620 lines
20 KiB
C
620 lines
20 KiB
C
//*****************************************************************************
|
|
//
|
|
// qei.c - Driver for the Quadrature Encoder with Index.
|
|
//
|
|
// Copyright (c) 2005-2009 Luminary Micro, Inc. All rights reserved.
|
|
// Software License Agreement
|
|
//
|
|
// Luminary Micro, Inc. (LMI) is supplying this software for use solely and
|
|
// exclusively on LMI's microcontroller products.
|
|
//
|
|
// The software is owned by LMI and/or its suppliers, and is protected under
|
|
// applicable copyright laws. All rights are reserved. You may not combine
|
|
// this software with "viral" open-source software in order to form a larger
|
|
// program. Any use in violation of the foregoing restrictions may subject
|
|
// the user to criminal sanctions under applicable laws, as well as to civil
|
|
// liability for the breach of the terms and conditions of this license.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
|
|
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
|
|
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
|
|
// LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
|
|
// CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
|
|
//
|
|
// This is part of revision 4694 of the Stellaris Peripheral Driver Library.
|
|
//
|
|
//*****************************************************************************
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! \addtogroup qei_api
|
|
//! @{
|
|
//
|
|
//*****************************************************************************
|
|
|
|
#include "inc/hw_ints.h"
|
|
#include "inc/hw_memmap.h"
|
|
#include "inc/hw_qei.h"
|
|
#include "inc/hw_types.h"
|
|
#include "driverlib/debug.h"
|
|
#include "driverlib/interrupt.h"
|
|
#include "driverlib/qei.h"
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Enables the quadrature encoder.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This will enable operation of the quadrature encoder module. It must be
|
|
//! configured before it is enabled.
|
|
//!
|
|
//! \sa QEIConfigure()
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIEnable(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Enable the QEI module.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) |= QEI_CTL_ENABLE;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Disables the quadrature encoder.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This will disable operation of the quadrature encoder module.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIDisable(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Disable the QEI module.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) &= ~(QEI_CTL_ENABLE);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures the quadrature encoder.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulConfig is the configuration for the quadrature encoder. See below
|
|
//! for a description of this parameter.
|
|
//! \param ulMaxPosition specifies the maximum position value.
|
|
//!
|
|
//! This will configure the operation of the quadrature encoder. The
|
|
//! \e ulConfig parameter provides the configuration of the encoder and is the
|
|
//! logical OR of several values:
|
|
//!
|
|
//! - \b QEI_CONFIG_CAPTURE_A or \b QEI_CONFIG_CAPTURE_A_B to specify if edges
|
|
//! on channel A or on both channels A and B should be counted by the
|
|
//! position integrator and velocity accumulator.
|
|
//! - \b QEI_CONFIG_NO_RESET or \b QEI_CONFIG_RESET_IDX to specify if the
|
|
//! position integrator should be reset when the index pulse is detected.
|
|
//! - \b QEI_CONFIG_QUADRATURE or \b QEI_CONFIG_CLOCK_DIR to specify if
|
|
//! quadrature signals are being provided on ChA and ChB, or if a direction
|
|
//! signal and a clock are being provided instead.
|
|
//! - \b QEI_CONFIG_NO_SWAP or \b QEI_CONFIG_SWAP to specify if the signals
|
|
//! provided on ChA and ChB should be swapped before being processed.
|
|
//!
|
|
//! \e ulMaxPosition is the maximum value of the position integrator, and is
|
|
//! the value used to reset the position capture when in index reset mode and
|
|
//! moving in the reverse (negative) direction.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIConfigure(unsigned long ulBase, unsigned long ulConfig,
|
|
unsigned long ulMaxPosition)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Write the new configuration to the hardware.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) = ((HWREG(ulBase + QEI_O_CTL) &
|
|
~(QEI_CTL_CAPMODE | QEI_CTL_RESMODE |
|
|
QEI_CTL_SIGMODE | QEI_CTL_SWAP)) |
|
|
ulConfig);
|
|
|
|
//
|
|
// Set the maximum position.
|
|
//
|
|
HWREG(ulBase + QEI_O_MAXPOS) = ulMaxPosition;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the current encoder position.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This returns the current position of the encoder. Depending upon the
|
|
//! configuration of the encoder, and the incident of an index pulse, this
|
|
//! value may or may not contain the expected data (that is, if in reset on
|
|
//! index mode, if an index pulse has not been encountered, the position
|
|
//! counter will not be aligned with the index pulse yet).
|
|
//!
|
|
//! \return The current position of the encoder.
|
|
//
|
|
//*****************************************************************************
|
|
unsigned long
|
|
QEIPositionGet(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Return the current position counter.
|
|
//
|
|
return(HWREG(ulBase + QEI_O_POS));
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Sets the current encoder position.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulPosition is the new position for the encoder.
|
|
//!
|
|
//! This sets the current position of the encoder; the encoder position will
|
|
//! then be measured relative to this value.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIPositionSet(unsigned long ulBase, unsigned long ulPosition)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Set the position counter.
|
|
//
|
|
HWREG(ulBase + QEI_O_POS) = ulPosition;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the current direction of rotation.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This returns the current direction of rotation. In this case, current
|
|
//! means the most recently detected direction of the encoder; it may not be
|
|
//! presently moving but this is the direction it last moved before it stopped.
|
|
//!
|
|
//! \return Returns 1 if moving in the forward direction or -1 if moving in the
|
|
//! reverse direction.
|
|
//
|
|
//*****************************************************************************
|
|
long
|
|
QEIDirectionGet(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Return the direction of rotation.
|
|
//
|
|
return((HWREG(ulBase + QEI_O_STAT) & QEI_STAT_DIRECTION) ? -1 : 1);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the encoder error indicator.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This returns the error indicator for the quadrature encoder. It is an
|
|
//! error for both of the signals of the quadrature input to change at the same
|
|
//! time.
|
|
//!
|
|
//! \return Returns \b true if an error has occurred and \b false otherwise.
|
|
//
|
|
//*****************************************************************************
|
|
tBoolean
|
|
QEIErrorGet(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Return the error indicator.
|
|
//
|
|
return((HWREG(ulBase + QEI_O_STAT) & QEI_STAT_ERROR) ? true : false);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Enables the velocity capture.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This will enable operation of the velocity capture in the quadrature
|
|
//! encoder module. It must be configured before it is enabled. Velocity
|
|
//! capture will not occur if the quadrature encoder is not enabled.
|
|
//!
|
|
//! \sa QEIVelocityConfigure() and QEIEnable()
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIVelocityEnable(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Enable the velocity capture.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) |= QEI_CTL_VELEN;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Disables the velocity capture.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This will disable operation of the velocity capture in the quadrature
|
|
//! encoder module.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIVelocityDisable(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Disable the velocity capture.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) &= ~(QEI_CTL_VELEN);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Configures the velocity capture.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulPreDiv specifies the predivider applied to the input quadrature
|
|
//! signal before it is counted; can be one of \b QEI_VELDIV_1,
|
|
//! \b QEI_VELDIV_2, \b QEI_VELDIV_4, \b QEI_VELDIV_8, \b QEI_VELDIV_16,
|
|
//! \b QEI_VELDIV_32, \b QEI_VELDIV_64, or \b QEI_VELDIV_128.
|
|
//! \param ulPeriod specifies the number of clock ticks over which to measure
|
|
//! the velocity; must be non-zero.
|
|
//!
|
|
//! This will configure the operation of the velocity capture portion of the
|
|
//! quadrature encoder. The position increment signal is predivided as
|
|
//! specified by \e ulPreDiv before being accumulated by the velocity capture.
|
|
//! The divided signal is accumulated over \e ulPeriod system clock before
|
|
//! being saved and resetting the accumulator.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIVelocityConfigure(unsigned long ulBase, unsigned long ulPreDiv,
|
|
unsigned long ulPeriod)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
ASSERT(!(ulPreDiv & ~(QEI_CTL_VELDIV_M)));
|
|
ASSERT(ulPeriod != 0);
|
|
|
|
//
|
|
// Set the velocity predivider.
|
|
//
|
|
HWREG(ulBase + QEI_O_CTL) = ((HWREG(ulBase + QEI_O_CTL) &
|
|
~(QEI_CTL_VELDIV_M)) | ulPreDiv);
|
|
|
|
//
|
|
// Set the timer period.
|
|
//
|
|
HWREG(ulBase + QEI_O_LOAD) = ulPeriod - 1;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the current encoder speed.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This returns the current speed of the encoder. The value returned is the
|
|
//! number of pulses detected in the specified time period; this number can be
|
|
//! multiplied by the number of time periods per second and divided by the
|
|
//! number of pulses per revolution to obtain the number of revolutions per
|
|
//! second.
|
|
//!
|
|
//! \return Returns the number of pulses captured in the given time period.
|
|
//
|
|
//*****************************************************************************
|
|
unsigned long
|
|
QEIVelocityGet(unsigned long ulBase)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Return the speed capture value.
|
|
//
|
|
return(HWREG(ulBase + QEI_O_SPEED));
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Registers an interrupt handler for the quadrature encoder interrupt.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param pfnHandler is a pointer to the function to be called when the
|
|
//! quadrature encoder interrupt occurs.
|
|
//!
|
|
//! This sets the handler to be called when a quadrature encoder interrupt
|
|
//! occurs. This will enable the global interrupt in the interrupt controller;
|
|
//! specific quadrature encoder interrupts must be enabled via QEIIntEnable().
|
|
//! It is the interrupt handler's responsibility to clear the interrupt source
|
|
//! via QEIIntClear().
|
|
//!
|
|
//! \sa IntRegister() for important information about registering interrupt
|
|
//! handlers.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIIntRegister(unsigned long ulBase, void (*pfnHandler)(void))
|
|
{
|
|
unsigned long ulInt;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Determine the interrupt number based on the QEI module.
|
|
//
|
|
ulInt = (ulBase == QEI0_BASE) ? INT_QEI0 : INT_QEI1;
|
|
|
|
//
|
|
// Register the interrupt handler, returning an error if an error occurs.
|
|
//
|
|
IntRegister(ulInt, pfnHandler);
|
|
|
|
//
|
|
// Enable the quadrature encoder interrupt.
|
|
//
|
|
IntEnable(ulInt);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Unregisters an interrupt handler for the quadrature encoder interrupt.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//!
|
|
//! This function will clear the handler to be called when a quadrature encoder
|
|
//! interrupt occurs. This will also mask off the interrupt in the interrupt
|
|
//! controller so that the interrupt handler no longer is called.
|
|
//!
|
|
//! \sa IntRegister() for important information about registering interrupt
|
|
//! handlers.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIIntUnregister(unsigned long ulBase)
|
|
{
|
|
unsigned long ulInt;
|
|
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Determine the interrupt number based on the QEI module.
|
|
//
|
|
ulInt = (ulBase == QEI0_BASE) ? INT_QEI0 : INT_QEI1;
|
|
|
|
//
|
|
// Disable the interrupt.
|
|
//
|
|
IntDisable(ulInt);
|
|
|
|
//
|
|
// Unregister the interrupt handler.
|
|
//
|
|
IntUnregister(ulInt);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Enables individual quadrature encoder interrupt sources.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulIntFlags is a bit mask of the interrupt sources to be enabled.
|
|
//! Can be any of the \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, or
|
|
//! \b QEI_INTINDEX values.
|
|
//!
|
|
//! Enables the indicated quadrature encoder interrupt sources. Only the
|
|
//! sources that are enabled can be reflected to the processor interrupt;
|
|
//! disabled sources have no effect on the processor.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIIntEnable(unsigned long ulBase, unsigned long ulIntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Enable the specified interrupts.
|
|
//
|
|
HWREG(ulBase + QEI_O_INTEN) |= ulIntFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Disables individual quadrature encoder interrupt sources.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulIntFlags is a bit mask of the interrupt sources to be disabled.
|
|
//! Can be any of the \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, or
|
|
//! \b QEI_INTINDEX values.
|
|
//!
|
|
//! Disables the indicated quadrature encoder interrupt sources. Only the
|
|
//! sources that are enabled can be reflected to the processor interrupt;
|
|
//! disabled sources have no effect on the processor.
|
|
//!
|
|
//! \return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
QEIIntDisable(unsigned long ulBase, unsigned long ulIntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Disable the specified interrupts.
|
|
//
|
|
HWREG(ulBase + QEI_O_INTEN) &= ~(ulIntFlags);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Gets the current interrupt status.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param bMasked is false if the raw interrupt status is required and true if
|
|
//! the masked interrupt status is required.
|
|
//!
|
|
//! This returns the interrupt status for the quadrature encoder module.
|
|
//! Either the raw interrupt status or the status of interrupts that are
|
|
//! allowed to reflect to the processor can be returned.
|
|
//!
|
|
//! \return Returns the current interrupt status, enumerated as a bit field of
|
|
//! \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, and \b QEI_INTINDEX.
|
|
//
|
|
//*****************************************************************************
|
|
unsigned long
|
|
QEIIntStatus(unsigned long ulBase, tBoolean bMasked)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Return either the interrupt status or the raw interrupt status as
|
|
// requested.
|
|
//
|
|
if(bMasked)
|
|
{
|
|
return(HWREG(ulBase + QEI_O_ISC));
|
|
}
|
|
else
|
|
{
|
|
return(HWREG(ulBase + QEI_O_RIS));
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! Clears quadrature encoder interrupt sources.
|
|
//!
|
|
//! \param ulBase is the base address of the quadrature encoder module.
|
|
//! \param ulIntFlags is a bit mask of the interrupt sources to be cleared.
|
|
//! Can be any of the \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, or
|
|
//! \b QEI_INTINDEX values.
|
|
//!
|
|
//! The specified quadrature encoder interrupt sources are cleared, so that
|
|
//! they no longer assert. This must be done in the interrupt handler to keep
|
|
//! it from being called again immediately upon exit.
|
|
//!
|
|
//! \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
|
|
QEIIntClear(unsigned long ulBase, unsigned long ulIntFlags)
|
|
{
|
|
//
|
|
// Check the arguments.
|
|
//
|
|
ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
|
|
|
|
//
|
|
// Clear the requested interrupt sources.
|
|
//
|
|
HWREG(ulBase + QEI_O_ISC) = ulIntFlags;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
// Close the Doxygen group.
|
|
//! @}
|
|
//
|
|
//*****************************************************************************
|