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/*
* W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
*
* (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
*
* Based on w83877f_wdt.c by Scott Jennings,
* and wdt977.c by Woody Suwalski
*
* -----------------------
*
* 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#define WATCHDOG_VERSION "1.00"
#define WATCHDOG_NAME "W83977F WDT"
#define IO_INDEX_PORT 0x3F0
#define IO_DATA_PORT (IO_INDEX_PORT+1)
#define UNLOCK_DATA 0x87
#define LOCK_DATA 0xAA
#define DEVICE_REGISTER 0x07
#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
static int timeout = DEFAULT_TIMEOUT;
static int timeoutW; /* timeout in watchdog counter units */
static unsigned long timer_alive;
static int testmode;
static char expect_close;
static DEFINE_SPINLOCK(spinlock);
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds (15..7635), default="
__MODULE_STRING(DEFAULT_TIMEOUT) ")");
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
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) ")");
/*
* Start the watchdog
*/
static int wdt_start(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* Unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/*
* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
* F2 has the timeout in watchdog counter units.
* F3 is set to enable watchdog LED blink at timeout.
* F4 is used to just clear the TIMEOUT'ed state (bit 0).
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(timeoutW, IO_DATA_PORT);
outb_p(0xF3, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF4, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
/* Set device Aux2 active */
outb_p(0x30, IO_INDEX_PORT);
outb_p(0x01, IO_DATA_PORT);
/*
* Select device Aux1 (dev=7) to set GP16 as the watchdog output
* (in reg E6) and GP13 as the watchdog LED output (in reg E3).
* Map GP16 at pin 119.
* In test mode watch the bit 0 on F4 to indicate "triggered" or
* check watchdog LED on SBC.
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x07, IO_DATA_PORT);
if (!testmode) {
unsigned pin_map;
outb_p(0xE6, IO_INDEX_PORT);
outb_p(0x0A, IO_DATA_PORT);
outb_p(0x2C, IO_INDEX_PORT);
pin_map = inb_p(IO_DATA_PORT);
pin_map |= 0x10;
pin_map &= ~(0x20);
outb_p(0x2C, IO_INDEX_PORT);
outb_p(pin_map, IO_DATA_PORT);
}
outb_p(0xE3, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
/* Set device Aux1 active */
outb_p(0x30, IO_INDEX_PORT);
outb_p(0x01, IO_DATA_PORT);
/* Lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
pr_info("activated\n");
return 0;
}
/*
* Stop the watchdog
*/
static int wdt_stop(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* Unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/*
* Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
* F2 is reset to its default value (watchdog timer disabled).
* F3 is reset to its default state.
* F4 clears the TIMEOUT'ed state (bit 0) - back to default.
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(0xFF, IO_DATA_PORT);
outb_p(0xF3, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
outb_p(0xF4, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(0x00, IO_DATA_PORT);
/*
* Select device Aux1 (dev=7) to set GP16 (in reg E6) and
* Gp13 (in reg E3) as inputs.
*/
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x07, IO_DATA_PORT);
if (!testmode) {
outb_p(0xE6, IO_INDEX_PORT);
outb_p(0x01, IO_DATA_PORT);
}
outb_p(0xE3, IO_INDEX_PORT);
outb_p(0x01, IO_DATA_PORT);
/* Lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
pr_info("shutdown\n");
return 0;
}
/*
* Send a keepalive ping to the watchdog
* This is done by simply re-writing the timeout to reg. 0xF2
*/
static int wdt_keepalive(void)
{
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* Unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* Select device Aux2 (device=8) to kick watchdog reg F2 */
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF2, IO_INDEX_PORT);
outb_p(timeoutW, IO_DATA_PORT);
/* Lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
return 0;
}
/*
* Set the watchdog timeout value
*/
static int wdt_set_timeout(int t)
{
int tmrval;
/*
* Convert seconds to watchdog counter time units, rounding up.
* On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
* value. This information is supplied in the PCM-5335 manual and was
* checked by me on a real board. This is a bit strange because W83977f
* datasheet says counter unit is in minutes!
*/
if (t < 15)
return -EINVAL;
tmrval = ((t + 15) + 29) / 30;
if (tmrval > 255)
return -EINVAL;
/*
* timeout is the timeout in seconds,
* timeoutW is the timeout in watchdog counter units.
*/
timeoutW = tmrval;
timeout = (timeoutW * 30) - 15;
return 0;
}
/*
* Get the watchdog status
*/
static int wdt_get_status(int *status)
{
int new_status;
unsigned long flags;
spin_lock_irqsave(&spinlock, flags);
/* Unlock the SuperIO chip */
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
outb_p(UNLOCK_DATA, IO_INDEX_PORT);
/* Select device Aux2 (device=8) to read watchdog reg F4 */
outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
outb_p(0x08, IO_DATA_PORT);
outb_p(0xF4, IO_INDEX_PORT);
new_status = inb_p(IO_DATA_PORT);
/* Lock the SuperIO chip */
outb_p(LOCK_DATA, IO_INDEX_PORT);
spin_unlock_irqrestore(&spinlock, flags);
*status = 0;
if (new_status & 1)
*status |= WDIOF_CARDRESET;
return 0;
}
/*
* /dev/watchdog handling
*/
static int wdt_open(struct inode *inode, struct file *file)
{
/* If the watchdog is alive we don't need to start it again */
if (test_and_set_bit(0, &timer_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
wdt_start();
return nonseekable_open(inode, file);
}
static int wdt_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
* Lock it in if it's a module and we set nowayout
*/
if (expect_close == 42) {
wdt_stop();
clear_bit(0, &timer_alive);
} else {
wdt_keepalive();
pr_crit("unexpected close, not stopping watchdog!\n");
}
expect_close = 0;
return 0;
}
/*
* wdt_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (count) {
if (!nowayout) {
size_t ofs;
/* note: just in case someone wrote the
magic character long ago */
expect_close = 0;
/* scan to see whether or not we got the
magic character */
for (ofs = 0;
|