You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
301 lines
6.8 KiB
301 lines
6.8 KiB
/*
|
|
* PIKA FPGA based Watchdog Timer
|
|
*
|
|
* Copyright (c) 2008 PIKA Technologies
|
|
* Sean MacLennan <smaclennan@pikatech.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of_platform.h>
|
|
|
|
#define DRV_NAME "PIKA-WDT"
|
|
#define PFX DRV_NAME ": "
|
|
|
|
/* Hardware timeout in seconds */
|
|
#define WDT_HW_TIMEOUT 2
|
|
|
|
/* Timer heartbeat (500ms) */
|
|
#define WDT_TIMEOUT (HZ/2)
|
|
|
|
/* User land timeout */
|
|
#define WDT_HEARTBEAT 15
|
|
static int heartbeat = WDT_HEARTBEAT;
|
|
module_param(heartbeat, int, 0);
|
|
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
|
|
"(default = " __MODULE_STRING(WDT_HEARTBEAT) ")");
|
|
|
|
static int nowayout = WATCHDOG_NOWAYOUT;
|
|
module_param(nowayout, int, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
|
|
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
static struct {
|
|
void __iomem *fpga;
|
|
unsigned long next_heartbeat; /* the next_heartbeat for the timer */
|
|
unsigned long open;
|
|
char expect_close;
|
|
int bootstatus;
|
|
struct timer_list timer; /* The timer that pings the watchdog */
|
|
} pikawdt_private;
|
|
|
|
static struct watchdog_info ident = {
|
|
.identity = DRV_NAME,
|
|
.options = WDIOF_CARDRESET |
|
|
WDIOF_SETTIMEOUT |
|
|
WDIOF_KEEPALIVEPING |
|
|
WDIOF_MAGICCLOSE,
|
|
};
|
|
|
|
/*
|
|
* Reload the watchdog timer. (ie, pat the watchdog)
|
|
*/
|
|
static inline void pikawdt_reset(void)
|
|
{
|
|
/* -- FPGA: Reset Control Register (32bit R/W) (Offset: 0x14) --
|
|
* Bit 7, WTCHDG_EN: When set to 1, the watchdog timer is enabled.
|
|
* Once enabled, it cannot be disabled. The watchdog can be
|
|
* kicked by performing any write access to the reset
|
|
* control register (this register).
|
|
* Bit 8-11, WTCHDG_TIMEOUT_SEC: Sets the watchdog timeout value in
|
|
* seconds. Valid ranges are 1 to 15 seconds. The value can
|
|
* be modified dynamically.
|
|
*/
|
|
unsigned reset = in_be32(pikawdt_private.fpga + 0x14);
|
|
/* enable with max timeout - 15 seconds */
|
|
reset |= (1 << 7) + (WDT_HW_TIMEOUT << 8);
|
|
out_be32(pikawdt_private.fpga + 0x14, reset);
|
|
}
|
|
|
|
/*
|
|
* Timer tick
|
|
*/
|
|
static void pikawdt_ping(unsigned long data)
|
|
{
|
|
if (time_before(jiffies, pikawdt_private.next_heartbeat) ||
|
|
(!nowayout && !pikawdt_private.open)) {
|
|
pikawdt_reset();
|
|
mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT);
|
|
} else
|
|
printk(KERN_CRIT PFX "I will reset your machine !\n");
|
|
}
|
|
|
|
|
|
static void pikawdt_keepalive(void)
|
|
{
|
|
pikawdt_private.next_heartbeat = jiffies + heartbeat * HZ;
|
|
}
|
|
|
|
static void pikawdt_start(void)
|
|
{
|
|
pikawdt_keepalive();
|
|
mod_timer(&pikawdt_private.timer, jiffies + WDT_TIMEOUT);
|
|
}
|
|
|
|
/*
|
|
* Watchdog device is opened, and watchdog starts running.
|
|
*/
|
|
static int pikawdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
/* /dev/watchdog can only be opened once */
|
|
if (test_and_set_bit(0, &pikawdt_private.open))
|
|
return -EBUSY;
|
|
|
|
pikawdt_start();
|
|
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
/*
|
|
* Close the watchdog device.
|
|
*/
|
|
static int pikawdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
/* stop internal ping */
|
|
if (!pikawdt_private.expect_close)
|
|
del_timer(&pikawdt_private.timer);
|
|
|
|
clear_bit(0, &pikawdt_private.open);
|
|
pikawdt_private.expect_close = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Pat the watchdog whenever device is written to.
|
|
*/
|
|
static ssize_t pikawdt_write(struct file *file, const char __user *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
if (!len)
|
|
return 0;
|
|
|
|
/* Scan for magic character */
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
pikawdt_private.expect_close = 0;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
char c;
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V') {
|
|
pikawdt_private.expect_close = 42;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
pikawdt_keepalive();
|
|
|
|
return len;
|
|
}
|
|
|
|
/*
|
|
* Handle commands from user-space.
|
|
*/
|
|
static long pikawdt_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
void __user *argp = (void __user *)arg;
|
|
int __user *p = argp;
|
|
int new_value;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
return put_user(0, p);
|
|
|
|
case WDIOC_GETBOOTSTATUS:
|
|
return put_user(pikawdt_private.bootstatus, p);
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
pikawdt_keepalive();
|
|
return 0;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
if (get_user(new_value, p))
|
|
return -EFAULT;
|
|
|
|
heartbeat = new_value;
|
|
pikawdt_keepalive();
|
|
|
|
return put_user(new_value, p); /* return current value */
|
|
|
|
case WDIOC_GETTIMEOUT:
|
|
return put_user(heartbeat, p);
|
|
}
|
|
return -ENOTTY;
|
|
}
|
|
|
|
|
|
static const struct file_operations pikawdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.open = pikawdt_open,
|
|
.release = pikawdt_release,
|
|
.write = pikawdt_write,
|
|
.unlocked_ioctl = pikawdt_ioctl,
|
|
};
|
|
|
|
static struct miscdevice pikawdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &pikawdt_fops,
|
|
};
|
|
|
|
static int __init pikawdt_init(void)
|
|
{
|
|
struct device_node *np;
|
|
void __iomem *fpga;
|
|
static u32 post1;
|
|
int ret;
|
|
|
|
np = of_find_compatible_node(NULL, NULL, "pika,fpga");
|
|
if (np == NULL) {
|
|
printk(KERN_ERR PFX "Unable to find fpga.\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
pikawdt_private.fpga = of_iomap(np, 0);
|
|
of_node_put(np);
|
|
if (pikawdt_private.fpga == NULL) {
|
|
printk(KERN_ERR PFX "Unable to map fpga.\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ident.firmware_version = in_be32(pikawdt_private.fpga + 0x1c) & 0xffff;
|
|
|
|
/* POST information is in the sd area. */
|
|
np = of_find_compatible_node(NULL, NULL, "pika,fpga-sd");
|
|
if (np == NULL) {
|
|
printk(KERN_ERR PFX "Unable to find fpga-sd.\n");
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
fpga = of_iomap(np, 0);
|
|
of_node_put(np);
|
|
if (fpga == NULL) {
|
|
printk(KERN_ERR PFX "Unable to map fpga-sd.\n");
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/* -- FPGA: POST Test Results Register 1 (32bit R/W) (Offset: 0x4040) --
|
|
* Bit 31, WDOG: Set to 1 when the last reset was caused by a watchdog
|
|
* timeout.
|
|
*/
|
|
post1 = in_be32(fpga + 0x40);
|
|
if (post1 & 0x80000000)
|
|
pikawdt_private.bootstatus = WDIOF_CARDRESET;
|
|
|
|
iounmap(fpga);
|
|
|
|
setup_timer(&pikawdt_private.timer, pikawdt_ping, 0);
|
|
|
|
ret = misc_register(&pikawdt_miscdev);
|
|
if (ret) {
|
|
printk(KERN_ERR PFX "Unable to register miscdev.\n");
|
|
goto out;
|
|
}
|
|
|
|
printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
|
|
heartbeat, nowayout);
|
|
return 0;
|
|
|
|
out:
|
|
iounmap(pikawdt_private.fpga);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit pikawdt_exit(void)
|
|
{
|
|
misc_deregister(&pikawdt_miscdev);
|
|
|
|
iounmap(pikawdt_private.fpga);
|
|
}
|
|
|
|
module_init(pikawdt_init);
|
|
module_exit(pikawdt_exit);
|
|
|
|
MODULE_AUTHOR("Sean MacLennan <smaclennan@pikatech.com>");
|
|
MODULE_DESCRIPTION("PIKA FPGA based Watchdog Timer");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
|
|
|
|