File content as of revision 74:23be10c32fa3:

/******************************************************************//**
* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
*
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* OTHER DEALINGS IN THE SOFTWARE.
*
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* 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
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**********************************************************************/

#include "DS248x.h"
#include "I2C.h"

using OneWire::Masters::OneWireMaster;
using OneWire::Masters::DS248x;

enum DS248X_STATUS_BITS
{
    STATUS_1WB = 0x01,
    STATUS_PPD = 0x02,
    STATUS_SD = 0x04,
    STATUS_LL = 0x08,
    STATUS_RST = 0x10,
    STATUS_SBR = 0x20,
    STATUS_TSB = 0x40,
    STATUS_DIR = 0x80
};

static const int I2C_WRITE_OK = 0;
static const int I2C_READ_OK = 0;

uint8_t DS248x::Config::readByte() const
{
    uint8_t config = 0;
    if (get1WS())
    {
        config |= 0x08;
    }
    if (getSPU())
    {
        config |= 0x04;
    }
    if (getPDN())
    {
        config |= 0x02;
    }
    if (getAPU())
    {
        config |= 0x01;
    }
    return config;
}

uint8_t DS248x::Config::writeByte() const
{
    uint8_t config = readByte();
    return ((~config << 4) | config);
}

void DS248x::Config::reset()
{
    set1WS(false);
    setSPU(false);
    setPDN(false);
    setAPU(true);
}

DS248x::DS248x(mbed::I2C & i2c_bus, uint8_t adrs)
    :_p_i2c_bus(&i2c_bus), _adrs(adrs), _i2c_owner(false)
{

}

DS248x::DS248x(PinName sda, PinName scl, uint8_t adrs)
    : _p_i2c_bus(new mbed::I2C(sda, scl)), _adrs(adrs), _i2c_owner(true)
{

}

DS248x::~DS248x()
{
    if (_i2c_owner)
    {
        delete _p_i2c_bus;
    }
}

OneWireMaster::CmdResult DS248x::OWInitMaster(void)
{
    OneWireMaster::CmdResult result;

    // reset DS2465 
    result = reset();
    if (result != OneWireMaster::Success)
    {
        return result;
    }

    // write the default configuration setup
    Config defaultConfig;
    result = writeConfig(defaultConfig, true);
    return result;
}

OneWireMaster::CmdResult DS248x::reset(void)
{
    // Device Reset
    //   S AD,0 [A] DRST [A] Sr AD,1 [A] [SS] A\ P
    //  [] indicates from slave
    //  SS status byte to read to verify state

    OneWireMaster::CmdResult result;
    uint8_t buf;

    result = sendCommand(CMD_DRST);

    if (result == OneWireMaster::Success)
    {
        result = readRegister(StatusReg, buf, true);
    }

    if (result == OneWireMaster::Success)
    {
        if ((buf & 0xF7) != 0x10)
        {
            result = OneWireMaster::OperationFailure;
        }
    }

    if (result == OneWireMaster::Success)
    {
        OWReset(); // do a command to get 1-Wire master reset out of holding state
    }

    return result;
}

OneWireMaster::CmdResult DS248x::selectChannel(uint8_t channel)
{
    OneWireMaster::CmdResult result;
    uint8_t ch, ch_read;

    // Channel Select (Case A)
    //   S AD,0 [A] CHSL [A] CC [A] Sr AD,1 [A] [RR] A\ P
    //  [] indicates from slave
    //  CC channel value
    //  RR channel read back

    switch (channel)
    {
    default:
    case 0:
        ch = 0xF0;
        ch_read = 0xB8;
        break;
    case 1:
        ch = 0xE1;
        ch_read = 0xB1;
        break;
    case 2:
        ch = 0xD2;
        ch_read = 0xAA;
        break;
    case 3:
        ch = 0xC3;
        ch_read = 0xA3;
        break;
    case 4:
        ch = 0xB4;
        ch_read = 0x9C;
        break;
    case 5:
        ch = 0xA5;
        ch_read = 0x95;
        break;
    case 6:
        ch = 0x96;
        ch_read = 0x8E;
        break;
    case 7:
        ch = 0x87;
        ch_read = 0x87;
        break;
    };

    result = sendCommand(CMD_CHSL, ch);
    if (result == OneWireMaster::Success)
    {
        result = readRegister(ChannelSelectReg, ch, true);
        if (result == OneWireMaster::Success)
        {
            // check for failure due to incorrect read back of channel
            if (ch != ch_read)
            {
                result = OneWireMaster::OperationFailure;
            }
        }
    }

    return result;
}

OneWireMaster::CmdResult DS248x::adjustOwPort(OwAdjustParam param, uint8_t val)
{
    OneWireMaster::CmdResult result;

    uint8_t read_port_config;
    uint8_t control_byte;

    control_byte = (((param & 0x0F) << 4) | (val & 0x0F));

    result = sendCommand(CMD_A1WP, control_byte);
    if (result != Success)
    {
        return result;
    }

    result = readRegister(PortConfigReg, read_port_config, true);
    if (result != Success)
    {
        return result;
    }

    if ((control_byte & 0x0F) != read_port_config)
    {
        result = OneWireMaster::OperationFailure;
    }

    return result;
}

OneWireMaster::CmdResult DS248x::OWTriplet(SearchDirection & search_direction, uint8_t & sbr, uint8_t & tsb)
{
    // 1-Wire Triplet (Case B)
    //   S AD,0 [A] 1WT [A] SS [A] Sr AD,1 [A] [Status] A [Status] A\ P
    //                                         \--------/
    //                           Repeat until 1WB bit has changed to 0
    //  [] indicates from slave
    //  SS indicates byte containing search direction bit value in msbit

    OneWireMaster::CmdResult result;
    result = sendCommand(CMD_1WT, (uint8_t)((search_direction == DIRECTION_WRITE_ONE) ? 0x80 : 0x00));
    if (result == OneWireMaster::Success)
    {
        uint8_t status;
        result = pollBusy(&status);
        if (result == OneWireMaster::Success)
        {
            // check bit results in status byte
            sbr = ((status & STATUS_SBR) == STATUS_SBR);
            tsb = ((status & STATUS_TSB) == STATUS_TSB);
            search_direction = ((status & STATUS_DIR) == STATUS_DIR) ? DIRECTION_WRITE_ONE : DIRECTION_WRITE_ZERO;
        }
    }
    return result;
}

OneWireMaster::CmdResult DS248x::OWReset(void)
{
    // 1-Wire reset (Case B)
    //   S AD,0 [A] 1WRS [A] Sr AD,1 [A] [Status] A [Status] A\ P
    //                                   \--------/
    //                       Repeat until 1WB bit has changed to 0
    //  [] indicates from slave

    OneWireMaster::CmdResult result;
    uint8_t buf;

    result = sendCommand(CMD_1WRS);

    if (result == OneWireMaster::Success)
    {
        result = pollBusy(&buf);
    }

    if (result == OneWireMaster::Success)
    {
        // check for presence detect
        if ((buf & STATUS_PPD) != STATUS_PPD)
        {
            result = OneWireMaster::OperationFailure;
        }
    }

    return result;
}

OneWireMaster::CmdResult DS248x::OWTouchBitSetLevel(uint8_t & sendrecvbit, OWLevel after_level)
{
    // 1-Wire bit (Case B)
    //   S AD,0 [A] 1WSB [A] BB [A] Sr AD,1 [A] [Status] A [Status] A\ P
    //                                          \--------/
    //                           Repeat until 1WB bit has changed to 0
    //  [] indicates from slave
    //  BB indicates byte containing bit value in msbit

    OneWireMaster::CmdResult result;

    result = configureLevel(after_level);
    if (result != OneWireMaster::Success)
    {
        return result;
    }

    uint8_t status;

    result = sendCommand(CMD_1WSB, (uint8_t)(sendrecvbit ? 0x80 : 0x00));

    if (result == OneWireMaster::Success)
    {
        result = pollBusy(&status);
    }

    if (result == OneWireMaster::Success)
    {
        sendrecvbit = (status & STATUS_SBR);
    }

    return result;
}

OneWireMaster::CmdResult DS248x::OWWriteByteSetLevel(uint8_t sendbyte, OWLevel after_level)
{
    // 1-Wire Write Byte (Case B)
    //   S AD,0 [A] 1WWB [A] DD [A] Sr AD,1 [A] [Status] A [Status] A\ P
    //                                          \--------/
    //                             Repeat until 1WB bit has changed to 0
    //  [] indicates from slave
    //  DD data to write

    OneWireMaster::CmdResult result;

    result = configureLevel(after_level);
    if (result != OneWireMaster::Success)
    {
        return result;
    }

    result = sendCommand(CMD_1WWB, sendbyte);
    if (result == OneWireMaster::Success)
    {
        result = pollBusy();
    }

    return result;
}

OneWireMaster::CmdResult DS248x::OWReadByteSetLevel(uint8_t & recvbyte, OWLevel after_level)
{
    // 1-Wire Read Bytes (Case C)
    //   S AD,0 [A] 1WRB [A] Sr AD,1 [A] [Status] A [Status] A\
    //                                   \--------/
    //                     Repeat until 1WB bit has changed to 0
    //   Sr AD,0 [A] SRP [A] E1 [A] Sr AD,1 [A] DD A\ P
    //
    //  [] indicates from slave
    //  DD data read

    OneWireMaster::CmdResult result;
    uint8_t buf;

    result = configureLevel(after_level);
    if (result != OneWireMaster::Success)
    {
        return result;
    }

    result = sendCommand(CMD_1WRB);

    if (result == OneWireMaster::Success)
    {
        result = pollBusy();
    }

    if (result == OneWireMaster::Success)
    {
        result = readRegister(ReadDataReg, buf);
    }

    if (result == OneWireMaster::Success)
    {
        recvbyte = buf;
    }

    return result;
}

OneWireMaster::CmdResult DS248x::OWSetSpeed(OWSpeed new_speed)
{
    // Requested speed is already set
    if (m_curConfig.get1WS() == (new_speed == SPEED_OVERDRIVE))
    {
        return OneWireMaster::Success;
    }

    // set the speed
    Config newConfig = m_curConfig;
    newConfig.set1WS(new_speed == SPEED_OVERDRIVE);

    // write the new config
    return writeConfig(newConfig, true);
}

OneWireMaster::CmdResult DS248x::OWSetLevel(OWLevel new_level)
{
    if (new_level == LEVEL_STRONG)
    {
        return OneWireMaster::OperationFailure;
    }

    return configureLevel(new_level);
}

OneWireMaster::CmdResult DS248x::writeConfig(const Config & config, bool verify)
{
    uint8_t configBuf;
    OneWireMaster::CmdResult result;

    configBuf = config.writeByte();
    result = sendCommand(CMD_WCFG, configBuf);
    if (verify)
    {
        if (result == OneWireMaster::Success)
        {
            result = readRegister(ConfigReg, configBuf);
        }
        if (result == OneWireMaster::Success)
        {
            if (configBuf != config.readByte())
            {
                result = OneWireMaster::OperationFailure;
            }
        }
    }

    if (result == OneWireMaster::Success)
    {
        m_curConfig = config;
    }

    return result;
}

OneWireMaster::CmdResult DS248x::readRegister(Register reg, uint8_t & buf, bool skipSetPointer) const
{
    CmdResult result;
    result = sendCommand(CMD_SRP, reg);
    if (result == Success)
    {
        if (_p_i2c_bus->read(_adrs, reinterpret_cast<char *>(&buf), 1) != I2C_READ_OK)
        {
            result = CommunicationReadError;
        }
    }
    return result;
}

OneWireMaster::CmdResult DS248x::pollBusy(uint8_t * pStatus)
{
    const unsigned int pollLimit = 200;

    OneWireMaster::CmdResult result;
    uint8_t status;
    unsigned int pollCount = 0;

    do
    {
        result = readRegister(StatusReg, status, true);
        if (result != OneWireMaster::Success)
        {
            return result;
        }
        if (pStatus != NULL)
        {
            *pStatus = status;
        }
        if (pollCount++ >= pollLimit)
        {
            return OneWireMaster::TimeoutError;
        }
    } while (status & STATUS_1WB);

    return OneWireMaster::Success;
}

OneWireMaster::CmdResult DS248x::configureLevel(OWLevel level)
{
    OneWireMaster::CmdResult result;
    if (m_curConfig.getSPU() != (level == LEVEL_STRONG))
    {
        Config newConfig = m_curConfig;
        newConfig.setSPU(level == LEVEL_STRONG);
        result = writeConfig(newConfig, true);
    }
    else
    {
        result = OneWireMaster::Success;
    }
    return result;
}

OneWireMaster::CmdResult DS248x::sendCommand(DS248X_CMDS cmd) const
{
    CmdResult result;
    if (_p_i2c_bus->write(_adrs, reinterpret_cast<const char *>(&cmd), 1) == I2C_WRITE_OK)
    {
        result = Success;
    }
    else
    {
        result = CommunicationWriteError;
    }
    return result;
}

OneWireMaster::CmdResult DS248x::sendCommand(DS248X_CMDS cmd, uint8_t param) const
{
    CmdResult result;
    char buf[2] = { cmd, param };
    if (_p_i2c_bus->write(_adrs, buf, 2) == I2C_WRITE_OK)
    {
        result = Success;
    }
    else
    {
        result = CommunicationWriteError;
    }
    return result;
}