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/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* UART driver for emulator */
#include <pthread.h>
#include <stdio.h>
#include <termio.h>
#include <unistd.h>
#include "board.h"
#include "config.h"
#include "queue.h"
#include "task.h"
#include "uart.h"
static int stopped;
static int int_disabled;
static int init_done;
static pthread_t input_thread;
#define INPUT_BUFFER_SIZE 16
/* TODO: Guard these data with mutex lock when we have interrupt support. */
static int char_available;
static char cached_char_buf[INPUT_BUFFER_SIZE];
static struct queue cached_char = {
.buf_bytes = INPUT_BUFFER_SIZE,
.unit_bytes = sizeof(char),
.buf = cached_char_buf,
};
static void trigger_interrupt(void)
{
/*
* TODO: Check global interrupt status when we have
* interrupt support.
*/
if (!int_disabled)
uart_process();
}
int uart_init_done(void)
{
return init_done;
}
void uart_tx_start(void)
{
stopped = 0;
trigger_interrupt();
}
void uart_tx_stop(void)
{
stopped = 1;
}
int uart_tx_stopped(void)
{
return stopped;
}
void uart_tx_flush(void)
{
/* Nothing */
}
int uart_tx_ready(void)
{
return 1;
}
int uart_rx_available(void)
{
return char_available;
}
void uart_write_char(char c)
{
printf("%c", c);
fflush(stdout);
}
int uart_read_char(void)
{
char ret;
queue_remove_unit(&cached_char, &ret);
--char_available;
return ret;
}
void uart_disable_interrupt(void)
{
int_disabled = 1;
}
void uart_enable_interrupt(void)
{
int_disabled = 0;
}
void *uart_monitor_stdin(void *d)
{
struct termios org_settings, new_settings;
char buf[INPUT_BUFFER_SIZE];
int rv;
tcgetattr(0, &org_settings);
new_settings = org_settings;
new_settings.c_lflag &= ~(ECHO | ICANON);
new_settings.c_cc[VTIME] = 0;
new_settings.c_cc[VMIN] = 1;
printf("Console input initialized\n");
while (1) {
tcsetattr(0, TCSANOW, &new_settings);
rv = read(0, buf, INPUT_BUFFER_SIZE);
if (queue_has_space(&cached_char, rv))
queue_add_units(&cached_char, buf, rv);
char_available = rv;
tcsetattr(0, TCSANOW, &org_settings);
/*
* TODO: Trigger emulated interrupt when we have
* interrupt support. Also, we will need a condition
* variable to indicate the character has been read.
*/
trigger_interrupt();
}
return 0;
}
void uart_init(void)
{
pthread_create(&input_thread, NULL, uart_monitor_stdin, NULL);
init_done = 1;
}
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