/************************************
* TRANSFER FUNCTIONS *
***********************************/
int serial_tx_asynch(serial_t *obj, const void *tx, size_t tx_length, uint8_t tx_width, uint32_t handler, uint32_t event, DMAUsage hint)
{
/* Sanity check arguments */
MBED_ASSERT(obj);
MBED_ASSERT(tx != (void*)0);
if(tx_length == 0) return 0;
serial_tx_buffer_set(obj, (void *)tx, tx_length, tx_width);
serial_tx_enable_event(obj, event, true);
NVIC_ClearPendingIRQ(get_serial_irq_num(obj));
NVIC_DisableIRQ(get_serial_irq_num(obj));
NVIC_SetVector(get_serial_irq_num(obj), (uint32_t)handler);
NVIC_EnableIRQ(get_serial_irq_num(obj));
if (pUSART_S(obj)) {
_USART(obj).INTENCLR.reg = SERCOM_USART_INTFLAG_TXC;
_USART(obj).INTENSET.reg = SERCOM_USART_INTFLAG_DRE;
}
return 0;
}
/**
* Begin asynchronous TX transfer. The used buffer is specified in the serial
* object, tx_buff
*
* @param obj The serial object
* @param tx The buffer for sending
* @param tx_length The number of words to transmit
* @param tx_width The bit width of buffer word
* @param handler The serial handler
* @param event The logical OR of events to be registered
* @param hint A suggestion for how to use DMA with this transfer
* @return Returns number of data transfered, or 0 otherwise
*/
int serial_tx_asynch(serial_t *obj, const void *tx, size_t tx_length, uint8_t tx_width, uint32_t handler, uint32_t event, DMAUsage hint)
{
// TODO: DMA usage is currently ignored
(void) hint;
// Check buffer is ok
MBED_ASSERT(tx != (void*)0);
MBED_ASSERT(tx_width == 8); // support only 8b width
struct serial_s *obj_s = SERIAL_S(obj);
UART_HandleTypeDef * huart = &uart_handlers[obj_s->index];
if (tx_length == 0) {
return 0;
}
// Set up buffer
serial_tx_buffer_set(obj, (void *)tx, tx_length, tx_width);
// Set up events
serial_enable_event(obj, SERIAL_EVENT_TX_ALL, 0); // Clear all events
serial_enable_event(obj, event, 1); // Set only the wanted events
// Enable interrupt
IRQn_Type irq_n = serial_get_irq_n(obj);
NVIC_ClearPendingIRQ(irq_n);
NVIC_DisableIRQ(irq_n);
NVIC_SetPriority(irq_n, 1);
NVIC_SetVector(irq_n, (uint32_t)handler);
NVIC_EnableIRQ(irq_n);
// the following function will enable UART_IT_TXE and error interrupts
if (HAL_UART_Transmit_IT(huart, (uint8_t*)tx, tx_length) != HAL_OK) {
return 0;
}
return tx_length;
}
