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remarkable-linux/drivers/watchdog/pnx833x_wdt.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

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PNX833x Hardware Watchdog Driver
* Copyright 2008 NXP Semiconductors
* Daniel Laird <daniel.j.laird@nxp.com>
* Andre McCurdy <andre.mccurdy@nxp.com>
*
* Heavily based upon - 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@redhat.com>
*/
#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 <asm/mach-pnx833x/pnx833x.h>
#define WATCHDOG_TIMEOUT 30 /* 30 sec Maximum timeout */
#define WATCHDOG_COUNT_FREQUENCY 68000000U /* Watchdog counts at 68MHZ. */
#define PNX_WATCHDOG_TIMEOUT (WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY)
#define PNX_TIMEOUT_VALUE 2040000000U
/** CONFIG block */
#define PNX833X_CONFIG (0x07000U)
#define PNX833X_CONFIG_CPU_WATCHDOG (0x54)
#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)
#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)
/** RESET block */
#define PNX833X_RESET (0x08000U)
#define PNX833X_RESET_CONFIG (0x08)
static int pnx833x_wdt_alive;
/* Set default timeout in MHZ.*/
static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT;
module_param(pnx833x_wdt_timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
__MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds).");
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) ")");
#define START_DEFAULT 1
static int start_enabled = START_DEFAULT;
module_param(start_enabled, int, 0);
MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
"(default=" __MODULE_STRING(START_DEFAULT) ")");
static void pnx833x_wdt_start(void)
{
/* Enable watchdog causing reset. */
PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1;
/* Set timeout.*/
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
/* Enable watchdog. */
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1;
pr_info("Started watchdog timer\n");
}
static void pnx833x_wdt_stop(void)
{
/* Disable watchdog causing reset. */
PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE;
/* Disable watchdog.*/
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE;
pr_info("Stopped watchdog timer\n");
}
static void pnx833x_wdt_ping(void)
{
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout;
}
/*
* Allow only one person to hold it open
*/
static int pnx833x_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &pnx833x_wdt_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Activate timer */
if (!start_enabled)
pnx833x_wdt_start();
pnx833x_wdt_ping();
pr_info("Started watchdog timer\n");
return stream_open(inode, file);
}
static int pnx833x_wdt_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)
pnx833x_wdt_stop(); /* Turn the WDT off */
clear_bit(0, &pnx833x_wdt_alive);
return 0;
}
static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
/* Refresh the timer. */
if (len)
pnx833x_wdt_ping();
return len;
}
static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int options, new_timeout = 0;
uint32_t timeout, timeout_left = 0;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
.firmware_version = 0,
.identity = "Hardware Watchdog for PNX833x",
};
switch (cmd) {
default:
return -ENOTTY;
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)
pnx833x_wdt_stop();
if (options & WDIOS_ENABLECARD)
pnx833x_wdt_start();
return 0;
case WDIOC_KEEPALIVE:
pnx833x_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
{
if (get_user(new_timeout, (int *)arg))
return -EFAULT;
pnx833x_wdt_timeout = new_timeout;
PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout;
return put_user(new_timeout, (int *)arg);
}
case WDIOC_GETTIMEOUT:
timeout = PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_WATCHDOG_COMPARE);
return put_user(timeout, (int *)arg);
case WDIOC_GETTIMELEFT:
timeout_left = PNX833X_REG(PNX833X_CONFIG +
PNX833X_CONFIG_CPU_WATCHDOG);
return put_user(timeout_left, (int *)arg);
}
}
static int pnx833x_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
pnx833x_wdt_stop(); /* Turn the WDT off */
return NOTIFY_DONE;
}
static const struct file_operations pnx833x_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = pnx833x_wdt_write,
.unlocked_ioctl = pnx833x_wdt_ioctl,
.open = pnx833x_wdt_open,
.release = pnx833x_wdt_release,
};
static struct miscdevice pnx833x_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &pnx833x_wdt_fops,
};
static struct notifier_block pnx833x_wdt_notifier = {
.notifier_call = pnx833x_wdt_notify_sys,
};
static int __init watchdog_init(void)
{
int ret, cause;
/* Lets check the reason for the reset.*/
cause = PNX833X_REG(PNX833X_RESET);
/*If bit 31 is set then watchdog was cause of reset.*/
if (cause & 0x80000000) {
pr_info("The system was previously reset due to the watchdog firing - please investigate...\n");
}
ret = register_reboot_notifier(&pnx833x_wdt_notifier);
if (ret) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
return ret;
}
ret = misc_register(&pnx833x_wdt_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&pnx833x_wdt_notifier);
return ret;
}
pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n");
if (start_enabled)
pnx833x_wdt_start();
return 0;
}
static void __exit watchdog_exit(void)
{
misc_deregister(&pnx833x_wdt_miscdev);
unregister_reboot_notifier(&pnx833x_wdt_notifier);
}
module_init(watchdog_init);
module_exit(watchdog_exit);
MODULE_AUTHOR("Daniel Laird/Andre McCurdy");
MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x");
MODULE_LICENSE("GPL");
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