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>
15 * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>
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.
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.
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
34 * The PDC console is a simple console, which can be used for debugging
35 * boot related problems on HP PA-RISC machines. It is also useful when no
36 * other console works.
38 * This code uses the ROM (=PDC) based functions to read and write characters
39 * from and to PDC's boot path.
42 /* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
43 * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
44 #define EARLY_BOOTUP_DEBUG
47 #include <linux/kernel.h>
48 #include <linux/console.h>
49 #include <linux/string.h>
50 #include <linux/init.h>
51 #include <linux/major.h>
52 #include <linux/tty.h>
53 #include <asm/pdc.h> /* for iodc_call() proto and friends */
55 static DEFINE_SPINLOCK(pdc_console_lock);
56 static struct console pdc_cons;
58 static void pdc_console_write(struct console *co, const char *s, unsigned count)
63 spin_lock_irqsave(&pdc_console_lock, flags);
65 i += pdc_iodc_print(s + i, count - i);
67 spin_unlock_irqrestore(&pdc_console_lock, flags);
70 int pdc_console_poll_key(struct console *co)
75 spin_lock_irqsave(&pdc_console_lock, flags);
77 spin_unlock_irqrestore(&pdc_console_lock, flags);
82 static int pdc_console_setup(struct console *co, char *options)
87 #if defined(CONFIG_PDC_CONSOLE)
88 #include <linux/vt_kern.h>
89 #include <linux/tty_flip.h>
91 #define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
93 static void pdc_console_poll(unsigned long unused);
94 static DEFINE_TIMER(pdc_console_timer, pdc_console_poll, 0, 0);
95 static struct tty_port tty_port;
97 static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
99 tty_port_tty_set(&tty_port, tty);
100 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
105 static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
108 del_timer_sync(&pdc_console_timer);
109 tty_port_tty_set(&tty_port, NULL);
113 static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
115 pdc_console_write(NULL, buf, count);
119 static int pdc_console_tty_write_room(struct tty_struct *tty)
121 return 32768; /* no limit, no buffer used */
124 static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
126 return 0; /* no buffer */
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,
137 static void pdc_console_poll(unsigned long unused)
140 struct tty_struct *tty = tty_port_tty_get(&tty_port);
146 data = pdc_console_poll_key(NULL);
149 tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL);
154 tty_flip_buffer_push(tty);
158 if (pdc_cons.flags & CON_ENABLED)
159 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
162 static struct tty_driver *pdc_console_tty_driver;
164 static int __init pdc_console_tty_driver_init(void)
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. */
175 for_each_console(tmp)
176 if (tmp == &pdc_cons)
181 printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
185 printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
186 pdc_cons.flags &= ~CON_BOOT;
188 tty_port_init(&tty_port);
190 pdc_console_tty_driver = alloc_tty_driver(1);
192 if (!pdc_console_tty_driver)
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);
205 err = tty_register_driver(pdc_console_tty_driver);
207 printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
214 module_init(pdc_console_tty_driver_init);
216 static struct tty_driver * pdc_console_device (struct console *c, int *index)
219 return pdc_console_tty_driver;
222 #define pdc_console_device NULL
225 static struct console pdc_cons = {
227 .write = pdc_console_write,
228 .device = pdc_console_device,
229 .setup = pdc_console_setup,
230 .flags = CON_BOOT | CON_PRINTBUFFER,
234 static int pdc_console_initialized;
236 static void pdc_console_init_force(void)
238 if (pdc_console_initialized)
240 ++pdc_console_initialized;
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));
246 /* register the pdc console */
247 register_console(&pdc_cons);
250 void __init pdc_console_init(void)
252 #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
253 pdc_console_init_force();
255 #ifdef EARLY_BOOTUP_DEBUG
256 printk(KERN_INFO "Initialized PDC Console for debugging.\n");
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
264 * properly initialised after the PDC IO reset. This routine unregisters
265 * all of the current consoles, reinitializes the pdc console and
269 void pdc_console_restart(void)
271 struct console *console;
273 if (pdc_console_initialized)
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;
280 while ((console = console_drivers) != NULL)
281 unregister_console(console_drivers);
283 /* force registering the pdc console */
284 pdc_console_init_force();