u-boot/cpu/i386/serial.c

503 lines
12 KiB
C

/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, daniel@omicron.se
*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program 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 2 of
* the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*------------------------------------------------------------------------------+ */
/*
* This source code has been made available to you by IBM on an AS-IS
* basis. Anyone receiving this source is licensed under IBM
* copyrights to use it in any way he or she deems fit, including
* copying it, modifying it, compiling it, and redistributing it either
* with or without modifications. No license under IBM patents or
* patent applications is to be implied by the copyright license.
*
* Any user of this software should understand that IBM cannot provide
* technical support for this software and will not be responsible for
* any consequences resulting from the use of this software.
*
* Any person who transfers this source code or any derivative work
* must include the IBM copyright notice, this paragraph, and the
* preceding two paragraphs in the transferred software.
*
* COPYRIGHT I B M CORPORATION 1995
* LICENSED MATERIAL - PROGRAM PROPERTY OF I B M
*/
/*------------------------------------------------------------------------------- */
#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <asm/ibmpc.h>
#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
#include <malloc.h>
#endif
DECLARE_GLOBAL_DATA_PTR;
#define UART_RBR 0x00
#define UART_THR 0x00
#define UART_IER 0x01
#define UART_IIR 0x02
#define UART_FCR 0x02
#define UART_LCR 0x03
#define UART_MCR 0x04
#define UART_LSR 0x05
#define UART_MSR 0x06
#define UART_SCR 0x07
#define UART_DLL 0x00
#define UART_DLM 0x01
/*-----------------------------------------------------------------------------+
| Line Status Register.
+-----------------------------------------------------------------------------*/
#define asyncLSRDataReady1 0x01
#define asyncLSROverrunError1 0x02
#define asyncLSRParityError1 0x04
#define asyncLSRFramingError1 0x08
#define asyncLSRBreakInterrupt1 0x10
#define asyncLSRTxHoldEmpty1 0x20
#define asyncLSRTxShiftEmpty1 0x40
#define asyncLSRRxFifoError1 0x80
#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
/*-----------------------------------------------------------------------------+
| Fifo
+-----------------------------------------------------------------------------*/
typedef struct {
char *rx_buffer;
ulong rx_put;
ulong rx_get;
int cts;
} serial_buffer_t;
volatile serial_buffer_t buf_info;
static int serial_buffer_active=0;
#endif
static int serial_div(int baudrate)
{
switch (baudrate) {
case 1200:
return 96;
case 9600:
return 12;
case 19200:
return 6;
case 38400:
return 3;
case 57600:
return 2;
case 115200:
return 1;
}
return 12;
}
/*
* Minimal serial functions needed to use one of the SMC ports
* as serial console interface.
*/
int serial_init(void)
{
volatile char val;
int bdiv = serial_div(gd->baudrate);
outb(0x80, UART0_BASE + UART_LCR); /* set DLAB bit */
outb(bdiv, UART0_BASE + UART_DLL); /* set baudrate divisor */
outb(bdiv >> 8, UART0_BASE + UART_DLM);/* set baudrate divisor */
outb(0x03, UART0_BASE + UART_LCR); /* clear DLAB; set 8 bits, no parity */
outb(0x01, UART0_BASE + UART_FCR); /* enable FIFO */
outb(0x0b, UART0_BASE + UART_MCR); /* Set DTR and RTS active */
val = inb(UART0_BASE + UART_LSR); /* clear line status */
val = inb(UART0_BASE + UART_RBR); /* read receive buffer */
outb(0x00, UART0_BASE + UART_SCR); /* set scratchpad */
outb(0x00, UART0_BASE + UART_IER); /* set interrupt enable reg */
return 0;
}
void serial_setbrg(void)
{
unsigned short bdiv;
bdiv = serial_div(gd->baudrate);
outb(0x80, UART0_BASE + UART_LCR); /* set DLAB bit */
outb(bdiv&0xff, UART0_BASE + UART_DLL); /* set baudrate divisor */
outb(bdiv >> 8, UART0_BASE + UART_DLM);/* set baudrate divisor */
outb(0x03, UART0_BASE + UART_LCR); /* clear DLAB; set 8 bits, no parity */
}
void serial_putc(const char c)
{
int i;
if (c == '\n')
serial_putc ('\r');
/* check THRE bit, wait for transmiter available */
for (i = 1; i < 3500; i++) {
if ((inb (UART0_BASE + UART_LSR) & 0x20) == 0x20) {
break;
}
udelay(100);
}
outb(c, UART0_BASE + UART_THR); /* put character out */
}
void serial_puts(const char *s)
{
while (*s) {
serial_putc(*s++);
}
}
int serial_getc(void)
{
unsigned char status = 0;
#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
if (serial_buffer_active) {
return serial_buffered_getc();
}
#endif
while (1) {
#if defined(CONFIG_HW_WATCHDOG)
WATCHDOG_RESET(); /* Reset HW Watchdog, if needed */
#endif /* CONFIG_HW_WATCHDOG */
status = inb(UART0_BASE + UART_LSR);
if ((status & asyncLSRDataReady1) != 0x0) {
break;
}
if ((status & ( asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1 )) != 0) {
outb(asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1, UART0_BASE + UART_LSR);
}
}
return (0x000000ff & (int) inb (UART0_BASE));
}
int serial_tstc(void)
{
unsigned char status;
#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
if (serial_buffer_active) {
return serial_buffered_tstc();
}
#endif
status = inb(UART0_BASE + UART_LSR);
if ((status & asyncLSRDataReady1) != 0x0) {
return (1);
}
if ((status & ( asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1 )) != 0) {
outb(asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1, UART0_BASE + UART_LSR);
}
return 0;
}
#ifdef CONFIG_SERIAL_SOFTWARE_FIFO
void serial_isr(void *arg)
{
int space;
int c;
int rx_put = buf_info.rx_put;
if (buf_info.rx_get <= rx_put) {
space = CONFIG_SERIAL_SOFTWARE_FIFO - (rx_put - buf_info.rx_get);
} else {
space = buf_info.rx_get - rx_put;
}
while (inb(UART0_BASE + UART_LSR) & 1) {
c = inb(UART0_BASE);
if (space) {
buf_info.rx_buffer[rx_put++] = c;
space--;
if (rx_put == buf_info.rx_get) {
buf_info.rx_get++;
if (rx_put == CONFIG_SERIAL_SOFTWARE_FIFO) {
buf_info.rx_get = 0;
}
}
if (rx_put == CONFIG_SERIAL_SOFTWARE_FIFO) {
rx_put = 0;
if (0 == buf_info.rx_get) {
buf_info.rx_get = 1;
}
}
}
if (space < CONFIG_SERIAL_SOFTWARE_FIFO / 4) {
/* Stop flow by setting RTS inactive */
outb(inb(UART0_BASE + UART_MCR) & (0xFF ^ 0x02),
UART0_BASE + UART_MCR);
}
}
buf_info.rx_put = rx_put;
}
void serial_buffered_init(void)
{
serial_puts ("Switching to interrupt driven serial input mode.\n");
buf_info.rx_buffer = malloc (CONFIG_SERIAL_SOFTWARE_FIFO);
buf_info.rx_put = 0;
buf_info.rx_get = 0;
if (inb (UART0_BASE + UART_MSR) & 0x10) {
serial_puts ("Check CTS signal present on serial port: OK.\n");
buf_info.cts = 1;
} else {
serial_puts ("WARNING: CTS signal not present on serial port.\n");
buf_info.cts = 0;
}
irq_install_handler ( VECNUM_U0 /*UART0 */ /*int vec */ ,
serial_isr /*interrupt_handler_t *handler */ ,
(void *) &buf_info /*void *arg */ );
/* Enable "RX Data Available" Interrupt on UART */
/* outb(inb(UART0_BASE + UART_IER) |0x01, UART0_BASE + UART_IER); */
outb(0x01, UART0_BASE + UART_IER);
/* Set DTR and RTS active, enable interrupts */
outb(inb (UART0_BASE + UART_MCR) | 0x0b, UART0_BASE + UART_MCR);
/* Setup UART FIFO: RX trigger level: 1 byte, Enable FIFO */
outb( /*(1 << 6) |*/ 1, UART0_BASE + UART_FCR);
serial_buffer_active = 1;
}
void serial_buffered_putc (const char c)
{
int i;
/* Wait for CTS */
#if defined(CONFIG_HW_WATCHDOG)
while (!(inb (UART0_BASE + UART_MSR) & 0x10))
WATCHDOG_RESET ();
#else
if (buf_info.cts) {
for (i=0;i<1000;i++) {
if ((inb (UART0_BASE + UART_MSR) & 0x10)) {
break;
}
}
if (i!=1000) {
buf_info.cts = 0;
}
} else {
if ((inb (UART0_BASE + UART_MSR) & 0x10)) {
buf_info.cts = 1;
}
}
#endif
serial_putc (c);
}
void serial_buffered_puts(const char *s)
{
serial_puts (s);
}
int serial_buffered_getc(void)
{
int space;
int c;
int rx_get = buf_info.rx_get;
int rx_put;
#if defined(CONFIG_HW_WATCHDOG)
while (rx_get == buf_info.rx_put)
WATCHDOG_RESET ();
#else
while (rx_get == buf_info.rx_put);
#endif
c = buf_info.rx_buffer[rx_get++];
if (rx_get == CONFIG_SERIAL_SOFTWARE_FIFO) {
rx_get = 0;
}
buf_info.rx_get = rx_get;
rx_put = buf_info.rx_put;
if (rx_get <= rx_put) {
space = CONFIG_SERIAL_SOFTWARE_FIFO - (rx_put - rx_get);
} else {
space = rx_get - rx_put;
}
if (space > CONFIG_SERIAL_SOFTWARE_FIFO / 2) {
/* Start flow by setting RTS active */
outb(inb (UART0_BASE + UART_MCR) | 0x02, UART0_BASE + UART_MCR);
}
return c;
}
int serial_buffered_tstc(void)
{
return (buf_info.rx_get != buf_info.rx_put) ? 1 : 0;
}
#endif /* CONFIG_SERIAL_SOFTWARE_FIFO */
#if (CONFIG_COMMANDS & CFG_CMD_KGDB)
/*
AS HARNOIS : according to CONFIG_KGDB_SER_INDEX kgdb uses serial port
number 0 or number 1
- if CONFIG_KGDB_SER_INDEX = 1 => serial port number 0 :
configuration has been already done
- if CONFIG_KGDB_SER_INDEX = 2 => serial port number 1 :
configure port 1 for serial I/O with rate = CONFIG_KGDB_BAUDRATE
*/
#if (CONFIG_KGDB_SER_INDEX & 2)
void kgdb_serial_init(void)
{
volatile char val;
bdiv = serial_div (CONFIG_KGDB_BAUDRATE);
/*
* Init onboard 16550 UART
*/
outb(0x80, UART1_BASE + UART_LCR); /* set DLAB bit */
outb(bdiv & 0xff), UART1_BASE + UART_DLL); /* set divisor for 9600 baud */
outb(bdiv >> 8), UART1_BASE + UART_DLM); /* set divisor for 9600 baud */
outb(0x03, UART1_BASE + UART_LCR); /* line control 8 bits no parity */
outb(0x00, UART1_BASE + UART_FCR); /* disable FIFO */
outb(0x00, UART1_BASE + UART_MCR); /* no modem control DTR RTS */
val = inb(UART1_BASE + UART_LSR); /* clear line status */
val = inb(UART1_BASE + UART_RBR); /* read receive buffer */
outb(0x00, UART1_BASE + UART_SCR); /* set scratchpad */
outb(0x00, UART1_BASE + UART_IER); /* set interrupt enable reg */
}
void putDebugChar(const char c)
{
if (c == '\n')
serial_putc ('\r');
outb(c, UART1_BASE + UART_THR); /* put character out */
/* check THRE bit, wait for transfer done */
while ((inb(UART1_BASE + UART_LSR) & 0x20) != 0x20);
}
void putDebugStr(const char *s)
{
while (*s) {
serial_putc(*s++);
}
}
int getDebugChar(void)
{
unsigned char status = 0;
while (1) {
status = inb(UART1_BASE + UART_LSR);
if ((status & asyncLSRDataReady1) != 0x0) {
break;
}
if ((status & ( asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1 )) != 0) {
outb(asyncLSRFramingError1 |
asyncLSROverrunError1 |
asyncLSRParityError1 |
asyncLSRBreakInterrupt1, UART1_BASE + UART_LSR);
}
}
return (0x000000ff & (int) inb(UART1_BASE));
}
void kgdb_interruptible(int yes)
{
return;
}
#else /* ! (CONFIG_KGDB_SER_INDEX & 2) */
void kgdb_serial_init(void)
{
serial_printf ("[on serial] ");
}
void putDebugChar(int c)
{
serial_putc (c);
}
void putDebugStr(const char *str)
{
serial_puts (str);
}
int getDebugChar(void)
{
return serial_getc ();
}
void kgdb_interruptible(int yes)
{
return;
}
#endif /* (CONFIG_KGDB_SER_INDEX & 2) */
#endif /* CFG_CMD_KGDB */