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 #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 56 static void pdc_console_write(struct console *co, const char *s, unsigned count) 57 { 58 pdc_iodc_print(s, count); 59 } 60 61 void pdc_printf(const char *fmt, ...) 62 { 63 va_list args; 64 char buf[1024]; 65 int i, len; 66 67 va_start(args, fmt); 68 len = vscnprintf(buf, sizeof(buf), fmt, args); 69 va_end(args); 70 71 pdc_iodc_print(buf, len); 72 } 73 74 int pdc_console_poll_key(struct console *co) 75 { 76 return pdc_iodc_getc(); 77 } 78 79 static int pdc_console_setup(struct console *co, char *options) 80 { 81 return 0; 82 } 83 84 #if defined(CONFIG_PDC_CONSOLE) 85 #include <linux/vt_kern.h> 86 87 static struct tty_driver * pdc_console_device (struct console *c, int *index) 88 { 89 extern struct tty_driver console_driver; 90 *index = c->index ? c->index-1 : fg_console; 91 return &console_driver; 92 } 93 #else 94 #define pdc_console_device NULL 95 #endif 96 97 static struct console pdc_cons = { 98 .name = "ttyB", 99 .write = pdc_console_write, 100 .device = pdc_console_device, 101 .setup = pdc_console_setup, 102 .flags = CON_BOOT | CON_PRINTBUFFER | CON_ENABLED, 103 .index = -1, 104 }; 105 106 static int pdc_console_initialized; 107 108 static void pdc_console_init_force(void) 109 { 110 if (pdc_console_initialized) 111 return; 112 ++pdc_console_initialized; 113 114 /* If the console is duplex then copy the COUT parameters to CIN. */ 115 if (PAGE0->mem_cons.cl_class == CL_DUPLEX) 116 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons)); 117 118 /* register the pdc console */ 119 register_console(&pdc_cons); 120 } 121 122 void __init pdc_console_init(void) 123 { 124 #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) 125 pdc_console_init_force(); 126 #endif 127 #ifdef EARLY_BOOTUP_DEBUG 128 printk(KERN_INFO "Initialized PDC Console for debugging.\n"); 129 #endif 130 } 131 132 133 /* 134 * Used for emergencies. Currently only used if an HPMC occurs. If an 135 * HPMC occurs, it is possible that the current console may not be 136 * properly initialised after the PDC IO reset. This routine unregisters 137 * all of the current consoles, reinitializes the pdc console and 138 * registers it. 139 */ 140 141 void pdc_console_restart(void) 142 { 143 struct console *console; 144 145 if (pdc_console_initialized) 146 return; 147 148 /* If we've already seen the output, don't bother to print it again */ 149 if (console_drivers != NULL) 150 pdc_cons.flags &= ~CON_PRINTBUFFER; 151 152 while ((console = console_drivers) != NULL) 153 unregister_console(console_drivers); 154 155 /* force registering the pdc console */ 156 pdc_console_init_force(); 157 } 158