/*
* PDC Console support - ie use firmware to dump text via boot console
*
* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
* Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
* Copyright (C) 2001 Helge Deller <deller at parisc-linux.org>
* Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
*
*
* 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
*/
/*
* The PDC console is a simple console, which can be used for debugging
* boot related problems on HP PA-RISC machines.
*
* This code uses the ROM (=PDC) based functions to read and write characters
* from and to PDC's boot path.
* Since all character read from that path must be polled, this code never
* can or will be a fully functional linux console.
*/
/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
* On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
#define EARLY_BOOTUP_DEBUG
#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/major.h>
#include <linux/tty.h>
#include <asm/pdc.h> /* for iodc_call() proto and friends */
static spinlock_t pdc_console_lock = SPIN_LOCK_UNLOCKED;
static void pdc_console_write(struct console *co, const char *s, unsigned count)
{
int i = 0;
unsigned long flags;
spin_lock_irqsave(&pdc_console_lock, flags);
do {
i += pdc_iodc_print(s + i, count - i);
} while (i < count);
spin_unlock_irqrestore(&pdc_console_lock, flags);
}
int pdc_console_poll_key(struct console *co)
{
int c;
unsigned long flags;
spin_lock_irqsave(&pdc_console_lock, flags);
c = pdc_iodc_getc();
spin_unlock_irqrestore(&pdc_console_lock, flags);
return c;
}
static int pdc_console_setup(struct console *co, char *options)
{
return 0;
}
#if defined(CONFIG_PDC_CONSOLE)
#include <linux/vt_kern.h>
static struct tty_driver * pdc_console_device (struct console *c, int *index)
{
extern struct tty_driver console_driver;
*index = c->index ? c->index-1 : fg_console;
return &console_driver;
}
#else
#define pdc_console_device NULL
#endif
static struct console pdc_cons = {
.name = "ttyB",
.write = pdc_console_write,
.device = pdc_console_device,
.setup = pdc_console_setup,
.flags = CON_BOOT | CON_PRINTBUFFER | CON_ENABLED,
.index = -1,
};
static int pdc_console_initialized;
static void pdc_console_init_force(void)
{
if (pdc_console_initialized)
return;
++pdc_console_initialized;
/* If the console is duplex then copy the COUT parameters to CIN. */
if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
/* register the pdc console */
register_console(&pdc_cons);
}
void __init pdc_console_init(void)
{
#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
pdc_console_init_force();
#endif
#ifdef EARLY_BOOTUP_DEBUG
printk(KERN_INFO "Initialized PDC Console for debugging.\n");
#endif
}
/*
* Used for emergencies. Currently only used if an HPMC occurs. If an
* HPMC occurs, it is possible that the current console may not be
* properly initialised after the PDC IO reset. This routine unregisters
* all of the current consoles, reinitializes the pdc console and
* registers it.
*/
void pdc_console_restart(void)
{
struct console *console;
if (pdc_console_initialized)
return;
/* If we've already seen the output, don't bother to print it again */
if (console_drivers != NULL)
pdc_cons.flags &= ~CON_PRINTBUFFER;
while ((console = console_drivers) != NULL)
unregister_console(console_drivers);
/* force registering the pdc console */
pdc_console_init_force();
}
