bool uart_sps_sw_flow_off(void)
{
bool flow_off = true;
do
{
// First check if no transmission is ongoing
if ((uart_temt_getf() == 0) || (uart_thre_getf() == 0) || !uart_sps_is_rx_fifo_empty())
{
flow_off = false;
break;
}
uart_txdata_setf(UART_XOFF_BYTE);
// Wait for 1 character duration to ensure host has not started a transmission at the
// same time
for (int i=0;i<UART_WAIT_BYTE_COUNTER;i++);
// Check if data has been received during wait time
if(!uart_sps_is_rx_fifo_empty())
{
// Re-enable UART flow
uart_sps_sw_flow_on();
// We failed stopping the flow
flow_off = false;
}
} while(false);
return (flow_off);
}
/**
****************************************************************************************
* @brief Serves the transmit data fill interrupt requests. It clears the requests and
* executes the callback function.
*
* The callback function is called as soon as the last byte of the provided data is
* put into the FIFO. The interrupt is disabled at the same time.
****************************************************************************************
*/
static void uart_thr_empty_isr(void)
{
void (*callback) (uint8_t) = NULL;
// Fill TX FIFO until there is no more room inside it
while (uart_txfifo_full_getf())
{
// Put a byte in the FIFO
uart_txdata_setf(*uart_env.tx.bufptr);
// Update TX parameters
uart_env.tx.size--;
uart_env.tx.bufptr++;
if (uart_env.tx.size == 0)
{
// Reset TX parameters
uart_env.tx.bufptr = NULL;
// Disable TX interrupt
uart_thr_empty_setf(0);
// Retrieve callback pointer
callback = uart_env.tx.callback;
if(callback != NULL)
{
// Clear callback pointer
uart_env.tx.callback = NULL;
// Call handler
callback(UART_STATUS_OK);
}
else
{
ASSERT_ERR(0);
}
// Exit loop
break;
}
}
}
void uart_sps_sw_flow_on(void)
{
uart_txdata_setf(UART_XON_BYTE);
}
/**
****************************************************************************************
* @brief Serves the transmit data fill interrupt requests. It clears the requests and
* executes the callback function. The callback function is called as soon as the
* last byte of the provided data is put into the FIFO. The interrupt is disabled
* at the same time.
*
* @return void
****************************************************************************************
*/
static void uart_sps_thr_empty_isr(void)
{
void (*callback) (uint8_t) = NULL;
// Fill TX FIFO until there is no more room inside it
while (uart_txfifo_full_getf())
{
#if (UART_SW_FLOW_ENABLED)
if(*uart_sps_env.tx.state == UART_NONE)
#endif
{
// Put a byte in the FIFO
uart_txdata_setf(*uart_sps_env.tx.bufptr);
// Update TX parameters
uart_sps_env.tx.size--;
uart_sps_env.tx.bufptr++;
}
#if (UART_SW_FLOW_ENABLED)
else if(*uart_sps_env.tx.state == UART_XOFF)
{
uart_txdata_setf(UART_XOFF_BYTE); //push UART XOFF byte
}
else if (*uart_sps_env.tx.state == UART_XON)
{
uart_txdata_setf(UART_XON_BYTE); //push UART XON byte
}
else //undefined state
{
while(1); //this should never happen
}
*uart_sps_env.tx.state = UART_NONE; //just send data from now on
#endif
if (uart_sps_env.tx.size == 0 && *uart_sps_env.tx.state == UART_NONE)
{
// Reset TX parameters
uart_sps_env.tx.bufptr = NULL;
// Disable TX interrupt
uart_thr_empty_setf(0);
// Retrieve callback pointer
callback = uart_sps_env.tx.callback;
if(callback != NULL)
{
// Clear callback pointer
uart_sps_env.tx.callback = NULL;
// Call handler
callback(UART_STATUS_OK);
}
else
{
ASSERT_ERR(0);
}
// Exit loop
break;
}
}
}
