laelaps::LaeGpio Class Reference

Laelaps Odroid GPIO base class. More...

#include <laeGpio.h>

Inheritance diagram for laelaps::LaeGpio:

Public Types
enum	TriState {   UNKNOWN = -1,   LOW = 0,   HIGH = 1 }
	GPIO tri-state value. More...
enum	Direction {   INPUT = GPIO_DIR_IN,   OUTPUT = GPIO_DIR_OUT }
	GPIO direction. More...

Public Member Functions
	LaeGpio (const std::string &strTag, const int gpio, const LaeGpio::Direction dir)
	Default intialization constructor. More...
virtual	~LaeGpio ()
	Destructor.
virtual void	sync ()
	Synchronized this with GPIO hardware state.
virtual int	writeValue (const LaeGpio::TriState value)
	Write value to gpio. More...
virtual int	writeValue (const int value)
	Write value to gpio. More...
virtual int	readValue (int &value)
	Read current value of gpio. More...
int	hasValue () const
	Get the current shadowed gpio value. More...
bool	isConfigured () const
	Is the exported GPIO number configured to match this ojbect? More...

Protected Member Functions
bool	checkConfig ()
	Check if the exported GPIO exists in /sys/class and that it has been configured to match this objects configuration. More...

Protected Attributes
std::string	m_gpioTag
	identifying tag
int	m_gpioNum
	exported GPIO number
LaeGpio::Direction	m_gpioDir
	GPIO direction.
int	m_gpioVal
	shadowed value
bool	m_gpioCfg
	GPIO is [not] configured (correctly)

Detailed Description

Laelaps Odroid GPIO base class.

Note

The configuration of the GPIO is assumed done elsewhere (e.g. at system initialization time).

Definition at line 75 of file laeGpio.h.

Member Enumeration Documentation

enum laelaps::LaeGpio::Direction

GPIO direction.

Enumerator
INPUT	input direction
OUTPUT	output direction

Definition at line 91 of file laeGpio.h.

    {
      INPUT   = GPIO_DIR_IN,  ///< input direction
      OUTPUT  = GPIO_DIR_OUT  ///< output direction
    };

enum laelaps::LaeGpio::TriState

GPIO tri-state value.

Enumerator
UNKNOWN	unknown state value
LOW	low value
HIGH	high value

Definition at line 81 of file laeGpio.h.

    {
      UNKNOWN = -1,     ///< unknown state value
      LOW     =  0,     ///< low value
      HIGH    =  1      ///< high value
    };

Constructor & Destructor Documentation

LaeGpio::LaeGpio	(	const std::string &	strTag,
		const int	gpio,
		const LaeGpio::Direction	dir
	)

Default intialization constructor.

No file I/O operations are perform.

Parameters

strTag	Tag identifier associated with GPIO pin.
gpio	Exported GPIO number.
dir	GPIO direction.

Definition at line 72 of file laeGpio.cxx.

References m_gpioCfg, m_gpioVal, and UNKNOWN.

                                             :
    m_gpioTag(strTag), m_gpioNum(gpio), m_gpioDir(dir)
{
  m_gpioVal = LaeGpio::UNKNOWN;
  m_gpioCfg = false;
}

Member Function Documentation

bool LaeGpio::checkConfig ( )

protected

Check if the exported GPIO exists in /sys/class and that it has been configured to match this objects configuration.

Returns

Returns true or false.

Definition at line 138 of file laeGpio.cxx.

References INPUT, m_gpioDir, and m_gpioNum.

Referenced by sync().

{
  char  buf[MAX_PATH];
  int   mode;

  gpioMakeDirname(m_gpioNum, buf, sizeof(buf));

  string strValFileName(buf);
  string strDirFileName(buf);
  
  strValFileName += "/value";
  strDirFileName += "/direction";

  if( m_gpioDir == LaeGpio::INPUT )
  {
    mode = R_OK;
  }
  else
  {
    mode = R_OK|W_OK;
  }

  return access(strValFileName.c_str(), mode) == 0;
}

int laelaps::LaeGpio::hasValue ( ) const

inline

Get the current shadowed gpio value.

Returns

Returns LaeGpio::TriState value as an integer.

Definition at line 157 of file laeGpio.h.

References m_gpioVal.

Referenced by laelaps::LaeMotorCtlrEnable::isEnabled(), laelaps::LaeAuxBattOutEnable::isEnabled(), laelaps::LaeAux5VOutEnable::isEnabled(), laelaps::LaeWatchDogReset::reset(), and laelaps::LaeI2CMuxReset::reset().

    {
      return m_gpioVal;
    }

bool laelaps::LaeGpio::isConfigured ( ) const

inline

Is the exported GPIO number configured to match this ojbect?

Ass Laelaps evolves, the test can distinguish between different platform versions. For example, Laelaps 2.0 does not have a gpio pin dedicated to enabling power to the motor controllers, while subsequent version do.

Returns

Returns true or false.

Definition at line 171 of file laeGpio.h.

References m_gpioCfg.

Referenced by laelaps::LaeMotorCtlrEnable::disable(), laelaps::LaeAuxBattOutEnable::disable(), laelaps::LaeAux5VOutEnable::disable(), laelaps::LaeMotorCtlrEnable::enable(), laelaps::LaeAuxBattOutEnable::enable(), laelaps::LaeAux5VOutEnable::enable(), laelaps::LaeWatchDogReset::reset(), laelaps::LaeI2CMuxReset::reset(), sync(), laelaps::LaeMotorCtlrEnable::sync(), laelaps::LaeWatchDogReset::sync(), laelaps::LaeI2CMuxReset::sync(), laelaps::LaeAuxBattOutEnable::sync(), and laelaps::LaeAux5VOutEnable::sync().

    {
      return m_gpioCfg;
    }

int LaeGpio::readValue ( int &  value )

virtual

Read current value of gpio.

Parameters

[out]

value

LOW/HIGH integer value.

Returns

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

Definition at line 115 of file laeGpio.cxx.

References laelaps::LAE_ECODE_IO, laelaps::LAE_OK, m_gpioNum, m_gpioTag, and m_gpioVal.

Referenced by sync(), and writeValue().

{
  int   val;
  int   rc;

  if( (val = gpioRead(m_gpioNum)) != RC_ERROR )
  {
    value = val;
    m_gpioVal = val;
    rc = LAE_OK;

    LOGDIAG3("%s GPIO %d: current value is %d.",
        m_gpioTag.c_str(), m_gpioNum, m_gpioVal);
  }
  else
  {
    LOGERROR("%s GPIO %d: Failed to read pin.", m_gpioTag.c_str(), m_gpioNum);
    rc = -LAE_ECODE_IO;
  }

  return rc;
}

virtual int laelaps::LaeGpio::writeValue ( const LaeGpio::TriState  value )

inlinevirtual

Write value to gpio.

Parameters

value

LOW/HIGH tri-state value.

Returns

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

Definition at line 129 of file laeGpio.h.

References readValue().

Referenced by laelaps::LaeMotorCtlrEnable::disable(), laelaps::LaeAuxBattOutEnable::disable(), laelaps::LaeAux5VOutEnable::disable(), laelaps::LaeMotorCtlrEnable::enable(), laelaps::LaeAuxBattOutEnable::enable(), laelaps::LaeAux5VOutEnable::enable(), laelaps::LaeWatchDogReset::reset(), and laelaps::LaeI2CMuxReset::reset().

    {
      return writeValue((const int)value);
    }

int LaeGpio::writeValue ( const int  value )

virtual

Write value to gpio.

Parameters

value

LOW/HIGH integer value.

Returns

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

Definition at line 92 of file laeGpio.cxx.

References laelaps::LAE_ECODE_IO, laelaps::LAE_OK, m_gpioNum, m_gpioTag, and m_gpioVal.

{
  int   rc;
  int   val = value? 1: 0;

  if( gpioWrite(m_gpioNum, val) == OK )
  {
    m_gpioVal = val;
    rc = LAE_OK;

    LOGDIAG3("%s GPIO %d: new value is %d.",
        m_gpioTag.c_str(), m_gpioNum, m_gpioVal);
  }
  else
  {
    LOGERROR("%s GPIO %d: Failed to write %d to pin.",
        m_gpioTag.c_str(), m_gpioNum, value);
    rc = -LAE_ECODE_IO;
  }

  return rc;
}

---

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

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