![Wim Van Sebroeck](/assets/img/avatar_default.png)
move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
232 lines
5.6 KiB
C
232 lines
5.6 KiB
C
/*
|
|
* mpc83xx_wdt.c - MPC83xx watchdog userspace interface
|
|
*
|
|
* Authors: Dave Updegraff <dave@cray.org>
|
|
* Kumar Gala <galak@kernel.crashing.org>
|
|
* Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
|
|
* ..and from sc520_wdt
|
|
*
|
|
* Note: it appears that you can only actually ENABLE or DISABLE the thing
|
|
* once after POR. Once enabled, you cannot disable, and vice versa.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/module.h>
|
|
#include <linux/watchdog.h>
|
|
#include <asm/io.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
struct mpc83xx_wdt {
|
|
__be32 res0;
|
|
__be32 swcrr; /* System watchdog control register */
|
|
#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
|
|
#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
|
|
#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
|
|
#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
|
|
__be32 swcnr; /* System watchdog count register */
|
|
u8 res1[2];
|
|
__be16 swsrr; /* System watchdog service register */
|
|
u8 res2[0xF0];
|
|
};
|
|
|
|
static struct mpc83xx_wdt __iomem *wd_base;
|
|
|
|
static u16 timeout = 0xffff;
|
|
module_param(timeout, ushort, 0);
|
|
MODULE_PARM_DESC(timeout, "Watchdog timeout in ticks. (0<timeout<65536, default=65535");
|
|
|
|
static int reset = 1;
|
|
module_param(reset, bool, 0);
|
|
MODULE_PARM_DESC(reset, "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
|
|
|
|
/*
|
|
* We always prescale, but if someone really doesn't want to they can set this
|
|
* to 0
|
|
*/
|
|
static int prescale = 1;
|
|
static unsigned int timeout_sec;
|
|
|
|
static unsigned long wdt_is_open;
|
|
static spinlock_t wdt_spinlock;
|
|
|
|
static void mpc83xx_wdt_keepalive(void)
|
|
{
|
|
/* Ping the WDT */
|
|
spin_lock(&wdt_spinlock);
|
|
out_be16(&wd_base->swsrr, 0x556c);
|
|
out_be16(&wd_base->swsrr, 0xaa39);
|
|
spin_unlock(&wdt_spinlock);
|
|
}
|
|
|
|
static ssize_t mpc83xx_wdt_write(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
if (count)
|
|
mpc83xx_wdt_keepalive();
|
|
return count;
|
|
}
|
|
|
|
static int mpc83xx_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
u32 tmp = SWCRR_SWEN;
|
|
if (test_and_set_bit(0, &wdt_is_open))
|
|
return -EBUSY;
|
|
|
|
/* Once we start the watchdog we can't stop it */
|
|
__module_get(THIS_MODULE);
|
|
|
|
/* Good, fire up the show */
|
|
if (prescale)
|
|
tmp |= SWCRR_SWPR;
|
|
if (reset)
|
|
tmp |= SWCRR_SWRI;
|
|
|
|
tmp |= timeout << 16;
|
|
|
|
out_be32(&wd_base->swcrr, tmp);
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static int mpc83xx_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
printk(KERN_CRIT "Unexpected close, not stopping watchdog!\n");
|
|
mpc83xx_wdt_keepalive();
|
|
clear_bit(0, &wdt_is_open);
|
|
return 0;
|
|
}
|
|
|
|
static int mpc83xx_wdt_ioctl(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
static struct watchdog_info ident = {
|
|
.options = WDIOF_KEEPALIVEPING,
|
|
.firmware_version = 1,
|
|
.identity = "MPC83xx",
|
|
};
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(0, p);
|
|
case WDIOC_KEEPALIVE:
|
|
mpc83xx_wdt_keepalive();
|
|
return 0;
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(timeout_sec, p);
|
|
default:
|
|
return -ENOTTY;
|
|
}
|
|
}
|
|
|
|
static const struct file_operations mpc83xx_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = mpc83xx_wdt_write,
|
|
.ioctl = mpc83xx_wdt_ioctl,
|
|
.open = mpc83xx_wdt_open,
|
|
.release = mpc83xx_wdt_release,
|
|
};
|
|
|
|
static struct miscdevice mpc83xx_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &mpc83xx_wdt_fops,
|
|
};
|
|
|
|
static int __devinit mpc83xx_wdt_probe(struct platform_device *dev)
|
|
{
|
|
struct resource *r;
|
|
int ret;
|
|
unsigned int *freq = dev->dev.platform_data;
|
|
|
|
/* get a pointer to the register memory */
|
|
r = platform_get_resource(dev, IORESOURCE_MEM, 0);
|
|
|
|
if (!r) {
|
|
ret = -ENODEV;
|
|
goto err_out;
|
|
}
|
|
|
|
wd_base = ioremap(r->start, sizeof (struct mpc83xx_wdt));
|
|
|
|
if (wd_base == NULL) {
|
|
ret = -ENOMEM;
|
|
goto err_out;
|
|
}
|
|
|
|
ret = misc_register(&mpc83xx_wdt_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR "cannot register miscdev on minor=%d "
|
|
"(err=%d)\n",
|
|
WATCHDOG_MINOR, ret);
|
|
goto err_unmap;
|
|
}
|
|
|
|
/* Calculate the timeout in seconds */
|
|
if (prescale)
|
|
timeout_sec = (timeout * 0x10000) / (*freq);
|
|
else
|
|
timeout_sec = timeout / (*freq);
|
|
|
|
printk(KERN_INFO "WDT driver for MPC83xx initialized. "
|
|
"mode:%s timeout=%d (%d seconds)\n",
|
|
reset ? "reset":"interrupt", timeout, timeout_sec);
|
|
|
|
spin_lock_init(&wdt_spinlock);
|
|
|
|
return 0;
|
|
|
|
err_unmap:
|
|
iounmap(wd_base);
|
|
err_out:
|
|
return ret;
|
|
}
|
|
|
|
static int __devexit mpc83xx_wdt_remove(struct platform_device *dev)
|
|
{
|
|
misc_deregister(&mpc83xx_wdt_miscdev);
|
|
iounmap(wd_base);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver mpc83xx_wdt_driver = {
|
|
.probe = mpc83xx_wdt_probe,
|
|
.remove = __devexit_p(mpc83xx_wdt_remove),
|
|
.driver = {
|
|
.name = "mpc83xx_wdt",
|
|
},
|
|
};
|
|
|
|
static int __init mpc83xx_wdt_init(void)
|
|
{
|
|
return platform_driver_register(&mpc83xx_wdt_driver);
|
|
}
|
|
|
|
static void __exit mpc83xx_wdt_exit(void)
|
|
{
|
|
platform_driver_unregister(&mpc83xx_wdt_driver);
|
|
}
|
|
|
|
module_init(mpc83xx_wdt_init);
|
|
module_exit(mpc83xx_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
|
|
MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx uProcessor");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|