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/*
ChibiOS - Copyright (C) 2016..2016 Stéphane D'Alu
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 NRF51/hal_qei_lld.c
* @brief NRF51 QEI subsystem low level driver header.
*
* @addtogroup QEI
* @{
*/
#include "hal.h"
#if (HAL_USE_QEI == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* To be moved in hal_qei */
/*===========================================================================*/
static inline
bool qei_adjust_count(qeicnt_t *count, qeidelta_t *delta,
qeicnt_t min, qeicnt_t max, qeioverflow_t mode) {
// See: https://www.securecoding.cert.org/confluence/display/c/INT32-C.+Ensure+that+operations+on+signed+integers+do+not+result+in+overflow
// 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;
case QEI_OVERFLOW_DISCARD:
*delta = _delta;
*count = _count;
break;
case QEI_OVERFLOW_MINMAX:
*delta = _count - (max - _delta);
*count = max;
break;
}
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;
case QEI_OVERFLOW_DISCARD:
*delta = _delta;
*count = _count;
break;
case QEI_OVERFLOW_MINMAX:
*delta = _count - (min - _delta);
*count = min;
break;
}
return true;
// Normal operation
} else {
*delta = 0;
*count = _count + _delta;
return false;
}
}
/**
* @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 Set counter value
*
* @param[in] qeip pointer to the @p QEIDriver object
* @param[in] value the 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();
}
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/**
* @brief QEID1 driver identifier.
*/
#if NRF51_QEI_USE_QDEC0 || defined(__DOXYGEN__)
QEIDriver QEID1;
#endif
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief Common IRQ handler.
*
* @param[in] qeip pointer to an QEIDriver
*/
static void serve_interrupt(QEIDriver *qeip) {
NRF_QDEC_Type *qdec = qeip->qdec;
/* Accumulator overflowed
*/
if (qdec->EVENTS_ACCOF) {
qdec->EVENTS_ACCOF = 0;
qeip->overflowed++;
if (qeip->config->overflowed_cb)
qeip->config->overflowed_cb(qeip);
}
/* Report ready
*/
if (qdec->EVENTS_REPORTRDY) {
qdec->EVENTS_REPORTRDY = 0;
// Read (and clear counters due to shortcut)
int16_t acc = ( int16_t)qdec->ACCREAD;
uint16_t accdbl = (uint16_t)qdec->ACCDBLREAD;
// Inverse direction if requested
if (qeip->config->dirinv)
acc = -acc; // acc is [-1024..+1023], its okay on int16_t
// Adjust counter
qei_lld_adjust_count(qeip, acc);
}
}
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
#if NRF51_QEI_USE_QDEC0 == TRUE
/**
* @brief Quadrature decoder vector (QDEC)
*
* @isr
*/
OSAL_IRQ_HANDLER(Vector88) {
OSAL_IRQ_PROLOGUE();
serve_interrupt(&QEID1);
OSAL_IRQ_EPILOGUE();
}
#endif
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level QEI driver initialization.
*
* @notapi
*/
void qei_lld_init(void) {
#if NRF51_QEI_USE_QDEC0 == TRUE
/* Driver initialization.*/
qeiObjectInit(&QEID1);
QEID1.qdec = NRF_QDEC;
#endif
}
/**
* @brief Configures and activates the QEI peripheral.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @notapi
*/
void qei_lld_start(QEIDriver *qeip) {
NRF_QDEC_Type *qdec = qeip->qdec;
const QEIConfig *cfg = qeip->config;
if (qeip->state == QEI_STOP) {
// Set Pins
palSetLineMode(cfg->phase_a, PAL_MODE_INPUT);
palSetLineMode(cfg->phase_b, PAL_MODE_INPUT);
#if NRF51_QEI_USE_LED == TRUE
if (cfg->led != PAL_NOLINE) {
palSetLineMode(cfg->led, PAL_MODE_INPUT);
}
#endif
// Set interrupt masks and enable interrupt
qdec->INTENSET = QDEC_INTENSET_REPORTRDY_Msk |
QDEC_INTENSET_ACCOF_Msk;
#if NRF51_QEI_USE_QDEC0 == TRUE
if (&QEID1 == qeip) {
nvicEnableVector(QDEC_IRQn, NRF51_QEI_QDEC0_IRQ_PRIORITY);
}
#endif
// Select pin for Phase A and Phase B
qdec->PSELA = PAL_PAD(cfg->phase_a);
qdec->PSELB = PAL_PAD(cfg->phase_b);
// Select (optional) pin for LED, and configure it
#if NRF51_QEI_USE_LED == TRUE
qdec->PSELLED = PAL_PAD(cfg->led);
qdec->LEDPOL = ((cfg->led_polarity == QEI_LED_POLARITY_LOW)
? QDEC_LEDPOL_LEDPOL_ActiveLow
: QDEC_LEDPOL_LEDPOL_ActiveHigh)
<< QDEC_LEDPOL_LEDPOL_Pos;
qdec->LEDPRE = cfg->led_warming;
#else
qdec->PSELLED = (uint32_t)-1;
#endif
// Set sampling resolution and debouncing
qdec->SAMPLEPER = cfg->resolution;
qdec->DBFEN = (cfg->debouncing ? QDEC_DBFEN_DBFEN_Enabled
: QDEC_DBFEN_DBFEN_Disabled)
<< QDEC_DBFEN_DBFEN_Pos;
// Define minimum sampling before reporting
// and create shortcut to clear accumulation
qdec->REPORTPER = cfg->report;
qdec->SHORTS = QDEC_SHORTS_REPORTRDY_READCLRACC_Msk;
// Enable peripheric
qdec->ENABLE = 1;
}
// Initially state is stopped, events cleared
qdec->TASKS_STOP = 1;
qdec->EVENTS_SAMPLERDY = 0;
qdec->EVENTS_REPORTRDY = 0;
qdec->EVENTS_ACCOF = 0;
}
/**
* @brief Deactivates the QEI peripheral.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @notapi
*/
void qei_lld_stop(QEIDriver *qeip) {
NRF_QDEC_Type *qdec = qeip->qdec;
const QEIConfig *cfg = qeip->config;
if (qeip->state == QEI_READY) {
qdec->TASKS_STOP = 1;
qdec->ENABLE = 0;
#if NRF51_QEI_USE_QDEC0 == TRUE
if (&QEID1 == qeip) {
nvicDisableVector(QDEC_IRQn);
}
#endif
qdec->INTENCLR = QDEC_INTENSET_REPORTRDY_Msk |
QDEC_INTENSET_ACCOF_Msk;
// Return pins to reset state
palSetLineMode(cfg->phase_a, PAL_MODE_RESET);
palSetLineMode(cfg->phase_b, PAL_MODE_RESET);
#if NRF51_QEI_USE_LED == TRUE
if (cfg->led != PAL_NOLINE) {
palSetLineMode(cfg->led, PAL_MODE_RESET);
}
#endif
}
}
/**
* @brief Enables the input capture.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @notapi
*/
void qei_lld_enable(QEIDriver *qeip) {
qeip->overflowed = 0;
qeip->qdec->EVENTS_SAMPLERDY = 0;
qeip->qdec->EVENTS_REPORTRDY = 0;
qeip->qdec->EVENTS_ACCOF = 0;
qeip->qdec->TASKS_START = 1;
}
/**
* @brief Disables the input capture.
*
* @param[in] qeip pointer to the @p QEIDriver object
*
* @notapi
*/
void qei_lld_disable(QEIDriver *qeip) {
qeip->qdec->TASKS_STOP = 1;
}
/**
* @brief Adjust counter
*
* @param[in] qeip pointer to the @p QEIDriver object
* @param[in] delta value to use for adjustement
* @return remaining adjustement that were not applied
*
* @notapi
*/
qeidelta_t qei_lld_adjust_count(QEIDriver *qeip, qeidelta_t delta) {
// Get boundaries
qeicnt_t min = QEI_COUNT_MIN;
qeicnt_t max = QEI_COUNT_MAX;
if (qeip->config->min != qeip->config->max) {
min = qeip->config->min;
max = qeip->config->max;
}
// Snapshot counter for later comparison
qeicnt_t count = qeip->count;
// Adjust counter value
bool overflowed = qei_adjust_count(&qeip->count, &delta,
min, max, qeip->config->overflow);
// Notify for value change
if ((qeip->count != count) && qeip->config->notify_cb)
qeip->config->notify_cb(qeip);
// Notify for overflow (passing the remaining delta)
if (overflowed && qeip->config->overflow_cb)
qeip->config->overflow_cb(qeip, delta);
// Remaining delta
return delta;
}
#endif /* HAL_USE_QEI */
/** @} */
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