/**
* \brief Get byte from UART.
*
* \param chn Communication channel [0, 1]
*
* \retval Byte received
* \retval -1 in case of no reception
*/
int buart_if_rx_char(uint8_t chn)
{
uint8_t buf[4] = {0, 0, 0, 0};
if (buart_if_read(chn, buf, 1) <= 0) {
return (-1);
}
return buf[0];
}
/**
* \brief Function to perform the USI RX process.
*/
void usi_process(void)
{
uint8_t i;
int nr_ch = 0;
uint8_t uc_delimiter = MSGMARK;
uint8_t *puc_next_token;
uint8_t *puc_rx_aux;
uint16_t us_token_size;
/* Check reception on every port */
for (i = 0; i < NUM_PORTS; i++) {
puc_rx_aux = &usi_cfg_aux_rx_buf[i].puc_buf[0];
/* Read all the data in the respective buffer (UART or USART) */
if (usi_cfg_map_ports[i].uc_s_type == UART_TYPE) {
nr_ch = buart_if_read(usi_cfg_map_ports[i].uc_chn, puc_rx_aux,
usi_cfg_map_ports[i].us_rx_size);
} else if (usi_cfg_map_ports[i].uc_s_type == USART_TYPE) {
nr_ch = busart_if_read(usi_cfg_map_ports[i].uc_chn, puc_rx_aux,
usi_cfg_map_ports[i].us_rx_size);
}
/* Go through the received data */
while (nr_ch > 0) {
/* Process received data */
puc_next_token = memchr(puc_rx_aux, uc_delimiter, nr_ch);
/* If token found */
if (puc_next_token != NULL) {
/* Update token size */
us_token_size = (puc_next_token - puc_rx_aux);
/* Skip the MSGMARK(s) */
if (us_token_size == 0) {
puc_rx_aux++;
nr_ch--;
uc_message_status = 1 - uc_message_status;
/* Corner case: the data starts with two MSGMARKs: one to close
* the previously received incomplete message, and the following
* to start a new one. */
if ((uc_message_status == MSG_END) && (usi_cfg_rx_buf[i].us_size > 0)) {
if (puc_rx_aux[0] == MSGMARK) {
if (_doEoMsg(i)) {
/* CRC is OK: process the message */
if (_process_msg(i)) {
if (usi_cfg_param[i].us_rx_block_timer != 0) {
/* Send internal command CMD_UNLOCK_PORT */
internal_command.puc_buf = &uc_int_cmd_unlock;
if (_usi_encode_and_send(i, &internal_command)) {
usi_cfg_param[i].us_rx_block_timer = 0;
}
}
} else {
if (usi_cfg_param[i].us_rx_block_timer == 0) {
/* Send internal command CMD_LOCK_PORT */
internal_command.puc_buf = &uc_int_cmd_lock;
if (_usi_encode_and_send(i, &internal_command)) {
usi_cfg_param[i].us_rx_block_timer = RX_BLOCK_TIMEOUT;
}
}
}
}
} else {
/* The next byte is not a MSGMARK: the incomplete data in
* puc_rx_buf is discarded */
uc_message_status = 1 - uc_message_status;
}
/* Update the buffer pointers and sizes */
usi_cfg_rx_buf[i].us_size = 0;
puc_rx_aux += us_token_size;
nr_ch -= us_token_size;
}
} else {
/* If a message or part of an incomplete message is expected */
if (uc_message_status == MSG_START) {
/* Compose the whole message */
usi_cfg_rx_buf[i].us_size += _decode_copy(&usi_cfg_rx_buf[i].puc_buf[0] + usi_cfg_rx_buf[i].us_size,
puc_rx_aux, us_token_size);
/* Calculate CRC */
if (_doEoMsg(i)) {
/* CRC is OK: process the message */
if (_process_msg(i)) {
/* If port was previously blocked, send message to indicate
* that now it is open. */
if (usi_cfg_param[i].us_rx_block_timer != 0) {
/* Send internal command CMD_UNLOCK_PORT */
internal_command.puc_buf = &uc_int_cmd_unlock;
if (_usi_encode_and_send(i, &internal_command)) {
/* If sent, change block status so message is not
* sent again. */
usi_cfg_param[i].us_rx_block_timer = 0;
}
}
} else {
/* Message could not be processed. Send Flow Control message
* to block port. */
if (usi_cfg_param[i].us_rx_block_timer == 0) {
/* Send internal command CMD_LOCK_PORT */
internal_command.puc_buf = &uc_int_cmd_lock;
if (_usi_encode_and_send(i, &internal_command)) {
/* If sent, change block status so message is not
* sent again. */
usi_cfg_param[i].us_rx_block_timer = RX_BLOCK_TIMEOUT;
}
}
}
}
} else {
/* USI protocol error: discard */
}
/* Update the buffer pointers and sizes */
usi_cfg_rx_buf[i].us_size = 0;
puc_rx_aux += us_token_size;
nr_ch -= us_token_size;
}
} /* end if (puc_next_token != NULL) */
else { /* No token found */
if (uc_message_status == MSG_START) {
usi_cfg_rx_buf[i].us_size
+= _decode_copy(&usi_cfg_rx_buf[i].puc_buf[0] + usi_cfg_rx_buf[i].us_size,
puc_rx_aux, nr_ch);
} else {
/* USI protocol error: discard */
}
nr_ch = 0;
}
} /* end while (nr_ch > 0) */
} /* end for (i = 0; i < NUM_PORTS; i++) */
}
