MityDSP::tcDspGpio Class Reference

Instances of this class handle sending, receiving, and configuring a register containing 32 general purpose I/O pins. More...

#include <core/DspGpio.h>

List of all members.

Public Types
typedef void(*	tfIsrCallback )(tcDspGpio , unsigned int, void )
	prototype for the ISR callback
Public Member Functions
	tcDspGpio (void *apAddress, int anLevel=gnAutoLevel)
	This constructor is used to open a GPIO core instance.
	~tcDspGpio ()
	Default destructor.
bool	configurePins (unsigned int anMask, teGpioDirection aeDir, bool abIntRising=false, bool abIntFalling=false, SEM_Handle apSem=NULL)
	This routine is used to configure a set of GPIO pins.
void	registerGlobalInputSemaphore (SEM_Handle ahGlobalSem)
	This routine is used to register the global input semaphore.
void	registerIsrCallback (tfIsrCallback afCallback, void *apUserArg=NULL)
	This method is used to register a callback that is activated whenever a configured input changes state.
unsigned int	readPins (unsigned int anMask)
	This routine is used to read current GPIO pin values.
void	writePins (unsigned int anMask, unsigned int anValues)
	This routine is used to write updated GPIO pin values.
Static Public Member Functions
static int	interrupt_dispatch (Arg arMyObject)
	Static interrupt dispatch routine.
Public Attributes
unsigned int	mnInterruptCount
	ISR counter (debug).
Protected Member Functions
void	Lock (unsigned int &arCsr)
void	Unlock (unsigned int anCsr)
void	gpioInterrupt (void)
	Interrupt service routine for the GPIO core.
Protected Attributes
unsigned int	mnLastDir
	Last known contents of DIR.
unsigned int	mnLastIorRead
	Last read contents of IOR.
unsigned int	mnLastIorWrite
	Last written contents of IOR.
unsigned int	mnLastIer
	Last known contents of IER.
unsigned int	mnLastIef
	Last known contents of IEF.
unsigned int	mnLastIpend
	Last known contents of IPEND.
SEM_Handle *	mhMySemaphores
	Pointer to registered semaphores.
LCK_Handle	mhMyMutex
	Semaphore to use as a mutex lock.
SEM_Handle	mhGlobalInputSem
	Posted whenever any other input sem is posted.
volatile unsigned int *	mpMyBaseReg
	GPIO base register.
unsigned short	mnMyIntMask
	GPIO interrupt mask.
int	mnMyIntLevel
	GPIO interrupt level.
int	mnMyIntVector
	GPIO interrupt vector.
tfIsrCallback	mfIsrCallback
	Registered ISR callback function.
void *	mpUserArg
	User-supplied argument for ISR callback.
Static Protected Attributes
static const int	gnDirOffset = 1
static const int	gnIorOffset = 2
static const int	gnIerOffset = 3
static const int	gnIefOffset = 4
static const int	gnIpendOffset = 5

Detailed Description

Instances of this class handle sending, receiving, and configuring a register containing 32 general purpose I/O pins.

Each pin may be configured as an output or input, and its values may be read/written accordingly. In addition, inputs may be registered to raise an interrupt on either rising or falling edges. The ISR notifies the application via a counting semaphore.

See also:: tcDspGpio Page

Member Typedef Documentation

typedef void(* MityDSP::tcDspGpio::tfIsrCallback)(tcDspGpio *, unsigned int, void *)

prototype for the ISR callback

Constructor & Destructor Documentation

tcDspGpio::tcDspGpio	(	void *	apAddress,
		int	anLevel = `gnAutoLevel`
	)

This constructor is used to open a GPIO core instance.

The base address and interrupt used by the core are provided. All pins are initially configured as inputs, with interrupts disabled. The default output values are all set to "0". An ISR is installed to detect and report input pin value changes.

Parameters:

`[in]`	apAddress	The base address of the GPIO core.
`[in]`	anLevel	The interrupt vector used by the core (default: gnAutoLevel).

Returns:: None.

See also:: DspGpio.h

tcDspGpio::~tcDspGpio ( )

Default destructor.

Member Function Documentation

int tcDspGpio::interrupt_dispatch ( Arg ahMyObject ) [static]

Static interrupt dispatch routine.

Required because of the hidden this pointer associated with a member function, which cannot be passed directly to the interrupt dispatcher.

Parameters:

ahMyObject

The "this->" pointer for the instance of tcDspGpio associated with this ISR.

Returns:: 0

bool tcDspGpio::configurePins	(	unsigned int	anMask,
		teGpioDirection	aeDir,
		bool	abIntRising = `false`,
		bool	abIntFalling = `false`,
		SEM_Handle	apSem = `NULL`
	)

This routine is used to configure a set of GPIO pins.

The mask field determines the pins being configured. The pin direction is set, as well as the rising and falling edge interrupt enables, and the callback semaphore for the ISR to use when an interrupt occurs.

The interrupt enables and semaphore are optional parameters and are only meaningful for pins configured as inputs.

Parameters:

`[in]`	anMask	The pins to be configured. This can be any of gnGPIO_0..gnGPIO_31 or'd together as needed.
`[in]`	aeDir	The pin direction (gnGpioInput or gnGpioOutput).
`[in]`	abIntRising	Boolean indicating whether rising edge interrupts are enabled.
`[in]`	abIntFalling	Boolean indicating whether falling edge interrupts are enabled.
`[in]`	apSem	Semaphore handle for the ISR to use when this pin's interrupt is pending.

Returns:: A boolean indicating whether or not a change was made.

void tcDspGpio::registerGlobalInputSemaphore ( SEM_Handle ahGlobalSem )

This routine is used to register the global input semaphore.

This is a semaphore that gets posted whenever any input event that has a registered individual semaphore occurs. This allows an application to pend on the global semaphore, and then check to see which of the individual semaphores actually occurred.

Parameters:

[in] ahGlobalSem The handle of the semaphore to use as the global input semaphore (NULL to unregister).

Returns:: None.

void tcDspGpio::registerIsrCallback	(	tfIsrCallback	afCallback,
		void *	apUserArg = `NULL`
	)

This method is used to register a callback that is activated whenever a configured input changes state.

The callback takes three parameters: A pointer to the current instance of tcDspGpio, a mask indicating the input(s) that triggered the interrupt, and the apUserArg supplied at time of registration (perhaps a this pointer to a C++ class instance).

Note:: The registered function is run in ISR space and therefore must not call any DSP/BIOS functions that can cause a context switch. In particular, the tcDspGpio read_pins method is safe, but write_pins may not be called.

Parameters:

`[in]`	afCallback	The ISR callback to register (NULL for none).
`[in]`	apUserArg	An argument to be supplied with the callback.

Returns:: None.

unsigned int tcDspGpio::readPins ( unsigned int anMask )

This routine is used to read current GPIO pin values.

Parameters:

[in] anMask The pins to be read. This can be any of gnGPIO_0..gnGPIO_31 or'd together as needed.

Returns:: The current value associated with each pin specified. Individual pin values are extracted by or'ing the return value with the appropriate pin mask (gnGPIO_0..gnGPIO_31).

void tcDspGpio::writePins	(	unsigned int	anMask,
		unsigned int	anValues
	)

This routine is used to write updated GPIO pin values.

Only the values specified by the supplied mask are changed.

Parameters:

`[in]`	anMask	The pins to be updated. This can be any of gnGPIO_0..gnGPIO_31 or'd together as needed.
`[in]`	anValues	The updated values. To set a "1", set the appropriate pin mask (gnGPIO_0..gnGPIO_31). To set a "0" clear the mask.

Returns:: None.

void MityDSP::tcDspGpio::Lock ( unsigned int & arCsr ) [inline, protected]

void MityDSP::tcDspGpio::Unlock ( unsigned int anCsr ) [inline, protected]

void tcDspGpio::gpioInterrupt ( void ) [protected]

Interrupt service routine for the GPIO core.

The ISR reads and clears any pending interrupts. If any of the pins with pending interrupts has a semaphore associated with it, the ISR increments the semaphore value.

"Interrupt-ness" is taken care of by the 'dispatcher' in DSP/BIOS. Installed by the constructor.