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 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; 96 97 static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp) 98 { 99 tty_port_tty_set(&tty_port, tty); 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_sync(&pdc_console_timer); 109 tty_port_tty_set(&tty_port, NULL); 110 } 111 } 112 113 static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) 114 { 115 pdc_console_write(NULL, buf, count); 116 return count; 117 } 118 119 static int pdc_console_tty_write_room(struct tty_struct *tty) 120 { 121 return 32768; /* no limit, no buffer used */ 122 } 123 124 static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty) 125 { 126 return 0; /* no buffer */ 127 } 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 int data, count = 0; 140 struct tty_struct *tty = tty_port_tty_get(&tty_port); 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 tty_kref_put(tty); 157 158 if (pdc_cons.flags & CON_ENABLED) 159 mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); 160 } 161 162 static struct tty_driver *pdc_console_tty_driver; 163 164 static int __init pdc_console_tty_driver_init(void) 165 { 166 int err; 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; 173 174 console_lock(); 175 for_each_console(tmp) 176 if (tmp == &pdc_cons) 177 break; 178 console_unlock(); 179 180 if (!tmp) { 181 printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name); 182 return -ENODEV; 183 } 184 185 printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n"); 186 pdc_cons.flags &= ~CON_BOOT; 187 188 tty_port_init(&tty_port); 189 190 pdc_console_tty_driver = alloc_tty_driver(1); 191 192 if (!pdc_console_tty_driver) 193 return -ENOMEM; 194 195 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); 204 205 err = tty_register_driver(pdc_console_tty_driver); 206 if (err) { 207 printk(KERN_ERR "Unable to register the PDC console TTY driver\n"); 208 return err; 209 } 210 211 return 0; 212 } 213 214 module_init(pdc_console_tty_driver_init); 215 216 static struct tty_driver * pdc_console_device (struct console *c, int *index) 217 { 218 *index = c->index; 219 return pdc_console_tty_driver; 220 } 221 #else 222 #define pdc_console_device NULL 223 #endif 224 225 static struct console pdc_cons = { 226 .name = "ttyB", 227 .write = pdc_console_write, 228 .device = pdc_console_device, 229 .setup = pdc_console_setup, 230 .flags = CON_BOOT | CON_PRINTBUFFER, 231 .index = -1, 232 }; 233 234 static int pdc_console_initialized; 235 236 static void pdc_console_init_force(void) 237 { 238 if (pdc_console_initialized) 239 return; 240 ++pdc_console_initialized; 241 242 /* 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)); 245 246 /* register the pdc console */ 247 register_console(&pdc_cons); 248 } 249 250 void __init pdc_console_init(void) 251 { 252 #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) 253 pdc_console_init_force(); 254 #endif 255 #ifdef EARLY_BOOTUP_DEBUG 256 printk(KERN_INFO "Initialized PDC Console for debugging.\n"); 257 #endif 258 } 259 260 261 /* 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 266 * registers it. 267 */ 268 269 void pdc_console_restart(void) 270 { 271 struct console *console; 272 273 if (pdc_console_initialized) 274 return; 275 276 /* 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; 279 280 while ((console = console_drivers) != NULL) 281 unregister_console(console_drivers); 282 283 /* force registering the pdc console */ 284 pdc_console_init_force(); 285 } 286