diff options
Diffstat (limited to 'arch/parisc/kernel/pdc_cons.c')
| -rw-r--r-- | arch/parisc/kernel/pdc_cons.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c new file mode 100644 index 00000000000..01f676d1673 --- /dev/null +++ b/arch/parisc/kernel/pdc_cons.c @@ -0,0 +1,189 @@ +/* + * PDC Console support - ie use firmware to dump text via boot console + * + * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org> + * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net> + * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org> + * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org> + * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org> + * Copyright (C) 2000 Michael Ang <mang with subcarrier.org> + * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org> + * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org> + * Copyright (C) 2001 Helge Deller <deller at parisc-linux.org> + * Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org> + * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* + * The PDC console is a simple console, which can be used for debugging + * boot related problems on HP PA-RISC machines. + * + * This code uses the ROM (=PDC) based functions to read and write characters + * from and to PDC's boot path. + * Since all character read from that path must be polled, this code never + * can or will be a fully functional linux console. + */ + +/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems. + * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */ +#undef EARLY_BOOTUP_DEBUG + + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/console.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/major.h> +#include <linux/tty.h> +#include <asm/page.h> +#include <asm/types.h> +#include <asm/system.h> +#include <asm/pdc.h> /* for iodc_call() proto and friends */ + + +static void pdc_console_write(struct console *co, const char *s, unsigned count) +{ + while(count--) + pdc_iodc_putc(*s++); +} + +void pdc_outc(unsigned char c) +{ + pdc_iodc_outc(c); +} + +void pdc_printf(const char *fmt, ...) +{ + va_list args; + char buf[1024]; + int i, len; + + va_start(args, fmt); + len = vscnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + for (i = 0; i < len; i++) + pdc_iodc_outc(buf[i]); +} + +int pdc_console_poll_key(struct console *co) +{ + return pdc_iodc_getc(); +} + +static int pdc_console_setup(struct console *co, char *options) +{ + return 0; +} + +#if defined(CONFIG_PDC_CONSOLE) +#define PDC_CONSOLE_DEVICE pdc_console_device +static struct tty_driver * pdc_console_device (struct console *c, int *index) +{ + extern struct tty_driver console_driver; + *index = c->index ? c->index-1 : fg_console; + return &console_driver; +} +#else +#define PDC_CONSOLE_DEVICE NULL +#endif + +static struct console pdc_cons = { + .name = "ttyB", + .write = pdc_console_write, + .device = PDC_CONSOLE_DEVICE, + .setup = pdc_console_setup, + .flags = CON_BOOT|CON_PRINTBUFFER|CON_ENABLED, + .index = -1, +}; + +static int pdc_console_initialized; +extern unsigned long con_start; /* kernel/printk.c */ +extern unsigned long log_end; /* kernel/printk.c */ + + +static void pdc_console_init_force(void) +{ + if (pdc_console_initialized) + return; + ++pdc_console_initialized; + + /* If the console is duplex then copy the COUT parameters to CIN. */ + if (PAGE0->mem_cons.cl_class == CL_DUPLEX) + memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons)); + + /* register the pdc console */ + register_console(&pdc_cons); +} + +void __init pdc_console_init(void) +{ +#if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) + pdc_console_init_force(); +#endif +#ifdef EARLY_BOOTUP_DEBUG + printk(KERN_INFO "Initialized PDC Console for debugging.\n"); +#endif +} + + +/* Unregister the pdc console with the printk console layer */ +void pdc_console_die(void) +{ + if (!pdc_console_initialized) + return; + --pdc_console_initialized; + + printk(KERN_INFO "Switching from PDC console\n"); + + /* Don't repeat what we've already printed */ + con_start = log_end; + + unregister_console(&pdc_cons); +} + + +/* + * Used for emergencies. Currently only used if an HPMC occurs. If an + * HPMC occurs, it is possible that the current console may not be + * properly initialed after the PDC IO reset. This routine unregisters all + * of the current consoles, reinitializes the pdc console and + * registers it. + */ + +void pdc_console_restart(void) +{ + struct console *console; + + if (pdc_console_initialized) + return; + + while ((console = console_drivers) != NULL) + unregister_console(console_drivers); + + /* Don't repeat what we've already printed */ + con_start = log_end; + + /* force registering the pdc console */ + pdc_console_init_force(); +} + |