linux_dsm_epyc7002/drivers/watchdog/wdt285.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

227 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Intel 21285 watchdog driver
* Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
*
* based on
*
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <linux/irq.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/system_info.h>
#include <asm/hardware/dec21285.h>
/*
* Define this to stop the watchdog actually rebooting the machine.
*/
#undef ONLY_TESTING
static unsigned int soft_margin = 60; /* in seconds */
static unsigned int reload;
static unsigned long timer_alive;
#ifdef ONLY_TESTING
/*
* If the timer expires..
*/
static void watchdog_fire(int irq, void *dev_id)
{
pr_crit("Would Reboot\n");
*CSR_TIMER4_CNTL = 0;
*CSR_TIMER4_CLR = 0;
}
#endif
/*
* Refresh the timer.
*/
static void watchdog_ping(void)
{
*CSR_TIMER4_LOAD = reload;
}
/*
* Allow only one person to hold it open
*/
static int watchdog_open(struct inode *inode, struct file *file)
{
int ret;
if (*CSR_SA110_CNTL & (1 << 13))
return -EBUSY;
if (test_and_set_bit(1, &timer_alive))
return -EBUSY;
reload = soft_margin * (mem_fclk_21285 / 256);
*CSR_TIMER4_CLR = 0;
watchdog_ping();
*CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD
| TIMER_CNTL_DIV256;
#ifdef ONLY_TESTING
ret = request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
if (ret) {
*CSR_TIMER4_CNTL = 0;
clear_bit(1, &timer_alive);
}
#else
/*
* Setting this bit is irreversible; once enabled, there is
* no way to disable the watchdog.
*/
*CSR_SA110_CNTL |= 1 << 13;
ret = 0;
#endif
stream_open(inode, file);
return ret;
}
/*
* Shut off the timer.
* Note: if we really have enabled the watchdog, there
* is no way to turn off.
*/
static int watchdog_release(struct inode *inode, struct file *file)
{
#ifdef ONLY_TESTING
free_irq(IRQ_TIMER4, NULL);
clear_bit(1, &timer_alive);
#endif
return 0;
}
static ssize_t watchdog_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/*
* Refresh the timer.
*/
if (len)
watchdog_ping();
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT,
.identity = "Footbridge Watchdog",
};
static long watchdog_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int __user *int_arg = (int __user *)arg;
int new_margin, ret = -ENOTTY;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = 0;
if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, int_arg);
break;
case WDIOC_KEEPALIVE:
watchdog_ping();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(new_margin, int_arg);
if (ret)
break;
/* Arbitrary, can't find the card's limits */
if (new_margin < 0 || new_margin > 60) {
ret = -EINVAL;
break;
}
soft_margin = new_margin;
reload = soft_margin * (mem_fclk_21285 / 256);
watchdog_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
ret = put_user(soft_margin, int_arg);
break;
}
return ret;
}
static const struct file_operations watchdog_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = watchdog_write,
.unlocked_ioctl = watchdog_ioctl,
.open = watchdog_open,
.release = watchdog_release,
};
static struct miscdevice watchdog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &watchdog_fops,
};
static int __init footbridge_watchdog_init(void)
{
int retval;
if (machine_is_netwinder())
return -ENODEV;
retval = misc_register(&watchdog_miscdev);
if (retval < 0)
return retval;
pr_info("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
soft_margin);
if (machine_is_cats())
pr_warn("Warning: Watchdog reset may not work on this machine\n");
return 0;
}
static void __exit footbridge_watchdog_exit(void)
{
misc_deregister(&watchdog_miscdev);
}
MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
MODULE_DESCRIPTION("Footbridge watchdog driver");
MODULE_LICENSE("GPL");
module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
module_init(footbridge_watchdog_init);
module_exit(footbridge_watchdog_exit);