alistair23-linux/arch/parisc/kernel/pdc_cons.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

268 lines
7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
/*
* 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();
}