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>
33 #define IOBASE lib_sysinfo.ser_ioport
35 #ifdef CONFIG_SERIAL_SET_SPEED
36 #define DIVISOR (115200 / CONFIG_SERIAL_BAUD_RATE)
39 void serial_init(void)
41 #ifdef CONFIG_SERIAL_SET_SPEED
44 /* Disable interrupts */
45 outb(0, IOBASE + 0x01);
47 /* Assert RTS and DTR */
48 outb(3, IOBASE + 0x04);
50 /* Set the divisor latch */
51 reg = inb(IOBASE + 0x03);
52 outb(reg | 0x80, IOBASE + 0x03);
54 /* Write the divisor */
55 outb(DIVISOR & 0xFF, IOBASE);
56 outb(DIVISOR >> 8 & 0xFF, IOBASE + 1);
58 /* Restore the previous value of the divisor */
59 outb(reg &= ~0x80, IOBASE + 0x03);
63 void serial_putchar(unsigned char c)
65 while((inb(IOBASE + 0x05) & 0x20) == 0);
69 int serial_havechar(void)
71 return inb(IOBASE + 0x05) & 0x01;
74 int serial_getchar(void)
76 while (!serial_havechar());
77 return (int) inb(IOBASE);