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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PDC early console support - use PDC firmware to dump text via boot console
4 *
5 * Copyright (C) 2001-2022 Helge Deller <deller@gmx.de>
6 */
7
8#include <linux/console.h>
9#include <linux/init.h>
10#include <linux/serial_core.h>
11#include <linux/kgdb.h>
12#include <asm/page.h> /* for PAGE0 */
13#include <asm/pdc.h> /* for iodc_call() proto and friends */
14
15static void pdc_console_write(struct console *co, const char *s, unsigned count)
16{
17 int i = 0;
18
19 do {
20 i += pdc_iodc_print(s + i, count - i);
21 } while (i < count);
22}
23
24#ifdef CONFIG_KGDB
25static int kgdb_pdc_read_char(void)
26{
27 int c = pdc_iodc_getc();
28
29 return (c <= 0) ? NO_POLL_CHAR : c;
30}
31
32static void kgdb_pdc_write_char(u8 chr)
33{
34 /* no need to print char as it's shown on standard console */
35 /* pdc_iodc_print(&chr, 1); */
36}
37
38static struct kgdb_io kgdb_pdc_io_ops = {
39 .name = "kgdb_pdc",
40 .read_char = kgdb_pdc_read_char,
41 .write_char = kgdb_pdc_write_char,
42};
43#endif
44
45static int __init pdc_earlycon_setup(struct earlycon_device *device,
46 const char *opt)
47{
48 struct console *earlycon_console;
49
50 /* If the console is duplex then copy the COUT parameters to CIN. */
51 if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
52 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
53
54 earlycon_console = device->con;
55 earlycon_console->write = pdc_console_write;
56 device->port.iotype = UPIO_MEM32BE;
57
58#ifdef CONFIG_KGDB
59 kgdb_register_io_module(&kgdb_pdc_io_ops);
60#endif
61
62 return 0;
63}
64
65EARLYCON_DECLARE(pdc, pdc_earlycon_setup);
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/pdc.h> /* for iodc_call() proto and friends */
54
55static DEFINE_SPINLOCK(pdc_console_lock);
56static struct console pdc_cons;
57
58static void pdc_console_write(struct console *co, const char *s, unsigned count)
59{
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);
68}
69
70int pdc_console_poll_key(struct console *co)
71{
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;
80}
81
82static int pdc_console_setup(struct console *co, char *options)
83{
84 return 0;
85}
86
87#if defined(CONFIG_PDC_CONSOLE)
88#include <linux/vt_kern.h>
89#include <linux/tty_flip.h>
90
91#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
92
93static struct timer_list pdc_console_timer;
94
95static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
96{
97
98 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
99
100 return 0;
101}
102
103static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
104{
105 if (!tty->count)
106 del_timer(&pdc_console_timer);
107}
108
109static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
110{
111 pdc_console_write(NULL, buf, count);
112 return count;
113}
114
115static int pdc_console_tty_write_room(struct tty_struct *tty)
116{
117 return 32768; /* no limit, no buffer used */
118}
119
120static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty)
121{
122 return 0; /* no buffer */
123}
124
125static struct tty_driver *pdc_console_tty_driver;
126
127static const struct tty_operations pdc_console_tty_ops = {
128 .open = pdc_console_tty_open,
129 .close = pdc_console_tty_close,
130 .write = pdc_console_tty_write,
131 .write_room = pdc_console_tty_write_room,
132 .chars_in_buffer = pdc_console_tty_chars_in_buffer,
133};
134
135static void pdc_console_poll(unsigned long unused)
136{
137
138 int data, count = 0;
139
140 struct tty_struct *tty = pdc_console_tty_driver->ttys[0];
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
156 if (tty->count && (pdc_cons.flags & CON_ENABLED))
157 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
158}
159
160static int __init pdc_console_tty_driver_init(void)
161{
162
163 int err;
164 struct tty_driver *drv;
165
166 /* Check if the console driver is still registered.
167 * It is unregistered if the pdc console was not selected as the
168 * primary console. */
169
170 struct console *tmp;
171
172 console_lock();
173 for_each_console(tmp)
174 if (tmp == &pdc_cons)
175 break;
176 console_unlock();
177
178 if (!tmp) {
179 printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
180 return -ENODEV;
181 }
182
183 printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
184 pdc_cons.flags &= ~CON_BOOT;
185
186 drv = alloc_tty_driver(1);
187
188 if (!drv)
189 return -ENOMEM;
190
191 drv->driver_name = "pdc_cons";
192 drv->name = "ttyB";
193 drv->major = MUX_MAJOR;
194 drv->minor_start = 0;
195 drv->type = TTY_DRIVER_TYPE_SYSTEM;
196 drv->init_termios = tty_std_termios;
197 drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
198 tty_set_operations(drv, &pdc_console_tty_ops);
199
200 err = tty_register_driver(drv);
201 if (err) {
202 printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
203 return err;
204 }
205
206 pdc_console_tty_driver = drv;
207
208 /* No need to initialize the pdc_console_timer if tty isn't allocated */
209 init_timer(&pdc_console_timer);
210 pdc_console_timer.function = pdc_console_poll;
211
212 return 0;
213}
214
215module_init(pdc_console_tty_driver_init);
216
217static struct tty_driver * pdc_console_device (struct console *c, int *index)
218{
219 *index = c->index;
220 return pdc_console_tty_driver;
221}
222#else
223#define pdc_console_device NULL
224#endif
225
226static struct console pdc_cons = {
227 .name = "ttyB",
228 .write = pdc_console_write,
229 .device = pdc_console_device,
230 .setup = pdc_console_setup,
231 .flags = CON_BOOT | CON_PRINTBUFFER,
232 .index = -1,
233};
234
235static int pdc_console_initialized;
236
237static void pdc_console_init_force(void)
238{
239 if (pdc_console_initialized)
240 return;
241 ++pdc_console_initialized;
242
243 /* If the console is duplex then copy the COUT parameters to CIN. */
244 if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
245 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
246
247 /* register the pdc console */
248 register_console(&pdc_cons);
249}
250
251void __init pdc_console_init(void)
252{
253#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
254 pdc_console_init_force();
255#endif
256#ifdef EARLY_BOOTUP_DEBUG
257 printk(KERN_INFO "Initialized PDC Console for debugging.\n");
258#endif
259}
260
261
262/*
263 * Used for emergencies. Currently only used if an HPMC occurs. If an
264 * HPMC occurs, it is possible that the current console may not be
265 * properly initialised after the PDC IO reset. This routine unregisters
266 * all of the current consoles, reinitializes the pdc console and
267 * registers it.
268 */
269
270void pdc_console_restart(void)
271{
272 struct console *console;
273
274 if (pdc_console_initialized)
275 return;
276
277 /* If we've already seen the output, don't bother to print it again */
278 if (console_drivers != NULL)
279 pdc_cons.flags &= ~CON_PRINTBUFFER;
280
281 while ((console = console_drivers) != NULL)
282 unregister_console(console_drivers);
283
284 /* force registering the pdc console */
285 pdc_console_init_force();
286}