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|
/*
* National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
* (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
* All Rights Reserved.
* Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
*
* 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.
*
* The author(s) of this software shall not be held liable for damages
* of any nature resulting due to the use of this software. This
* software is provided AS-IS with no warranties.
*
* Changelog:
* 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
* 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik
* and Alan Cox.
* 20020222 Zwane Mwaikambo Added probing.
* 20020225 Zwane Mwaikambo Added ISAPNP support.
* 20020412 Rob Radez Broke out start/stop functions
* <rob@osinvestor.com> Return proper status instead of
* temperature warning
* Add WDIOC_GETBOOTSTATUS and
* WDIOC_SETOPTIONS ioctls
* Fix CONFIG_WATCHDOG_NOWAYOUT
* 20020530 Joel Becker Add Matt Domsch's nowayout module
* option
* 20030116 Adam Belay Updated to the latest pnp code
*
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/pnp.h>
#include <linux/fs.h>
#include <linux/semaphore.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define SC1200_MODULE_VER "build 20020303"
#define SC1200_MODULE_NAME "sc1200wdt"
#define PFX SC1200_MODULE_NAME ": "
#define MAX_TIMEOUT 255 /* 255 minutes */
#define PMIR (io) /* Power Management Index Register */
#define PMDR (io+1) /* Power Management Data Register */
/* Data Register indexes */
#define FER1 0x00 /* Function enable register 1 */
#define FER2 0x01 /* Function enable register 2 */
#define PMC1 0x02 /* Power Management Ctrl 1 */
#define PMC2 0x03 /* Power Management Ctrl 2 */
#define PMC3 0x04 /* Power Management Ctrl 3 */
#define WDTO 0x05 /* Watchdog timeout register */
#define WDCF 0x06 /* Watchdog config register */
#define WDST 0x07 /* Watchdog status register */
/* WDCF bitfields - which devices assert WDO */
#define KBC_IRQ 0x01 /* Keyboard Controller */
#define MSE_IRQ 0x02 /* Mouse */
#define UART1_IRQ 0x03 /* Serial0 */
#define UART2_IRQ 0x04 /* Serial1 */
/* 5 -7 are reserved */
static char banner[] __initdata = PFX SC1200_MODULE_VER;
static int timeout = 1;
static int io = -1;
static int io_len = 2; /* for non plug and play */
static unsigned long open_flag;
static char expect_close;
static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
#if defined CONFIG_PNP
static int isapnp = 1;
static struct pnp_dev *wdt_dev;
module_param(isapnp, int, 0);
MODULE_PARM_DESC(isapnp,
"When set to 0 driver ISA PnP support will be disabled");
#endif
module_param(io, int, 0);
MODULE_PARM_DESC(io, "io port");
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
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) ")");
/* Read from Data Register */
static inline void __sc1200wdt_read_data(unsigned char index,
unsigned char *data)
{
outb_p(index, PMIR);
*data = inb(PMDR);
}
static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
{
spin_lock(&sc1200wdt_lock);
__sc1200wdt_read_data(index, data);
spin_unlock(&sc1200wdt_lock);
}
/* Write to Data Register */
static inline void __sc1200wdt_write_data(unsigned char index,
unsigned char data)
{
outb_p(index, PMIR);
outb(data, PMDR);
}
static inline void sc1200wdt_write_data(unsigned char index,
unsigned char data)
{
spin_lock(&sc1200wdt_lock);
__sc1200wdt_write_data(index, data);
spin_unlock(&sc1200wdt_lock);
}
static void sc1200wdt_start(void)
{
unsigned char reg;
spin_lock(&sc1200wdt_lock);
__sc1200wdt_read_data(WDCF, ®);
/* assert WDO when any of the following interrupts are triggered too */
reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
__sc1200wdt_write_data(WDCF, reg);
/* set the timeout and get the ball rolling */
__sc1200wdt_write_data(WDTO, timeout);
spin_unlock(&sc1200wdt_lock);
}
static void sc1200wdt_stop(void)
{
sc1200wdt_write_data(WDTO, 0);
}
/* This returns the status of the WDO signal, inactive high. */
static inline int sc1200wdt_status(void)
{
unsigned char ret;
sc1200wdt_read_data(WDST, &ret);
/* If the bit is inactive, the watchdog is enabled, so return
* KEEPALIVEPING which is a bit of a kludge because there's nothing
* else for enabled/disabled status
*/
return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
}
static int sc1200wdt_open(struct inode *inode, struct file *file)
{
/* allow one at a time */
if (test_and_set_bit(0, &open_flag))
return -EBUSY;
if (timeout > MAX_TIMEOUT)
timeout = MAX_TIMEOUT;
sc1200wdt_start();
printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);
return nonseekable_open(inode, file);
}
static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_timeout;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "PC87307/PC97307",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof ident))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
return put_user(sc1200wdt_status(), p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
sc1200wdt_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
sc1200wdt_start();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
sc1200wdt_write_data(WDTO, timeout);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
/* the API states this is given in secs */
new_timeout /= 60;
if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
return -EINVAL;
timeout = new_timeout;
sc1200wdt_write_data(WDTO, timeout);
/* fall through and return the new timeout */
case WDIOC_GETTIMEOUT:
return put_user(timeout * 60, p);
default:
return -ENOTTY;
}
}
static int sc1200wdt_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
sc1200wdt_stop();
printk(KERN_INFO PFX "Watchdog disabled\n");
} else {
sc1200wdt_write_data(WDTO, timeout);
printk(KERN_CRIT PFX
"Unexpected close!, timeout = %d min(s)\n", timeout);
}
clear_bit(0, &open_flag);
expect_close = 0;
return 0;
}
static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
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;
}
}
sc1200wdt_write_data(WDTO, timeout);
return len;
}
return 0;
}
static int sc1200wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
sc1200wdt_stop();
return NOTIFY_DONE;
}
static struct notifier_block sc1200wdt_notifier = {
|