Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
| 16 | * |
| 17 | * This program is free software; you can redistribute it and/or modify |
| 18 | * it under the terms of the GNU General Public License as published by |
| 19 | * the Free Software Foundation; either version 2 of the License, or |
| 20 | * (at your option) any later version. |
| 21 | * |
| 22 | * This program is distributed in the hope that it will be useful, |
| 23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 25 | * GNU General Public License for more details. |
| 26 | * |
| 27 | * You should have received a copy of the GNU General Public License |
| 28 | * along with this program; if not, write to the Free Software |
| 29 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * The PDC console is a simple console, which can be used for debugging |
| 34 | * boot related problems on HP PA-RISC machines. |
| 35 | * |
| 36 | * This code uses the ROM (=PDC) based functions to read and write characters |
| 37 | * from and to PDC's boot path. |
| 38 | * Since all character read from that path must be polled, this code never |
| 39 | * can or will be a fully functional linux console. |
| 40 | */ |
| 41 | |
| 42 | /* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems. |
| 43 | * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */ |
| 44 | #undef EARLY_BOOTUP_DEBUG |
| 45 | |
| 46 | |
| 47 | #include <linux/config.h> |
| 48 | #include <linux/kernel.h> |
| 49 | #include <linux/console.h> |
| 50 | #include <linux/string.h> |
| 51 | #include <linux/init.h> |
| 52 | #include <linux/delay.h> |
| 53 | #include <linux/sched.h> |
| 54 | #include <linux/interrupt.h> |
| 55 | #include <linux/major.h> |
| 56 | #include <linux/tty.h> |
| 57 | #include <asm/page.h> |
| 58 | #include <asm/types.h> |
| 59 | #include <asm/system.h> |
| 60 | #include <asm/pdc.h> /* for iodc_call() proto and friends */ |
| 61 | |
| 62 | |
| 63 | static void pdc_console_write(struct console *co, const char *s, unsigned count) |
| 64 | { |
| 65 | while(count--) |
| 66 | pdc_iodc_putc(*s++); |
| 67 | } |
| 68 | |
| 69 | void pdc_outc(unsigned char c) |
| 70 | { |
| 71 | pdc_iodc_outc(c); |
| 72 | } |
| 73 | |
| 74 | void pdc_printf(const char *fmt, ...) |
| 75 | { |
| 76 | va_list args; |
| 77 | char buf[1024]; |
| 78 | int i, len; |
| 79 | |
| 80 | va_start(args, fmt); |
| 81 | len = vscnprintf(buf, sizeof(buf), fmt, args); |
| 82 | va_end(args); |
| 83 | |
| 84 | for (i = 0; i < len; i++) |
| 85 | pdc_iodc_outc(buf[i]); |
| 86 | } |
| 87 | |
| 88 | int pdc_console_poll_key(struct console *co) |
| 89 | { |
| 90 | return pdc_iodc_getc(); |
| 91 | } |
| 92 | |
| 93 | static int pdc_console_setup(struct console *co, char *options) |
| 94 | { |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | #if defined(CONFIG_PDC_CONSOLE) |
| 99 | #define PDC_CONSOLE_DEVICE pdc_console_device |
| 100 | static struct tty_driver * pdc_console_device (struct console *c, int *index) |
| 101 | { |
| 102 | extern struct tty_driver console_driver; |
| 103 | *index = c->index ? c->index-1 : fg_console; |
| 104 | return &console_driver; |
| 105 | } |
| 106 | #else |
| 107 | #define PDC_CONSOLE_DEVICE NULL |
| 108 | #endif |
| 109 | |
| 110 | static struct console pdc_cons = { |
| 111 | .name = "ttyB", |
| 112 | .write = pdc_console_write, |
| 113 | .device = PDC_CONSOLE_DEVICE, |
| 114 | .setup = pdc_console_setup, |
| 115 | .flags = CON_BOOT|CON_PRINTBUFFER|CON_ENABLED, |
| 116 | .index = -1, |
| 117 | }; |
| 118 | |
| 119 | static int pdc_console_initialized; |
| 120 | extern unsigned long con_start; /* kernel/printk.c */ |
| 121 | extern unsigned long log_end; /* kernel/printk.c */ |
| 122 | |
| 123 | |
| 124 | static void pdc_console_init_force(void) |
| 125 | { |
| 126 | if (pdc_console_initialized) |
| 127 | return; |
| 128 | ++pdc_console_initialized; |
| 129 | |
| 130 | /* If the console is duplex then copy the COUT parameters to CIN. */ |
| 131 | if (PAGE0->mem_cons.cl_class == CL_DUPLEX) |
| 132 | memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons)); |
| 133 | |
| 134 | /* register the pdc console */ |
| 135 | register_console(&pdc_cons); |
| 136 | } |
| 137 | |
| 138 | void __init pdc_console_init(void) |
| 139 | { |
| 140 | #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) |
| 141 | pdc_console_init_force(); |
| 142 | #endif |
| 143 | #ifdef EARLY_BOOTUP_DEBUG |
| 144 | printk(KERN_INFO "Initialized PDC Console for debugging.\n"); |
| 145 | #endif |
| 146 | } |
| 147 | |
| 148 | |
| 149 | /* Unregister the pdc console with the printk console layer */ |
| 150 | void pdc_console_die(void) |
| 151 | { |
| 152 | if (!pdc_console_initialized) |
| 153 | return; |
| 154 | --pdc_console_initialized; |
| 155 | |
| 156 | printk(KERN_INFO "Switching from PDC console\n"); |
| 157 | |
| 158 | /* Don't repeat what we've already printed */ |
| 159 | con_start = log_end; |
| 160 | |
| 161 | unregister_console(&pdc_cons); |
| 162 | } |
| 163 | |
| 164 | |
| 165 | /* |
| 166 | * Used for emergencies. Currently only used if an HPMC occurs. If an |
| 167 | * HPMC occurs, it is possible that the current console may not be |
| 168 | * properly initialed after the PDC IO reset. This routine unregisters all |
| 169 | * of the current consoles, reinitializes the pdc console and |
| 170 | * registers it. |
| 171 | */ |
| 172 | |
| 173 | void pdc_console_restart(void) |
| 174 | { |
| 175 | struct console *console; |
| 176 | |
| 177 | if (pdc_console_initialized) |
| 178 | return; |
| 179 | |
| 180 | while ((console = console_drivers) != NULL) |
| 181 | unregister_console(console_drivers); |
| 182 | |
| 183 | /* Don't repeat what we've already printed */ |
| 184 | con_start = log_end; |
| 185 | |
| 186 | /* force registering the pdc console */ |
| 187 | pdc_console_init_force(); |
| 188 | } |
| 189 | |