kernel-ark/arch/ppc/xmon/start.c
Josh Boyer b7e89214aa [POWERPC] PPC 4xx: Enable XMON on PPC 4xx boards
The following patch allows XMON to run on the 4xx platform.  Tested on
Walnut, Ebony, and Nova (440GX based) eval boards.  440EP, 440SP, and
440SPE boards should work as well.  Patch is against 2.6.18-rc6.

Signed-off-by: Josh Boyer <jdub@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-09-13 18:39:52 +10:00

347 lines
5.6 KiB
C

/*
* Copyright (C) 1996 Paul Mackerras.
*/
#include <linux/string.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/page.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sysrq.h>
#include <linux/bitops.h>
#include <asm/xmon.h>
#include <asm/machdep.h>
#include <asm/errno.h>
#include <asm/processor.h>
#include <asm/delay.h>
#include <asm/btext.h>
#include <asm/ibm4xx.h>
static volatile unsigned char *sccc, *sccd;
unsigned int TXRDY, RXRDY, DLAB;
static int xmon_expect(const char *str, unsigned int timeout);
static int via_modem;
#define TB_SPEED 25000000
static inline unsigned int readtb(void)
{
unsigned int ret;
asm volatile("mftb %0" : "=r" (ret) :);
return ret;
}
void buf_access(void)
{
if (DLAB)
sccd[3] &= ~DLAB; /* reset DLAB */
}
#ifdef CONFIG_MAGIC_SYSRQ
static void sysrq_handle_xmon(int key, struct pt_regs *regs,
struct tty_struct *tty)
{
xmon(regs);
}
static struct sysrq_key_op sysrq_xmon_op =
{
.handler = sysrq_handle_xmon,
.help_msg = "Xmon",
.action_msg = "Entering xmon",
};
#endif
void
xmon_map_scc(void)
{
#if defined(CONFIG_GEMINI)
/* should already be mapped by the kernel boot */
sccd = (volatile unsigned char *) 0xffeffb08;
#elif defined(CONFIG_405GP)
sccd = (volatile unsigned char *)0xef600300;
#elif defined(CONFIG_440EP)
sccd = (volatile unsigned char *) ioremap(PPC440EP_UART0_ADDR, 8);
#elif defined(CONFIG_440SP)
sccd = (volatile unsigned char *) ioremap64(PPC440SP_UART0_ADDR, 8);
#elif defined(CONFIG_440SPE)
sccd = (volatile unsigned char *) ioremap64(PPC440SPE_UART0_ADDR, 8);
#elif defined(CONFIG_44x)
/* This is the default for 44x platforms. Any boards that have a
different UART address need to be put in cases before this or the
port will be mapped incorrectly */
sccd = (volatile unsigned char *) ioremap64(PPC440GP_UART0_ADDR, 8);
#endif /* platform */
#ifndef CONFIG_PPC_PREP
sccc = sccd + 5;
TXRDY = 0x20;
RXRDY = 1;
DLAB = 0x80;
#endif
register_sysrq_key('x', &sysrq_xmon_op);
}
static int scc_initialized;
void xmon_init_scc(void);
int
xmon_write(void *handle, void *ptr, int nb)
{
char *p = ptr;
int i, c, ct;
#ifdef CONFIG_SMP
static unsigned long xmon_write_lock;
int lock_wait = 1000000;
int locked;
while ((locked = test_and_set_bit(0, &xmon_write_lock)) != 0)
if (--lock_wait == 0)
break;
#endif
if (!scc_initialized)
xmon_init_scc();
ct = 0;
for (i = 0; i < nb; ++i) {
while ((*sccc & TXRDY) == 0)
;
c = p[i];
if (c == '\n' && !ct) {
c = '\r';
ct = 1;
--i;
} else {
ct = 0;
}
buf_access();
*sccd = c;
eieio();
}
#ifdef CONFIG_SMP
if (!locked)
clear_bit(0, &xmon_write_lock);
#endif
return nb;
}
int xmon_wants_key;
int
xmon_read(void *handle, void *ptr, int nb)
{
char *p = ptr;
int i;
if (!scc_initialized)
xmon_init_scc();
for (i = 0; i < nb; ++i) {
while ((*sccc & RXRDY) == 0)
;
buf_access();
*p++ = *sccd;
}
return i;
}
int
xmon_read_poll(void)
{
if ((*sccc & RXRDY) == 0) {
;
return -1;
}
buf_access();
return *sccd;
}
void
xmon_init_scc(void)
{
scc_initialized = 1;
if (via_modem) {
for (;;) {
xmon_write(NULL, "ATE1V1\r", 7);
if (xmon_expect("OK", 5)) {
xmon_write(NULL, "ATA\r", 4);
if (xmon_expect("CONNECT", 40))
break;
}
xmon_write(NULL, "+++", 3);
xmon_expect("OK", 3);
}
}
}
void *xmon_stdin;
void *xmon_stdout;
void *xmon_stderr;
void
xmon_init(int arg)
{
xmon_map_scc();
}
int
xmon_putc(int c, void *f)
{
char ch = c;
if (c == '\n')
xmon_putc('\r', f);
return xmon_write(f, &ch, 1) == 1? c: -1;
}
int
xmon_putchar(int c)
{
return xmon_putc(c, xmon_stdout);
}
int
xmon_fputs(char *str, void *f)
{
int n = strlen(str);
return xmon_write(f, str, n) == n? 0: -1;
}
int
xmon_readchar(void)
{
char ch;
for (;;) {
switch (xmon_read(xmon_stdin, &ch, 1)) {
case 1:
return ch;
case -1:
xmon_printf("read(stdin) returned -1\r\n", 0, 0);
return -1;
}
}
}
static char line[256];
static char *lineptr;
static int lineleft;
int xmon_expect(const char *str, unsigned int timeout)
{
int c;
unsigned int t0;
timeout *= TB_SPEED;
t0 = readtb();
do {
lineptr = line;
for (;;) {
c = xmon_read_poll();
if (c == -1) {
if (readtb() - t0 > timeout)
return 0;
continue;
}
if (c == '\n')
break;
if (c != '\r' && lineptr < &line[sizeof(line) - 1])
*lineptr++ = c;
}
*lineptr = 0;
} while (strstr(line, str) == NULL);
return 1;
}
int
xmon_getchar(void)
{
int c;
if (lineleft == 0) {
lineptr = line;
for (;;) {
c = xmon_readchar();
if (c == -1 || c == 4)
break;
if (c == '\r' || c == '\n') {
*lineptr++ = '\n';
xmon_putchar('\n');
break;
}
switch (c) {
case 0177:
case '\b':
if (lineptr > line) {
xmon_putchar('\b');
xmon_putchar(' ');
xmon_putchar('\b');
--lineptr;
}
break;
case 'U' & 0x1F:
while (lineptr > line) {
xmon_putchar('\b');
xmon_putchar(' ');
xmon_putchar('\b');
--lineptr;
}
break;
default:
if (lineptr >= &line[sizeof(line) - 1])
xmon_putchar('\a');
else {
xmon_putchar(c);
*lineptr++ = c;
}
}
}
lineleft = lineptr - line;
lineptr = line;
}
if (lineleft == 0)
return -1;
--lineleft;
return *lineptr++;
}
char *
xmon_fgets(char *str, int nb, void *f)
{
char *p;
int c;
for (p = str; p < str + nb - 1; ) {
c = xmon_getchar();
if (c == -1) {
if (p == str)
return NULL;
break;
}
*p++ = c;
if (c == '\n')
break;
}
*p = 0;
return str;
}
void
xmon_enter(void)
{
}
void
xmon_leave(void)
{
}