Add LTC26x7 decoder.

Signed-off-by: Teo Perisanu <Teo.Perisanu@analog.com>

2 files changed, 204 insertions, 0 deletions

diff --git a/decoders/ltc26x7/__init__.py b/decoders/ltc26x7/__init__.py
new file mode 100644
index 0000000..efedd4d
--- /dev/null
+++ b/decoders/ltc26x7/__init__.py
@@ -0,0 +1,25 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2020 Analog Devices Inc.
+##
+## 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, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+This decoder stacks on top of the 'i2c' PD and decodes the
+Linear Technology LTC2607/LTC2617/LTC2627 protocol.
+'''
+
+from .pd import Decoder
diff --git a/decoders/ltc26x7/pd.py b/decoders/ltc26x7/pd.py
new file mode 100644
index 0000000..ea05a25
--- /dev/null
+++ b/decoders/ltc26x7/pd.py
@@ -0,0 +1,179 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2020 Analog Devices Inc.
+##
+## 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, see <http://www.gnu.org/licenses/>.
+##
+
+import sigrokdecode as srd
+
+slave_address = {
+    0x00: ['GND', 'GND', 'GND', 'G'],
+    0x01: ['FLOAT', 'FLOAT', 'FLOAT', 'F'],
+    0x02: ['VCC', 'VCC', 'VCC', 'V'],
+}
+
+commands = {
+    0x00: ['Write Input Register', 'Write In Reg', 'Wr In Reg', 'WIR'],
+    0x01: ['Update DAC', 'Update', 'U'],
+    0x03: ['Write and Power Up DAC', 'Write & Power Up', 'W&PU'],
+    0x04: ['Power Down DAC', 'Power Down', 'PD'],
+    0x0F: ['No Operation', 'No Op', 'NO'],
+}
+
+addresses = {
+    0x00: ['DAC A', 'A'],
+    0x01: ['DAC B', 'B'],
+    0x0F: ['All DACs', 'All'],
+}
+
+input_voltage_format = ['%fV', '%fV', '%.6fV', '%.2fV']
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'ltc26x7'
+    name = 'LTC26x7'
+    longname = 'Linear Technology LTC26x7'
+    desc = 'Linear Technology LTC26x7 16-/14-/12-bit rail-to-rail DACs.'
+    license = 'gplv2+'
+    inputs = ['i2c']
+    outputs = []
+    tags = ['Display']
+    options = (
+        {'id': 'part', 'desc': 'Part', 'default': 'ltc26x7',
+            'values': ('ltc2607', 'ltc2617', 'ltc2627')},
+        {'id': 'ref', 'desc': 'Reference voltage', 'default': 1.5},
+    )
+    annotations = (
+        ('slave_addr', 'Slave address'),
+        ('command', 'Command'),
+        ('address', 'Address'),
+        ('data', '2 byte data'),
+    )
+    annotation_rows = (
+        ('ltc26x7', 'LTC26x7 data', (0, 1, 2, 3)),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.state = 'IDLE'
+        self.ss = -1
+        self.data = 0x00
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+
+    def convert_ternary_str(self, n):
+        if n == 0:
+            return [0, 0, 0]
+        nums = []
+        while n:
+            n, r = divmod(n, 3)
+            nums.append(r)
+        while len(nums) < 3:
+            nums.append(0)
+        return list(reversed(nums))
+
+    def handle_slave_addr(self, data):
+        if data == 0x73:
+            ann = ['Global address', 'Global addr', 'Glob addr', 'GA']
+            self.put(self.ss, self.es, self.out_ann, [0, ann])
+            return
+        ann = ['CA2=%s CA1=%s CA0=%s', '2=%s 1=%s 0=%s', '%s %s %s', '%s %s %s']
+        addr = 0
+        for i in range(7):
+            if i in [2, 3]:
+                continue
+            offset = i
+            if i > 3:
+                offset -= 2
+            mask = 1 << i
+            if data & mask:
+                mask = 1 << offset
+                addr |= mask
+
+        addr -= 0x04
+        ternary_values = self.convert_ternary_str(addr)
+        for i in range(len(ann)):
+            ann[i] = ann[i] % (slave_address[ternary_values[0]][i],
+                               slave_address[ternary_values[1]][i],
+                               slave_address[ternary_values[2]][i])
+        self.put(self.ss, self.es, self.out_ann, [0, ann])
+
+    def handle_cmd_addr(self, data):
+        cmd_val = (data >> 4) & 0x0F
+        dac_val = (data & 0x0F)
+        sm = (self.ss + self.es) // 2
+
+        self.put(self.ss, sm, self.out_ann, [1, commands[cmd_val]])
+        self.put(sm, self.es, self.out_ann, [2, addresses[dac_val]])
+
+    def handle_data(self, data):
+        self.data = (self.data << 8) & 0xFF00
+        self.data += data
+        if self.options['part'] == 'ltc2617':
+            self.data = (self.data >> 2)
+            self.data = (self.options['ref'] * self.data) / 0x3FFF
+        elif self.options['part'] == 'ltc2627':
+            self.data = (self.data >> 4)
+            self.data = (self.options['ref'] * self.data) / 0x0FFF
+        else:
+            self.data = (self.options['ref'] * self.data) / 0xFFFF
+        ann = []
+        for format in input_voltage_format:
+            ann.append(format % self.data)
+        self.data = 0
+
+        self.put(self.ss, self.es, self.out_ann, [3, ann])
+
+    def decode(self, ss, es, data):
+        cmd, databyte = data
+        self.es = es
+
+        # State machine.
+        if self.state == 'IDLE':
+            # Wait for an I²C START condition.
+            if cmd != 'START':
+                return
+            self.state = 'GET SLAVE ADDR'
+        elif self.state == 'GET SLAVE ADDR':
+            # Wait for an address write operation.
+            if cmd != 'ADDRESS WRITE':
+                return
+            self.ss = ss
+            self.handle_slave_addr(databyte)
+            self.ss = -1
+            self.state = 'GET CMD ADDR'
+        elif self.state == 'GET CMD ADDR':
+            if cmd != 'DATA WRITE':
+                return
+            self.ss = ss
+            self.handle_cmd_addr(databyte)
+            self.ss = -1
+            self.state = 'WRITE DATA'
+        elif self.state == 'WRITE DATA':
+            if cmd == 'DATA WRITE':
+                if self.ss == -1:
+                    self.ss = ss
+                    self.data = databyte
+                    return
+                self.handle_data(databyte)
+                self.ss = -1
+            elif cmd == 'STOP':
+                self.state = 'IDLE'
+            else:
+                return