qi: Add Qi charger protocol decoder

2 files changed, 270 insertions, 0 deletions

diff --git a/decoders/qi/__init__.py b/decoders/qi/__init__.py
new file mode 100644
index 0000000..35ffe5b
--- /dev/null
+++ b/decoders/qi/__init__.py
@@ -0,0 +1,26 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2015 Josef Gajdusek <atx@atx.name>
+##
+## 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
+##
+
+'''
+This decoder decodes demodulated data streams used by the Qi standard
+for communication from the receiver to the charging station.
+'''
+
+from .pd import Decoder
diff --git a/decoders/qi/pd.py b/decoders/qi/pd.py
new file mode 100644
index 0000000..cba4ce9
--- /dev/null
+++ b/decoders/qi/pd.py
@@ -0,0 +1,244 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2015 Josef Gajdusek <atx@atx.name>
+##
+## 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
+##
+
+import sigrokdecode as srd
+import operator
+import collections
+from functools import reduce
+
+end_codes = (
+    'Unknown',
+    'Charge Complete',
+    'Internal Fault',
+    'Over Temperature',
+    'Over Voltage',
+    'Over Current',
+    'Battery Failure',
+    'Reconfigure',
+    'No Response',
+)
+
+class SamplerateError(Exception):
+    pass
+
+def calc_checksum(packet):
+    return reduce(operator.xor, packet[:-1])
+
+def bits_to_uint(bits):
+    # LSB first
+    return reduce(lambda i, v: (i >> 1) | (v << (len(bits) - 1)), bits, 0)
+
+class Decoder(srd.Decoder):
+    api_version = 2
+    id = 'qi'
+    name = 'Qi'
+    longname = 'Qi charger protocol'
+    desc = 'Protocol used by Qi receiver'
+    license = 'gplv2+'
+    inputs = ['logic']
+    outputs = ['qi']
+    channels = (
+        {'id': 'qi', 'name': 'Qi', 'desc': 'Demodulated Qi data line'},
+    )
+    annotations = (
+        ('bits', 'Bits'),
+        ('bytes-errors', 'Bit errors'),
+        ('bytes-start', 'Start bits'),
+        ('bytes-info', 'Info bits'),
+        ('bytes-data', 'Data bytes'),
+        ('packets-data', 'Packet data'),
+        ('packets-checksum-ok', 'Packet checksum'),
+        ('packets-checksum-err', 'Packet checksum'),
+    )
+    annotation_rows = (
+        ('bits', 'Bits', (0,)),
+        ('bytes', 'Bytes', (1, 2, 3, 4)),
+        ('packets', 'Packets', (5, 6, 7)),
+    )
+
+    def __init__(self, **kwargs):
+        self.samplerate = None
+        self.reset_variables()
+
+    def reset_variables(self):
+        self.counter = 0
+        self.prev = None
+        self.state = 'IDLE'
+        self.lastbit = 0
+        self.bytestart = 0
+        self.deq = collections.deque(maxlen = 2)
+        self.bits = []
+        self.bitsi = [0]
+        self.bytesi = []
+        self.packet = []
+
+    def metadata(self, key, value):
+        if key == srd.SRD_CONF_SAMPLERATE:
+            self.samplerate = value
+            self.bit_width = float(self.samplerate) / 2e3
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+        self.reset_variables()
+
+    def packet_len(self, byte):
+        if 0x00 <= byte <= 0x1f:
+            return int(1 + (byte - 0) / 32)
+        if 0x20 <= byte <= 0x7f:
+            return int(2 + (byte - 32) / 16)
+        if 0x80 <= byte <= 0xdf:
+            return int(8 + (byte - 128) / 8)
+        if 0xe0 <= byte <= 0xff:
+            return int(20 + (byte - 224) / 4)
+
+    def in_tolerance(self, l):
+        return (0.75 * self.bit_width) < l < (1.25 * self.bit_width)
+
+    def putp(self, data):
+        self.put(self.bytesi[0], self.bytesi[-1], self.out_ann, [5, data])
+
+    def process_packet(self):
+        if self.packet[0] == 0x01: # Signal Strength
+            self.putp(['Signal Strength: %d' % self.packet[1],
+                       'SS: %d' % self.packet[1], 'SS'])
+        elif self.packet[0] == 0x02: # End Power Transfer
+            reason = end_codes[self.packet[1]] if self.packet[1] < len(end_codes) else 'Reserved'
+            self.putp(['End Power Transfer: %s' % reason,
+                       'EPT: %s' % reason, 'EPT'])
+        elif self.packet[0] == 0x03: # Control Error
+            val = self.packet[1] if self.packet[1] < 128 else (self.packet[1] & 0x7f) - 128
+            self.putp(['Control Error: %d' % val, 'CE: %d' % val, 'CE'])
+        elif self.packet[0] == 0x04: # Received Power
+            self.putp(['Received Power: %d' % self.packet[1],
+                       'RP: %d' % self.packet[1], 'RP'])
+        elif self.packet[0] == 0x05: # Charge Status
+            self.putp(['Charge Status: %d' % self.packet[1],
+                       'CS: %d' % self.packet[1], 'CS'])
+        elif self.packet[0] == 0x06: # Power Control Hold-off
+            self.putp(['Power Control Hold-off: %dms' % self.packet[1],
+                       'PCH: %d' % self.packet[1]], 'PCH')
+        elif self.packet[0] == 0x51: # Configuration
+            powerclass = (self.packet[1] & 0xc0) >> 7
+            maxpower = self.packet[1] & 0x3f
+            prop = (self.packet[3] & 0x80) >> 7
+            count = self.packet[3] & 0x07
+            winsize = (self.packet[4] & 0xf8) >> 3
+            winoff = self.packet[4] & 0x07
+            self.putp(['Configuration: Power Class = %d, Maximum Power = %d, Prop = %d,'
+                       'Count = %d, Window Size = %d, Window Offset = %d' %
+                       (powerclass, maxpower, prop, count, winsize, winoff),
+                       'C: PC = %d MP = %d P = %d C = %d WS = %d WO = %d' %
+                       (powerclass, maxpower, prop, count, winsize, winoff),
+                       'Configuration', 'C'])
+        elif self.packet[0] == 0x71: # Identification 
+            version = '%d.%d' % ((self.packet[1] & 0xf0) >> 4, self.packet[1] & 0x0f)
+            mancode = '%02x%02x' % (self.packet[2], self.packet[3])
+            devid = '%02x%02x%02x%02x' % (self.packet[4] & ~0x80,
+                    self.packet[5], self.packet[6], self.packet[7])
+            self.putp(['Identification: Version = %s, Manufacturer = %s, ' \
+                       'Device = %s' % (version, mancode, devid),
+                       'ID: %s %s %s' % (version, mancode, devid), 'ID'])
+        elif self.packet[0] == 0x81: # Extended Identification
+            edevid = '%02x%02x%02x%02x%02x%02x%02x%02x' % self.packet[1:-1]
+            self.putp(['Extended Identification: %s' % edevid,
+                       'EI: %s' % edevid, 'EI'])
+        elif self.packet[0] in (0x18, 0x19, 0x28, 0x29, 0x38, 0x48, 0x58, 0x68,
+                0x78, 0x85, 0xa4, 0xc4, 0xe2): # Proprietary
+            self.putp(['Proprietary', 'P'])
+        else: # Unknown
+            self.putp(['Unknown', '?'])
+        self.put(self.bytesi[-1], self.samplenum, self.out_ann,
+                 [6, ['Checksum OK', 'OK']] if \
+                 calc_checksum(self.packet) == self.packet[-1]
+                 else [6, ['Checksum error', 'ERR']])
+
+    def process_byte(self):
+        self.put(self.bytestart, self.bitsi[0], self.out_ann,
+                 ([2, ['Start bit', 'Start', 'S']]) if self.bits[0] == 0 else
+                 ([1, ['Start error', 'Start err', 'SE']]))
+        databits = self.bits[1:9]
+        data = bits_to_uint(databits)
+        parity = reduce(lambda i, v: (i + v) % 2, databits, 1)
+        self.put(self.bitsi[0], self.bitsi[8], self.out_ann, [4, ['%02x' % data]])
+        self.put(self.bitsi[8], self.bitsi[9], self.out_ann,
+                 ([3, ['Parity bit', 'Parity', 'P']]) if self.bits[9] == parity else
+                 ([1, ['Parity error', 'Parity err', 'PE']]))
+        self.put(self.bitsi[9], self.bitsi[10], self.out_ann,
+                 ([3, ['Stop bit', 'Stop', 'S']]) if self.bits[10] == 1 else
+                 ([1, ['Stop error', 'Stop err', 'SE']]))
+
+        self.bytesi.append(self.bytestart)
+        self.packet.append(data)
+        if self.packet_len(self.packet[0]) + 2 == len(self.packet):
+            self.process_packet()
+            self.bytesi.clear()
+            self.packet.clear()
+
+    def add_bit(self, bit):
+        self.bits.append(bit)
+        self.bitsi.append(self.samplenum)
+
+        if self.state == 'IDLE' and len(self.bits) >= 5 and \
+                                    self.bits[-5:] == [1, 1, 1, 1, 0]:
+            self.state = 'DATA'
+            self.bytestart = self.bitsi[-2]
+            self.bits = [0]
+            self.bitsi = [self.samplenum]
+            self.packet.clear()
+        elif self.state == 'DATA' and len(self.bits) == 11:
+            self.process_byte()
+            self.bytestart = self.samplenum
+            self.bits.clear()
+            self.bitsi.clear()
+        if self.state != 'IDLE':
+            self.put(self.lastbit, self.samplenum, self.out_ann, [0, ['%d' % bit]])
+        self.lastbit = self.samplenum
+
+    def handle_transition(self, l, htl):
+        self.deq.append(l)
+        if len(self.deq) >= 2 and \
+                (self.in_tolerance(self.deq[-1] + self.deq[-2]) or \
+                htl and self.in_tolerance(l * 2) and \
+                self.deq[-2] > 1.25 * self.bit_width):
+            self.add_bit(1)
+            self.deq.clear()
+        elif self.in_tolerance(l):
+            self.add_bit(0)
+            self.deq.clear()
+        elif l > (1.25 * self.bit_width):
+            self.state = 'IDLE'
+            self.bytesi.clear()
+            self.packet.clear()
+            self.bits.clear()
+            self.bitsi.clear()
+
+    def next_sample(self, s):
+        if s == self.prev:
+            self.counter += 1
+        else:
+            self.handle_transition(self.counter, s == 0)
+            self.prev = s
+            self.counter = 1
+
+    def decode(self, ss, es, data):
+        if not self.samplerate:
+            raise SamplerateError('Cannot decode without samplerate.')
+        for (self.samplenum, (qi,)) in data:
+            self.next_sample(qi)