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/*
ChibiOS - Copyright (C) 2006..2016 Martino Migliavacca
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* @file hal_qei.c
* @brief QEI Driver code.
*
* @addtogroup QEI
* @{
*/
#include "hal.h"
#if (HAL_USE_QEI == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Helper for correclty handling overflow/underflow
*
* @details Underflow/overflow will be handled according to mode:
* QEI_OVERFLOW_WRAP: counter value will wrap around.
* QEI_OVERFLOW_DISCARD: counter will not change
* QEI_OVERFLOW_MINMAX: counter will be updated upto min or max.
*
* @note This function is for use by low level driver.
*
* @param[in,out] count counter value
* @param[in,out] delta adjustment value
* @param[in] min minimum allowed value for counter
* @param[in] max maximum allowed value for counter
* @param[in] mode how to handle overflow
*
* @return true if counter underflow/overflow occured or
* was due to occur
*
*/
bool qei_adjust_count(qeicnt_t *count, qeidelta_t *delta,
qeicnt_t min, qeicnt_t max, qeioverflow_t mode) {
/* For information on signed integer overflow see:
* https://www.securecoding.cert.org/confluence/x/RgE
*/
/* Get values */
const qeicnt_t _count = *count;
const qeidelta_t _delta = *delta;
/* Overflow operation
*/
if ((_delta > 0) && (_count > (max - _delta))) {
switch(mode) {
case QEI_OVERFLOW_WRAP:
*delta = 0;
*count = (min + (_count - (max - _delta))) - 1;
break;
#if QEI_USE_OVERFLOW_DISCARD == TRUE
case QEI_OVERFLOW_DISCARD:
*delta = _delta;
*count = _count;
break;
#endif
#if QEI_USE_OVERFLOW_MINMAX == TRUE
case QEI_OVERFLOW_MINMAX:
*delta = _count - (max - _delta);
*count = max;
break;
#endif
}
return true;
/* Underflow operation
*/
} else if ((_delta < 0) && (_count < (min - _delta))) {
switch(mode) {
case QEI_OVERFLOW_WRAP:
*delta = 0;
*count = (max + (_count - (min - _delta))) + 1;
break;
#if QEI_USE_OVERFLOW_DISCARD == TRUE
case QEI_OVERFLOW_DISCARD:
*delta = _delta;
*count = _count;
break;
#endif
#if QEI_USE_OVERFLOW_MINMAX == TRUE
case QEI_OVERFLOW_MINMAX:
*delta = _count - (min - _delta);
*count = min;
break;
#endif
}
return true;
/* Normal operation
*/
} else {
*delta = 0;
*count = _count + _delta;
return false;
}
}
/**
* @brief QEI Driver initialization.
* @note This function is implicitly invoked by @p halInit(), there is
* no need to explicitly initialize the driver.
*
* @init
*/
void qeiInit(void) {
qei_lld_init();
}
/**
* @brief Initializes the standard part of a @p QEIDriver structure.
*
* @param[out] qeip pointer to the @p QEIDriver object
*
* @init
*/
void qeiObjectInit(QEIDriver *qeip) {
qeip->state = QEI_STOP;
qeip->last = 0;
qeip->config = NULL;
}
/**
* @brief Configures and activates the QEI peripheral.
*
* @param[in] qeip pointer to the @p QEIDriver object
* @param[in] config pointer to the @p QEIConfig object
*
* @api
*/
void qeiStart(QEIDriver *qeip, const QEIConfig *config) {
osalDbgCheck((qeip != NULL) && (config != NULL));
osalSysLock();
osalDbgAssert((qeip->state == QEI_STOP) || (qeip->state == QEI_READY),
"invalid state");
qeip->config = config;
qei_lld_start(qeip);
qeip->state = QEI_READY;
osalSysUnlock();
}
/**
* @brief Deactivates the QEI peripheral.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @api
*/
void qeiStop(QEIDriver *qeip) {
osalDbgCheck(qeip != NULL);
osalSysLock();
osalDbgAssert((qeip->state == QEI_STOP) || (qeip->state == QEI_READY),
"invalid state");
qei_lld_stop(qeip);
qeip->state = QEI_STOP;
osalSysUnlock();
}
/**
* @brief Enables the quadrature encoder interface.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @api
*/
void qeiEnable(QEIDriver *qeip) {
osalDbgCheck(qeip != NULL);
osalSysLock();
osalDbgAssert(qeip->state == QEI_READY, "invalid state");
qei_lld_enable(qeip);
qeip->state = QEI_ACTIVE;
osalSysUnlock();
}
/**
* @brief Disables the quadrature encoder interface.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @api
*/
void qeiDisable(QEIDriver *qeip) {
osalDbgCheck(qeip != NULL);
osalSysLock();
osalDbgAssert((qeip->state == QEI_READY) || (qeip->state == QEI_ACTIVE),
"invalid state");
qei_lld_disable(qeip);
qeip->state = QEI_READY;
osalSysUnlock();
}
/**
* @brief Returns the counter value.
*
* @param[in] qeip pointer to the @p QEIDriver object
* @return The current counter value.
*
* @api
*/
qeicnt_t qeiGetCount(QEIDriver *qeip) {
qeicnt_t cnt;
osalSysLock();
cnt = qeiGetCountI(qeip);
osalSysUnlock();
return cnt;
}
/**
* @brief Set counter value.
*
* @param[in] qeip pointer to the @p QEIDriver object.
* @param[in] value the new counter value.
*
* @api
*/
void qeiSetCount(QEIDriver *qeip, qeicnt_t value) {
osalDbgCheck(qeip != NULL);
osalDbgAssert((qeip->state == QEI_READY) || (qeip->state == QEI_ACTIVE),
"invalid state");
osalSysLock();
qei_lld_set_count(qeip, value);
osalSysUnlock();
}
/**
* @brief Adjust the counter by delta.
*
* @param[in] qeip pointer to the @p QEIDriver object.
* @param[in] delta the adjustement value.
* @return the remaining delta (can occur during overflow).
*
* @api
*/
qeidelta_t qeiAdjust(QEIDriver *qeip, qeidelta_t delta) {
osalDbgCheck(qeip != NULL);
osalDbgAssert((qeip->state == QEI_ACTIVE), "invalid state");
osalSysLock();
delta = qei_lld_adjust_count(qeip, delta);
osalSysUnlock();
return delta;
}
/**
* @brief Returns the counter delta from last reading.
*
* @param[in] qeip pointer to the @p QEIDriver object
* @return The delta from last read.
*
* @api
*/
qeidelta_t qeiUpdate(QEIDriver *qeip) {
qeidelta_t diff;
osalSysLock();
diff = qeiUpdateI(qeip);
osalSysUnlock();
return diff;
}
/**
* @brief Returns the counter delta from last reading.
*
* @param[in] qeip pointer to the @p QEIDriver object
* @return The delta from last read.
*
* @iclass
*/
qeidelta_t qeiUpdateI(QEIDriver *qeip) {
qeicnt_t cnt;
qeidelta_t delta;
osalDbgCheckClassI();
osalDbgCheck(qeip != NULL);
osalDbgAssert((qeip->state == QEI_READY) || (qeip->state == QEI_ACTIVE),
"invalid state");
cnt = qei_lld_get_count(qeip);
delta = cnt - qeip->last;
qeip->last = cnt;
return delta;
}
#endif /* HAL_USE_QEI == TRUE */
/** @} */
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