/*
* \brief TAL task handling
*
* This function
* - Checks and allocates the receive buffer.
* - Processes the TAL incoming frame queue.
* - Implements the TAL state machine.
*/
void tal_task(void)
{
/* Check if the receiver needs to be switched on. */
if (tal_rx_on_required && (tal_state == TAL_IDLE))
{
/* Check if a receive buffer has not been available before. */
if (tal_rx_buffer == NULL)
{
tal_rx_buffer = bmm_buffer_alloc(LARGE_BUFFER_SIZE);
}
/* Check if buffer could be allocated */
if (NULL != tal_rx_buffer)
{
/*
* Note:
* This flag needs to be reset BEFORE the received is switched on.
*/
tal_rx_on_required = false;
#ifdef PROMISCUOUS_MODE
if (tal_pib.PromiscuousMode)
{
set_trx_state(CMD_RX_ON);
}
else
{
set_trx_state(CMD_RX_AACK_ON);
}
#else /* Normal operation */
set_trx_state(CMD_RX_AACK_ON);
#endif
}
}
else
{
/* no free buffer is available; try next time again */
}
/*
* If the transceiver has received a frame and it has been placed
* into the queue of the TAL, the frame needs to be processed further.
*/
if (tal_incoming_frame_queue.size > 0)
{
buffer_t *rx_frame;
/* Check if there are any pending data in the incoming_frame_queue. */
rx_frame = qmm_queue_remove(&tal_incoming_frame_queue, NULL);
if (NULL != rx_frame)
{
process_incoming_frame(rx_frame);
}
}
/* Handle the TAL state machines */
switch (tal_state)
{
case TAL_IDLE:
/* Do nothing, but fall through... */
case TAL_TX_AUTO:
/* Wait until state is changed to TAL_TX_DONE inside tx end ISR */
break;
#ifdef SW_CONTROLLED_CSMA
case TAL_BACKOFF:
/* Do nothing, but fall through... */
case TAL_CCA:
/* Do nothing */
break;
case TAL_CSMA_CONTINUE:
csma_continue();
break;
case TAL_CCA_DONE:
cca_done_handling();
break;
#endif
case TAL_TX_DONE:
tx_done_handling(); // see tal_tx.c
break;
#ifdef BEACON_SUPPORT
case TAL_SLOTTED_CSMA:
slotted_csma_state_handling(); // see tal_slotted_csma.c
break;
#endif /* BEACON_SUPPORT */
#if (MAC_SCAN_ED_REQUEST_CONFIRM == 1)
case TAL_ED_RUNNING:
/* Do nothing here. Wait until ED is completed. */
break;
case TAL_ED_DONE:
ed_scan_done();
break;
#endif /* (MAC_SCAN_ED_REQUEST_CONFIRM == 1) */
default:
Assert("tal_state is not handled" == 0);
break;
}
} /* tal_task() */
/*
* \brief TAL task handling
*
* This function
* - Checks and allocates the receive buffer.
* - Processes the TAL incoming frame queue.
* - Implements the TAL state machine.
*/
void tal_task(void)
{
/* Check if the receiver needs to be switched on. */
if (tal_rx_on_required && (tal_state == TAL_IDLE)) {
/* Check if a receive buffer has not been available before. */
if (tal_rx_buffer == NULL) {
tal_rx_buffer = bmm_buffer_alloc(LARGE_BUFFER_SIZE);
}
/* Check if buffer could be allocated */
if (NULL != tal_rx_buffer) {
/*
* Note:
* This flag needs to be reset BEFORE the received is
*switched on.
*/
tal_rx_on_required = false;
/*
* Release the protected buffer and set it again for
*further protection
* since the buffer is available now.
*/
trx_bit_write(SR_RX_SAFE_MODE, RX_SAFE_MODE_DISABLE); /*
*Disable
*buffer
*protection
*mode
**/
pal_timer_delay(2); /* Allow pin change to get effective */
trx_bit_write(SR_RX_SAFE_MODE, RX_SAFE_MODE_ENABLE); /*
*Enable
*buffer
*protection
*mode
**/
CONF_REG_WRITE();
#ifdef PROMISCUOUS_MODE
if (tal_pib.PromiscuousMode) {
set_trx_state(CMD_RX_ON);
} else {
set_trx_state(CMD_RX_AACK_ON);
}
#else /* Normal operation */
set_trx_state(CMD_RX_AACK_ON);
#endif
}
} else {
/* no free buffer is available; try next time again */
}
/*
* If the transceiver has received a frame and it has been placed
* into the queue of the TAL, the frame needs to be processed further.
*/
if (tal_incoming_frame_queue.size > 0) {
buffer_t *rx_frame;
/* Check if there are any pending data in the
*incoming_frame_queue. */
rx_frame = qmm_queue_remove(&tal_incoming_frame_queue, NULL);
if (NULL != rx_frame) {
process_incoming_frame(rx_frame);
}
}
/* Handle the TAL state machines */
switch (tal_state) {
case TAL_IDLE:
/* Do nothing, but fall through... */
case TAL_TX_AUTO:
/* Wait until state is changed to TAL_TX_DONE inside tx end ISR
**/
break;
case TAL_TX_DONE:
tx_done_handling(); /* see tal_tx.c */
break;
#ifdef BEACON_SUPPORT
case TAL_SLOTTED_CSMA:
slotted_csma_state_handling(); /* see tal_slotted_csma.c */
break;
#endif /* BEACON_SUPPORT */
#if (MAC_SCAN_ED_REQUEST_CONFIRM == 1)
case TAL_ED_RUNNING:
/* Do nothing here. Wait until ED is completed. */
break;
case TAL_ED_DONE:
ed_scan_done();
break;
#endif /* (MAC_SCAN_ED_REQUEST_CONFIRM == 1) */
default:
Assert("tal_state is not handled" == 0);
break;
}
} /* tal_task() */
/**
* @brief Starts the timer for the backoff period and enables receiver.
*
* @param trx_id Transceiver identifier
*/
static void start_backoff(trx_id_t trx_id)
{
/* Start backoff timer to trigger CCA */
uint8_t backoff_8;
backoff_8 = (uint8_t)(rand() & (((uint16_t)1 << BE[trx_id]) - 1));
if (backoff_8 > 0) {
uint8_t timer_id;
uint16_t backoff_16;
uint32_t backoff_duration_us;
backoff_16 = backoff_8 * aUnitBackoffPeriod;
backoff_duration_us
= (uint32_t)tal_pib[trx_id].SymbolDuration_us *
(uint32_t)backoff_16;
#ifdef REDUCED_BACKOFF_DURATION
backoff_duration_us = REDUCED_BACKOFF_DURATION;
#endif
if (trx_id == RF09) {
timer_id = TAL_T_0;
} else {
timer_id = TAL_T_1;
}
retval_t status
= pal_timer_start(timer_id, backoff_duration_us,
TIMEOUT_RELATIVE,
(FUNC_PTR)cca_start,
(void *)&timer_cb_parameter[trx_id]);
if (status != MAC_SUCCESS) {
tx_done_handling(trx_id, status);
return;
}
tx_state[trx_id] = TX_BACKOFF;
#ifdef RX_WHILE_BACKOFF
/* Keep receiver on during backoff */
if ((trx_default_state[trx_id] == RF_RX) &&
(tal_pib[trx_id].NumRxFramesDuringBackoff <
tal_pib[trx_id].MaxNumRxFramesDuringBackoff)) {
if (trx_state[trx_id] != RF_RX) {
if (trx_state[trx_id] == RF_TRXOFF) {
switch_to_txprep(trx_id);
}
switch_to_rx(trx_id);
}
} else
#endif
{
#ifdef USE_TXPREP_DURING_BACKOFF
/* Switch to TXPREP during backoff */
if (trx_state[trx_id] != RF_TXPREP) {
switch_to_txprep(trx_id);
}
#else
/* Switch to TRXOFF during backoff */
if (trx_state[trx_id] != RF_TRXOFF) {
uint16_t reg_offset = RF_BASE_ADDR_OFFSET *
trx_id;
trx_reg_write(reg_offset + RG_RF09_CMD,
RF_TRXOFF);
trx_state[trx_id] = RF_TRXOFF;
}
#endif
}
} else { /* no backoff required */
/* Start CCA immediately - no backoff */
cca_start((void *)&timer_cb_parameter[trx_id]);
}
}
