Add Dallas DS1307 RTC protocol decoder

Dallas DS1307 RTC protocol decoder that works stacked
with the I2C PD. Based on the rtc8564 protocol decoder.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>

3 files changed, 232 insertions, 0 deletions

diff --git a/decoders/ds1307/Makefile.am b/decoders/ds1307/Makefile.am
new file mode 100644
index 0000000..5ea58e4
--- /dev/null
+++ b/decoders/ds1307/Makefile.am
@@ -0,0 +1,26 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2013 Matt Ranostay <mranostay@gmail.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 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)/ds1307
+
+dist_pkgdata_DATA = __init__.py pd.py
+
+CLEANFILES = *.pyc
+
diff --git a/decoders/ds1307/__init__.py b/decoders/ds1307/__init__.py
new file mode 100644
index 0000000..0a7fd39
--- /dev/null
+++ b/decoders/ds1307/__init__.py
@@ -0,0 +1,29 @@
+##
+## This file is part of the sigrok project.
+##
+## Copyright (C) 2013 Matt Ranostay <mranostay@gmail.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 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
+##
+
+'''
+Dallas DS1307 RTC protocol decoder.
+
+Details:
+TODO
+'''
+
+from .pd import *
+
diff --git a/decoders/ds1307/pd.py b/decoders/ds1307/pd.py
new file mode 100644
index 0000000..273226c
--- /dev/null
+++ b/decoders/ds1307/pd.py
@@ -0,0 +1,177 @@
+##
+## This file is part of the sigrok project.
+## 
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+## Copyright (C) 2013 Matt Ranostay <mranostay@gmail.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 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
+##
+
+# Dallas DS1307 RTC protocol decoder
+
+import sigrokdecode as srd
+
+days_of_week = [
+    'Sunday',
+    'Monday',
+    'Tuesday',
+    'Wednesday',
+    'Thursday',
+    'Friday',
+    'Saturday',
+]
+
+# Return the specified BCD number (max. 8 bits) as integer.
+def bcd2int(b):
+    return (b & 0x0f) + ((b >> 4) * 10)
+
+class Decoder(srd.Decoder):
+    api_version = 1
+    id = 'ds1307'
+    name = 'DS1307'
+    longname = 'Dallas DS1307'
+    desc = 'Realtime clock module protocol.'
+    license = 'gplv2+'
+    inputs = ['i2c']
+    outputs = ['ds1307']
+    probes = []
+    optional_probes = []
+    options = {}
+    annotations = [
+        ['Text', 'Human-readable text'],
+    ]
+
+    def __init__(self, **kwargs):
+        self.state = 'IDLE'
+        self.hours = -1
+        self.minutes = -1
+        self.seconds = -1
+        self.days = -1
+        self.date = -1
+        self.months = -1
+        self.years = -1
+
+    def start(self, metadata):
+        self.out_ann = self.add(srd.OUTPUT_ANN, 'ds1307')
+
+    def report(self):
+        pass
+
+    def putx(self, data):
+        self.put(self.ss, self.es, self.out_ann, data)
+
+    def handle_reg_0x00(self, b): # Seconds
+        self.seconds = bcd2int(b & 0x7f)
+        self.putx([0, ['Seconds: %d' % self.seconds]])
+
+    def handle_reg_0x01(self, b): # Minutes
+        self.minutes = bcd2int(b & 0x7f)
+        self.putx([0, ['Minutes: %d' % self.minutes]])
+
+    def handle_reg_0x02(self, b): # Hours
+        self.hours = bcd2int(b & 0x3f)
+        self.putx([0, ['Hours: %d' % self.hours]])
+
+    def handle_reg_0x03(self, b): # Day of week
+        self.days = bcd2int(b & 0x7)
+        self.putx([0, ['Day of Week: %s' % days_of_week[self.days - 1]]])
+
+    def handle_reg_0x04(self, b): # Date
+        self.date =  bcd2int(b & 0x3f)
+        self.putx([0, ['Days: %d' % self.date]])
+
+    def handle_reg_0x05(self, b): # Month
+        self.months = bcd2int(b & 0x1f)
+        self.putx([0, ['Months: %d' % self.months]])
+
+    def handle_reg_0x06(self, b): # Year
+        self.years = bcd2int(b & 0xff) + 2000;
+        self.putx([0, ['Years: %d' % self.years]])
+
+    def handle_reg_0x07(self, b): # Control Register
+        pass
+
+    def decode(self, ss, es, data):
+        cmd, databyte = data
+
+        # Store the start/end samples of this I2C packet.
+        self.ss, self.es = ss, es
+
+        # State machine.
+        if self.state == 'IDLE':
+            # Wait for an I2C START condition.
+            if cmd != 'START':
+                return
+            self.state = 'GET SLAVE ADDR'
+            self.block_start_sample = ss
+        elif self.state == 'GET SLAVE ADDR':
+            # Wait for an address write operation.
+            # TODO: We should only handle packets to the RTC slave (0x68).
+            if cmd != 'ADDRESS WRITE':
+                return
+            self.state = 'GET REG ADDR'
+        elif self.state == 'GET REG ADDR':
+            # Wait for a data write (master selects the slave register).
+            if cmd != 'DATA WRITE':
+                return
+            self.reg = databyte
+            self.state = 'WRITE RTC REGS'
+        elif self.state == 'WRITE RTC REGS':
+            # If we see a Repeated Start here, it's probably an RTC read.
+            if cmd == 'START REPEAT':
+                self.state = 'READ RTC REGS'
+                return
+            # Otherwise: Get data bytes until a STOP condition occurs.
+            if cmd == 'DATA WRITE':
+                handle_reg = getattr(self, 'handle_reg_0x%02x' % self.reg)
+                handle_reg(databyte)
+                self.reg += 1
+                # TODO: Check for NACK!
+            elif cmd == 'STOP':
+                # TODO: Handle read/write of only parts of these items.
+                d = '%02d.%02d.%02d %02d:%02d:%02d' % (self.days, self.date,
+                    self.months, self.years, self.hours, self.minutes,
+                    self.seconds)
+                self.put(self.block_start_sample, es, self.out_ann,
+                         [0, ['Written date/time: %s' % d]])
+                self.state = 'IDLE'
+            else:
+                pass # TODO
+        elif self.state == 'READ RTC REGS':
+            # Wait for an address read operation.
+            # TODO: We should only handle packets to the RTC slave (0x68).
+            if cmd == 'ADDRESS READ':
+                self.state = 'READ RTC REGS2'
+                return
+            else:
+                pass # TODO
+        elif self.state == 'READ RTC REGS2':
+            if cmd == 'DATA READ':
+                handle_reg = getattr(self, 'handle_reg_0x%02x' % self.reg)
+                handle_reg(databyte)
+                self.reg += 1
+                # TODO: Check for NACK!
+            elif cmd == 'STOP':
+                d = '%02d.%02d.%02d.%02d %02d:%02d:%02d' % (self.days,
+                    self.date, self.months, self.years, self.hours,
+                    self.minutes, self.seconds)
+                self.put(self.block_start_sample, es, self.out_ann,
+                         [0, ['Read date/time: %s' % d]])
+                self.state = 'IDLE'
+            else:
+                pass # TODO?
+        else:
+            raise Exception('Invalid state: %s' % self.state)
+