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 } 189 190