2 * PDC Console support - ie use firmware to dump text via boot console
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>
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 * The PDC console is a simple console, which can be used for debugging
34 * boot related problems on HP PA-RISC machines.
36 * This code uses the ROM (=PDC) based functions to read and write characters
37 * from and to PDC's boot path.
38 * Since all character read from that path must be polled, this code never
39 * can or will be a fully functional linux console.
42 /* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
43 * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
44 #undef EARLY_BOOTUP_DEBUG
47 #include <linux/config.h>
48 #include <linux/kernel.h>
49 #include <linux/console.h>
50 #include <linux/string.h>
51 #include <linux/init.h>
52 #include <linux/delay.h>
53 #include <linux/sched.h>
54 #include <linux/interrupt.h>
55 #include <linux/major.h>
56 #include <linux/tty.h>
58 #include <asm/types.h>
59 #include <asm/system.h>
60 #include <asm/pdc.h> /* for iodc_call() proto and friends */
63 static void pdc_console_write(struct console
*co
, const char *s
, unsigned count
)
69 void pdc_outc(unsigned char c
)
75 int pdc_console_poll_key(struct console
*co
)
77 return pdc_iodc_getc();
80 static int pdc_console_setup(struct console
*co
, char *options
)
85 #if defined(CONFIG_PDC_CONSOLE)
86 #define PDC_CONSOLE_DEVICE pdc_console_device
87 static struct tty_driver
* pdc_console_device (struct console
*c
, int *index
)
89 extern struct tty_driver console_driver
;
90 *index
= c
->index
? c
->index
-1 : fg_console
;
91 return &console_driver
;
94 #define PDC_CONSOLE_DEVICE NULL
97 static struct console pdc_cons
= {
99 .write
= pdc_console_write
,
100 .device
= PDC_CONSOLE_DEVICE
,
101 .setup
= pdc_console_setup
,
102 .flags
= CON_BOOT
|CON_PRINTBUFFER
|CON_ENABLED
,
106 static int pdc_console_initialized
;
107 extern unsigned long con_start
; /* kernel/printk.c */
108 extern unsigned long log_end
; /* kernel/printk.c */
111 static void pdc_console_init_force(void)
113 if (pdc_console_initialized
)
115 ++pdc_console_initialized
;
117 /* If the console is duplex then copy the COUT parameters to CIN. */
118 if (PAGE0
->mem_cons
.cl_class
== CL_DUPLEX
)
119 memcpy(&PAGE0
->mem_kbd
, &PAGE0
->mem_cons
, sizeof(PAGE0
->mem_cons
));
121 /* register the pdc console */
122 register_console(&pdc_cons
);
125 void __init
pdc_console_init(void)
127 #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
128 pdc_console_init_force();
130 #ifdef EARLY_BOOTUP_DEBUG
131 printk(KERN_INFO
"Initialized PDC Console for debugging.\n");
136 /* Unregister the pdc console with the printk console layer */
137 void pdc_console_die(void)
139 if (!pdc_console_initialized
)
141 --pdc_console_initialized
;
143 printk(KERN_INFO
"Switching from PDC console\n");
145 /* Don't repeat what we've already printed */
148 unregister_console(&pdc_cons
);
153 * Used for emergencies. Currently only used if an HPMC occurs. If an
154 * HPMC occurs, it is possible that the current console may not be
155 * properly initialed after the PDC IO reset. This routine unregisters all
156 * of the current consoles, reinitializes the pdc console and
160 void pdc_console_restart(void)
162 struct console
*console
;
164 if (pdc_console_initialized
)
167 while ((console
= console_drivers
) != NULL
)
168 unregister_console(console_drivers
);
170 /* Don't repeat what we've already printed */
173 /* force registering the pdc console */
174 pdc_console_init_force();