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>
15 * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>
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
35 * boot related problems on HP PA-RISC machines. It is also useful when no
36 * other console works.
37 *
38 * This code uses the ROM (=PDC) based functions to read and write characters
39 * from and to PDC's boot path.
40 */
41
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
45
46
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/page.h> /* for PAGE0 */
54 #include <asm/pdc.h> /* for iodc_call() proto and friends */
55
56 static DEFINE_SPINLOCK(pdc_console_lock);
57 static struct console pdc_cons;
58
pdc_console_write(struct console * co,const char * s,unsigned count)59 static void pdc_console_write(struct console *co, const char *s, unsigned count)
60 {
61 int i = 0;
62 unsigned long flags;
63
64 spin_lock_irqsave(&pdc_console_lock, flags);
65 do {
66 i += pdc_iodc_print(s + i, count - i);
67 } while (i < count);
68 spin_unlock_irqrestore(&pdc_console_lock, flags);
69 }
70
pdc_console_poll_key(struct console * co)71 int pdc_console_poll_key(struct console *co)
72 {
73 int c;
74 unsigned long flags;
75
76 spin_lock_irqsave(&pdc_console_lock, flags);
77 c = pdc_iodc_getc();
78 spin_unlock_irqrestore(&pdc_console_lock, flags);
79
80 return c;
81 }
82
pdc_console_setup(struct console * co,char * options)83 static int pdc_console_setup(struct console *co, char *options)
84 {
85 return 0;
86 }
87
88 #if defined(CONFIG_PDC_CONSOLE)
89 #include <linux/vt_kern.h>
90 #include <linux/tty_flip.h>
91
92 #define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
93
94 static void pdc_console_poll(unsigned long unused);
95 static DEFINE_TIMER(pdc_console_timer, pdc_console_poll, 0, 0);
96 static struct tty_port tty_port;
97
pdc_console_tty_open(struct tty_struct * tty,struct file * filp)98 static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
99 {
100 tty_port_tty_set(&tty_port, tty);
101 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
102
103 return 0;
104 }
105
pdc_console_tty_close(struct tty_struct * tty,struct file * filp)106 static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
107 {
108 if (tty->count == 1) {
109 del_timer_sync(&pdc_console_timer);
110 tty_port_tty_set(&tty_port, NULL);
111 }
112 }
113
pdc_console_tty_write(struct tty_struct * tty,const unsigned char * buf,int count)114 static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
115 {
116 pdc_console_write(NULL, buf, count);
117 return count;
118 }
119
pdc_console_tty_write_room(struct tty_struct * tty)120 static int pdc_console_tty_write_room(struct tty_struct *tty)
121 {
122 return 32768; /* no limit, no buffer used */
123 }
124
pdc_console_tty_chars_in_buffer(struct tty_struct * tty)125 static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
126 {
127 return 0; /* no buffer */
128 }
129
130 static const struct tty_operations pdc_console_tty_ops = {
131 .open = pdc_console_tty_open,
132 .close = pdc_console_tty_close,
133 .write = pdc_console_tty_write,
134 .write_room = pdc_console_tty_write_room,
135 .chars_in_buffer = pdc_console_tty_chars_in_buffer,
136 };
137
pdc_console_poll(unsigned long unused)138 static void pdc_console_poll(unsigned long unused)
139 {
140 int data, count = 0;
141
142 while (1) {
143 data = pdc_console_poll_key(NULL);
144 if (data == -1)
145 break;
146 tty_insert_flip_char(&tty_port, data & 0xFF, TTY_NORMAL);
147 count ++;
148 }
149
150 if (count)
151 tty_flip_buffer_push(&tty_port);
152
153 if (pdc_cons.flags & CON_ENABLED)
154 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
155 }
156
157 static struct tty_driver *pdc_console_tty_driver;
158
pdc_console_tty_driver_init(void)159 static int __init pdc_console_tty_driver_init(void)
160 {
161 int err;
162
163 /* Check if the console driver is still registered.
164 * It is unregistered if the pdc console was not selected as the
165 * primary console. */
166
167 struct console *tmp;
168
169 console_lock();
170 for_each_console(tmp)
171 if (tmp == &pdc_cons)
172 break;
173 console_unlock();
174
175 if (!tmp) {
176 printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
177 return -ENODEV;
178 }
179
180 printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
181 pdc_cons.flags &= ~CON_BOOT;
182
183 pdc_console_tty_driver = alloc_tty_driver(1);
184
185 if (!pdc_console_tty_driver)
186 return -ENOMEM;
187
188 tty_port_init(&tty_port);
189
190 pdc_console_tty_driver->driver_name = "pdc_cons";
191 pdc_console_tty_driver->name = "ttyB";
192 pdc_console_tty_driver->major = MUX_MAJOR;
193 pdc_console_tty_driver->minor_start = 0;
194 pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
195 pdc_console_tty_driver->init_termios = tty_std_termios;
196 pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW |
197 TTY_DRIVER_RESET_TERMIOS;
198 tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops);
199 tty_port_link_device(&tty_port, pdc_console_tty_driver, 0);
200
201 err = tty_register_driver(pdc_console_tty_driver);
202 if (err) {
203 printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
204 tty_port_destroy(&tty_port);
205 return err;
206 }
207
208 return 0;
209 }
210 device_initcall(pdc_console_tty_driver_init);
211
pdc_console_device(struct console * c,int * index)212 static struct tty_driver * pdc_console_device (struct console *c, int *index)
213 {
214 *index = c->index;
215 return pdc_console_tty_driver;
216 }
217 #else
218 #define pdc_console_device NULL
219 #endif
220
221 static struct console pdc_cons = {
222 .name = "ttyB",
223 .write = pdc_console_write,
224 .device = pdc_console_device,
225 .setup = pdc_console_setup,
226 .flags = CON_BOOT | CON_PRINTBUFFER,
227 .index = -1,
228 };
229
230 static int pdc_console_initialized;
231
pdc_console_init_force(void)232 static void pdc_console_init_force(void)
233 {
234 if (pdc_console_initialized)
235 return;
236 ++pdc_console_initialized;
237
238 /* If the console is duplex then copy the COUT parameters to CIN. */
239 if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
240 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
241
242 /* register the pdc console */
243 register_console(&pdc_cons);
244 }
245
pdc_console_init(void)246 void __init pdc_console_init(void)
247 {
248 #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
249 pdc_console_init_force();
250 #endif
251 #ifdef EARLY_BOOTUP_DEBUG
252 printk(KERN_INFO "Initialized PDC Console for debugging.\n");
253 #endif
254 }
255
256
257 /*
258 * Used for emergencies. Currently only used if an HPMC occurs. If an
259 * HPMC occurs, it is possible that the current console may not be
260 * properly initialised after the PDC IO reset. This routine unregisters
261 * all of the current consoles, reinitializes the pdc console and
262 * registers it.
263 */
264
pdc_console_restart(void)265 void pdc_console_restart(void)
266 {
267 struct console *console;
268
269 if (pdc_console_initialized)
270 return;
271
272 /* If we've already seen the output, don't bother to print it again */
273 if (console_drivers != NULL)
274 pdc_cons.flags &= ~CON_PRINTBUFFER;
275
276 while ((console = console_drivers) != NULL)
277 unregister_console(console_drivers);
278
279 /* force registering the pdc console */
280 pdc_console_init_force();
281 }
282