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Diffstat (limited to 'driverlib/qei.c')
| -rw-r--r-- | driverlib/qei.c | 633 |
1 files changed, 633 insertions, 0 deletions
diff --git a/driverlib/qei.c b/driverlib/qei.c new file mode 100644 index 0000000..237f484 --- /dev/null +++ b/driverlib/qei.c @@ -0,0 +1,633 @@ +//*****************************************************************************
+//
+// qei.c - Driver for the Quadrature Encoder with Index.
+//
+// Copyright (c) 2005-2012 Texas Instruments Incorporated. All rights reserved.
+// Software License Agreement
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions
+// are met:
+//
+// Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//
+// Redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the
+// distribution.
+//
+// Neither the name of Texas Instruments Incorporated nor the names of
+// its contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// This is part of revision 9453 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 function enables operation of the quadrature encoder module. The
+//! module 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 function disables 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 function configures 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 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 specify if the
+//! position integrator should be reset when the index pulse is detected.
+//! - \b QEI_CONFIG_QUADRATURE or \b QEI_CONFIG_CLOCK_DIR 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 function 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 is not yet aligned with the index pulse).
+//!
+//! \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 function sets the current position of the encoder; the encoder
+//! position is then 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 function 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 function 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 function enables operation of the velocity capture in the quadrature
+//! encoder module. The module must be configured before velocity capture is
+//! 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 function disables 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 function configures 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 function 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 function registers the handler to be called when a quadrature encoder
+//! interrupt occurs. This function enables 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 unregisters the handler to be called when a quadrature
+//! encoder interrupt occurs. This function also masks 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.
+//!
+//! This function 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.
+//! This parameter can be any of the \b QEI_INTERROR, \b QEI_INTDIR,
+//! \b QEI_INTTIMER, or \b QEI_INTINDEX values.
+//!
+//! This function 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 function 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.
+//! This parameter 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 function must be called in the interrupt
+//! handler to keep the interrupt from being triggered again immediately upon
+//! exit.
+//!
+//! \note Because there is a write buffer in the Cortex-M 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 (because the interrupt controller 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.
+//! @}
+//
+//*****************************************************************************
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