/**
* @brief Can frame receive.
* @details The function waits until a frame is received.
* @note Trying to receive while in sleep mode simply enqueues the thread.
*
* @param[in] canp pointer to the @p CANDriver object
* @param[in] mailbox mailbox number, @p CAN_ANY_MAILBOX for any mailbox
* @param[out] crfp pointer to the buffer where the CAN frame is copied
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout (useful in an
* event driven scenario where a thread never blocks
* for I/O).
* - @a TIME_INFINITE no timeout.
* .
* @return The operation result.
* @retval MSG_OK a frame has been received and placed in the buffer.
* @retval MSG_TIMEOUT The operation has timed out.
* @retval MSG_RESET The driver has been stopped while waiting.
*
* @api
*/
msg_t canReceiveTimeout(CANDriver *canp,
canmbx_t mailbox,
CANRxFrame *crfp,
systime_t timeout) {
osalDbgCheck((canp != NULL) && (crfp != NULL) &&
(mailbox <= (canmbx_t)CAN_RX_MAILBOXES));
osalSysLock();
osalDbgAssert((canp->state == CAN_READY) || (canp->state == CAN_SLEEP),
"invalid state");
/*lint -save -e9007 [13.5] Right side is supposed to be pure.*/
while ((canp->state == CAN_SLEEP) || !can_lld_is_rx_nonempty(canp, mailbox)) {
/*lint -restore*/
msg_t msg = osalThreadEnqueueTimeoutS(&canp->rxqueue, timeout);
if (msg != MSG_OK) {
osalSysUnlock();
return msg;
}
}
can_lld_receive(canp, mailbox, crfp);
osalSysUnlock();
return MSG_OK;
}
/**
* @brief Can frame receive attempt.
* @details The function tries to fetch a frame from a mailbox.
*
* @param[in] canp pointer to the @p CANDriver object
* @param[in] mailbox mailbox number, @p CAN_ANY_MAILBOX for any mailbox
* @param[out] crfp pointer to the buffer where the CAN frame is copied
* @return The operation result.
* @retval false Frame fetched.
* @retval true Mailbox empty.
*
* @iclass
*/
bool canTryReceiveI(CANDriver *canp,
canmbx_t mailbox,
CANRxFrame *crfp) {
osalDbgCheckClassI();
osalDbgCheck((canp != NULL) && (crfp != NULL) &&
(mailbox <= (canmbx_t)CAN_RX_MAILBOXES));
osalDbgAssert((canp->state == CAN_READY) || (canp->state == CAN_SLEEP),
"invalid state");
/* If the RX mailbox is empty then the function fails.*/
if (!can_lld_is_rx_nonempty(canp, mailbox)) {
return true;
}
/* Fetching the frame.*/
can_lld_receive(canp, mailbox, crfp);
return false;
}
/**
* @brief Can frame receive.
* @details The function waits until a frame is received.
* @note Trying to receive while in sleep mode simply enqueues the thread.
*
* @param[in] canp pointer to the @p CANDriver object
* @param[in] mailbox mailbox number, @p CAN_ANY_MAILBOX for any mailbox
* @param[out] crfp pointer to the buffer where the CAN frame is copied
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout (useful in an
* event driven scenario where a thread never blocks
* for I/O).
* - @a TIME_INFINITE no timeout.
* .
* @return The operation result.
* @retval MSG_OK a frame has been received and placed in the buffer.
* @retval MSG_TIMEOUT The operation has timed out.
* @retval MSG_RESET The driver has been stopped while waiting.
*
* @api
*/
msg_t canReceive(CANDriver *canp,
canmbx_t mailbox,
CANRxFrame *crfp,
systime_t timeout) {
osalDbgCheck((canp != NULL) && (crfp != NULL) &&
(mailbox < CAN_RX_MAILBOXES));
osalSysLock();
osalDbgAssert((canp->state == CAN_READY) || (canp->state == CAN_SLEEP),
"invalid state");
while ((canp->state == CAN_SLEEP) || !can_lld_is_rx_nonempty(canp, mailbox)) {
msg_t msg = osalThreadEnqueueTimeoutS(&canp->rxqueue, timeout);
if (msg != MSG_OK) {
osalSysUnlock();
return msg;
}
}
can_lld_receive(canp, mailbox, crfp);
osalSysUnlock();
return MSG_OK;
}