2 * This file is part of the libpayload project.
4 * Copyright (C) 2008 Advanced Micro Devices, Inc.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <libpayload.h>
32 #define IOBASE lib_sysinfo.ser_ioport
34 #ifdef CONFIG_SERIAL_SET_SPEED
35 #define DIVISOR (115200 / CONFIG_SERIAL_BAUD_RATE)
38 void serial_init(void)
40 #ifdef CONFIG_SERIAL_SET_SPEED
43 /* Disable interrupts. */
44 outb(0, IOBASE + 0x01);
46 /* Assert RTS and DTR. */
47 outb(3, IOBASE + 0x04);
49 /* Set the divisor latch. */
50 reg = inb(IOBASE + 0x03);
51 outb(reg | 0x80, IOBASE + 0x03);
53 /* Write the divisor. */
54 outb(DIVISOR & 0xFF, IOBASE);
55 outb(DIVISOR >> 8 & 0xFF, IOBASE + 1);
57 /* Restore the previous value of the divisor. */
58 outb(reg &= ~0x80, IOBASE + 0x03);
62 void serial_putchar(unsigned char c)
64 while ((inb(IOBASE + 0x05) & 0x20) == 0) ;
68 int serial_havechar(void)
70 return inb(IOBASE + 0x05) & 0x01;
73 int serial_getchar(void)
75 while (!serial_havechar()) ;
76 return (int)inb(IOBASE);