remarkable-linux/drivers/watchdog/indydog.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

204 lines
4.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
*
* (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>,
* All Rights Reserved.
*
* based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
*/
#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/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <asm/sgi/mc.h>
static unsigned long indydog_alive;
static DEFINE_SPINLOCK(indydog_lock);
#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static void indydog_start(void)
{
spin_lock(&indydog_lock);
sgimc->cpuctrl0 |= SGIMC_CCTRL0_WDOG;
spin_unlock(&indydog_lock);
}
static void indydog_stop(void)
{
spin_lock(&indydog_lock);
sgimc->cpuctrl0 &= ~SGIMC_CCTRL0_WDOG;
spin_unlock(&indydog_lock);
pr_info("Stopped watchdog timer\n");
}
static void indydog_ping(void)
{
sgimc->watchdogt = 0;
}
/*
* Allow only one person to hold it open
*/
static int indydog_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &indydog_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Activate timer */
indydog_start();
indydog_ping();
pr_info("Started watchdog timer\n");
return stream_open(inode, file);
}
static int indydog_release(struct inode *inode, struct file *file)
{
/* Shut off the timer.
* Lock it in if it's a module and we defined ...NOWAYOUT */
if (!nowayout)
indydog_stop(); /* Turn the WDT off */
clear_bit(0, &indydog_alive);
return 0;
}
static ssize_t indydog_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
/* Refresh the timer. */
if (len)
indydog_ping();
return len;
}
static long indydog_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int options, retval = -EINVAL;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING,
.firmware_version = 0,
.identity = "Hardware Watchdog for SGI IP22",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user((struct watchdog_info *)arg,
&ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_SETOPTIONS:
{
if (get_user(options, (int *)arg))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
indydog_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
indydog_start();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
indydog_ping();
return 0;
case WDIOC_GETTIMEOUT:
return put_user(WATCHDOG_TIMEOUT, (int *)arg);
default:
return -ENOTTY;
}
}
static int indydog_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
indydog_stop(); /* Turn the WDT off */
return NOTIFY_DONE;
}
static const struct file_operations indydog_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = indydog_write,
.unlocked_ioctl = indydog_ioctl,
.open = indydog_open,
.release = indydog_release,
};
static struct miscdevice indydog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &indydog_fops,
};
static struct notifier_block indydog_notifier = {
.notifier_call = indydog_notify_sys,
};
static int __init watchdog_init(void)
{
int ret;
ret = register_reboot_notifier(&indydog_notifier);
if (ret) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
return ret;
}
ret = misc_register(&indydog_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&indydog_notifier);
return ret;
}
pr_info("Hardware Watchdog Timer for SGI IP22: 0.3\n");
return 0;
}
static void __exit watchdog_exit(void)
{
misc_deregister(&indydog_miscdev);
unregister_reboot_notifier(&indydog_notifier);
}
module_init(watchdog_init);
module_exit(watchdog_exit);
MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
MODULE_LICENSE("GPL");