[deliverable/linux.git] / arch / parisc / kernel / pdc_cons.c

/* 
 *    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/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;

	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>
#include <linux/tty_flip.h>

#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)

static void pdc_console_poll(unsigned long unused);
static DEFINE_TIMER(pdc_console_timer, pdc_console_poll, 0, 0);
static struct tty_port tty_port;

static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
{
	tty_port_tty_set(&tty_port, tty);
	mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);

	return 0;
}

static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
{
	if (!tty->count) {
		del_timer_sync(&pdc_console_timer);
		tty_port_tty_set(&tty_port, NULL);
	}
}

static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
	pdc_console_write(NULL, buf, count);
	return count;
}

static int pdc_console_tty_write_room(struct tty_struct *tty)
{
	return 32768; /* no limit, no buffer used */
}

static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
{
	return 0; /* no buffer */
}

static const struct tty_operations pdc_console_tty_ops = {
	.open = pdc_console_tty_open,
	.close = pdc_console_tty_close,
	.write = pdc_console_tty_write,
	.write_room = pdc_console_tty_write_room,
	.chars_in_buffer = pdc_console_tty_chars_in_buffer,
};

static void pdc_console_poll(unsigned long unused)
{
	int data, count = 0;
	struct tty_struct *tty = tty_port_tty_get(&tty_port);

	if (!tty)
		return;

	while (1) {
		data = pdc_console_poll_key(NULL);
		if (data == -1)
			break;
		tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL);
		count ++;
	}

	if (count)
		tty_flip_buffer_push(tty);

	tty_kref_put(tty);

	if (pdc_cons.flags & CON_ENABLED)
		mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
}

static struct tty_driver *pdc_console_tty_driver;

static int __init pdc_console_tty_driver_init(void)
{
	int err;

	/* Check if the console driver is still registered.
	 * It is unregistered if the pdc console was not selected as the
	 * primary console. */

	struct console *tmp;

	console_lock();
	for_each_console(tmp)
		if (tmp == &pdc_cons)
			break;
	console_unlock();

	if (!tmp) {
		printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
		return -ENODEV;
	}

	printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
	pdc_cons.flags &= ~CON_BOOT;

	tty_port_init(&tty_port);

	pdc_console_tty_driver = alloc_tty_driver(1);

	if (!pdc_console_tty_driver)
		return -ENOMEM;

	pdc_console_tty_driver->driver_name = "pdc_cons";
	pdc_console_tty_driver->name = "ttyB";
	pdc_console_tty_driver->major = MUX_MAJOR;
	pdc_console_tty_driver->minor_start = 0;
	pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
	pdc_console_tty_driver->init_termios = tty_std_termios;
	pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW |
		TTY_DRIVER_RESET_TERMIOS;
	tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops);

	err = tty_register_driver(pdc_console_tty_driver);
	if (err) {
		printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
		return err;
	}

	return 0;
}

module_init(pdc_console_tty_driver_init);

static struct tty_driver * pdc_console_device (struct console *c, int *index)
{
	*index = c->index;
	return pdc_console_tty_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,
	.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();
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* PDC Console support - ie use firmware to dump text via boot console
	3	*
	4	* Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
	5	* Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
	6	* Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
	7	* Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
	8	* Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
	9	* Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
	10	* Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
	11	* Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
	12	* Copyright (C) 2001 Helge Deller <deller at parisc-linux.org>
	13	* Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
	14	* Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
650a35f8	15	* Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>
1da177e4 LT	16	*
	17	*
	18	* This program is free software; you can redistribute it and/or modify
	19	* it under the terms of the GNU General Public License as published by
	20	* the Free Software Foundation; either version 2 of the License, or
	21	* (at your option) any later version.
	22	*
	23	* This program is distributed in the hope that it will be useful,
	24	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	25	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	26	* GNU General Public License for more details.
	27	*
	28	* You should have received a copy of the GNU General Public License
	29	* along with this program; if not, write to the Free Software
	30	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	31	*/
	32
	33	/*
	34	* The PDC console is a simple console, which can be used for debugging
650a35f8 GM	35	* boot related problems on HP PA-RISC machines. It is also useful when no
650a35f8 GM	36	* other console works.
1da177e4 LT	37	*
	38	* This code uses the ROM (=PDC) based functions to read and write characters
	39	* from and to PDC's boot path.
1da177e4 LT	40	*/
	41
	42	/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
	43	* On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
7c92e972	44	#define EARLY_BOOTUP_DEBUG
1da177e4 LT	45
1da177e4 LT	46
1da177e4 LT	47	#include <linux/kernel.h>
	48	#include <linux/console.h>
	49	#include <linux/string.h>
	50	#include <linux/init.h>
1da177e4 LT	51	#include <linux/major.h>
1da177e4 LT	52	#include <linux/tty.h>
1da177e4 LT	53	#include <asm/pdc.h> /* for iodc_call() proto and friends */
1da177e4 LT	54
aefa8b6b	55	static DEFINE_SPINLOCK(pdc_console_lock);
650a35f8	56	static struct console pdc_cons;
1da177e4 LT	57
	58	static void pdc_console_write(struct console co, const char s, unsigned count)
	59	{
ef1afd4d KM	60	int i = 0;
	61	unsigned long flags;
	62
	63	spin_lock_irqsave(&pdc_console_lock, flags);
	64	do {
	65	i += pdc_iodc_print(s + i, count - i);
	66	} while (i < count);
	67	spin_unlock_irqrestore(&pdc_console_lock, flags);
1da177e4 LT	68	}
1da177e4 LT	69
1da177e4 LT	70	int pdc_console_poll_key(struct console *co)
1da177e4 LT	71	{
ef1afd4d KM	72	int c;
	73	unsigned long flags;
	74
	75	spin_lock_irqsave(&pdc_console_lock, flags);
	76	c = pdc_iodc_getc();
	77	spin_unlock_irqrestore(&pdc_console_lock, flags);
	78
	79	return c;
1da177e4 LT	80	}
	81
	82	static int pdc_console_setup(struct console co, char options)
	83	{
	84	return 0;
	85	}
	86
	87	#if defined(CONFIG_PDC_CONSOLE)
a8f340e3	88	#include <linux/vt_kern.h>
650a35f8 GM	89	#include <linux/tty_flip.h>
	90
	91	#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
	92
52b762f7 JS	93	static void pdc_console_poll(unsigned long unused);
52b762f7 JS	94	static DEFINE_TIMER(pdc_console_timer, pdc_console_poll, 0, 0);
5dd5bc40	95	static struct tty_port tty_port;
650a35f8	96
650a35f8 GM	97	static int pdc_console_tty_open(struct tty_struct tty, struct file filp)
650a35f8 GM	98	{
5dd5bc40	99	tty_port_tty_set(&tty_port, tty);
650a35f8 GM	100	mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
	101
	102	return 0;
	103	}
	104
	105	static void pdc_console_tty_close(struct tty_struct tty, struct file filp)
	106	{
5dd5bc40	107	if (!tty->count) {
e380a81e	108	del_timer_sync(&pdc_console_timer);
5dd5bc40 JS	109	tty_port_tty_set(&tty_port, NULL);
5dd5bc40 JS	110	}
650a35f8 GM	111	}
	112
	113	static int pdc_console_tty_write(struct tty_struct tty, const unsigned char buf, int count)
	114	{
	115	pdc_console_write(NULL, buf, count);
	116	return count;
	117	}
	118
	119	static int pdc_console_tty_write_room(struct tty_struct *tty)
	120	{
	121	return 32768; /* no limit, no buffer used */
	122	}
	123
	124	static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
	125	{
	126	return 0; /* no buffer */
	127	}
	128
650a35f8 GM	129	static const struct tty_operations pdc_console_tty_ops = {
	130	.open = pdc_console_tty_open,
	131	.close = pdc_console_tty_close,
	132	.write = pdc_console_tty_write,
	133	.write_room = pdc_console_tty_write_room,
	134	.chars_in_buffer = pdc_console_tty_chars_in_buffer,
	135	};
	136
	137	static void pdc_console_poll(unsigned long unused)
	138	{
650a35f8	139	int data, count = 0;
5dd5bc40	140	struct tty_struct *tty = tty_port_tty_get(&tty_port);
650a35f8 GM	141
	142	if (!tty)
	143	return;
	144
	145	while (1) {
	146	data = pdc_console_poll_key(NULL);
	147	if (data == -1)
	148	break;
	149	tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL);
	150	count ++;
	151	}
	152
	153	if (count)
	154	tty_flip_buffer_push(tty);
	155
5dd5bc40 JS	156	tty_kref_put(tty);
5dd5bc40 JS	157
e380a81e	158	if (pdc_cons.flags & CON_ENABLED)
650a35f8 GM	159	mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
	160	}
	161
5dd5bc40 JS	162	static struct tty_driver *pdc_console_tty_driver;
5dd5bc40 JS	163
650a35f8 GM	164	static int __init pdc_console_tty_driver_init(void)
650a35f8 GM	165	{
650a35f8	166	int err;
650a35f8 GM	167
	168	/* Check if the console driver is still registered.
	169	* It is unregistered if the pdc console was not selected as the
	170	* primary console. */
	171
597c606f	172	struct console *tmp;
650a35f8	173
ac751efa	174	console_lock();
597c606f	175	for_each_console(tmp)
650a35f8 GM	176	if (tmp == &pdc_cons)
650a35f8 GM	177	break;
ac751efa	178	console_unlock();
650a35f8 GM	179
	180	if (!tmp) {
	181	printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
	182	return -ENODEV;
	183	}
	184
	185	printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
	186	pdc_cons.flags &= ~CON_BOOT;
	187
5dd5bc40 JS	188	tty_port_init(&tty_port);
5dd5bc40 JS	189
0b479d54	190	pdc_console_tty_driver = alloc_tty_driver(1);
650a35f8	191
0b479d54	192	if (!pdc_console_tty_driver)
650a35f8 GM	193	return -ENOMEM;
650a35f8 GM	194
0b479d54 JS	195	pdc_console_tty_driver->driver_name = "pdc_cons";
	196	pdc_console_tty_driver->name = "ttyB";
	197	pdc_console_tty_driver->major = MUX_MAJOR;
	198	pdc_console_tty_driver->minor_start = 0;
	199	pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
	200	pdc_console_tty_driver->init_termios = tty_std_termios;
	201	pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW \|
	202	TTY_DRIVER_RESET_TERMIOS;
	203	tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops);
	204
	205	err = tty_register_driver(pdc_console_tty_driver);
650a35f8 GM	206	if (err) {
	207	printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
	208	return err;
	209	}
	210
650a35f8 GM	211	return 0;
	212	}
	213
	214	module_init(pdc_console_tty_driver_init);
a8f340e3	215
1da177e4 LT	216	static struct tty_driver * pdc_console_device (struct console c, int index)
1da177e4 LT	217	{
650a35f8 GM	218	*index = c->index;
650a35f8 GM	219	return pdc_console_tty_driver;
1da177e4 LT	220	}
1da177e4 LT	221	#else
7c92e972	222	#define pdc_console_device NULL
1da177e4 LT	223	#endif
	224
	225	static struct console pdc_cons = {
	226	.name = "ttyB",
	227	.write = pdc_console_write,
7c92e972	228	.device = pdc_console_device,
1da177e4	229	.setup = pdc_console_setup,
650a35f8	230	.flags = CON_BOOT \| CON_PRINTBUFFER,
1da177e4 LT	231	.index = -1,
	232	};
	233
	234	static int pdc_console_initialized;
1da177e4 LT	235
	236	static void pdc_console_init_force(void)
	237	{
	238	if (pdc_console_initialized)
	239	return;
	240	++pdc_console_initialized;
	241
	242	/* If the console is duplex then copy the COUT parameters to CIN. */
	243	if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
	244	memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
	245
	246	/* register the pdc console */
	247	register_console(&pdc_cons);
	248	}
	249
	250	void __init pdc_console_init(void)
	251	{
	252	#if defined(EARLY_BOOTUP_DEBUG) \|\| defined(CONFIG_PDC_CONSOLE)
	253	pdc_console_init_force();
	254	#endif
	255	#ifdef EARLY_BOOTUP_DEBUG
	256	printk(KERN_INFO "Initialized PDC Console for debugging.\n");
	257	#endif
	258	}
	259
	260
1da177e4 LT	261	/*
	262	* Used for emergencies. Currently only used if an HPMC occurs. If an
	263	* HPMC occurs, it is possible that the current console may not be
7c92e972 MW	264	* properly initialised after the PDC IO reset. This routine unregisters
7c92e972 MW	265	* all of the current consoles, reinitializes the pdc console and
1da177e4 LT	266	* registers it.
	267	*/
	268
	269	void pdc_console_restart(void)
	270	{
	271	struct console *console;
	272
	273	if (pdc_console_initialized)
	274	return;
	275
7c92e972 MW	276	/* If we've already seen the output, don't bother to print it again */
	277	if (console_drivers != NULL)
	278	pdc_cons.flags &= ~CON_PRINTBUFFER;
	279
1da177e4 LT	280	while ((console = console_drivers) != NULL)
	281	unregister_console(console_drivers);
	282
1da177e4 LT	283	/* force registering the pdc console */
	284	pdc_console_init_force();
	285	}