + return pid + ' ' + data + +class Decoder(srd.Decoder): + api_version = 1 + id = 'usb_protocol' + name = 'USB protocol' + longname = 'Universal Serial Bus (LS/FS) protocol' + desc = 'USB 1.x (low-speed and full-speed) serial protocol.' + license = 'gplv2+' + inputs = ['usb_signalling'] + outputs = ['usb_protocol'] + probes = [] + optional_probes = [] + options = { + 'signalling': ['Signalling', 'full-speed'], + } + annotations = [ + ['Text', 'Human-readable text'] + ] + + def __init__(self): + self.sym = 'J' + self.samplenum = 0 + self.scount = 0 + self.packet = '' + self.state = 'IDLE' + + def start(self, metadata): + self.samplerate = metadata['samplerate'] + self.out_proto = self.add(srd.OUTPUT_PROTO, 'usb_protocol') + self.out_ann = self.add(srd.OUTPUT_ANN, 'usb_protocol') + + def report(self): + pass + + def decode(self, ss, es, data): + (ptype, pdata) = data + + if ptype == 'PACKET': + self.put(0, 0, self.out_ann, [0, [packet_decode(pdata)]]) + + # TODO. + diff --git a/decoders/usb_signalling/Makefile.am b/decoders/usb_signalling/Makefile.am new file mode 100644 index 0000000..316c62c --- /dev/null +++ b/decoders/usb_signalling/Makefile.am @@ -0,0 +1,26 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +pkgdatadir = $(DECODERS_DIR)/usb_signalling + +dist_pkgdata_DATA = __init__.py usb_signalling.py + +CLEANFILES = *.pyc + diff --git a/decoders/usb_signalling/__init__.py b/decoders/usb_signalling/__init__.py new file mode 100644 index 0000000..026875c --- /dev/null +++ b/decoders/usb_signalling/__init__.py @@ -0,0 +1,55 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +''' +USB (low-speed and full-speed) signalling protocol decoder. + +Electrical/signalling layer (USB spec, chapter 7): + +USB signalling consists of two signal lines, both driven at 3.3V +logic levels. The signals are DP (D+) and DM (D-), and normally operate in +differential mode. + +Low-speed: The state where DP=1,DM=0 is K, the state DP=0,DM=1 is J. +Full-speed: The state where DP=1,DM=0 is J, the state DP=0,DM=1 is K. + +A state SE0 is defined where DP=DM=0. This common mode signal is used to +signal a reset or end of packet (EOP). A state SE1 is defined where DP=DM=1. + +Data transmitted on the USB is encoded with NRZI. A transition from J to K +or vice-versa indicates a logic 0, while no transition indicates a logic 1. +If 6 ones are transmitted consecutively, a zero is inserted to force a +transition. This is known as bit stuffing. + +Data is transferred at a rate of 1.5Mbit/s (low-speed) / 12Mbit/s (full-speed). + +The SE0 transmitted to signal an end-of-packet is two bit intervals long +(low-speed: 1.25uS - 1.50uS, full-speed: 160ns - 175ns). + +Protocol output format: +TODO + +Details: +https://en.wikipedia.org/wiki/USB +http://www.usb.org/developers/docs/ +''' + +from .usb_signalling import * + diff --git a/decoders/usb_signalling/usb_signalling.py b/decoders/usb_signalling/usb_signalling.py new file mode 100644 index 0000000..512703d --- /dev/null +++ b/decoders/usb_signalling/usb_signalling.py @@ -0,0 +1,146 @@ +## +## This file is part of the sigrok project. +## +## Copyright (C) 2011 Gareth McMullin +## Copyright (C) 2012 Uwe Hermann +## +## 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 +## + +# USB signalling (low-speed and full-speed) protocol decoder + +import sigrokdecode as srd + +# Low-/full-speed symbols (used as states of our state machine, too). +# Note: Low-speed J and K are inverted compared to the full-speed J and K! +symbols_ls = { + # (, ): + (0, 0): 'SE0', + (1, 0): 'K', + (0, 1): 'J', + (1, 1): 'SE1', +} +symbols_fs = { + # (, ): + (0, 0): 'SE0', + (1, 0): 'J', + (0, 1): 'K', + (1, 1): 'SE1', +} + +class Decoder(srd.Decoder): + api_version = 1 + id = 'usb_signalling' + name = 'USB signalling' + longname = 'Universal Serial Bus (LS/FS) signalling' + desc = 'USB 1.x (low-speed and full-speed) signalling protocol.' + license = 'gplv2+' + inputs = ['logic'] + outputs = ['usb_signalling'] + probes = [ + {'id': 'dp', 'name': 'D+', 'desc': 'USB D+ signal'}, + {'id': 'dm', 'name': 'D-', 'desc': 'USB D- signal'}, + ] + optional_probes = [] + options = { + 'signalling': ['Signalling', 'full-speed'], + } + annotations = [ + ['Text', 'Human-readable text'] + ] + + def __init__(self): + self.sym = 'J' # The "idle" state is J. + self.samplenum = 0 + self.scount = 0 + self.packet = '' + self.syms = [] + + def start(self, metadata): + self.samplerate = metadata['samplerate'] + self.out_proto = self.add(srd.OUTPUT_PROTO, 'usb_signalling') + self.out_ann = self.add(srd.OUTPUT_ANN, 'usb_signalling') + + def report(self): + pass + + def decode(self, ss, es, data): + for (self.samplenum, (dp, dm)) in data: + + # Note: self.samplenum is the absolute sample number, whereas + # self.scount only counts the number of samples since the + # last change in the D+/D- lines. + self.scount += 1 + + if self.options['signalling'] == 'low-speed': + sym = symbols_ls[dp, dm] + elif self.options['signalling'] == 'full-speed': + sym = symbols_fs[dp, dm] + + self.put(0, 0, self.out_ann, [0, [sym]]) + self.put(0, 0, self.out_proto, ['SYM', sym]) + + # Wait for a symbol change (i.e., change in D+/D- lines). + if sym == self.sym: + continue + + ## # Debug code: + ## self.syms.append(sym + ' ') + ## if len(self.syms) == 16: + ## self.put(0, 0, self.out_ann, [0, [''.join(self.syms)]]) + ## self.syms = [] + # continue + + # How many bits since the last transition? + if self.packet != '' or self.sym != 'J': + if self.options['signalling'] == 'low-speed': + bitrate = 1500000 # 1.5Mb/s (+/- 1.5%) + elif self.options['signalling'] == 'full-speed': + bitrate = 12000000 # 12Mb/s (+/- 0.25%) + bitcount = int((self.scount - 1) * bitrate / self.samplerate) + else: + bitcount = 0 + + if self.sym == 'SE0': + if bitcount == 1: + # End-Of-Packet (EOP) + # self.put(0, 0, self.out_ann, + # [0, [packet_decode(self.packet), self.packet]]) + if self.packet != '': # FIXME? + self.put(0, 0, self.out_ann, [0, ['PACKET: %s' % self.packet]]) + self.put(0, 0, self.out_proto, ['PACKET', self.packet]) + else: + # Longer than EOP, assume reset. + self.put(0, 0, self.out_ann, [0, ['RESET']]) + self.put(0, 0, self.out_proto, ['RESET', None]) + # self.put(0, 0, self.out_ann, [0, [self.packet]]) + self.scount = 0 + self.sym = sym + self.packet = '' + continue + + # Add bits to the packet string. + self.packet += '1' * bitcount + + # Handle bit stuffing. + if bitcount < 6 and sym != 'SE0': + self.packet += '0' + elif bitcount > 6: + self.put(0, 0, self.out_ann, [0, ['BIT STUFF ERROR']]) + self.put(0, 0, self.out_proto, ['BIT STUFF ERROR', None]) + + self.scount = 0 + self.sym = sym +