Loading...
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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PDC Console support - ie use firmware to dump text via boot console
4 *
5 * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
6 * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net>
7 * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org>
8 * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
9 * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org>
10 * Copyright (C) 2000 Michael Ang <mang with subcarrier.org>
11 * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org>
12 * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org>
13 * Copyright (C) 2001 Helge Deller <deller at parisc-linux.org>
14 * Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
15 * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org>
16 * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be>
17 */
18
19/*
20 * The PDC console is a simple console, which can be used for debugging
21 * boot related problems on HP PA-RISC machines. It is also useful when no
22 * other console works.
23 *
24 * This code uses the ROM (=PDC) based functions to read and write characters
25 * from and to PDC's boot path.
26 */
27
28/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems.
29 * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */
30#define EARLY_BOOTUP_DEBUG
31
32
33#include <linux/kernel.h>
34#include <linux/console.h>
35#include <linux/string.h>
36#include <linux/init.h>
37#include <linux/major.h>
38#include <linux/tty.h>
39#include <asm/page.h> /* for PAGE0 */
40#include <asm/pdc.h> /* for iodc_call() proto and friends */
41
42static DEFINE_SPINLOCK(pdc_console_lock);
43static struct console pdc_cons;
44
45static void pdc_console_write(struct console *co, const char *s, unsigned count)
46{
47 int i = 0;
48 unsigned long flags;
49
50 spin_lock_irqsave(&pdc_console_lock, flags);
51 do {
52 i += pdc_iodc_print(s + i, count - i);
53 } while (i < count);
54 spin_unlock_irqrestore(&pdc_console_lock, flags);
55}
56
57int pdc_console_poll_key(struct console *co)
58{
59 int c;
60 unsigned long flags;
61
62 spin_lock_irqsave(&pdc_console_lock, flags);
63 c = pdc_iodc_getc();
64 spin_unlock_irqrestore(&pdc_console_lock, flags);
65
66 return c;
67}
68
69static int pdc_console_setup(struct console *co, char *options)
70{
71 return 0;
72}
73
74#if defined(CONFIG_PDC_CONSOLE)
75#include <linux/vt_kern.h>
76#include <linux/tty_flip.h>
77
78#define PDC_CONS_POLL_DELAY (30 * HZ / 1000)
79
80static void pdc_console_poll(struct timer_list *unused);
81static DEFINE_TIMER(pdc_console_timer, pdc_console_poll);
82static struct tty_port tty_port;
83
84static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
85{
86 tty_port_tty_set(&tty_port, tty);
87 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
88
89 return 0;
90}
91
92static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
93{
94 if (tty->count == 1) {
95 del_timer_sync(&pdc_console_timer);
96 tty_port_tty_set(&tty_port, NULL);
97 }
98}
99
100static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
101{
102 pdc_console_write(NULL, buf, count);
103 return count;
104}
105
106static unsigned int pdc_console_tty_write_room(struct tty_struct *tty)
107{
108 return 32768; /* no limit, no buffer used */
109}
110
111static const struct tty_operations pdc_console_tty_ops = {
112 .open = pdc_console_tty_open,
113 .close = pdc_console_tty_close,
114 .write = pdc_console_tty_write,
115 .write_room = pdc_console_tty_write_room,
116};
117
118static void pdc_console_poll(struct timer_list *unused)
119{
120 int data, count = 0;
121
122 while (1) {
123 data = pdc_console_poll_key(NULL);
124 if (data == -1)
125 break;
126 tty_insert_flip_char(&tty_port, data & 0xFF, TTY_NORMAL);
127 count ++;
128 }
129
130 if (count)
131 tty_flip_buffer_push(&tty_port);
132
133 if (pdc_cons.flags & CON_ENABLED)
134 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY);
135}
136
137static struct tty_driver *pdc_console_tty_driver;
138
139static int __init pdc_console_tty_driver_init(void)
140{
141 int err;
142
143 /* Check if the console driver is still registered.
144 * It is unregistered if the pdc console was not selected as the
145 * primary console. */
146
147 struct console *tmp;
148
149 console_lock();
150 for_each_console(tmp)
151 if (tmp == &pdc_cons)
152 break;
153 console_unlock();
154
155 if (!tmp) {
156 printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name);
157 return -ENODEV;
158 }
159
160 printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n");
161 pdc_cons.flags &= ~CON_BOOT;
162
163 pdc_console_tty_driver = alloc_tty_driver(1);
164
165 if (!pdc_console_tty_driver)
166 return -ENOMEM;
167
168 tty_port_init(&tty_port);
169
170 pdc_console_tty_driver->driver_name = "pdc_cons";
171 pdc_console_tty_driver->name = "ttyB";
172 pdc_console_tty_driver->major = MUX_MAJOR;
173 pdc_console_tty_driver->minor_start = 0;
174 pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
175 pdc_console_tty_driver->init_termios = tty_std_termios;
176 pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW |
177 TTY_DRIVER_RESET_TERMIOS;
178 tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops);
179 tty_port_link_device(&tty_port, pdc_console_tty_driver, 0);
180
181 err = tty_register_driver(pdc_console_tty_driver);
182 if (err) {
183 printk(KERN_ERR "Unable to register the PDC console TTY driver\n");
184 tty_port_destroy(&tty_port);
185 return err;
186 }
187
188 return 0;
189}
190device_initcall(pdc_console_tty_driver_init);
191
192static struct tty_driver * pdc_console_device (struct console *c, int *index)
193{
194 *index = c->index;
195 return pdc_console_tty_driver;
196}
197#else
198#define pdc_console_device NULL
199#endif
200
201static struct console pdc_cons = {
202 .name = "ttyB",
203 .write = pdc_console_write,
204 .device = pdc_console_device,
205 .setup = pdc_console_setup,
206 .flags = CON_BOOT | CON_PRINTBUFFER,
207 .index = -1,
208};
209
210static int pdc_console_initialized;
211
212static void pdc_console_init_force(void)
213{
214 if (pdc_console_initialized)
215 return;
216 ++pdc_console_initialized;
217
218 /* If the console is duplex then copy the COUT parameters to CIN. */
219 if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
220 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
221
222 /* register the pdc console */
223 register_console(&pdc_cons);
224}
225
226void __init pdc_console_init(void)
227{
228#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE)
229 pdc_console_init_force();
230#endif
231#ifdef EARLY_BOOTUP_DEBUG
232 printk(KERN_INFO "Initialized PDC Console for debugging.\n");
233#endif
234}
235
236
237/*
238 * Used for emergencies. Currently only used if an HPMC occurs. If an
239 * HPMC occurs, it is possible that the current console may not be
240 * properly initialised after the PDC IO reset. This routine unregisters
241 * all of the current consoles, reinitializes the pdc console and
242 * registers it.
243 */
244
245void pdc_console_restart(void)
246{
247 struct console *console;
248
249 if (pdc_console_initialized)
250 return;
251
252 /* If we've already seen the output, don't bother to print it again */
253 if (console_drivers != NULL)
254 pdc_cons.flags &= ~CON_PRINTBUFFER;
255
256 while ((console = console_drivers) != NULL)
257 unregister_console(console_drivers);
258
259 /* force registering the pdc console */
260 pdc_console_init_force();
261}