diff options
Diffstat (limited to 'payloads/libpayload/drivers/serial.c')
-rw-r--r-- | payloads/libpayload/drivers/serial.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/payloads/libpayload/drivers/serial.c b/payloads/libpayload/drivers/serial.c new file mode 100644 index 0000000000..bcf60df614 --- /dev/null +++ b/payloads/libpayload/drivers/serial.c @@ -0,0 +1,78 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2008 Advanced Micro Devices, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <libpayload.h> +#include <sysinfo.h> + +#define IOBASE lib_sysinfo.ser_ioport + +#ifdef CONFIG_SERIAL_SET_SPEED +#define DIVISOR (115200 / CONFIG_SERIAL_BAUD_RATE) +#endif + +void serial_init(void) +{ +#ifdef CONFIG_SERIAL_SET_SPEED + unsigned char reg; + + /* Disable interrupts */ + outb(0, IOBASE + 0x01); + + /* Assert RTS and DTR */ + outb(3, IOBASE + 0x04); + + /* Set the divisor latch */ + reg = inb(IOBASE + 0x03); + outb(reg | 0x80, IOBASE + 0x03); + + /* Write the divisor */ + outb(DIVISOR & 0xFF, IOBASE); + outb(DIVISOR >> 8 & 0xFF, IOBASE + 1); + + /* Restore the previous value of the divisor */ + outb(reg &= ~0x80, IOBASE + 0x03); +#endif +} + +void serial_putchar(unsigned char c) +{ + while((inb(IOBASE + 0x05) & 0x20) == 0); + outb(c, IOBASE); +} + +int serial_havechar(void) +{ + return inb(IOBASE + 0x05) & 0x01; +} + +int serial_getchar(void) +{ + while (!serial_havechar()); + return (int) inb(IOBASE); +} |