diff options
Diffstat (limited to 'arch/parisc/kernel/pdc_cons.c')
| -rw-r--r-- | arch/parisc/kernel/pdc_cons.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c new file mode 100644 index 000000000..c46bf29ae --- /dev/null +++ b/arch/parisc/kernel/pdc_cons.c @@ -0,0 +1,281 @@ +/* + * 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> + * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be> + * + * + * 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. It is also useful when no + * other console works. + * + * This code uses the ROM (=PDC) based functions to read and write characters + * from and to PDC's boot path. + */ + +/* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems. + * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */ +#define EARLY_BOOTUP_DEBUG + + +#include <linux/kernel.h> +#include <linux/console.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/major.h> +#include <linux/tty.h> +#include <asm/page.h> /* for PAGE0 */ +#include <asm/pdc.h> /* for iodc_call() proto and friends */ + +static DEFINE_SPINLOCK(pdc_console_lock); +static struct console pdc_cons; + +static void pdc_console_write(struct console *co, const char *s, unsigned count) +{ + int i = 0; + unsigned long flags; + + spin_lock_irqsave(&pdc_console_lock, flags); + do { + i += pdc_iodc_print(s + i, count - i); + } while (i < count); + spin_unlock_irqrestore(&pdc_console_lock, flags); +} + +int pdc_console_poll_key(struct console *co) +{ + int c; + unsigned long flags; + + spin_lock_irqsave(&pdc_console_lock, flags); + c = pdc_iodc_getc(); + spin_unlock_irqrestore(&pdc_console_lock, flags); + + return c; +} + +static int pdc_console_setup(struct console *co, char *options) +{ + return 0; +} + +#if defined(CONFIG_PDC_CONSOLE) +#include <linux/vt_kern.h> +#include <linux/tty_flip.h> + +#define PDC_CONS_POLL_DELAY (30 * HZ / 1000) + +static void pdc_console_poll(struct timer_list *unused); +static DEFINE_TIMER(pdc_console_timer, pdc_console_poll); +static struct tty_port tty_port; + +static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp) +{ + tty_port_tty_set(&tty_port, tty); + mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); + + return 0; +} + +static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp) +{ + if (tty->count == 1) { + del_timer_sync(&pdc_console_timer); + tty_port_tty_set(&tty_port, NULL); + } +} + +static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) +{ + pdc_console_write(NULL, buf, count); + return count; +} + +static int pdc_console_tty_write_room(struct tty_struct *tty) +{ + return 32768; /* no limit, no buffer used */ +} + +static int pdc_console_tty_chars_in_buffer(struct tty_struct *tty) +{ + return 0; /* no buffer */ +} + +static const struct tty_operations pdc_console_tty_ops = { + .open = pdc_console_tty_open, + .close = pdc_console_tty_close, + .write = pdc_console_tty_write, + .write_room = pdc_console_tty_write_room, + .chars_in_buffer = pdc_console_tty_chars_in_buffer, +}; + +static void pdc_console_poll(struct timer_list *unused) +{ + int data, count = 0; + + while (1) { + data = pdc_console_poll_key(NULL); + if (data == -1) + break; + tty_insert_flip_char(&tty_port, data & 0xFF, TTY_NORMAL); + count ++; + } + + if (count) + tty_flip_buffer_push(&tty_port); + + if (pdc_cons.flags & CON_ENABLED) + mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); +} + +static struct tty_driver *pdc_console_tty_driver; + +static int __init pdc_console_tty_driver_init(void) +{ + int err; + + /* Check if the console driver is still registered. + * It is unregistered if the pdc console was not selected as the + * primary console. */ + + struct console *tmp; + + console_lock(); + for_each_console(tmp) + if (tmp == &pdc_cons) + break; + console_unlock(); + + if (!tmp) { + printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name); + return -ENODEV; + } + + printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n"); + pdc_cons.flags &= ~CON_BOOT; + + pdc_console_tty_driver = alloc_tty_driver(1); + + if (!pdc_console_tty_driver) + return -ENOMEM; + + tty_port_init(&tty_port); + + pdc_console_tty_driver->driver_name = "pdc_cons"; + pdc_console_tty_driver->name = "ttyB"; + pdc_console_tty_driver->major = MUX_MAJOR; + pdc_console_tty_driver->minor_start = 0; + pdc_console_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; + pdc_console_tty_driver->init_termios = tty_std_termios; + pdc_console_tty_driver->flags = TTY_DRIVER_REAL_RAW | + TTY_DRIVER_RESET_TERMIOS; + tty_set_operations(pdc_console_tty_driver, &pdc_console_tty_ops); + tty_port_link_device(&tty_port, pdc_console_tty_driver, 0); + + err = tty_register_driver(pdc_console_tty_driver); + if (err) { + printk(KERN_ERR "Unable to register the PDC console TTY driver\n"); + tty_port_destroy(&tty_port); + return err; + } + + return 0; +} +device_initcall(pdc_console_tty_driver_init); + +static struct tty_driver * pdc_console_device (struct console *c, int *index) +{ + *index = c->index; + return pdc_console_tty_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, + .index = -1, +}; + +static int pdc_console_initialized; + +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 +} + + +/* + * 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 initialised 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; + + /* If we've already seen the output, don't bother to print it again */ + if (console_drivers != NULL) + pdc_cons.flags &= ~CON_PRINTBUFFER; + + while ((console = console_drivers) != NULL) + unregister_console(console_drivers); + + /* force registering the pdc console */ + pdc_console_init_force(); +} |