617 lines
20 KiB
C
617 lines
20 KiB
C
//*****************************************************************************
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//
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// qei.c - Driver for the Quadrature Encoder with Index.
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//
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// Copyright (c) 2005-2010 Texas Instruments Incorporated. All rights reserved.
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// Software License Agreement
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//
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// Texas Instruments (TI) is supplying this software for use solely and
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// exclusively on TI's microcontroller products. The software is owned by
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// TI and/or its suppliers, and is protected under applicable copyright
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// laws. You may not combine this software with "viral" open-source
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// software in order to form a larger program.
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//
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// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
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// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
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// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
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// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
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// DAMAGES, FOR ANY REASON WHATSOEVER.
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//
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// This is part of revision 6459 of the Stellaris Peripheral Driver Library.
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//
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//*****************************************************************************
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//*****************************************************************************
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//
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//! \addtogroup qei_api
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//! @{
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//
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//*****************************************************************************
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#include "inc/hw_ints.h"
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#include "inc/hw_memmap.h"
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#include "inc/hw_qei.h"
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#include "inc/hw_types.h"
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#include "driverlib/debug.h"
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#include "driverlib/interrupt.h"
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#include "driverlib/qei.h"
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//*****************************************************************************
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//
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//! Enables the quadrature encoder.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This will enable operation of the quadrature encoder module. It must be
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//! configured before it is enabled.
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//!
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//! \sa QEIConfigure()
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIEnable(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Enable the QEI module.
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//
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HWREG(ulBase + QEI_O_CTL) |= QEI_CTL_ENABLE;
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}
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//*****************************************************************************
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//
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//! Disables the quadrature encoder.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This will disable operation of the quadrature encoder module.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIDisable(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Disable the QEI module.
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//
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HWREG(ulBase + QEI_O_CTL) &= ~(QEI_CTL_ENABLE);
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}
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//*****************************************************************************
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//
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//! Configures the quadrature encoder.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param ulConfig is the configuration for the quadrature encoder. See below
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//! for a description of this parameter.
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//! \param ulMaxPosition specifies the maximum position value.
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//!
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//! This will configure the operation of the quadrature encoder. The
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//! \e ulConfig parameter provides the configuration of the encoder and is the
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//! logical OR of several values:
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//!
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//! - \b QEI_CONFIG_CAPTURE_A or \b QEI_CONFIG_CAPTURE_A_B to specify if edges
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//! on channel A or on both channels A and B should be counted by the
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//! position integrator and velocity accumulator.
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//! - \b QEI_CONFIG_NO_RESET or \b QEI_CONFIG_RESET_IDX to specify if the
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//! position integrator should be reset when the index pulse is detected.
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//! - \b QEI_CONFIG_QUADRATURE or \b QEI_CONFIG_CLOCK_DIR to specify if
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//! quadrature signals are being provided on ChA and ChB, or if a direction
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//! signal and a clock are being provided instead.
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//! - \b QEI_CONFIG_NO_SWAP or \b QEI_CONFIG_SWAP to specify if the signals
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//! provided on ChA and ChB should be swapped before being processed.
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//!
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//! \e ulMaxPosition is the maximum value of the position integrator, and is
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//! the value used to reset the position capture when in index reset mode and
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//! moving in the reverse (negative) direction.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIConfigure(unsigned long ulBase, unsigned long ulConfig,
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unsigned long ulMaxPosition)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Write the new configuration to the hardware.
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//
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HWREG(ulBase + QEI_O_CTL) = ((HWREG(ulBase + QEI_O_CTL) &
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~(QEI_CTL_CAPMODE | QEI_CTL_RESMODE |
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QEI_CTL_SIGMODE | QEI_CTL_SWAP)) |
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ulConfig);
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//
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// Set the maximum position.
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//
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HWREG(ulBase + QEI_O_MAXPOS) = ulMaxPosition;
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}
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//*****************************************************************************
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//
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//! Gets the current encoder position.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This returns the current position of the encoder. Depending upon the
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//! configuration of the encoder, and the incident of an index pulse, this
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//! value may or may not contain the expected data (that is, if in reset on
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//! index mode, if an index pulse has not been encountered, the position
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//! counter will not be aligned with the index pulse yet).
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//!
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//! \return The current position of the encoder.
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//
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//*****************************************************************************
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unsigned long
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QEIPositionGet(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Return the current position counter.
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//
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return(HWREG(ulBase + QEI_O_POS));
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}
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//*****************************************************************************
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//
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//! Sets the current encoder position.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param ulPosition is the new position for the encoder.
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//!
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//! This sets the current position of the encoder; the encoder position will
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//! then be measured relative to this value.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIPositionSet(unsigned long ulBase, unsigned long ulPosition)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Set the position counter.
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//
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HWREG(ulBase + QEI_O_POS) = ulPosition;
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}
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//*****************************************************************************
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//
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//! Gets the current direction of rotation.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This returns the current direction of rotation. In this case, current
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//! means the most recently detected direction of the encoder; it may not be
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//! presently moving but this is the direction it last moved before it stopped.
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//!
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//! \return Returns 1 if moving in the forward direction or -1 if moving in the
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//! reverse direction.
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//
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//*****************************************************************************
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long
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QEIDirectionGet(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Return the direction of rotation.
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//
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return((HWREG(ulBase + QEI_O_STAT) & QEI_STAT_DIRECTION) ? -1 : 1);
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}
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//*****************************************************************************
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//
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//! Gets the encoder error indicator.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This returns the error indicator for the quadrature encoder. It is an
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//! error for both of the signals of the quadrature input to change at the same
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//! time.
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//!
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//! \return Returns \b true if an error has occurred and \b false otherwise.
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//
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//*****************************************************************************
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tBoolean
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QEIErrorGet(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Return the error indicator.
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//
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return((HWREG(ulBase + QEI_O_STAT) & QEI_STAT_ERROR) ? true : false);
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}
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//*****************************************************************************
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//
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//! Enables the velocity capture.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This will enable operation of the velocity capture in the quadrature
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//! encoder module. It must be configured before it is enabled. Velocity
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//! capture will not occur if the quadrature encoder is not enabled.
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//!
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//! \sa QEIVelocityConfigure() and QEIEnable()
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIVelocityEnable(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Enable the velocity capture.
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//
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HWREG(ulBase + QEI_O_CTL) |= QEI_CTL_VELEN;
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}
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//*****************************************************************************
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//
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//! Disables the velocity capture.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This will disable operation of the velocity capture in the quadrature
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//! encoder module.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIVelocityDisable(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Disable the velocity capture.
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//
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HWREG(ulBase + QEI_O_CTL) &= ~(QEI_CTL_VELEN);
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}
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//*****************************************************************************
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//
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//! Configures the velocity capture.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param ulPreDiv specifies the predivider applied to the input quadrature
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//! signal before it is counted; can be one of \b QEI_VELDIV_1,
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//! \b QEI_VELDIV_2, \b QEI_VELDIV_4, \b QEI_VELDIV_8, \b QEI_VELDIV_16,
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//! \b QEI_VELDIV_32, \b QEI_VELDIV_64, or \b QEI_VELDIV_128.
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//! \param ulPeriod specifies the number of clock ticks over which to measure
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//! the velocity; must be non-zero.
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//!
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//! This will configure the operation of the velocity capture portion of the
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//! quadrature encoder. The position increment signal is predivided as
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//! specified by \e ulPreDiv before being accumulated by the velocity capture.
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//! The divided signal is accumulated over \e ulPeriod system clock before
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//! being saved and resetting the accumulator.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIVelocityConfigure(unsigned long ulBase, unsigned long ulPreDiv,
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unsigned long ulPeriod)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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ASSERT(!(ulPreDiv & ~(QEI_CTL_VELDIV_M)));
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ASSERT(ulPeriod != 0);
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//
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// Set the velocity predivider.
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//
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HWREG(ulBase + QEI_O_CTL) = ((HWREG(ulBase + QEI_O_CTL) &
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~(QEI_CTL_VELDIV_M)) | ulPreDiv);
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//
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// Set the timer period.
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//
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HWREG(ulBase + QEI_O_LOAD) = ulPeriod - 1;
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}
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//*****************************************************************************
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//
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//! Gets the current encoder speed.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This returns the current speed of the encoder. The value returned is the
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//! number of pulses detected in the specified time period; this number can be
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//! multiplied by the number of time periods per second and divided by the
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//! number of pulses per revolution to obtain the number of revolutions per
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//! second.
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//!
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//! \return Returns the number of pulses captured in the given time period.
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//
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//*****************************************************************************
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unsigned long
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QEIVelocityGet(unsigned long ulBase)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Return the speed capture value.
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//
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return(HWREG(ulBase + QEI_O_SPEED));
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}
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//*****************************************************************************
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//
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//! Registers an interrupt handler for the quadrature encoder interrupt.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param pfnHandler is a pointer to the function to be called when the
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//! quadrature encoder interrupt occurs.
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//!
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//! This sets the handler to be called when a quadrature encoder interrupt
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//! occurs. This will enable the global interrupt in the interrupt controller;
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//! specific quadrature encoder interrupts must be enabled via QEIIntEnable().
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//! It is the interrupt handler's responsibility to clear the interrupt source
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//! via QEIIntClear().
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//!
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//! \sa IntRegister() for important information about registering interrupt
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//! handlers.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIIntRegister(unsigned long ulBase, void (*pfnHandler)(void))
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{
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unsigned long ulInt;
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Determine the interrupt number based on the QEI module.
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//
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ulInt = (ulBase == QEI0_BASE) ? INT_QEI0 : INT_QEI1;
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//
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// Register the interrupt handler, returning an error if an error occurs.
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//
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IntRegister(ulInt, pfnHandler);
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//
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// Enable the quadrature encoder interrupt.
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//
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IntEnable(ulInt);
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}
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//*****************************************************************************
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//
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//! Unregisters an interrupt handler for the quadrature encoder interrupt.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//!
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//! This function will clear the handler to be called when a quadrature encoder
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//! interrupt occurs. This will also mask off the interrupt in the interrupt
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//! controller so that the interrupt handler no longer is called.
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//!
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//! \sa IntRegister() for important information about registering interrupt
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//! handlers.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIIntUnregister(unsigned long ulBase)
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{
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unsigned long ulInt;
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Determine the interrupt number based on the QEI module.
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//
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ulInt = (ulBase == QEI0_BASE) ? INT_QEI0 : INT_QEI1;
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//
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// Disable the interrupt.
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//
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IntDisable(ulInt);
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//
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// Unregister the interrupt handler.
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//
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IntUnregister(ulInt);
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}
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//*****************************************************************************
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//
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//! Enables individual quadrature encoder interrupt sources.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param ulIntFlags is a bit mask of the interrupt sources to be enabled.
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//! Can be any of the \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, or
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//! \b QEI_INTINDEX values.
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//!
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//! Enables the indicated quadrature encoder interrupt sources. Only the
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//! sources that are enabled can be reflected to the processor interrupt;
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//! disabled sources have no effect on the processor.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIIntEnable(unsigned long ulBase, unsigned long ulIntFlags)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Enable the specified interrupts.
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//
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HWREG(ulBase + QEI_O_INTEN) |= ulIntFlags;
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}
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//*****************************************************************************
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//
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//! Disables individual quadrature encoder interrupt sources.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param ulIntFlags is a bit mask of the interrupt sources to be disabled.
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//! Can be any of the \b QEI_INTERROR, \b QEI_INTDIR, \b QEI_INTTIMER, or
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//! \b QEI_INTINDEX values.
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//!
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//! Disables the indicated quadrature encoder interrupt sources. Only the
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//! sources that are enabled can be reflected to the processor interrupt;
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//! disabled sources have no effect on the processor.
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//!
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//! \return None.
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//
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//*****************************************************************************
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void
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QEIIntDisable(unsigned long ulBase, unsigned long ulIntFlags)
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{
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//
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// Check the arguments.
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//
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ASSERT((ulBase == QEI0_BASE) || (ulBase == QEI1_BASE));
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//
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// Disable the specified interrupts.
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//
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HWREG(ulBase + QEI_O_INTEN) &= ~(ulIntFlags);
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}
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//*****************************************************************************
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//
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//! Gets the current interrupt status.
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//!
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//! \param ulBase is the base address of the quadrature encoder module.
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//! \param bMasked is false if the raw interrupt status is required and true if
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//! the masked interrupt status is required.
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//!
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//! This returns the interrupt status for the quadrature encoder module.
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//! Either the raw interrupt status or the status of interrupts that are
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//! allowed to reflect to the processor can be returned.
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//!
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//! \return Returns the current interrupt status, enumerated as a bit field of
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//! \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.
|
|
//! @}
|
|
//
|
|
//*****************************************************************************
|