gpio.c

CAN_FIFO收发例程

//! The parameter \e ulStrength can be one of the following values:
//!
//! - \b GPIO_STRENGTH_2MA
//! - \b GPIO_STRENGTH_4MA
//! - \b GPIO_STRENGTH_8MA
//! - \b GPIO_STRENGTH_8MA_SC
//!
//! where \b GPIO_STRENGTH_xMA specifies either 2, 4, or 8 mA output drive
//! strength, and \b GPIO_OUT_STRENGTH_8MA_SC specifies 8 mA output drive with
//! slew control.
//!
//! The parameter \e ulPinType can be one of the following values:
//!
//! - \b GPIO_PIN_TYPE_STD
//! - \b GPIO_PIN_TYPE_STD_WPU
//! - \b GPIO_PIN_TYPE_STD_WPD
//! - \b GPIO_PIN_TYPE_OD
//! - \b GPIO_PIN_TYPE_OD_WPU
//! - \b GPIO_PIN_TYPE_OD_WPD
//! - \b GPIO_PIN_TYPE_ANALOG
//!
//! where \b GPIO_PIN_TYPE_STD* specifies a push-pull pin, \b GPIO_PIN_TYPE_OD*
//! specifies an open-drain pin, \b *_WPU specifies a weak pull-up, \b *_WPD
//! specifies a weak pull-down, and \b GPIO_PIN_TYPE_ANALOG specifies an
//! analog input (for the comparators).
//!
//! The pin(s) are specified using a bit-packed byte, where each bit that is
//! set identifies the pin to be accessed, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPadConfigSet(unsigned long ulPort, unsigned char ucPins,
                 unsigned long ulStrength, unsigned long ulPinType)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));
    ASSERT((ulStrength == GPIO_STRENGTH_2MA) ||
           (ulStrength == GPIO_STRENGTH_4MA) ||
           (ulStrength == GPIO_STRENGTH_8MA) ||
           (ulStrength == GPIO_STRENGTH_8MA_SC));
    ASSERT((ulPinType == GPIO_PIN_TYPE_STD) ||
           (ulPinType == GPIO_PIN_TYPE_STD_WPU) ||
           (ulPinType == GPIO_PIN_TYPE_STD_WPD) ||
           (ulPinType == GPIO_PIN_TYPE_OD) ||
           (ulPinType == GPIO_PIN_TYPE_OD_WPU) ||
           (ulPinType == GPIO_PIN_TYPE_OD_WPD) ||
           (ulPinType == GPIO_PIN_TYPE_ANALOG))

    //
    // Set the output drive strength.
    //
    HWREG(ulPort + GPIO_O_DR2R) = ((ulStrength & 1) ?
                                   (HWREG(ulPort + GPIO_O_DR2R) | ucPins) :
                                   (HWREG(ulPort + GPIO_O_DR2R) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_DR4R) = ((ulStrength & 2) ?
                                   (HWREG(ulPort + GPIO_O_DR4R) | ucPins) :
                                   (HWREG(ulPort + GPIO_O_DR4R) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_DR8R) = ((ulStrength & 4) ?
                                   (HWREG(ulPort + GPIO_O_DR8R) | ucPins) :
                                   (HWREG(ulPort + GPIO_O_DR8R) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_SLR) = ((ulStrength & 8) ?
                                  (HWREG(ulPort + GPIO_O_SLR) | ucPins) :
                                  (HWREG(ulPort + GPIO_O_SLR) & ~(ucPins)));

    //
    // Set the pin type.
    //
    HWREG(ulPort + GPIO_O_ODR) = ((ulPinType & 1) ?
                                  (HWREG(ulPort + GPIO_O_ODR) | ucPins) :
                                  (HWREG(ulPort + GPIO_O_ODR) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_PUR) = ((ulPinType & 2) ?
                                  (HWREG(ulPort + GPIO_O_PUR) | ucPins) :
                                  (HWREG(ulPort + GPIO_O_PUR) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_PDR) = ((ulPinType & 4) ?
                                  (HWREG(ulPort + GPIO_O_PDR) | ucPins) :
                                  (HWREG(ulPort + GPIO_O_PDR) & ~(ucPins)));
    HWREG(ulPort + GPIO_O_DEN) = ((ulPinType & 8) ?
                                  (HWREG(ulPort + GPIO_O_DEN) | ucPins) :
                                  (HWREG(ulPort + GPIO_O_DEN) & ~(ucPins)));

    //
    // Set the analog mode select register.  This register only appears in
    // DustDevil-class (and later) devices, but is a harmless write on
    // Sandstorm- and Fury-class devices.
    //
    HWREG(ulPort + GPIO_O_AMSEL) =
        ((ulPinType == GPIO_PIN_TYPE_ANALOG) ?
         (HWREG(ulPort + GPIO_O_AMSEL) | ucPins) :
         (HWREG(ulPort + GPIO_O_AMSEL) & ~(ucPins)));
}

//*****************************************************************************
//
//! Gets the pad configuration for a pin.
//!
//! \param ulPort is the base address of the GPIO port.
//! \param ucPin is the pin number.
//! \param pulStrength is a pointer to storage for the output drive strength.
//! \param pulPinType is a pointer to storage for the output drive type.
//!
//! This function gets the pad configuration for a specified pin on the
//! selected GPIO port.  The values returned in \e pulStrength and
//! \e pulPinType correspond to the values used in GPIOPadConfigSet().  This
//! function also works for pin(s) configured as input pin(s); however, the
//! only meaningful data returned is whether the pin is terminated with a
//! pull-up or down resistor.
//!
//! \return None
//
//*****************************************************************************
void
GPIOPadConfigGet(unsigned long ulPort, unsigned char ucPin,
                 unsigned long *pulStrength, unsigned long *pulPinType)
{
    unsigned long ulTemp1, ulTemp2, ulTemp3, ulTemp4;

    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));
    ASSERT(ucPin < 8);

    //
    // Convert from a pin number to a bit position.
    //
    ucPin = (1 << ucPin);

    //
    // Get the drive strength for this pin.
    //
    ulTemp1 = HWREG(ulPort + GPIO_O_DR2R);
    ulTemp2 = HWREG(ulPort + GPIO_O_DR4R);
    ulTemp3 = HWREG(ulPort + GPIO_O_DR8R);
    ulTemp4 = HWREG(ulPort + GPIO_O_SLR);
    *pulStrength = (((ulTemp1 & ucPin) ? 1 : 0) | ((ulTemp2 & ucPin) ? 2 : 0) |
                    ((ulTemp3 & ucPin) ? 4 : 0) | ((ulTemp4 & ucPin) ? 8 : 0));

    //
    // Get the pin type.
    //
    ulTemp1 = HWREG(ulPort + GPIO_O_ODR);
    ulTemp2 = HWREG(ulPort + GPIO_O_PUR);
    ulTemp3 = HWREG(ulPort + GPIO_O_PDR);
    ulTemp4 = HWREG(ulPort + GPIO_O_DEN);
    *pulPinType = (((ulTemp1 & ucPin) ? 1 : 0) | ((ulTemp2 & ucPin) ? 2 : 0) |
                   ((ulTemp3 & ucPin) ? 4 : 0) | ((ulTemp4 & ucPin) ? 8 : 0));
}

//*****************************************************************************
//
//! Enables interrupts for the specified pin(s).
//!
//! \param ulPort is the base address of the GPIO port.
//! \param ucPins is the bit-packed representation of the pin(s).
//!
//! Unmasks the interrupt for the specified pin(s).
//!
//! The pin(s) are specified using a bit-packed byte, where each bit that is
//! set identifies the pin to be accessed, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPinIntEnable(unsigned long ulPort, unsigned char ucPins)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Enable the interrupts.
    //
    HWREG(ulPort + GPIO_O_IM) |= ucPins;
}

//*****************************************************************************
//
//! Disables interrupts for the specified pin(s).
//!
//! \param ulPort is the base address of the GPIO port.
//! \param ucPins is the bit-packed representation of the pin(s).
//!
//! Masks the interrupt for the specified pin(s).
//!
//! The pin(s) are specified using a bit-packed byte, where each bit that is
//! set identifies the pin to be accessed, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPinIntDisable(unsigned long ulPort, unsigned char ucPins)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Disable the interrupts.
    //
    HWREG(ulPort + GPIO_O_IM) &= ~(ucPins);
}

//*****************************************************************************
//
//! Gets interrupt status for the specified GPIO port.
//!
//! \param ulPort is the base address of the GPIO port.
//! \param bMasked specifies whether masked or raw interrupt status is
//! returned.
//!
//! If \e bMasked is set as \b true, then the masked interrupt status is
//! returned; otherwise, the raw interrupt status will be returned.
//!
//! \return Returns a bit-packed byte, where each bit that is set identifies
//! an active masked or raw interrupt, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//! Bits 31:8 should be ignored.
//
//*****************************************************************************
long
GPIOPinIntStatus(unsigned long ulPort, tBoolean bMasked)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Return the interrupt status.
    //
    if(bMasked)
    {
        return(HWREG(ulPort + GPIO_O_MIS));
    }
    else
    {
        return(HWREG(ulPort + GPIO_O_RIS));
    }
}

//*****************************************************************************
//
//! Clears the interrupt for the specified pin(s).
//!
//! \param ulPort is the base address of the GPIO port.
//! \param ucPins is the bit-packed representation of the pin(s).
//!
//! Clears the interrupt for the specified pin(s).
//!
//! The pin(s) are specified using a bit-packed byte, where each bit that is
//! set identifies the pin to be accessed, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//!
//! \note Since there is a write buffer in the Cortex-M3 processor, it may take
//! several clock cycles before the interrupt source is actually cleared.
//! Therefore, it is recommended that the interrupt source be cleared early in
//! the interrupt handler (as opposed to the very last action) to avoid
//! returning from the interrupt handler before the interrupt source is
//! actually cleared.  Failure to do so may result in the interrupt handler
//! being immediately reentered (since NVIC still sees the interrupt source
//! asserted).
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPinIntClear(unsigned long ulPort, unsigned char ucPins)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Clear the interrupts.
    //
    HWREG(ulPort + GPIO_O_ICR) = ucPins;
}

//*****************************************************************************
//
//! Registers an interrupt handler for a GPIO port.
//!
//! \param ulPort is the base address of the GPIO port.
//! \param pfnIntHandler is a pointer to the GPIO port interrupt handling
//! function.
//!
//! This function will ensure that the interrupt handler specified by
//! \e pfnIntHandler is called when an interrupt is detected from the selected
//! GPIO port.  This function will also enable the corresponding GPIO interrupt
//! in the interrupt controller; individual pin interrupts and interrupt
//! sources must be enabled with GPIOPinIntEnable().
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPortIntRegister(unsigned long ulPort, void (*pfnIntHandler)(void))
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Get the interrupt number associated with the specified GPIO.
    //
    ulPort = GPIOGetIntNumber(ulPort);

    //
    // Register the interrupt handler.
    //
    IntRegister(ulPort, pfnIntHandler);

    //
    // Enable the GPIO interrupt.
    //
    IntEnable(ulPort);
}

//*****************************************************************************
//
//! Removes an interrupt handler for a GPIO port.
//!
//! \param ulPort is the base address of the GPIO port.
//!
//! This function will unregister the interrupt handler for the specified
//! GPIO port.  This function will also disable the corresponding
//! GPIO port interrupt in the interrupt controller; individual GPIO interrupts
//! and interrupt sources must be disabled with GPIOPinIntDisable().
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.
//!
//! \return None.
//
//*****************************************************************************
void
GPIOPortIntUnregister(unsigned long ulPort)
{
    //
    // Check the arguments.
    //
    ASSERT(GPIOBaseValid(ulPort));

    //
    // Get the interrupt number associated with the specified GPIO.
    //
    ulPort = GPIOGetIntNumber(ulPort);

    //
    // Disable the GPIO interrupt.
    //
    IntDisable(ulPort);

    //
    // Unregister the interrupt handler.
    //
    IntUnregister(ulPort);
}

//*****************************************************************************
//
//! Reads the values present of the specified pin(s).
//!
//! \param ulPort is the base address of the GPIO port.
//! \param ucPins is the bit-packed representation of the pin(s).
//!
//! The values at the specified pin(s) are read, as specified by \e ucPins.
//! Values are returned for both input and output pin(s), and the value
//! for pin(s) that are not specified by \e ucPins are set to 0.
//!
//! The pin(s) are specified using a bit-packed byte, where each bit that is
//! set identifies the pin to be accessed, and where bit 0 of the byte
//! represents GPIO port pin 0, bit 1 represents GPIO port pin 1, and so on.
//!
//! \return Returns a bit-packed byte providing the state of the specified
//! pin, where bit 0 of the byte represents GPIO port pin 0, bit 1 represents
//! GPIO port pin 1, and so on.  Any bit that is not specified by \e ucPins
//! is returned as a 0.  Bits 31:8 should be ignored.
//
//*****************************************************************************
long
GPIOPinRead(unsigned long ulPort, unsigned char ucPins)
{
    //
    // Check the arguments.