Add HDCP traffic decoder to stack on i2c

This decoder annotates i2c traffic to indicate the type of HDCP
message contained. It includes HDCP2.2 and HDCP1.4. Useful for
analysing HDCP negotiation failures.

2 files changed, 231 insertions, 0 deletions

diff --git a/decoders/hdcp/__init__.py b/decoders/hdcp/__init__.py
new file mode 100644
index 0000000..8ead98b
--- /dev/null
+++ b/decoders/hdcp/__init__.py
@@ -0,0 +1,27 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2018 Dave Craig<dcraig@brightsign.biz>
+##
+## 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 stacks on top of the 'i2c' PD and decodes HDCP messages.
+
+Details:
+https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf
+'''
+
+from .pd import Decoder
diff --git a/decoders/hdcp/pd.py b/decoders/hdcp/pd.py
new file mode 100644
index 0000000..861cd5c
--- /dev/null
+++ b/decoders/hdcp/pd.py
@@ -0,0 +1,204 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2018 Dave Craig<dcraig@brightsign.biz>
+##
+## 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
+
+msg_ids = {
+    2: 'AKE_Init',
+    3: 'AKE_Send_Cert',
+    4: 'AKE_No_stored_km',
+    5: 'AKE_Stored_km',
+
+    7: 'AKE_Send_H_prime',
+    8: 'AKE_Send_Pairing_Info',
+
+    9: 'LC_Init',
+    10: 'LC_Send_L_prime',
+
+    11: 'SKE_Send_Eks',
+    12: 'RepeaterAuth_Send_ReceiverID_List',
+
+    15: 'RepeaterAuth_Send_Ack',
+    16: 'RepeaterAuth_Stream_Manage',
+    17: 'RepeaterAuth_Stream_Ready',
+}
+
+class Decoder(srd.Decoder):
+    api_version = 3
+    id = 'hdcp'
+    name = 'HDCP'
+    longname = 'HDCP over HDMI'
+    desc = 'HDCP protocol over HDMI.'
+    license = 'gplv2+'
+    inputs = ['i2c']
+    outputs = ['hdcp']
+    annotations = \
+        tuple(('message-0x%02X' % i, 'Message 0x%02X' % i) for i in range(18)) + (
+        ('summary', 'Summary'),
+        ('warnings', 'Warnings'),
+    )
+    annotation_rows = (
+        ('messages', 'Messages', tuple(range(18))),
+        ('summary', 'Summary', (18,)),
+        ('warnings', 'Warnings', (19,)),
+    )
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.state = 'IDLE'
+        self.stack = []
+        self.msg = -1
+        self.ss = self.es = self.ss_block = self.es_block = 0
+        self.init_seq = []
+        self.valid = 0
+        self.type = ''
+
+    def start(self):
+        self.out_ann = self.register(srd.OUTPUT_ANN)
+
+    def putb(self, data):
+        self.put(self.ss_block, self.es_block, self.out_ann, data)
+
+    def decode(self, ss, es, data):
+        cmd, databyte = data
+
+        # Collect the 'BITS' packet, then return. The next packet is
+        # guaranteed to belong to these bits we just stored.
+        if cmd == 'BITS':
+            self.bits = databyte
+            return
+
+        self.ss, self.es = ss, es
+
+        # State machine.
+        if self.state == 'IDLE':
+            # Wait for an I2C START condition.
+            if cmd == 'START':
+                self.reset()
+                self.ss_block = ss
+            elif cmd != 'START REPEAT':
+                return
+            self.state = 'GET SLAVE ADDR'
+
+        elif self.state == 'GET SLAVE ADDR':
+            if cmd == 'ADDRESS READ':
+                self.state = 'BUFFER DATA'
+                if databyte != 0x3a:
+                    self.state = 'IDLE'
+            elif cmd == 'ADDRESS WRITE':
+                self.state = 'WRITE OFFSET'
+                if databyte != 0x3a:
+                    self.state = 'IDLE'
+
+        elif self.state == 'WRITE OFFSET':
+            if cmd == 'DATA WRITE':
+                if databyte == 0x00:
+                    self.type = '1.4 Bksv - Receiver KSV'
+                elif databyte == 0x08:
+                    self.type = '1.4 Ri\' - Link Verification'
+                elif databyte == 0x0a:
+                    self.type = '1.4 Pj\' - Enhanced Link Verification'
+                elif databyte == 0x10:
+                    self.type = '1.4 Aksv - Transmitter KSV'
+                    self.state = 'BUFFER DATA'
+                elif databyte == 0x15:
+                    self.type = '1.4 Ainfo- Transmitter KSV'
+                    self.state = 'BUFFER DATA'
+                elif databyte == 0x18:
+                    self.type = '1.4 An- Session random number'
+                    self.state = 'BUFFER DATA'
+                elif databyte == 0x20:
+                    self.type = '1.4 V\'H0'
+                elif databyte == 0x24:
+                    self.type = '1.4 V\'H1'
+                elif databyte == 0x28:
+                    self.type = '1.4 V\'H2'
+                elif databyte == 0x2c:
+                    self.type = '1.4 V\'H3'
+                elif databyte == 0x30:
+                    self.type = '1.4 V\'H4'
+                elif databyte == 0x40:
+                    self.type = '1.4 Bcaps'
+                elif databyte == 0x41:
+                    self.type = '1.4 Bstatus'
+                elif databyte == 0x43:
+                    self.type = '1.4 KSV FIFO'
+                elif databyte == 0x50:
+                    self.type = 'HDCP2Version'
+                elif databyte == 0x60:
+                    self.type = 'Write_Message'
+                    self.state = 'BUFFER DATA'
+                elif databyte == 0x70:
+                    self.type = 'RxStatus'
+                elif databyte == 0x80:
+                    self.type = 'Read_Message'
+
+                # If we are reading, then jump back to IDLE for a start repeat.
+                # If we are writing, then just continue onwards.
+                if self.state == 'BUFFER DATA':
+                    self.state = 'BUFFER DATA'
+                elif self.type != '':
+                    self.state = 'IDLE'
+
+        elif self.state == 'BUFFER DATA':
+            if (cmd == 'STOP') or (cmd == 'NACK'):
+                self.es_block = es
+                self.state = 'IDLE'
+                if self.type != '':
+                    if self.stack:
+                        if self.type == 'RxStatus':
+                            rxstatus = (self.stack.pop() << 8) | self.stack.pop()
+                            reauth_req = (rxstatus & 0x800) != 0
+                            ready = (rxstatus & 0x400) != 0
+                            length = rxstatus & 0x3ff
+                            text = '%s, reauth %s, ready %s, length %s' % (self.type, reauth_req, ready, length)
+                            self.putb([18, [text]])
+                        elif self.type == '1.4 Bstatus':
+                            bstatus = (self.stack.pop() << 8) | self.stack.pop()
+                            device_count = bstatus & 0x7f
+                            max_devs_exceeded = (bstatus & 0x80) != 0
+                            depth = ((bstatus & 0x700) >> 8)
+                            max_cascase_exceeded = bstatus & 0x800
+                            hdmi_mode = (bstatus & 0x1000) != 0
+                            text = '%s, %s devices, depth %s, hdmi mode %s' % (self.type, device_count, depth, hdmi_mode)
+                            self.putb([18, [text]])
+                        elif self.type == 'Read_Message':
+                            msg = self.stack.pop(0)
+                            self.putb([msg, ['%s, %s' % (self.type, msg_ids.get(msg, 'Invalid'))]])
+                        elif self.type == 'Write_Message':
+                            msg = self.stack.pop(0)
+                            self.putb([msg, ['%s, %s' % (self.type, msg_ids.get(msg, 'Invalid'))]])
+                        elif self.type == 'HDCP2Version':
+                            version = self.stack.pop(0)
+                            if (version & 0x4):
+                                self.putb([18, ['HDCP2']])
+                            else:
+                                self.putb([18, ['NOT HDCP2']])
+                        else:
+                            self.putb([18, ['%s' % (self.type)]])
+                    else:
+                        self.putb([18, ['%s' % (self.type)]])
+            elif cmd == 'DATA READ':
+                # Stack up our data bytes.
+                self.stack.append(databyte)
+            elif cmd == 'DATA WRITE':
+                # Stack up our data bytes.
+                self.stack.append(databyte)