Diff: Links/RomCommands.cpp

Revision:

0:f77ad7f72d04

Child:

6:a8c83a2e6fa4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Links/RomCommands.cpp	Mon Nov 06 14:39:18 2017 -0600
@@ -0,0 +1,222 @@
+/*******************************************************************************
+* Copyright (C) 2017 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************/
+
+#include <algorithm>
+#include "RomCommands.hpp"
+
+namespace MaximInterface {
+
+enum RomCmd {
+  ReadRomCmd = 0x33,
+  MatchRomCmd = 0x55,
+  SearchRomCmd = 0xF0,
+  SkipRomCmd = 0xCC,
+  ResumeRomCmd = 0xA5,
+  OverdriveSkipRomCmd = 0x3C,
+  OverdriveMatchRomCmd = 0x69
+};
+
+void skipCurrentFamily(SearchRomState & searchState) {
+  // set the Last discrepancy to last family discrepancy
+  searchState.lastDiscrepancy = searchState.lastFamilyDiscrepancy;
+
+  // clear the last family discrepancy
+  searchState.lastFamilyDiscrepancy = 0;
+
+  // check for end of list
+  if (searchState.lastDiscrepancy == 0) {
+    searchState.lastDevice = true;
+  }
+}
+
+error_code verifyRom(OneWireMaster & master, const RomId & romId) {
+  SearchRomState searchState(romId);
+  error_code result = searchRom(master, searchState);
+  if (!result) {
+    // check if same device found
+    if (romId != searchState.romId) {
+      result = make_error_code(OneWireMaster::NoSlaveError);
+    }
+  }
+  return result;
+}
+
+error_code readRom(OneWireMaster & master, RomId & romId) {
+  error_code result = master.reset();
+  if (!result) {
+    result = master.writeByte(ReadRomCmd);
+  }
+
+  // read the ROM
+  RomId readId;
+  if (!result) {
+    result = master.readBlock(readId.data(), readId.size());
+  }
+
+  // verify CRC8
+  if (!result) {
+    if (valid(readId)) {
+      romId = readId;
+    } else {
+      result = make_error_code(OneWireMaster::NoSlaveError);
+    }
+  }
+
+  return result;
+}
+
+error_code skipRom(OneWireMaster & master) {
+  error_code result = master.reset();
+  if (!result) {
+    result = master.writeByte(SkipRomCmd);
+  }
+  return result;
+}
+
+error_code matchRom(OneWireMaster & master, const RomId & romId) {
+  // use MatchROM
+  error_code result = master.reset();
+  if (!result) {
+    uint_least8_t buf[1 + RomId::csize];
+    buf[0] = MatchRomCmd;
+    std::copy(romId.begin(), romId.end(), buf + 1);
+    // send command and rom
+    result = master.writeBlock(buf, sizeof(buf) / sizeof(buf[0]));
+  }
+  return result;
+}
+
+error_code overdriveSkipRom(OneWireMaster & master) {
+  error_code result = master.setSpeed(OneWireMaster::StandardSpeed);
+
+  if (!result) {
+    result = master.reset();
+  }
+
+  if (!result) {
+    result = master.writeByte(OverdriveSkipRomCmd);
+  }
+
+  if (!result) {
+    result = master.setSpeed(OneWireMaster::OverdriveSpeed);
+  }
+
+  return result;
+}
+
+error_code overdriveMatchRom(OneWireMaster & master, const RomId & romId) {
+  // use overdrive MatchROM
+  master.setSpeed(OneWireMaster::StandardSpeed);
+
+  error_code result = master.reset();
+  if (!result) {
+    result = master.writeByte(OverdriveMatchRomCmd);
+    if (!result) {
+      master.setSpeed(OneWireMaster::OverdriveSpeed);
+      // send ROM
+      result = master.writeBlock(romId.data(), romId.size());
+    }
+  }
+  return result;
+}
+
+error_code resumeRom(OneWireMaster & master) {
+  error_code result = master.reset();
+  if (!result) {
+    result = master.writeByte(ResumeRomCmd);
+  }
+  return result;
+}
+
+error_code searchRom(OneWireMaster & master, SearchRomState & searchState) {
+  if (searchState.lastDevice) {
+    searchState = SearchRomState();
+  }
+
+  error_code result = master.reset();
+  if (result) {
+    return result;
+  }
+  result = master.writeByte(SearchRomCmd);
+  if (result) {
+    return result;
+  }
+
+  SearchRomState newSearchState = searchState;
+  for (int idBitNumber = 1; idBitNumber <= 64; idBitNumber++) {
+    const int idByteNumber = (idBitNumber - 1) / 8;
+    const unsigned int idBitMask = 1 << ((idBitNumber - 1) % 8);
+
+    OneWireMaster::TripletData tripletData;
+    if (idBitNumber == newSearchState.lastDiscrepancy) {
+      tripletData.writeBit = 1;
+    } else if (idBitNumber > newSearchState.lastDiscrepancy) {
+      tripletData.writeBit = 0;
+    } else // idBitNumber < searchState.lastDiscrepancy
+    {
+      tripletData.writeBit =
+          (newSearchState.romId[idByteNumber] & idBitMask) == idBitMask;
+    }
+
+    result = master.triplet(tripletData);
+    if (result) {
+      return result;
+    }
+    if (tripletData.readBit && tripletData.readBitComplement) {
+      return make_error_code(OneWireMaster::NoSlaveError);
+    }
+
+    if (tripletData.writeBit) {
+      newSearchState.romId[idByteNumber] |= idBitMask;
+    } else {
+      newSearchState.romId[idByteNumber] &= ~idBitMask;
+      if (!tripletData.readBit && !tripletData.readBitComplement) {
+        newSearchState.lastDiscrepancy = idBitNumber;
+        if (idBitNumber <= 8) {
+          newSearchState.lastFamilyDiscrepancy = idBitNumber;
+        }
+      }
+    }
+  }
+
+  if (valid(newSearchState.romId)) {
+    if (newSearchState.lastDiscrepancy == searchState.lastDiscrepancy) {
+      newSearchState.lastDevice = true;
+    }
+    searchState = newSearchState;
+  } else {
+    result = make_error_code(OneWireMaster::NoSlaveError);
+  }
+  return result;
+}
+
+} // namespace MaximInterface