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#include <stdio.h>
#include <gran/uart/simple_uart.h>
struct simple_uart {
struct component component;
struct component *send;
struct packet pkt;
bool busy;
};
static stat simple_uart_clock(struct simple_uart *uart)
{
if (!uart->busy)
return OK;
stat r = SEND(uart, uart->send, uart->pkt);
if (r == EBUSY)
return OK;
uart->busy = false;
return OK;
}
static stat simple_uart_receive(struct simple_uart *uart, struct component *from, struct packet pkt)
{
if (uart->busy)
return EBUSY;
uart->busy = true;
uart->send = from;
uart->pkt = response(pkt);
size_t size = packet_convsize(&pkt);
if (size != 1) {
set_flags(&uart->pkt, PACKET_ERROR);
return OK;
}
putchar(packet_convu8(&pkt));
set_flags(&uart->pkt, PACKET_DONE);
return OK;
}
struct component *create_simple_uart()
{
struct simple_uart *uart = calloc(1, sizeof(struct simple_uart));
if (!uart)
return NULL;
uart->component.receive = (receive_callback)simple_uart_receive;
uart->component.clock = (clock_callback)simple_uart_clock;
return (struct component *)uart;
}
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