/**
* @brief Start CCA.
*
* @param parameter Pointer to trx_id
*/
static void cca_start(void *parameter)
{
trx_id_t trx_id = *(trx_id_t *)parameter;
/* Check if trx is currently detecting a frame ota */
if (trx_state[trx_id] == RF_RX) {
uint16_t reg_offset = RF_BASE_ADDR_OFFSET * trx_id;
uint8_t agc_freeze
= trx_bit_read(reg_offset + SR_RF09_AGCC_FRZS);
if (agc_freeze) {
csma_continue(trx_id);
} else {
#ifdef SUPPORT_MODE_SWITCH
if (tal_pib[trx_id].ModeSwitchEnabled) {
trigger_cca_meaurement(trx_id);
} else
#endif
{
transmit_frame(trx_id, WITH_CCA);
}
}
} else {
#ifdef SUPPORT_MODE_SWITCH
if (tal_pib[trx_id].ModeSwitchEnabled) {
trigger_cca_meaurement(trx_id);
} else
#endif
{
transmit_frame(trx_id, WITH_CCA);
}
}
}
/**
* @brief Callback function for CCA completion.
*
* @param trx_id Transceiver identifier
*/
void cca_done_handling(trx_id_t trx_id)
{
switch_to_txprep(trx_id); /* Leave state Rx */
/* Switch BB on again */
uint16_t reg_offset = RF_BASE_ADDR_OFFSET * trx_id;
trx_bit_write(reg_offset + SR_BBC0_PC_BBEN, 1);
/* Determine if channel is idle */
if (tal_current_ed_val[trx_id] < tal_pib[trx_id].CCAThreshold) {
/* Idle */
tx_ms_ppdu(trx_id);
} else {
/* Busy */
csma_continue(trx_id);
}
}
/*
* \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() */
