Added mazda radar checksum to opendbc

opendbc/can/common.cc

@@ -69,6 +69,14 @@ unsigned int chrysler_checksum(unsigned int address, uint64_t d, int l) {
   return ~checksum & 0xFF;
 }
 
+uint8_t mazda_checksum(uint64_t data) {
+    uint8_t sum = 0;
+    for (int i = 0; i < 8; i++) {
+        sum += data >> (56 - 8*i);
+    }
+    return ~sum;
+}
+
 // Static lookup table for fast computation of CRC8 poly 0x2F, aka 8H2F/AUTOSAR
 uint8_t crc8_lut_8h2f[256];
 

opendbc/can/common.h

@@ -19,6 +19,7 @@ unsigned int honda_checksum(unsigned int address, uint64_t d, int l);
 unsigned int toyota_checksum(unsigned int address, uint64_t d, int l);
 unsigned int subaru_checksum(unsigned int address, uint64_t d, int l);
 unsigned int chrysler_checksum(unsigned int address, uint64_t d, int l);
+uint8_t mazda_checksum(uint64_t data);
 void init_crc_lookup_tables();
 unsigned int volkswagen_crc(unsigned int address, uint64_t d, int l);
 unsigned int pedal_checksum(uint64_t d, int l);

opendbc/can/common.pxd

@@ -20,7 +20,8 @@ cdef extern from "common_dbc.h":
     VOLKSWAGEN_CHECKSUM,
     VOLKSWAGEN_COUNTER,
     SUBARU_CHECKSUM,
-    CHRYSLER_CHECKSUM
+    CHRYSLER_CHECKSUM,
+    MAZDA_CHECKSUM
 
   cdef struct Signal:
     const char* name

opendbc/can/common_dbc.h

@@ -41,6 +41,7 @@ enum SignalType {
   VOLKSWAGEN_COUNTER,
   SUBARU_CHECKSUM,
   CHRYSLER_CHECKSUM,
+  MAZDA_CHECKSUM,
 };
 
 struct Signal {

opendbc/can/dbc_template.cc

@@ -33,6 +33,8 @@ const Signal sigs_{{address}}[] = {
       .type = SignalType::SUBARU_CHECKSUM,
       {% elif checksum_type == "chrysler" and sig.name == "CHECKSUM" %}
       .type = SignalType::CHRYSLER_CHECKSUM,
+      {% elif checksum_type == "mazda" and sig.name == "CHECKSUM" %}
+      .type = SignalType::MAZDA_CHECKSUM,
       {% elif address in [512, 513] and sig.name == "CHECKSUM_PEDAL" %}
       .type = SignalType::PEDAL_CHECKSUM,
       {% elif address in [512, 513] and sig.name == "COUNTER_PEDAL" %}

opendbc/can/packer.cc

@@ -104,6 +104,9 @@ uint64_t CANPacker::pack(uint32_t address, const std::vector<SignalPackValue> &s
     } else if (sig.type == SignalType::CHRYSLER_CHECKSUM) {
       unsigned int chksm = chrysler_checksum(address, ReverseBytes(ret), message_lookup[address].size);
       ret = set_value(ret, sig, chksm);
+    } else if (sig.type == SignalType::MAZDA_CHECKSUM) {
+      unsigned int chksm = mazda_checksum(ret);
+      ret = set_value(ret, sig, chksm);
     } else {
       //WARN("CHECKSUM signal type not valid\n");
     }

opendbc/can/process_dbc.py

@@ -61,6 +61,13 @@ def process(in_fn, out_fn):
     checksum_start_bit = 7
     counter_start_bit = None
     little_endian = False
+  elif can_dbc.name.startswith(("mazda_")):
+    checksum_type = "mazda"
+    checksum_size = 8
+    counter_size = None
+    checksum_start_bit = 0
+    counter_start_bit = None
+    little_endian = True
   else:
     checksum_type = None
     checksum_size = None