Contributors: 17
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds |
454 |
49.62% |
4 |
12.90% |
| David S. Miller |
284 |
31.04% |
4 |
12.90% |
| Dave Jones |
72 |
7.87% |
1 |
3.23% |
| Al Viro |
22 |
2.40% |
2 |
6.45% |
| Joe Perches |
20 |
2.19% |
1 |
3.23% |
| Thomas Gleixner |
12 |
1.31% |
3 |
9.68% |
| Rusty Russell |
10 |
1.09% |
1 |
3.23% |
| Grant C. Likely |
9 |
0.98% |
3 |
9.68% |
| Jingoo Han |
9 |
0.98% |
2 |
6.45% |
| Arnd Bergmann |
5 |
0.55% |
1 |
3.23% |
| Wim Van Sebroeck |
5 |
0.55% |
3 |
9.68% |
| Randy Dunlap |
4 |
0.44% |
1 |
3.23% |
| Tejun Heo |
3 |
0.33% |
1 |
3.23% |
| Gustavo A. R. Silva |
2 |
0.22% |
1 |
3.23% |
| Axel Lin |
2 |
0.22% |
1 |
3.23% |
| Arjan van de Ven |
1 |
0.11% |
1 |
3.23% |
| Kirill Smelkov |
1 |
0.11% |
1 |
3.23% |
| Total |
915 |
|
31 |
|
// SPDX-License-Identifier: GPL-2.0-only
/* riowd.c - driver for hw watchdog inside Super I/O of RIO
*
* Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
/* RIO uses the NatSemi Super I/O power management logical device
* as its' watchdog.
*
* When the watchdog triggers, it asserts a line to the BBC (Boot Bus
* Controller) of the machine. The BBC can only be configured to
* trigger a power-on reset when the signal is asserted. The BBC
* can be configured to ignore the signal entirely as well.
*
* The only Super I/O device register we care about is at index
* 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
* If set to zero, this disables the watchdog. When set, the system
* must periodically (before watchdog expires) clear (set to zero) and
* re-set the watchdog else it will trigger.
*
* There are two other indexed watchdog registers inside this Super I/O
* logical device, but they are unused. The first, at index 0x06 is
* the watchdog control and can be used to make the watchdog timer re-set
* when the PS/2 mouse or serial lines show activity. The second, at
* index 0x07 is merely a sampling of the line from the watchdog to the
* BBC.
*
* The watchdog device generates no interrupts.
*/
MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
MODULE_LICENSE("GPL");
#define DRIVER_NAME "riowd"
#define PFX DRIVER_NAME ": "
struct riowd {
void __iomem *regs;
spinlock_t lock;
};
static struct riowd *riowd_device;
#define WDTO_INDEX 0x05
static int riowd_timeout = 1; /* in minutes */
module_param(riowd_timeout, int, 0);
MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
static void riowd_writereg(struct riowd *p, u8 val, int index)
{
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
writeb(index, p->regs + 0);
writeb(val, p->regs + 1);
spin_unlock_irqrestore(&p->lock, flags);
}
static int riowd_open(struct inode *inode, struct file *filp)
{
stream_open(inode, filp);
return 0;
}
static int riowd_release(struct inode *inode, struct file *filp)
{
return 0;
}
static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
static const struct watchdog_info info = {
.options = WDIOF_SETTIMEOUT,
.firmware_version = 1,
.identity = DRIVER_NAME,
};
void __user *argp = (void __user *)arg;
struct riowd *p = riowd_device;
unsigned int options;
int new_margin;
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &info, sizeof(info)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
if (put_user(0, (int __user *)argp))
return -EFAULT;
break;
case WDIOC_KEEPALIVE:
riowd_writereg(p, riowd_timeout, WDTO_INDEX);
break;
case WDIOC_SETOPTIONS:
if (copy_from_user(&options, argp, sizeof(options)))
return -EFAULT;
if (options & WDIOS_DISABLECARD)
riowd_writereg(p, 0, WDTO_INDEX);
else if (options & WDIOS_ENABLECARD)
riowd_writereg(p, riowd_timeout, WDTO_INDEX);
else
return -EINVAL;
break;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int __user *)argp))
return -EFAULT;
if ((new_margin < 60) || (new_margin > (255 * 60)))
return -EINVAL;
riowd_timeout = (new_margin + 59) / 60;
riowd_writereg(p, riowd_timeout, WDTO_INDEX);
fallthrough;
case WDIOC_GETTIMEOUT:
return put_user(riowd_timeout * 60, (int __user *)argp);
default:
return -EINVAL;
}
return 0;
}
static ssize_t riowd_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct riowd *p = riowd_device;
if (count) {
riowd_writereg(p, riowd_timeout, WDTO_INDEX);
return 1;
}
return 0;
}
static const struct file_operations riowd_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = riowd_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = riowd_open,
.write = riowd_write,
.release = riowd_release,
};
static struct miscdevice riowd_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &riowd_fops
};
static int riowd_probe(struct platform_device *op)
{
struct riowd *p;
int err = -EINVAL;
if (riowd_device)
goto out;
err = -ENOMEM;
p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
if (!p)
goto out;
spin_lock_init(&p->lock);
p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);
if (!p->regs) {
pr_err("Cannot map registers\n");
goto out;
}
/* Make miscdev useable right away */
riowd_device = p;
err = misc_register(&riowd_miscdev);
if (err) {
pr_err("Cannot register watchdog misc device\n");
goto out_iounmap;
}
pr_info("Hardware watchdog [%i minutes], regs at %p\n",
riowd_timeout, p->regs);
platform_set_drvdata(op, p);
return 0;
out_iounmap:
riowd_device = NULL;
of_iounmap(&op->resource[0], p->regs, 2);
out:
return err;
}
static int riowd_remove(struct platform_device *op)
{
struct riowd *p = platform_get_drvdata(op);
misc_deregister(&riowd_miscdev);
of_iounmap(&op->resource[0], p->regs, 2);
return 0;
}
static const struct of_device_id riowd_match[] = {
{
.name = "pmc",
},
{},
};
MODULE_DEVICE_TABLE(of, riowd_match);
static struct platform_driver riowd_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = riowd_match,
},
.probe = riowd_probe,
.remove = riowd_remove,
};
module_platform_driver(riowd_driver);