Simple decoder for ST7735 TFT controller

2 files changed, 202 insertions, 0 deletions

diff --git a/decoders/st7735/__init__.py b/decoders/st7735/__init__.py
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+++ b/decoders/st7735/__init__.py
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+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2018 Aleksander Alekseev <afiskon@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, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+This decoder decodes the ST7735 TFT controller protocol.
+
+Details:
+http://www.displayfuture.com/Display/datasheet/controller/ST7735.pdf
+'''
+
+from .pd import Decoder
diff --git a/decoders/st7735/pd.py b/decoders/st7735/pd.py
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index 0000000..f704c03
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+++ b/decoders/st7735/pd.py
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+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2018 Aleksander Alekseev <afiskon@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, see <http://www.gnu.org/licenses/>.
+
+import sigrokdecode as srd
+
+MAX_DATA_LEN = 128
+
+# Command ID -> name, short description
+META = {
+    0x00: {'name': 'NOP    ', 'desc': 'No operation'},
+    0x01: {'name': 'SWRESET', 'desc': 'Software reset'},
+    0x04: {'name': 'RDDID  ', 'desc': 'Read display ID'},
+    0x09: {'name': 'RDDST  ', 'desc': 'Read display status'},
+    0x10: {'name': 'SLPIN  ', 'desc': 'Sleep in & booster off'},
+    0x11: {'name': 'SLPOUT ', 'desc': 'Sleep out & booster on'},
+    0x12: {'name': 'PTLON  ', 'desc': 'Partial mode on'},
+    0x13: {'name': 'NORON  ', 'desc': 'Partial off (normal)'},
+    0x20: {'name': 'INVOFF ', 'desc': 'Display inversion off'},
+    0x21: {'name': 'INVON  ', 'desc': 'Display inversion on'},
+    0x28: {'name': 'DISPOFF', 'desc': 'Display off'},
+    0x29: {'name': 'DISPON ', 'desc': 'Display on'},
+    0x2A: {'name': 'CASET  ', 'desc': 'Column address set'},
+    0x2B: {'name': 'RASET  ', 'desc': 'Row address set'},
+    0x2C: {'name': 'RAMWR  ', 'desc': 'Memory write'},
+    0x2E: {'name': 'RAMRD  ', 'desc': 'Memory read'},
+    0x30: {'name': 'PTLAR  ', 'desc': 'Partial start/end address set'},
+    0x36: {'name': 'MADCTL ', 'desc': 'Memory data address control'},
+    0x3A: {'name': 'COLMOD ', 'desc': 'Interface pixel format'},
+    0xB1: {'name': 'FRMCTR1', 'desc': 'Frame rate control (in normal mode / full colors)'},
+    0xB2: {'name': 'FRMCTR2', 'desc': 'Frame rate control (in idle mode / 8-colors)'},
+    0xB3: {'name': 'FRMCTR3', 'desc': 'Frame rate control (in partial mode / full colors) '},
+    0xB4: {'name': 'INVCTR ', 'desc': 'Display inversion control'},
+    0xB6: {'name': 'DISSET5', 'desc': 'Display function set 5'},
+    0xC0: {'name': 'PWCTR1 ', 'desc': 'Power control 1'},
+    0xC1: {'name': 'PWCTR2 ', 'desc': 'Power control 2'},
+    0xC2: {'name': 'PWCTR3 ', 'desc': 'Power control 3'},
+    0xC3: {'name': 'PWCTR4 ', 'desc': 'Power control 4'},
+    0xC4: {'name': 'PWCTR5 ', 'desc': 'Power control 5'},
+    0xC5: {'name': 'VMCTR1 ', 'desc': 'VCOM control 1'},
+    0xDA: {'name': 'RDID1  ', 'desc': 'Read ID1'},
+    0xDB: {'name': 'RDID2  ', 'desc': 'Read ID2'},
+    0xDC: {'name': 'RDID3  ', 'desc': 'Read ID3'},
+    0xDD: {'name': 'RDID4  ', 'desc': 'Read ID4'},
+    0xFC: {'name': 'PWCTR6 ', 'desc': 'Power control 6'},
+    0xE0: {'name': 'GMCTRP1', 'desc': 'Gamma \'+\'polarity correction characteristics setting'},
+    0xE1: {'name': 'GMCTRN1', 'desc': 'Gamma \'-\'polarity correction characteristics setting'},
+}
+
+class Ann:
+    BITS, CMD, DATA, DESC = range(4)
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'st7735'
+    name = 'ST7735'
+    longname = 'Sitronix ST7735'
+    desc = 'Sitronix ST7735 TFT controller protocol.'
+    license = 'gplv2+'
+    inputs = ['logic']
+    outputs = ['st7735']
+    channels = (
+        {'id': 'cs', 'name': 'CS#', 'desc': 'Chip-select'},
+        {'id': 'clk', 'name': 'CLK', 'desc': 'Clock'},
+        {'id': 'mosi', 'name': 'MOSI', 'desc': 'Master out, slave in'},
+        {'id': 'dc', 'name': 'DC', 'desc': 'Data or command'}
+    )
+    annotations = (
+        ('bit', 'Bit'),
+        ('command', 'Command'),
+        ('data', 'Data'),
+        ('description', 'Description'),
+    )
+    annotation_rows = (
+        ('bits', 'Bits', (Ann.BITS,)),
+        ('fields', 'Fields', (Ann.CMD, Ann.DATA)),
+        ('description', 'Description', (Ann.DESC,)),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        pass
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+
+    def reset_state(self):
+        self.accum_byte = 0
+        self.accum_bits_num = 0
+        self.bit_ss = -1
+        self.byte_ss = -1
+        self.current_bit = -1
+
+    def put_desc(self, ss, es, cmd, data):
+        if cmd == -1:
+            return
+        if META[cmd]:
+            self.put(ss, es, self.out_ann, [Ann.DESC,
+                ['%s: %s' % (META[cmd]['name'].strip(), META[cmd]['desc'])]])
+        else:
+            # Default description:
+            dots = ''
+            if len(data) == MAX_DATA_LEN:
+                data = data[:-1]
+                dots = '...'
+            data_str = '(none)'
+            if len(data) > 0:
+                data_str = ' '.join(['%02X' % b for b in data])
+            self.put(ss, es, self.out_ann, [Ann.DESC,
+                ['Unknown command: %02X. Data: %s%s' % (cmd, data_str, dots)]])
+
+    def decode(self):
+        current_cmd = -1
+        current_data = []
+        desc_ss = -1
+        desc_es = -1
+        self.reset_state()
+        while True:
+            # Check data on both CLK edges.
+            (cs, clk, mosi, dc) = self.wait({1: 'e'})
+
+            if cs == 1: # Wait for CS = low, ignore the rest.
+                self.reset_state()
+                continue
+
+            if clk == 1:
+                # Read one bit.
+                self.bit_ss = self.samplenum
+                if self.accum_bits_num == 0:
+                    self.byte_ss = self.samplenum
+                self.current_bit = mosi
+
+            if (clk == 0) and (self.current_bit >= 0):
+                # Process one bit.
+                self.put(self.bit_ss, self.samplenum, self.out_ann,
+                         [Ann.BITS, [str(self.current_bit)]])
+                self.accum_byte = (self.accum_byte << 1) | self.current_bit # MSB-first.
+                self.accum_bits_num += 1
+                if self.accum_bits_num == 8:
+                    # Process one byte.
+                    ann = Ann.DATA if dc else Ann.CMD # DC = low for commands.
+                    self.put(self.byte_ss, self.samplenum, self.out_ann,
+                             [ann, ['%02X' % self.accum_byte]])
+                    if ann == Ann.CMD:
+                        self.put_desc(desc_ss, desc_es, current_cmd, current_data)
+                        desc_ss = self.byte_ss
+                        desc_es = self.samplenum # For cmds without data.
+                        current_cmd = self.accum_byte
+                        current_data = []
+                    else:
+                        if len(current_data) < MAX_DATA_LEN:
+                            current_data += [self.accum_byte]
+                        desc_es = self.samplenum
+
+                    self.accum_bits_num = 0
+                    self.accum_byte = 0
+                    self.byte_ss = -1
+                self.current_bit = -1
+                self.bit_ss = -1