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 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 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 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 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 } 105 106 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 } 113 114 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 } 119 120 static int pdc_console_tty_write_room(struct tty_struct *tty) 121 { 122 return 32768; /* no limit, no buffer used */ 123 } 124 125 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 }; 137 138 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; 158 159 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); 211 212 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; 231 232 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 } 245 246 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 */ 264 265 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