Move libprotocan to hardware/interfaces/automotive domain
Bug: 203756395
Change-Id: I4d0a1dcff2d6a974b40bccd403cecdc5cd03ac4f
diff --git a/automotive/can/1.0/tools/libprotocan/Signal.cpp b/automotive/can/1.0/tools/libprotocan/Signal.cpp
new file mode 100644
index 0000000..bc3e070
--- /dev/null
+++ b/automotive/can/1.0/tools/libprotocan/Signal.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <libprotocan/Signal.h>
+
+#include <android-base/logging.h>
+
+namespace android::hardware::automotive::protocan {
+
+static uint8_t calculateLastByteMask(uint16_t start, uint8_t length) {
+ unsigned lastByteBits = (start + length) % 8;
+ unsigned lastBytePadding = (8 - lastByteBits) % 8;
+ return 0xFF >> lastBytePadding;
+}
+
+static uint8_t calculateFirstByteMask(uint16_t firstByte, uint8_t firstBit, uint16_t lastByte,
+ uint8_t lastMask) {
+ uint8_t firstMask = 0xFF << firstBit;
+ if (firstByte == lastByte) firstMask &= lastMask;
+ return firstMask;
+}
+
+Signal::Signal(uint16_t start, uint8_t length, value defVal)
+ : maxValue((1u << length) - 1),
+ kFirstByte(start / 8),
+ kFirstBit(start % 8),
+ kFirstByteBits(8 - kFirstBit),
+ kLastByte((start + length - 1) / 8),
+ kLastMask(calculateLastByteMask(start, length)),
+ kFirstMask(calculateFirstByteMask(kFirstByte, kFirstBit, kLastByte, kLastMask)),
+ kDefVal(defVal) {
+ CHECK(length > 0) << "Signal length must not be zero";
+}
+
+Signal::value Signal::get(const can::V1_0::CanMessage& msg) const {
+ CHECK(msg.payload.size() > kLastByte)
+ << "Message is too short. Did you call MessageDef::validate?";
+
+ Signal::value v = 0;
+ if (kLastByte != kFirstByte) v = kLastMask & msg.payload[kLastByte];
+
+ for (int i = kLastByte - 1; i > kFirstByte; i--) {
+ v = (v << 8) | msg.payload[i];
+ }
+
+ return (v << kFirstByteBits) | ((msg.payload[kFirstByte] & kFirstMask) >> kFirstBit);
+}
+
+void Signal::set(can::V1_0::CanMessage& msg, Signal::value val) const {
+ CHECK(msg.payload.size() > kLastByte)
+ << "Signal requires message of length " << (kLastByte + 1)
+ << " which is beyond message length of " << msg.payload.size();
+
+ uint8_t firstByte = val << kFirstBit;
+ val >>= kFirstByteBits;
+
+ msg.payload[kFirstByte] = (msg.payload[kFirstByte] & ~kFirstMask) | (firstByte & kFirstMask);
+
+ for (int i = kFirstByte + 1; i < kLastByte; i++) {
+ msg.payload[i] = val & 0xFF;
+ val >>= 8;
+ }
+
+ if (kLastByte != kFirstByte) {
+ msg.payload[kLastByte] = (msg.payload[kLastByte] & ~kLastMask) | (val & kLastMask);
+ }
+}
+
+void Signal::setDefault(can::V1_0::CanMessage& msg) const { set(msg, kDefVal); }
+
+} // namespace android::hardware::automotive::protocan