/*
* MixCom Watchdog: A Simple Hardware Watchdog Device
* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
*
* Author: Gergely Madarasz <gorgo@itc.hu>
*
* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
*
* 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.
*
* Version 0.1 (99/04/15):
* - first version
*
* Version 0.2 (99/06/16):
* - added kernel timer watchdog ping after close
* since the hardware does not support watchdog shutdown
*
* Version 0.3 (99/06/21):
* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
*
* Version 0.3.1 (99/06/22):
* - allow module removal while internal timer is active,
* print warning about probable reset
*
* Version 0.4 (99/11/15):
* - support for one more type board
*
* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
* - added nowayout module option to override
* CONFIG_WATCHDOG_NOWAYOUT
*
* Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com>
* - make mixcomwd_opened unsigned,
* removed lock_kernel/unlock_kernel from mixcomwd_release,
* modified ioctl a bit to conform to API
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define VERSION "0.6"
#define WATCHDOG_NAME "mixcomwd"
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <linux/io.h>
/*
* We have two types of cards that can be probed:
* 1) The Mixcom cards: these cards can be found at addresses
* 0x180, 0x280, 0x380 with an additional offset of 0xc10.
* (Or 0xd90, 0xe90, 0xf90).
* 2) The FlashCOM cards: these cards can be set up at
* 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04.
* (Or 0x304 -> 0x37c in 0x8 jumps).
* Each card has it's own ID.
*/
#define MIXCOM_ID 0x11
#define FLASHCOM_ID 0x18
static struct {
int ioport;
int id;
} mixcomwd_io_info[] = {
/* The Mixcom cards */
{0x0d90, MIXCOM_ID},
{0x0e90, MIXCOM_ID},
{0x0f90, MIXCOM_ID},
/* The FlashCOM cards */
{0x0304, FLASHCOM_ID},
{0x030c, FLASHCOM_ID},
{0x0314, FLASHCOM_ID},
{0x031c, FLASHCOM_ID},
{0x0324, FLASHCOM_ID},
{0x032c, FLASHCOM_ID},
{0x0334, FLASHCOM_ID},
{0x033c, FLASHCOM_ID},
{0x0344, FLASHCOM_ID},
{0x034c, FLASHCOM_ID},
{0x0354, FLASHCOM_ID},
{0x035c, FLASHCOM_ID},
{0x0364, FLASHCOM_ID},
{0x036c, FLASHCOM_ID},
{0x0374, FLASHCOM_ID},
{0x037c, FLASHCOM_ID},
/* The end of the list */
{0x0000, 0},
};
static void mixcomwd_timerfun(unsigned long d);
static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */
static int watchdog_port;
static int mixcomwd_timer_alive;
static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0);
static char expect_close;
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 mixcomwd_ping(void)
{
outb_p(55, watchdog_port);
return;
}
static void mixcomwd_timerfun(unsigned long d)
{
mixcomwd_ping();
mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
}
/*
* Allow only one person to hold it open
*/
static int mixcomwd_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &mixcomwd_opened))
return -EBUSY;
mixcomwd_ping();
if (nowayout)
/*
* fops_get() code via open() has already done
* a try_module_get() so it is safe to do the
* __module_get().
*/
__module_get(THIS_MODULE);
else {
if (mixcomwd_timer_alive) {
del_timer(&mixcomwd_timer);
mixcomwd_timer_alive = 0;
}
}
return nonseekable_open(inode, file);
}
static int mixcomwd_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
if (mixcomwd_timer_alive) {
pr_err("release called while internal timer alive\n");
return -EBUSY;
}
mixcomwd_timer_alive = 1;
mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
} else
pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
clear_bit(0, &mixcomwd_opened);
expect_close = 0;
return 0;
}
static ssize_t mixcomwd_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
mixcomwd_ping();
}
return len;
}
static long mixcomwd_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int status;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "MixCOM watchdog",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
status = mixcomwd_opened;
if (!nowayout)
status |= mixcomwd_timer_alive;
return put_user(status, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
mixcomwd_ping();
break;
default:
return -ENOTTY;
}
return 0;
}
static const struct file_operations mixcomwd_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mixcomwd_write,
.unlocked_ioctl = mixcomwd_ioctl,
.open = mixcomwd_open,
.release = mixcomwd_release,
};
static struct miscdevice mixcomwd_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mixcomwd_fops,
};
static int __init checkcard(int port, int card_id)
{
int id;
if (!request_region(port, 1, "MixCOM watchdog"))
return 0;
id = inb_p(port);
if (card_id == MIXCOM_ID)
id &= 0x3f;
if (id != card_id) {
release_region(port, 1);
return 0;
}
return 1;
}
static int __init mixcomwd_init(void)
{
int i, ret, found = 0;
for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) {
if (checkcard(mixcomwd_io_info[i].ioport,
mixcomwd_io_info[i].id)) {
found = 1;
watchdog_port = mixcomwd_io_info[i].ioport;
}
}
if (!found) {
pr_err("No card detected, or port not available\n");
return -ENODEV;
}
ret = misc_register(&mixcomwd_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto error_misc_register_watchdog;
}
pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",
VERSION, watchdog_port);
return 0;
error_misc_register_watchdog:
release_region(watchdog_port, 1);
watchdog_port = 0x0000;
return ret;
}
static void __exit mixcomwd_exit(void)
{
if (!nowayout) {
if (mixcomwd_timer_alive) {
pr_warn("I quit now, hardware will probably reboot!\n");
del_timer_sync(&mixcomwd_timer);
mixcomwd_timer_alive = 0;
}
}
misc_deregister(&mixcomwd_miscdev);
release_region(watchdog_port, 1);
}
module_init(mixcomwd_init);
module_exit(mixcomwd_exit);
MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
MODULE_DESCRIPTION("MixCom Watchdog driver");
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
