ch32v203-eth-node/onewire.c

/*

Single-File One Wire Communication Functions for CH32V003

Relies on the CH32V003fun library from:
  https://github.com/cnlohr/ch32v003fun

This is very heavily derived from the Arduino OneWire library,
  at https://github.com/PaulStoffregen/OneWire


Original copyright notices follow:
--------------------------------------------

Copyright (c) 2007, Jim Studt  (original old version - many contributors since)

The latest version of this library may be found at:
  http://www.pjrc.com/teensy/td_libs_OneWire.html

OneWire has been maintained by Paul Stoffregen (paul@pjrc.com) since
January 2010.

DO NOT EMAIL for technical support, especially not for ESP chips!
All project support questions must be posted on public forums
relevant to the board or chips used.  If using Arduino, post on
Arduino's forum.  If using ESP, post on the ESP community forums.
There is ABSOLUTELY NO TECH SUPPORT BY PRIVATE EMAIL!

Github's issue tracker for OneWire should be used only to report
specific bugs.  DO NOT request project support via Github.  All
project and tech support questions must be posted on forums, not
github issues.  If you experience a problem and you are not
absolutely sure it's an issue with the library, ask on a forum
first.  Only use github to report issues after experts have
confirmed the issue is with OneWire rather than your project.

Back in 2010, OneWire was in need of many bug fixes, but had
been abandoned the original author (Jim Studt).  None of the known
contributors were interested in maintaining OneWire.  Paul typically
works on OneWire every 6 to 12 months.  Patches usually wait that
long.  If anyone is interested in more actively maintaining OneWire,
please contact Paul (this is pretty much the only reason to use
private email about OneWire).

OneWire is now very mature code.  No changes other than adding
definitions for newer hardware support are anticipated.

  ESP32 mods authored by stickbreaker:
  @stickbreaker 30APR2018 add IRAM_ATTR to read_bit() OneWireWriteBit() to solve
ICache miss timing failure. thanks @everslick re:
https://github.com/espressif/arduino-esp32/issues/1335 Altered by garyd9 for
clean merge with Paul Stoffregen's source

Version 2.3:
  Unknown chip fallback mode, Roger Clark
  Teensy-LC compatibility, Paul Stoffregen
  Search bug fix, Love Nystrom

Version 2.2:
  Teensy 3.0 compatibility, Paul Stoffregen, paul@pjrc.com
  Arduino Due compatibility, http://arduino.cc/forum/index.php?topic=141030
  Fix DS18B20 example negative temperature
  Fix DS18B20 example's low res modes, Ken Butcher
  Improve reset timing, Mark Tillotson
  Add const qualifiers, Bertrik Sikken
  Add initial value input to crc16, Bertrik Sikken
  Add target_search() function, Scott Roberts

Version 2.1:
  Arduino 1.0 compatibility, Paul Stoffregen
  Improve temperature example, Paul Stoffregen
  DS250x_PROM example, Guillermo Lovato
  PIC32 (chipKit) compatibility, Jason Dangel, dangel.jason AT gmail.com
  Improvements from Glenn Trewitt:
  - crc16() now works
  - check_crc16() does all of calculation/checking work.
  - Added read_bytes() and write_bytes(), to reduce tedious loops.
  - Added ds2408 example.
  Delete very old, out-of-date readme file (info is here)

Version 2.0: Modifications by Paul Stoffregen, January 2010:
http://www.pjrc.com/teensy/td_libs_OneWire.html
  Search fix from Robin James
    http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
  Use direct optimized I/O in all cases
  Disable interrupts during timing critical sections
    (this solves many random communication errors)
  Disable interrupts during read-modify-write I/O
  Reduce RAM consumption by eliminating unnecessary
    variables and trimming many to 8 bits
  Optimize both crc8 - table version moved to flash

Modified to work with larger numbers of devices - avoids loop.
Tested in Arduino 11 alpha with 12 sensors.
26 Sept 2008 -- Robin James
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27

Updated to work with arduino-0008 and to include skip() as of
2007/07/06. --RJL20

Modified to calculate the 8-bit CRC directly, avoiding the need for
the 256-byte lookup table to be loaded in RAM.  Tested in arduino-0010
-- Tom Pollard, Jan 23, 2008

Jim Studt's original library was modified by Josh Larios.

Tom Pollard, pollard@alum.mit.edu, contributed around May 20, 2008

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 THE AUTHORS OR COPYRIGHT HOLDERS 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.

Much of the code was inspired by Derek Yerger's code, though I don't
think much of that remains.  In any event that was..
    (copyleft) 2006 by Derek Yerger - Free to distribute freely.

The CRC code was excerpted and inspired by the Dallas Semiconductor
sample code bearing this copyright.
//---------------------------------------------------------------------------
// Copyright (C) 2000 Dallas Semiconductor Corporation, 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 DALLAS SEMICONDUCTOR 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 Dallas Semiconductor
// shall not be used except as stated in the Dallas Semiconductor
// Branding Policy.
//--------------------------------------------------------------------------
*/

#include "onewire.h"

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "ch32v003fun.h"

// global search state
unsigned char ROM_NO[8];
uint8_t LastDiscrepancy;
uint8_t LastFamilyDiscrepancy;
bool LastDeviceFlag;

void OneWireBegin(void);

// Perform a 1-Wire reset cycle. Returns 1 if a device responds
// with a presence pulse.  Returns 0 if there is no device or the
// bus is shorted or otherwise held low for more than 250uS
uint8_t OneWireReset(void);

// Issue a 1-Wire rom select command, you do the reset first.
void OneWireSelect(const uint8_t rom[8]);

// Issue a 1-Wire rom skip command, to address all on bus.
// void skip(void);

// Write a byte. If 'power' is one then the wire is held high at
// the end for parasitically powered devices. You are responsible
// for eventually depowering it by calling depower() or doing
// another read or write.
void OneWireWrite(uint8_t v, uint8_t power);

void OneWireWriteBytes(const uint8_t *buf, uint16_t count, bool power);

// Read a byte.
uint8_t OneWireRead(void);

void OneWireReadBytes(uint8_t *buf, uint16_t count);

// Write a bit. The bus is always left powered at the end, see
// note in write() about that.
void OneWireWriteBit(uint8_t v);

// Read a bit.
uint8_t OneWireReadBit(void);

// Stop forcing power onto the bus. You only need to do this if
// you used the 'power' flag to write() or used a write_bit() call
// and aren't about to do another read or write. You would rather
// not leave this powered if you don't have to, just in case
// someone shorts your bus.
void OneWireDepower(void);

// Clear the search state so that if will start from the beginning again.
void OneWireResetSearch();

// Setup the search to find the device type 'family_code' on the next call
// to search(*newAddr) if it is present.
void OneWireTargetSearch(uint8_t family_code);

// Look for the next device. Returns 1 if a new address has been
// returned. A zero might mean that the bus is shorted, there are
// no devices, or you have already retrieved all of them.  It
// might be a good idea to check the CRC to make sure you didn't
// get garbage.  The order is deterministic. You will always get
// the same devices in the same order.
bool OneWireSearch(uint8_t *newAddr, bool search_mode);

// Compute a Dallas Semiconductor 8 bit CRC, these are used in the
// ROM and scratchpad registers.
uint8_t OneWireCrc8(const uint8_t *addr, uint8_t len);

// Compute the 1-Wire CRC16 and compare it against the received CRC.
// Example usage (reading a DS2408):
//    // Put everything in a buffer so we can compute the CRC easily.
//    uint8_t buf[13];
//    buf[0] = 0xF0;    // Read PIO Registers
//    buf[1] = 0x88;    // LSB address
//    buf[2] = 0x00;    // MSB address
//    WriteBytes(net, buf, 3);    // Write 3 cmd bytes
//    ReadBytes(net, buf+3, 10);  // Read 6 data bytes, 2 0xFF, 2 CRC16
//    if (!CheckCRC16(buf, 11, &buf[11])) {
//        // Handle error.
//    }
//
// @param input - Array of bytes to checksum.
// @param len - How many bytes to use.
// @param inverted_crc - The two CRC16 bytes in the received data.
//                       This should just point into the received data,
//                       *not* at a 16-bit integer.
// @param crc - The crc starting value (optional)
// @return True, iff the CRC matches.
bool OneWireCheckCrc16(const uint8_t *input, uint16_t len,
                       const uint8_t *inverted_crc, uint16_t crc);

// Compute a Dallas Semiconductor 16 bit CRC.  This is required to check
// the integrity of data received from many 1-Wire devices.  Note that the
// CRC computed here is *not* what you'll get from the 1-Wire network,
// for two reasons:
//   1) The CRC is transmitted bitwise inverted.
//   2) Depending on the endian-ness of your processor, the binary
//      representation of the two-byte return value may have a different
//      byte order than the two bytes you get from 1-Wire.
// @param input - Array of bytes to checksum.
// @param len - How many bytes to use.
// @param crc - The crc starting value (optional)
// @return The CRC16, as defined by Dallas Semiconductor.
uint16_t OneWireCrc16(const uint8_t *input, uint16_t len, uint16_t crc);

void OneWireBegin() {
  directModeInput();
  OneWireResetSearch();
}

// Perform the onewire reset function.  We will wait up to 250uS for
// the bus to come high, if it doesn't then it is broken or shorted
// and we return a 0;
//
// Returns 1 if a device asserted a presence pulse, 0 otherwise.
//
uint8_t OneWireReset(void) {
  uint8_t r;
  uint8_t retries = 125;

  DIRECT_MODE_INPUT();

  // wait until the wire is high... just in case
  do {
    if (--retries == 0) return 0;
    Delay_Us(ONEWIRE_RESET_RETRY_TIME);
  } while (!DIRECT_READ());

  DIRECT_WRITE_LOW();
  DIRECT_MODE_OUTPUT();  // drive output low

  Delay_Us(ONEWIRE_RESET_LOW_TIME);

  DIRECT_MODE_INPUT();  // allow it to float
  Delay_Us(ONEWIRE_RESET_SAMPLE_TIME);
  r = !DIRECT_READ();

  Delay_Us(ONEWIRE_RESET_POST_TIME);
  return r;
}

//
// Write a bit. Port and bit is used to cut lookup time and provide
// more certain timing.
//
void OneWireWriteBit(uint8_t v) {
  if (v & 1) {
    DIRECT_WRITE_LOW();
    DIRECT_MODE_OUTPUT();  // drive output low
    Delay_Us(ONEWIRE_WRITE_1_LOW_TIME);
    DIRECT_WRITE_HIGH();  // drive output high

    Delay_Us(ONEWIRE_WRITE_1_TOTAL_TIME - ONEWIRE_WRITE_1_LOW_TIME);
  } else {
    DIRECT_WRITE_LOW();
    DIRECT_MODE_OUTPUT();  // drive output low
    Delay_Us(ONEWIRE_WRITE_0_LOW_TIME);
    DIRECT_WRITE_HIGH();  // drive output high

    Delay_Us(ONEWIRE_WRITE_0_TOTAL_TIME - ONEWIRE_WRITE_0_LOW_TIME);
  }
}

//
// Read a bit. Port and bit is used to cut lookup time and provide
// more certain timing.
//
uint8_t OneWireReadBit(void) {
  uint8_t r;

  DIRECT_MODE_OUTPUT();
  DIRECT_WRITE_LOW();
  Delay_Us(ONEWIRE_READ_INIT_LOW_TIME);  // 6us initial low pulse

  DIRECT_MODE_INPUT();                 // let pin float, pull up will raise
  Delay_Us(ONEWIRE_READ_SAMPLE_TIME);  // 8us until sample point
  r = DIRECT_READ();

  // Wait for remainder of the read timeslot
  // Total - init_low - sample = 64 - 6 - 8 = 50us
  Delay_Us(ONEWIRE_READ_TOTAL_TIME - ONEWIRE_READ_INIT_LOW_TIME -
           ONEWIRE_READ_SAMPLE_TIME);

  return r;
}

//
// Write a byte. The writing code uses the active drivers to raise the
// pin high, if you need power after the write (e.g. DS18S20 in
// parasite power mode) then set 'power' to 1, otherwise the pin will
// go tri-state at the end of the write to avoid heating in a short or
// other mishap.
//
void OneWireWrite(uint8_t v, uint8_t power /* = 0 */) {
  uint8_t bitMask;

  for (bitMask = 0x01; bitMask; bitMask <<= 1) {
    OneWireWriteBit((bitMask & v) ? 1 : 0);
  }
  if (!power) {
    DIRECT_MODE_INPUT();
    DIRECT_WRITE_LOW();
  }
}

void OneWireWriteBytes(const uint8_t *buf, uint16_t count, bool power) {
  for (uint16_t i = 0; i < count; i++) OneWireWrite(buf[i], 0);
  if (!power) {
    DIRECT_MODE_INPUT();
    DIRECT_WRITE_LOW();
  }
}

//
// Read a byte
//
uint8_t OneWireRead() {
  uint8_t bitMask;
  uint8_t r = 0;

  for (bitMask = 0x01; bitMask; bitMask <<= 1) {
    if (OneWireReadBit()) r |= bitMask;
  }
  return r;
}

void OneWireReadBytes(uint8_t *buf, uint16_t count) {
  for (uint16_t i = 0; i < count; i++) buf[i] = OneWireRead();
}

//
// Do a ROM select
//
void OneWireSelect(const uint8_t rom[8]) {
  uint8_t i;

  OneWireWrite(0x55, 0);  // Choose ROM

  for (i = 0; i < 8; i++) OneWireWrite(rom[i], 0);
}

//
// Do a ROM skip
//
void OneWireSkip() {
  OneWireWrite(0xCC, 0);  // Skip ROM
}

void OneWireDepower() { DIRECT_MODE_INPUT(); }

//
// You need to use this function to start a search again from the beginning.
// You do not need to do it for the first search, though you could.
//
void OneWireResetSearch() {
  // reset the search state
  LastDiscrepancy = 0;
  LastDeviceFlag = false;
  LastFamilyDiscrepancy = 0;
  for (int i = 7;; i--) {
    ROM_NO[i] = 0;
    if (i == 0) break;
  }
}

// Setup the search to find the device type 'family_code' on the next call
// to search(*newAddr) if it is present.
//
void OneWireTargetSearch(uint8_t family_code) {
  // set the search state to find SearchFamily type devices
  ROM_NO[0] = family_code;
  for (uint8_t i = 1; i < 8; i++) ROM_NO[i] = 0;
  LastDiscrepancy = 64;
  LastFamilyDiscrepancy = 0;
  LastDeviceFlag = false;
}

//
// Perform a search. If this function returns a '1' then it has
// enumerated the next device and you may retrieve the ROM from the
// OneWireAddress variable. If there are no devices, no further
// devices, or something horrible happens in the middle of the
// enumeration then a 0 is returned.  If a new device is found then
// its address is copied to newAddr.  Use OneWireReset_search() to
// start over.
//
// --- Replaced by the one from the Dallas Semiconductor web site ---
//--------------------------------------------------------------------------
// Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
// search state.
// Return TRUE  : device found, ROM number in ROM_NO buffer
//        FALSE : device not found, end of search
//
bool OneWireSearch(uint8_t *newAddr, bool search_mode /* = true */) {
  uint8_t id_bit_number;
  uint8_t last_zero, rom_byte_number;
  bool search_result;
  uint8_t id_bit, cmp_id_bit;

  unsigned char rom_byte_mask, search_direction;

  // initialize for search
  id_bit_number = 1;
  last_zero = 0;
  rom_byte_number = 0;
  rom_byte_mask = 1;
  search_result = false;

  // if the last call was not the last one
  if (!LastDeviceFlag) {
    // 1-Wire reset
    if (!OneWireReset()) {
      // reset the search
      LastDiscrepancy = 0;
      LastDeviceFlag = false;
      LastFamilyDiscrepancy = 0;
      return false;
    }

    // issue the search command
    if (search_mode == true) {
      OneWireWrite(0xF0, 0);  // NORMAL SEARCH
    } else {
      OneWireWrite(0xEC, 0);  // CONDITIONAL SEARCH
    }

    // loop to do the search
    do {
      // read a bit and its complement
      id_bit = OneWireReadBit();
      cmp_id_bit = OneWireReadBit();

      // check for no devices on 1-wire
      if ((id_bit == 1) && (cmp_id_bit == 1)) {
        break;
      } else {
        // all devices coupled have 0 or 1
        if (id_bit != cmp_id_bit) {
          search_direction = id_bit;  // bit write value for search
        } else {
          // if this discrepancy if before the Last Discrepancy
          // on a previous next then pick the same as last time
          if (id_bit_number < LastDiscrepancy) {
            search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
          } else {
            // if equal to last pick 1, if not then pick 0
            search_direction = (id_bit_number == LastDiscrepancy);
          }
          // if 0 was picked then record its position in LastZero
          if (search_direction == 0) {
            last_zero = id_bit_number;

            // check for Last discrepancy in family
            if (last_zero < 9) LastFamilyDiscrepancy = last_zero;
          }
        }

        // set or clear the bit in the ROM byte rom_byte_number
        // with mask rom_byte_mask
        if (search_direction == 1)
          ROM_NO[rom_byte_number] |= rom_byte_mask;
        else
          ROM_NO[rom_byte_number] &= ~rom_byte_mask;

        // serial number search direction write bit
        OneWireWriteBit(search_direction);

        // increment the byte counter id_bit_number
        // and shift the mask rom_byte_mask
        id_bit_number++;
        rom_byte_mask <<= 1;

        // if the mask is 0 then go to new SerialNum byte rom_byte_number and
        // reset mask
        if (rom_byte_mask == 0) {
          rom_byte_number++;
          rom_byte_mask = 1;
        }
      }
    } while (rom_byte_number < 8);  // loop until through all ROM bytes 0-7

    // if the search was successful then
    if (!(id_bit_number < 65)) {
      // search successful so set LastDiscrepancy,LastDeviceFlag,search_result
      LastDiscrepancy = last_zero;

      // check for last device
      if (LastDiscrepancy == 0) {
        LastDeviceFlag = true;
      }
      search_result = true;
    }
  }

  // if no device found then reset counters so next 'search' will be like a
  // first
  if (!search_result || !ROM_NO[0]) {
    LastDiscrepancy = 0;
    LastDeviceFlag = false;
    LastFamilyDiscrepancy = 0;
    search_result = false;
  } else {
    for (int i = 0; i < 8; i++) newAddr[i] = ROM_NO[i];
  }
  return search_result;
}

// The 1-Wire CRC scheme is described in Maxim Application Note 27:
// "Understanding and Using Cyclic Redundancy Checks with Maxim iButton
// Products"
//

//
// Compute a Dallas Semiconductor 8 bit CRC directly.
// this is much slower, but a little smaller, than the lookup table.
//
uint8_t OneWireCrc8(const uint8_t *addr, uint8_t len) {
  uint8_t crc = 0;

  while (len--) {
    uint8_t inbyte = *addr++;
    for (uint8_t i = 8; i; i--) {
      uint8_t mix = (crc ^ inbyte) & 0x01;
      crc >>= 1;
      if (mix) crc ^= 0x8C;
      inbyte >>= 1;
    }
  }
  return crc;
}

bool OneWireCheckCrc16(const uint8_t *input, uint16_t len,
                       const uint8_t *inverted_crc, uint16_t crc) {
  crc = ~OneWireCrc16(input, len, crc);
  return (crc & 0xFF) == inverted_crc[0] && (crc >> 8) == inverted_crc[1];
}

uint16_t OneWireCrc16(const uint8_t *input, uint16_t len, uint16_t crc) {
  static const uint8_t oddparity[16] = {0, 1, 1, 0, 1, 0, 0, 1,
                                        1, 0, 0, 1, 0, 1, 1, 0};

  for (uint16_t i = 0; i < len; i++) {
    // Even though we're just copying a byte from the input,
    // we'll be doing 16-bit computation with it.
    uint16_t cdata = input[i];
    cdata = (cdata ^ crc) & 0xff;
    crc >>= 8;

    if (oddparity[cdata & 0x0F] ^ oddparity[cdata >> 4]) crc ^= 0xC001;

    cdata <<= 6;
    crc ^= cdata;
    cdata <<= 1;
    crc ^= cdata;
  }

  return crc;
}