int SerialBase::read(uint16_t *buffer, int length, const event_callback_t& callback, int event, unsigned char char_match)
{
if (serial_rx_active(&_serial)) {
return -1; // transaction ongoing
}
start_read((void*)buffer, length, 16, callback, event, char_match);
return 0;
}
int SerialBase::read(const Buffer& buffer, const event_callback_t& callback, int event, unsigned char char_match)
{
if (serial_rx_active(&_serial)) {
return -1; // transaction ongoing
}
start_read(buffer, 8, callback, event, char_match);
return 0;
}
/**
* Configure the RX buffer for an asynchronous write serial transaction
*
* @param obj The serial object.
* @param tx The buffer for sending.
* @param tx_length The number of words to transmit.
*/
static void serial_rx_buffer_set(serial_t *obj, void *rx, int rx_length, uint8_t width)
{
(void)width;
// Exit if a reception is already on-going
if (serial_rx_active(obj)) {
return;
}
obj->rx_buff.buffer = rx;
obj->rx_buff.length = rx_length;
obj->rx_buff.pos = 0;
}
void serial_rx_buffer_set(serial_t *obj, void *rx, int rx_length, uint8_t width)
{
/* Sanity check arguments */
MBED_ASSERT(obj);
MBED_ASSERT(rx != (void*)0);
// We only support byte buffers for now
MBED_ASSERT(width == 8);
if(serial_rx_active(obj)) return;
obj->rx_buff.buffer = rx;
obj->rx_buff.length = rx_length;
obj->rx_buff.pos = 0;
return;
}
/** Begin asynchronous RX transfer (enable interrupt for data collecting)
* The used buffer is specified in the serial object - rx_buff
*
* @param obj The serial object
* @param rx The receive buffer
* @param rx_length The number of bytes to receive
* @param rx_width Deprecated argument
* @param handler The serial handler
* @param event The logical OR of events to be registered
* @param handler The serial handler
* @param char_match A character in range 0-254 to be matched
* @param hint A suggestion for how to use DMA with this transfer
*/
void serial_rx_asynch(serial_t *obj, void *rx, size_t rx_length, uint8_t rx_width, uint32_t handler, uint32_t event, uint8_t char_match, DMAUsage hint)
{
struct serial_s *p_obj = GET_SERIAL_S(obj);
IRQn_Type irq = usart_irq_n[p_obj->index];
if ((rx_length == 0) || (rx_width != 8)) {
return;
}
/* disable all events first */
serial_event_disable(obj, SERIAL_EVENT_RX_ALL);
/* enable the specific event */
serial_event_enable(obj, event);
obj->char_match = char_match;
if (serial_rx_active(obj)) {
/* some reception is in progress */
return;
}
obj->rx_buff.buffer = rx;
obj->rx_buff.length = rx_length;
obj->rx_buff.pos = 0;
/* enable interrupt */
/* clear pending IRQ */
NVIC_ClearPendingIRQ(irq);
/* disable the IRQ first */
NVIC_DisableIRQ(irq);
/* set the priority(higher than Tx) and vector */
NVIC_SetPriority(irq, 0);
NVIC_SetVector(irq, (uint32_t)handler);
/* enable IRQ */
NVIC_EnableIRQ(irq);
usart_rx_interrupt_preprocess(p_obj, (uint8_t *)rx, rx_length);
}