linux-imx

/* 

 *    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>

 *    Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>

 *

 *

 *    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. It is also useful when no

 *  other console works.

 *

 *  This code uses the ROM (=PDC) based functions to read and write characters

 *  from and to PDC's boot path.

 */

​

/* 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/page.h>       /* for PAGE0 */

#include <asm/pdc.h>        /* for iodc_call() proto and friends */

​

static DEFINE_SPINLOCK(pdc_console_lock);

static struct console pdc_cons;

​

static void pdc_console_write(struct console *co, const char *s, unsigned count)

{

    int i = 0;

    unsigned long flags;

​