coreboot-kgpe-d16/payloads/libpayload/drivers/serial/8250.c

172 lines
4.5 KiB
C

/*
* This file is part of the libpayload project.
*
* Copyright (C) 2008 Advanced Micro Devices, Inc.
* Copyright (C) 2008 Ulf Jordan <jordan@chalmers.se>
*
* 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-config.h>
#include <libpayload.h>
#define IOBASE lib_sysinfo.serial->baseaddr
#define MEMBASE (phys_to_virt(IOBASE))
static int serial_hardware_is_present = 0;
static int serial_is_mem_mapped = 0;
static uint8_t serial_read_reg(int offset)
{
offset *= lib_sysinfo.serial->regwidth;
#if CONFIG(LP_IO_ADDRESS_SPACE)
if (!serial_is_mem_mapped)
return inb(IOBASE + offset);
else
#endif
if (lib_sysinfo.serial->regwidth == 4)
return readl(MEMBASE + offset) & 0xff;
else
return readb(MEMBASE + offset);
}
static void serial_write_reg(uint8_t val, int offset)
{
offset *= lib_sysinfo.serial->regwidth;
#if CONFIG(LP_IO_ADDRESS_SPACE)
if (!serial_is_mem_mapped)
outb(val, IOBASE + offset);
else
#endif
if (lib_sysinfo.serial->regwidth == 4)
writel(val & 0xff, MEMBASE + offset);
else
writeb(val, MEMBASE + offset);
}
#if CONFIG(LP_SERIAL_SET_SPEED)
static void serial_hardware_init(int speed, int word_bits,
int parity, int stop_bits)
{
unsigned char reg;
#if !CONFIG(LP_PL011_SERIAL_CONSOLE)
/* Disable interrupts. */
serial_write_reg(0, 0x01);
/* Assert RTS and DTR. */
serial_write_reg(3, 0x04);
/* Set the divisor latch. */
reg = serial_read_reg(0x03);
serial_write_reg(reg | 0x80, 0x03);
/* Write the divisor. */
uint16_t divisor = 115200 / speed;
serial_write_reg(divisor & 0xFF, 0x00);
serial_write_reg(divisor >> 8, 0x01);
/* Restore the previous value of the divisor.
* And set 8 bits per character */
serial_write_reg((reg & ~0x80) | 3, 0x03);
#endif
}
#endif
static struct console_input_driver consin = {
.havekey = &serial_havechar,
.getchar = &serial_getchar
};
static struct console_output_driver consout = {
.putchar = &serial_putchar
};
void serial_init(void)
{
if (!lib_sysinfo.serial)
return;
serial_is_mem_mapped =
(lib_sysinfo.serial->type == CB_SERIAL_TYPE_MEMORY_MAPPED);
if (!serial_is_mem_mapped) {
#if CONFIG(LP_IO_ADDRESS_SPACE)
if ((inb(IOBASE + 0x05) == 0xFF) &&
(inb(IOBASE + 0x06) == 0xFF)) {
printf("IO space mapped serial not present.");
return;
}
#else
printf("IO space mapped serial not supported.");
return;
#endif
}
#if CONFIG(LP_SERIAL_SET_SPEED)
serial_hardware_init(CONFIG_LP_SERIAL_BAUD_RATE, 8, 0, 1);
#endif
}
void serial_console_init(void)
{
if (!lib_sysinfo.serial)
return;
serial_init();
serial_hardware_is_present = 1;
console_add_input_driver(&consin);
console_add_output_driver(&consout);
}
void serial_putchar(unsigned int c)
{
if (!serial_hardware_is_present)
return;
#if !CONFIG(LP_PL011_SERIAL_CONSOLE)
while ((serial_read_reg(0x05) & 0x20) == 0) ;
#endif
serial_write_reg(c, 0x00);
if (c == '\n')
serial_putchar('\r');
}
int serial_havechar(void)
{
if (!serial_hardware_is_present)
return 0;
return serial_read_reg(0x05) & 0x01;
}
int serial_getchar(void)
{
if (!serial_hardware_is_present)
return -1;
while (!serial_havechar()) ;
return serial_read_reg(0x00);
}