/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2000,2001,2002,2003,2004,2005,2007,2008,2009,2010 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see .
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#ifdef GRUB_MACHINE_PCBIOS
#include
static const unsigned short *serial_hw_io_addr = (const unsigned short *) GRUB_MEMORY_MACHINE_BIOS_DATA_AREA_ADDR;
#define GRUB_SERIAL_PORT_NUM 4
#else
#include
static const grub_port_t serial_hw_io_addr[] = GRUB_MACHINE_SERIAL_PORTS;
#define GRUB_SERIAL_PORT_NUM (ARRAY_SIZE(serial_hw_io_addr))
#endif
static int dead_ports = 0;
#ifdef GRUB_MACHINE_MIPS_LOONGSON
#define DEFAULT_BASE_CLOCK (2 * 115200)
#else
#define DEFAULT_BASE_CLOCK 115200
#endif
/* Convert speed to divisor. */
static unsigned short
serial_get_divisor (const struct grub_serial_port *port __attribute__ ((unused)),
const struct grub_serial_config *config)
{
grub_uint32_t base_clock;
grub_uint32_t divisor;
grub_uint32_t actual_speed, error;
base_clock = config->base_clock ? (config->base_clock >> 4) : DEFAULT_BASE_CLOCK;
divisor = (base_clock + (config->speed / 2)) / config->speed;
if (divisor > 0xffff || divisor == 0)
return 0;
actual_speed = base_clock / divisor;
error = actual_speed > config->speed ? (actual_speed - config->speed)
: (config->speed - actual_speed);
if (error > (config->speed / 30 + 1))
return 0;
return divisor;
}
static void
do_real_config (struct grub_serial_port *port)
{
int divisor;
unsigned char status = 0;
grub_uint64_t endtime;
const unsigned char parities[] = {
[GRUB_SERIAL_PARITY_NONE] = UART_NO_PARITY,
[GRUB_SERIAL_PARITY_ODD] = UART_ODD_PARITY,
[GRUB_SERIAL_PARITY_EVEN] = UART_EVEN_PARITY
};
const unsigned char stop_bits[] = {
[GRUB_SERIAL_STOP_BITS_1] = UART_1_STOP_BIT,
[GRUB_SERIAL_STOP_BITS_2] = UART_2_STOP_BITS,
};
if (port->configured)
return;
port->broken = 0;
divisor = serial_get_divisor (port, &port->config);
/* Turn off the interrupt. */
grub_outb (0, port->port + UART_IER);
/* Set DLAB. */
grub_outb (UART_DLAB, port->port + UART_LCR);
/* Set the baud rate. */
grub_outb (divisor & 0xFF, port->port + UART_DLL);
grub_outb (divisor >> 8, port->port + UART_DLH);
/* Set the line status. */
status |= (parities[port->config.parity]
| (port->config.word_len - 5)
| stop_bits[port->config.stop_bits]);
grub_outb (status, port->port + UART_LCR);
if (port->config.rtscts)
{
/* Enable the FIFO. */
grub_outb (UART_ENABLE_FIFO_TRIGGER1, port->port + UART_FCR);
/* Turn on DTR and RTS. */
grub_outb (UART_ENABLE_DTRRTS, port->port + UART_MCR);
}
else
{
/* Enable the FIFO. */
grub_outb (UART_ENABLE_FIFO_TRIGGER14, port->port + UART_FCR);
/* Turn on DTR, RTS, and OUT2. */
grub_outb (UART_ENABLE_DTRRTS | UART_ENABLE_OUT2, port->port + UART_MCR);
}
/* Drain the input buffer. */
endtime = grub_get_time_ms () + 1000;
while (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
{
grub_inb (port->port + UART_RX);
if (grub_get_time_ms () > endtime)
{
port->broken = 1;
break;
}
}
port->configured = 1;
}
/* Fetch a key. */
static int
serial_hw_fetch (struct grub_serial_port *port)
{
do_real_config (port);
if (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
return grub_inb (port->port + UART_RX);
return -1;
}
/* Put a character. */
static void
serial_hw_put (struct grub_serial_port *port, const int c)
{
grub_uint64_t endtime;
do_real_config (port);
if (port->broken > 5)
endtime = grub_get_time_ms ();
else if (port->broken > 1)
endtime = grub_get_time_ms () + 50;
else
endtime = grub_get_time_ms () + 200;
/* Wait until the transmitter holding register is empty. */
while ((grub_inb (port->port + UART_LSR) & UART_EMPTY_TRANSMITTER) == 0)
{
if (grub_get_time_ms () > endtime)
{
port->broken++;
/* There is something wrong. But what can I do? */
return;
}
}
if (port->broken)
port->broken--;
grub_outb (c, port->port + UART_TX);
}
/* Initialize a serial device. PORT is the port number for a serial device.
SPEED is a DTE-DTE speed which must be one of these: 2400, 4800, 9600,
19200, 38400, 57600 and 115200. WORD_LEN is the word length to be used
for the device. Likewise, PARITY is the type of the parity and
STOP_BIT_LEN is the length of the stop bit. The possible values for
WORD_LEN, PARITY and STOP_BIT_LEN are defined in the header file as
macros. */
static grub_err_t
serial_hw_configure (struct grub_serial_port *port,
struct grub_serial_config *config)
{
unsigned short divisor;
divisor = serial_get_divisor (port, config);
if (divisor == 0)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unsupported serial port speed"));
if (config->parity != GRUB_SERIAL_PARITY_NONE
&& config->parity != GRUB_SERIAL_PARITY_ODD
&& config->parity != GRUB_SERIAL_PARITY_EVEN)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unsupported serial port parity"));
if (config->stop_bits != GRUB_SERIAL_STOP_BITS_1
&& config->stop_bits != GRUB_SERIAL_STOP_BITS_2)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unsupported serial port stop bits number"));
if (config->word_len < 5 || config->word_len > 8)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unsupported serial port word length"));
port->config = *config;
port->configured = 0;
/* FIXME: should check if the serial terminal was found. */
return GRUB_ERR_NONE;
}
struct grub_serial_driver grub_ns8250_driver =
{
.configure = serial_hw_configure,
.fetch = serial_hw_fetch,
.put = serial_hw_put
};
static char com_names[GRUB_SERIAL_PORT_NUM][20];
static struct grub_serial_port com_ports[GRUB_SERIAL_PORT_NUM];
void
grub_ns8250_init (void)
{
unsigned i;
for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
if (serial_hw_io_addr[i])
{
grub_err_t err;
grub_outb (0x5a, serial_hw_io_addr[i] + UART_SR);
if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0x5a)
{
dead_ports |= (1 << i);
continue;
}
grub_outb (0xa5, serial_hw_io_addr[i] + UART_SR);
if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0xa5)
{
dead_ports |= (1 << i);
continue;
}
grub_snprintf (com_names[i], sizeof (com_names[i]), "com%d", i);
com_ports[i].name = com_names[i];
com_ports[i].driver = &grub_ns8250_driver;
com_ports[i].port = serial_hw_io_addr[i];
err = grub_serial_config_defaults (&com_ports[i]);
if (err)
grub_print_error ();
grub_serial_register (&com_ports[i]);
}
}
/* Return the port number for the UNITth serial device. */
grub_port_t
grub_ns8250_hw_get_port (const unsigned int unit)
{
if (unit < GRUB_SERIAL_PORT_NUM
&& !(dead_ports & (1 << unit)))
return serial_hw_io_addr[unit];
else
return 0;
}
char *
grub_serial_ns8250_add_port (grub_port_t port)
{
struct grub_serial_port *p;
unsigned i;
for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
if (com_ports[i].port == port)
{
if (dead_ports & (1 << i))
return NULL;
return com_names[i];
}
grub_outb (0x5a, port + UART_SR);
if (grub_inb (port + UART_SR) != 0x5a)
return NULL;
grub_outb (0xa5, port + UART_SR);
if (grub_inb (port + UART_SR) != 0xa5)
return NULL;
p = grub_malloc (sizeof (*p));
if (!p)
return NULL;
p->name = grub_xasprintf ("port%lx", (unsigned long) port);
if (!p->name)
{
grub_free (p);
return NULL;
}
p->driver = &grub_ns8250_driver;
grub_serial_config_defaults (p);
p->port = port;
grub_serial_register (p);
return p->name;
}