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 55 static DEFINE_SPINLOCK(pdc_console_lock); 56 static struct console pdc_cons; 57 58 static 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 70 int 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 82 static 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 93 static struct timer_list pdc_console_timer; 94 95 extern struct console * console_drivers; 96 97 static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp) 98 { 99 100 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); 101 102 return 0; 103 } 104 105 static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp) 106 { 107 if (!tty->count) 108 del_timer(&pdc_console_timer); 109 } 110 111 static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) 112 { 113 pdc_console_write(NULL, buf, count); 114 return count; 115 } 116 117 static int pdc_console_tty_write_room(struct tty_struct *tty) 118 { 119 return 32768; /* no limit, no buffer used */ 120 } 121 122 static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty) 123 { 124 return 0; /* no buffer */ 125 } 126 127 static struct tty_driver *pdc_console_tty_driver; 128 129 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, 135 }; 136 137 static void pdc_console_poll(unsigned long unused) 138 { 139 140 int data, count = 0; 141 142 struct tty_struct *tty = pdc_console_tty_driver->ttys[0]; 143 144 if (!tty) 145 return; 146 147 while (1) { 148 data = pdc_console_poll_key(NULL); 149 if (data == -1) 150 break; 151 tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL); 152 count ++; 153 } 154 155 if (count) 156 tty_flip_buffer_push(tty); 157 158 if (tty->count && (pdc_cons.flags & CON_ENABLED)) 159 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); 160 } 161 162 static int __init pdc_console_tty_driver_init(void) 163 { 164 165 int err; 166 struct tty_driver *drv; 167 168 /* Check if the console driver is still registered. 169 * It is unregistered if the pdc console was not selected as the 170 * primary console. */ 171 172 struct console *tmp = console_drivers; 173 174 for (tmp = console_drivers; tmp; tmp = tmp->next) 175 if (tmp == &pdc_cons) 176 break; 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 } 214 215 module_init(pdc_console_tty_driver_init); 216 217 static 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 225 226 static 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 }; 234 235 static int pdc_console_initialized; 236 237 static 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 } 250 251 void __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 */ 269 270 void 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 } 287