+##
+## 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)
+
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