laelaps::LaeI2CMux Class Reference

control register mask More...

#include <laeI2CMux.h>

Public Member Functions
	LaeI2CMux (LaeI2C &i2cBus, uint_t addr=LaeI2CMuxAddrDft)
	Initialization constructor. More...
virtual	~LaeI2CMux ()
	Destructor.
virtual int	read (int chan, uint_t addr, byte_t buf[], size_t len)
	Read from a multiplexed I2C slave endpoint device. More...
virtual int	write (int chan, uint_t addr, byte_t buf[], size_t len)
	Write from an I2C endpoint device. More...
virtual int	transact (int chan, uint_t addr, const byte_t wbuf[], size_t wlen, byte_t rbuf[], size_t rlen, long usec=0)
	Perform a write/read transaction to/from an I2C slave endpoint device. More...
virtual int	readChannelStates (byte_t &chanBits)
	Read the current I2C multiplexer enable state. More...
virtual int	reset ()
	Reset I2C devices on multiplexer bus. More...
bool	isChanEnabled (int chan, byte_t chanBits)
	Check if a channel is enabled in the channel bit map. More...
std::string	getDevName ()
	Get associated I2C device name. More...
bool	isOpen ()
	Check if bound I2C device is open. More...

Protected Member Functions
void	lock ()
	Lock the shared resource. More...
void	unlock ()
	Unlock the shared resource. More...
int	setChannel (int chan)
	Set channel. More...

Protected Attributes
LaeI2C &	m_i2cBus
	boulnd I2C bus instance
uint_t	m_addrMux
	I2C multiplexer address.
int	m_chan
	current active channel
pthread_mutex_t	m_mutex
	mutex

Detailed Description

control register mask

TI PCA9548A I²C mulitplexer switch class.

Definition at line 100 of file laeI2CMux.h.

Constructor & Destructor Documentation

LaeI2CMux::LaeI2CMux	(	LaeI2C &	i2cBus,
		uint_t	addr = LaeI2CMuxAddrDft
	)

Initialization constructor.

Parameters

i2cbus	Bound open I2C bus instance.
addr	I2C Mux address.

Definition at line 63 of file laeI2CMux.cxx.

References laelaps::LaeI2CMuxChanNone, m_chan, and m_mutex.

                                                :
    m_i2cBus(i2cBus), m_addrMux(addr)
{
  m_chan = LaeI2CMuxChanNone;

  pthread_mutex_init(&m_mutex, NULL);
}

Member Function Documentation

std::string laelaps::LaeI2CMux::getDevName ( )

inline

Get associated I²C device name.

Returns

Returns device name string. Empty if no device.

Definition at line 206 of file laeI2CMux.h.

References laelaps::LaeI2C::getDevName(), and m_i2cBus.

    {
      return m_i2cBus.getDevName();
    }

bool laelaps::LaeI2CMux::isChanEnabled ( int  chan, byte_t  chanBits  )

inline

Check if a channel is enabled in the channel bit map.

Parameters

chan	Multiplexed channel number.
chanBits	Bit map of enable/disable channels.

Returns

True or false.

Definition at line 196 of file laeI2CMux.h.

    {
      return (LaeI2CMuxCtlRegMask & ((byte_t)(1 << chan) & chanBits)) != 0;
    }

bool laelaps::LaeI2CMux::isOpen ( )

inline

Check if bound I2C device is open.

Returns

Returns true or false.

Definition at line 216 of file laeI2CMux.h.

References laelaps::LaeI2C::isOpen(), and m_i2cBus.

Referenced by Laelaps.WatchDog.WatchDog::cmdConfigDPin(), Laelaps.WatchDog.WatchDog::cmdEnableAuxPort5V(), Laelaps.WatchDog.WatchDog::cmdEnableAuxPortBatt(), Laelaps.WatchDog.WatchDog::cmdEnableMotorCtlrs(), Laelaps.WatchDog.WatchDog::cmdGetFwVersion(), Laelaps.WatchDog.WatchDog::cmdPetTheDog(), Laelaps.WatchDog.WatchDog::cmdReadAPin(), Laelaps.WatchDog.WatchDog::cmdReadDPin(), Laelaps.WatchDog.WatchDog::cmdReadEnables(), Laelaps.WatchDog.WatchDog::cmdReadVoltages(), Laelaps.WatchDog.WatchDog::cmdResetRgbLed(), Laelaps.WatchDog.WatchDog::cmdSetAlarms(), Laelaps.WatchDog.WatchDog::cmdSetBatterySoC(), Laelaps.WatchDog.WatchDog::cmdSetRgbLed(), and Laelaps.WatchDog.WatchDog::cmdWriteDPin().

    {
      return m_i2cBus.isOpen();
    }

void laelaps::LaeI2CMux::lock ( )

inlineprotected

Lock the shared resource.

The lock()/unlock() primitives provide for safe multi-threading.

Context:

Any.

Definition at line 237 of file laeI2CMux.h.

Referenced by read(), readChannelStates(), transact(), and write().

    {
      pthread_mutex_lock(&m_mutex);
    }

int LaeI2CMux::read ( int  chan, uint_t  addr, byte_t  buf[], size_t  len  )

virtual

Read from a multiplexed I²C slave endpoint device.

Reads data from a device at the given address on the bound I²C bus.

Parameters

	chan	Multiplexed channel number.
	addr	Endpoint I2C device's 7/10-bit address.
[out]	buf	Pointer to the buffer that will receive the data bytes.
	len	Number of bytes to read.

Returns

On success, returns ≥ 0 number of bytes read.
Else returns < 0 error code.

Definition at line 76 of file laeI2CMux.cxx.

References laelaps::LAE_ECODE_IO, laelaps::LAE_OK, lock(), m_chan, m_i2cBus, laelaps::LaeI2C::read(), setChannel(), and unlock().

{
  int   n;
  int   rc;

  lock();

  if( (rc = setChannel(chan)) == LAE_OK )
  {
    if( (n = m_i2cBus.read(addr, buf, len)) < 0 )
    {
      LOGDIAG3("I2C Mux: Channel %d I2C device address 0x%02x: "
          "Failed to read from endpoint device data.",
          m_chan, addr);
      rc = -LAE_ECODE_IO;
    }

    if( n != (int)len )
    {
      LOGWARN("I2C Mux: Channel %d I2C device address 0x%02x: "
          "Only %d/%d bytes read from endpoint device.",
          m_chan, addr, n, (int)len);
    }
  }

  unlock();

  return rc < 0? rc: n;
}

int LaeI2CMux::readChannelStates ( byte_t &  chanBits )

virtual

Read the current I²C multiplexer enable state.

Parameters

[out]

chanBits

Bit map of enable/disable channels.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Definition at line 163 of file laeI2CMux.cxx.

References laelaps::LAE_ECODE_IO, laelaps::LAE_OK, lock(), m_addrMux, m_i2cBus, laelaps::LaeI2C::read(), and unlock().

{
  int   rc;

  lock();

  if( m_i2cBus.read(m_addrMux, &chanBits, 1) < 0 )
  {
    LOGSYSERROR("I2C Mux: Address 0x%02x: Failed to read channel states.",
          m_addrMux);
      rc = -LAE_ECODE_IO;
  }
  else
  {
    rc = LAE_OK;
  }

  unlock();

  return rc;
}

virtual int laelaps::LaeI2CMux::reset ( )

inlinevirtual

Reset I²C devices on multiplexer bus.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Definition at line 182 of file laeI2CMux.h.

References laelaps::LAE_ECODE_INTERNAL.

    {
      // TODO
      return -LAE_ECODE_INTERNAL;
    }

int LaeI2CMux::setChannel ( int  chan )

protected

Set channel.

This function does not call the lock/unlock mutex.

Parameters

chan	Multiplexed channel number.

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Definition at line 185 of file laeI2CMux.cxx.

References laelaps::LAE_ECODE_BAD_VAL, laelaps::LAE_ECODE_IO, laelaps::LAE_OK, laelaps::LaeI2CMuxChanMax, laelaps::LaeI2CMuxChanMin, m_addrMux, m_chan, m_i2cBus, and laelaps::LaeI2C::write().

Referenced by read(), transact(), unlock(), and write().

{
  if( (chan < LaeI2CMuxChanMin) || (chan > LaeI2CMuxChanMax) )
  {
    LOGERROR("I2C Mux: %d channel: Out-of-range.", chan);
    return -LAE_ECODE_BAD_VAL;
  }

  else if( m_chan != chan )
  {
    byte_t  ctl = (byte_t)(1 << chan);    // control register data

    if( m_i2cBus.write(m_addrMux, &ctl, 1) < 0 )
    {
      LOGSYSERROR("I2C Mux: Address 0x%02x: Failed to select channel.",
          m_addrMux);
      return -LAE_ECODE_IO;
    }
    else
    {
      m_chan = chan;
      usleep(100);
    }
  }

  return LAE_OK;
}

int LaeI2CMux::transact ( int  chan, uint_t  addr, const byte_t  wbuf[], size_t  wlen, byte_t  rbuf[], size_t  rlen, long  usec = 0  )

virtual

Perform a write/read transaction to/from an I²C slave endpoint device.

Parameters

	chan	Multiplexed channel number.
	addr	Endpoint I2C device's 7/10-bit address.
[in]	wbuf	Pointer to the buffer that contains the data to be written.
	wlen	Number of bytes to write.
[out]	rbuf	Pointer to the buffer that will receive the data.
	rlen	Number of bytes to read.
	usec	Delay between write and read operations (usecs).

Returns

On success, OK(0) is returned.
On error, RC_ERROR(-1) is returned.

Definition at line 136 of file laeI2CMux.cxx.

References laelaps::LAE_OK, lock(), m_chan, m_i2cBus, setChannel(), unlock(), and laelaps::LaeI2C::write_read().

Referenced by sensor::vl6180::LaeVL6180Mux::readReg16(), and sensor::vl6180::LaeVL6180Mux::readReg8().

{
  int   n;
  int   rc;

  lock();

  if( (rc = setChannel(chan)) == LAE_OK )
  {
    rc = m_i2cBus.write_read(addr, wbuf, wlen, rbuf, rlen, usec);

    if( rc != LAE_OK )
    {
      LOGDIAG3("I2C Mux: Channel %d I2C device address 0x%02x: "
          "Failed to write_read to device data.",
          m_chan, addr);
    }
  }

  unlock();

  return rc < 0? rc: n;
}

void laelaps::LaeI2CMux::unlock ( )

inlineprotected

Unlock the shared resource.

Context:

Any.

Definition at line 248 of file laeI2CMux.h.

References setChannel().

Referenced by read(), readChannelStates(), transact(), and write().

    {
      pthread_mutex_unlock(&m_mutex);
    }

int LaeI2CMux::write ( int  chan, uint_t  addr, byte_t  buf[], size_t  len  )

virtual

Write from an I²C endpoint device.

Write data to a device at the given address on the bound I²C bus.

Parameters

chan	Multiplexed channel number.
addr	Endpoint I2C device's 7/10-bit address.
[int]	buf Pointer to the buffer that will be written.
len	Number of bytes to write.

Returns

On success, returns ≥ 0 number of bytes read.
Else returns < 0 error code.

Definition at line 106 of file laeI2CMux.cxx.

References laelaps::LAE_ECODE_IO, laelaps::LAE_OK, lock(), m_chan, m_i2cBus, setChannel(), unlock(), and laelaps::LaeI2C::write().

Referenced by sensor::vl6180::LaeVL6180Mux::writeReg16(), and sensor::vl6180::LaeVL6180Mux::writeReg8().

{
  int   n;
  int   rc;

  lock();

  if( (rc = setChannel(chan)) == LAE_OK )
  {
    if( (n = m_i2cBus.write(addr, buf, len)) < 0 )
    {
      LOGDIAG3("I2C Mux: Channel %d I2C device address 0x%02x: "
          "Failed to write to device data.",
          m_chan, addr);
      rc = -LAE_ECODE_IO;
    }

    else if( n != (int)len )
    {
      LOGWARN("I2C Mux: Channel %d I2C device address 0x%02x: "
          "Only %d/%d bytes written to endpoint device.",
          m_chan, addr, n, (int)len);
    }
  }

  unlock();

  return rc < 0? rc: n;
}

---

The documentation for this class was generated from the following files:

• include/Laelaps/laeI2CMux.h
• sw/liblaelaps/laeI2CMux.cxx