int uart_send(uint8_t num, char c)
{
/* if cannot send the char */
if (uart_send_nowait(num, c) == -1) {
/* if irq lock are masked and interrupt mode is on, we
* have to poll the status register */
if (GLOBAL_IRQ_ARE_MASKED() && (*uart_regs[num].REGISTER_FOR_UART_IE & (1 << RXCIE)) ) {
while( !(*uart_regs[num].ucsra & (1 << UDRE)) );
/* send the next char in the fifo to free a
* place */
uart_send_next_char(num);
cirbuf_add_head(&g_tx_fifo[num], c);
}
else {
/* if irq are not locked, we can loop to emit */
while(uart_send_nowait(num, c) == -1);
}
}
return 0;
}
int uart_send(uart_t *u, uint8_t v)
{
while(uart_send_nowait(u, v) < 0) {
if( !(CPU_SREG & CPU_I_bm) || !(PMIC.CTRL & INTLVL_BM(UART_INTLVL)) || (PMIC.STATUS & INTLVL_BM(UART_INTLVL)) ) {
// UART interrupt disabled or blocked, avoid deadlock
while( !(u->usart->STATUS & USART_DREIF_bm) ) ;
// pop one byte from the buffer, should be the last iteration
uart_send_buf_byte(u);
}
}
return 0;
}
