- 根目录:
- drivers
- watchdog
- f71808e_wdt.c
/***************************************************************************
* Copyright (C) 2006 by Hans Edgington <hans@edgington.nl> *
* Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com> *
* Copyright (C) 2010 Giel van Schijndel <me@mortis.eu> *
* *
* 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. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the *
* Free Software Foundation, Inc., *
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
***************************************************************************/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#define DRVNAME "f71808e_wdt"
#define SIO_F71808FG_LD_WDT 0x07 /* Watchdog timer logical device */
#define SIO_UNLOCK_KEY 0x87 /* Key to enable Super-I/O */
#define SIO_LOCK_KEY 0xAA /* Key to diasble Super-I/O */
#define SIO_REG_LDSEL 0x07 /* Logical device select */
#define SIO_REG_DEVID 0x20 /* Device ID (2 bytes) */
#define SIO_REG_DEVREV 0x22 /* Device revision */
#define SIO_REG_MANID 0x23 /* Fintek ID (2 bytes) */
#define SIO_REG_ROM_ADDR_SEL 0x27 /* ROM address select */
#define SIO_REG_MFUNCT1 0x29 /* Multi function select 1 */
#define SIO_REG_MFUNCT2 0x2a /* Multi function select 2 */
#define SIO_REG_MFUNCT3 0x2b /* Multi function select 3 */
#define SIO_REG_ENABLE 0x30 /* Logical device enable */
#define SIO_REG_ADDR 0x60 /* Logical device address (2 bytes) */
#define SIO_FINTEK_ID 0x1934 /* Manufacturers ID */
#define SIO_F71808_ID 0x0901 /* Chipset ID */
#define SIO_F71858_ID 0x0507 /* Chipset ID */
#define SIO_F71862_ID 0x0601 /* Chipset ID */
#define SIO_F71869_ID 0x0814 /* Chipset ID */
#define SIO_F71882_ID 0x0541 /* Chipset ID */
#define SIO_F71889_ID 0x0723 /* Chipset ID */
#define F71808FG_REG_WDO_CONF 0xf0
#define F71808FG_REG_WDT_CONF 0xf5
#define F71808FG_REG_WD_TIME 0xf6
#define F71808FG_FLAG_WDOUT_EN 7
#define F71808FG_FLAG_WDTMOUT_STS 5
#define F71808FG_FLAG_WD_EN 5
#define F71808FG_FLAG_WD_PULSE 4
#define F71808FG_FLAG_WD_UNIT 3
/* Default values */
#define WATCHDOG_TIMEOUT 60 /* 1 minute default timeout */
#define WATCHDOG_MAX_TIMEOUT (60 * 255)
#define WATCHDOG_PULSE_WIDTH 125 /* 125 ms, default pulse width for
watchdog signal */
#define WATCHDOG_F71862FG_PIN 63 /* default watchdog reset output
pin number 63 */
static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");
static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
static int timeout = WATCHDOG_TIMEOUT; /* default timeout in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. 1<= timeout <="
__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
module_param(pulse_width, uint, 0);
MODULE_PARM_DESC(pulse_width,
"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
module_param(f71862fg_pin, uint, 0);
MODULE_PARM_DESC(f71862fg_pin,
"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
static unsigned int start_withtimeout;
module_param(start_withtimeout, uint, 0);
MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
" given initial timeout. Zero (default) disables this feature.");
enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg };
static const char *f71808e_names[] = {
"f71808fg",
"f71858fg",
"f71862fg",
"f71869",
"f71882fg",
"f71889fg",
};
/* Super-I/O Function prototypes */
static inline int superio_inb(int base, int reg);
static inline int superio_inw(int base, int reg);
static inline void superio_outb(int base, int reg, u8 val);
static inline void superio_set_bit(int base, int reg, int bit);
static inline void superio_clear_bit(int base, int reg, int bit);
static inline int superio_enter(int base);
static inline void superio_select(int base, int ld);
static inline void superio_exit(int base);
struct watchdog_data {
unsigned short sioaddr;
enum chips type;
unsigned long opened;
struct mutex lock;
char expect_close;
struct watchdog_info ident;
unsigned short timeout;
u8 timer_val; /* content for the wd_time register */
char minutes_mode;
u8 pulse_val; /* pulse width flag */
char pulse_mode; /* enable pulse output mode? */
char caused_reboot; /* last reboot was by the watchdog */
};
static struct watchdog_data watchdog = {
.lock = __MUTEX_INITIALIZER(watchdog.lock),
};
/* Super I/O functions */
static inline int superio_inb(int base, int reg)
{
outb(reg, base);
return inb(base + 1);
}
static int superio_inw(int base, int reg)
{
int val;
val = superio_inb(base, reg) << 8;
val |= superio_inb(base, reg + 1);
return val;
}
static inline void superio_outb(int base, int reg, u8 val)
{
outb(reg, base);
outb(val, base + 1);
}
static inline void superio_set_bit(int base, int reg, int bit)
{
unsigned long val = superio_inb(base, reg);
__set_bit(bit, &val);
superio_outb(base, reg, val);
}
static inline void superio_clear_bit(int base, int reg, int bit)
{
unsigned long val = superio_inb(base, reg);
__clear_bit(bit, &val);
superio_outb(base, reg, val);
}
static inline int superio_enter(int base)
{
/* Don't step on other drivers' I/O space by accident */
if (!request_muxed_region(base, 2, DRVNAME)) {
pr_err("I/O address 0x%04x already in use\n", (int)base);
return -EBUSY;
}
/* according to the datasheet the key must be send twice! */
outb(SIO_UNLOCK_KEY, base);
outb(SIO_UNLOCK_KEY, base);
return 0;
}
static inline void superio_select(int base, int ld)
{
outb(SIO_REG_LDSEL, base);
outb(ld, base + 1);
}
static inline void superio_exit(int base)
{
outb(SIO_LOCK_KEY, base);
release_region(base, 2);
}
static int watchdog_set_timeout(int timeout)
{
if (timeout <= 0
|| timeout > max_timeout) {
pr_err("watchdog timeout out of range\n");
return -EINVAL;
}
mutex_lock(&watchdog.lock);
watchdog.timeout = timeout;
if (timeout > 0xff) {
watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
watchdog.minutes_mode = true;
} else {
watchdog.timer_val = timeout;
watchdog.minutes_mode = false;
}
mutex_unlock(&watchdog.lock);
return 0;
}
static int watchdog_set_pulse_width(unsigned int pw)
{
int err = 0;
mutex_lock(&watchdog.lock);
if (pw <= 1) {
watchdog.pulse_val = 0;
} else if (pw <= 25) {
watchdog.pulse_val = 1;
} else if (pw <= 125) {
watchdog.pulse_val = 2;
} else if (pw <= 5000) {
watchdog.pulse_val = 3;
} else {
pr_err("pulse width out of range\n");
err = -EINVAL;
goto exit_unlock;
}
watchdog.pulse_mode = pw;
exit_unlock:
mutex_unlock(&watchdog.lock);
return err;
}
static int watchdog_keepalive(void)
{
int err = 0;
mutex_lock(&watchdog.lock);
err = superio_enter(watchdog.sioaddr);
if (err)
goto exit_unlock;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
if (watchdog.minutes_mode)
/* select minutes for timer units */
superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_UNIT);
else
/* select seconds for timer units */
superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_UNIT);
/* Set timer value */
superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
watchdog.timer_val);
superio_exit(watchdog.sioaddr);
exit_unlock:
mutex_unlock(&watchdog.lock);
return err;
}
static int f71862fg_pin_configure(unsigned short ioaddr)
{
/* When ioaddr is non-zero the calling function has to take care of
mutex handling and superio preparation! */
if (f71862fg_pin == 63) {
if (ioaddr) {
/* SPI must be disabled first to use this pin! */
superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
}
} else if (f71862fg_pin == 56) {
if (ioaddr)
superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
} else {
pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
return -EINVAL;
}
return 0;
}
static int watchdog_start(void)
{
/* Make sure we don't die as soon as the watchdog is enabled below */
int err = watchdog_keepalive();
if (err)
return err;
mutex_lock(&watchdog.lock);
err = superio_enter(watchdog.sioaddr);
if (err)
goto exit_unlock;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
/* Watchdog pin configuration */
switch (watchdog.type) {
case f71808fg:
/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
break;
case f71862fg:
err = f71862fg_pin_configure(watchdog.sioaddr);
if (err)
goto exit_superio;
break;
case f71869:
/* GPIO14 --> WDTRST# */
superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
break;
case f71882fg:
/* Set pin 56 to WDTRST# */
superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
break;
case f71889fg:
/* set pin 40 to WDTRST# */
superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
break;
default:
/*
* 'default' label to shut up the compiler and catch
* programmer errors
*/
err = -ENODEV;
goto exit_superio;
}
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
F71808FG_FLAG_WDOUT_EN);
superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_EN);
if (watchdog.pulse_mode) {
/* Select "pulse" output mode with given duration */
u8 wdt_conf = superio_inb(watchdog.sioaddr,
F71808FG_REG_WDT_CONF);
/* Set WD_PSWIDTH bits (1:0) */
wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
/* Set WD_PULSE to "pulse" mode */
wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
wdt_conf);
} else {
/* Select "level" output mode */
superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_PULSE);
}
exit_superio:
superio_exit(watchdog.sioaddr);
exit_unlock:
mutex_unlock(&watchdog.lock);
return err;
}
static int watchdog_stop(void)
{
int err = 0;
mutex_lock(&watchdog.lock);
err = superio_enter(watchdog.sioaddr);
if (err)
goto exit_unlock;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_EN);
superio_exit(watchdog.sioaddr);
exit_unlock:
mutex_unlock(&watchdog.lock);
return err;
}
static int watchdog_get_status(void)
{
int status = 0;
mutex_lock(&watchdog.lock);
status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
mutex_unlock(&watchdog.lock);
return status;
}
static bool watchdog_is_running(void)
{
/*
* if we fail to determine the watchdog's status assume it to be
* running to be on the safe side
*/
bool is_running = true;
mutex_lock(&watchdog.lock);
if (superio_enter(watchdog.sioaddr))
goto exit_unlock;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
& F71808FG_FLAG_WD_EN);
superio_exit(watchdog.sioaddr);
exit_unlock:
mutex_unlock(&watchdog.lock);
return is_running;
}
/* /dev/watchdog api */
static int watchdog_open(struct inode *inode, struct file *file)
{
int err;
/* If the watchdog is alive we don't need to start it again */
if (test_and_set_bit(0, &watchdog.opened))
return -EBUSY;
err = watchdog_start();
if (err) {
clear_bit(0, &watchdog.opened);
return err;
}
if (nowayout)
__module_get(THIS_MODULE);
watchdog.expect_close = 0;
return nonseekable_open(inode, file);
}
static int watchdog_release(struct inode *inode, struct file *file)
{
clear_bit(0, &watchdog.opened);
if (!watchdog.expect_close) {
watchdog_keepalive();
pr_crit("Unexpected close, not stopping watchdog!\n");
} else if (!nowayout) {
watchdog_stop();
}
return 0;
}
/*
* watchdog_write:
* @file: file handle to the watchdog
* @buf: buffer to write
* @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 watchdog_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
bool expect_close = false;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
expect_close = (c == 'V');
}
/* Properly order writes across fork()ed processes */
mutex_lock(&watchdog.lock);
watchdog.expect_close = expect_close;
mutex_unlock(&watchdog.lock);
}
/* someone wrote to us, we should restart timer */
watchdog_keepalive();
}
return count;
}
/*
* watchdog_ioctl:
* @inode: inode of the device
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features.
*/
static long watchdog_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int status;
int new_options;
int new_timeout;
union {
struct watchdog_info __user *ident;
int __user *i;
} uarg;
uarg.i = (int __user *)arg;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(uarg.ident, &watchdog.ident,
sizeof(watchdog.ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
status = watchdog_get_status();
if (status < 0)
return status;
return put_user(status, uarg.i);
case WDIOC_GETBOOTSTATUS:
return put_user(0, uarg.i);
case WDIOC_SETOPTIONS:
if (get_user(new_options, uarg.i))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD)
watchdog_stop();
if (new_options & WDIOS_ENABLECARD)
return watchdog_start();
case WDIOC_KEEPALIVE:
watchdog_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, uarg.i))
return -EFAULT;
if (watchdog_set_timeout(new_timeout))
return -EINVAL;
watchdog_keepalive();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(watchdog.timeout, uarg.i);
default:
return -ENOTTY;
}
}
static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
watchdog_stop();
return NOTIFY_DONE;
}
static const struct file_operations watchdog_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = watchdog_open,
.release = watchdog_release,
.write = watchdog_write,
.unlocked_ioctl = watchdog_ioctl,
};
static struct miscdevice watchdog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &watchdog_fops,
};
static struct notifier_block watchdog_notifier = {
.notifier_call = watchdog_notify_sys,
};
static int __init watchdog_init(int sioaddr)
{
int wdt_conf, err = 0;
/* No need to lock watchdog.lock here because no entry points
* into the module have been registered yet.
*/
watchdog.sioaddr = sioaddr;
watchdog.ident.options = WDIOC_SETTIMEOUT
| WDIOF_MAGICCLOSE
| WDIOF_KEEPALIVEPING;
snprintf(watchdog.ident.identity,
sizeof(watchdog.ident.identity), "%s watchdog",
f71808e_names[watchdog.type]);
err = superio_enter(sioaddr);
if (err)
return err;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;
superio_exit(sioaddr);
err = watchdog_set_timeout(timeout);
if (err)
return err;
err = watchdog_set_pulse_width(pulse_width);
if (err)
return err;
err = register_reboot_notifier(&watchdog_notifier);
if (err)
return err;
err = misc_register(&watchdog_miscdev);
if (err) {
pr_err("cannot register miscdev on minor=%d\n",
watchdog_miscdev.minor);
goto exit_reboot;
}
if (start_withtimeout) {
if (start_withtimeout <= 0
|| start_withtimeout > max_timeout) {
pr_err("starting timeout out of range\n");
err = -EINVAL;
goto exit_miscdev;
}
err = watchdog_start();
if (err) {
pr_err("cannot start watchdog timer\n");
goto exit_miscdev;
}
mutex_lock(&watchdog.lock);
err = superio_enter(sioaddr);
if (err)
goto exit_unlock;
superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
if (start_withtimeout > 0xff) {
/* select minutes for timer units */
superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_UNIT);
superio_outb(sioaddr, F71808FG_REG_WD_TIME,
DIV_ROUND_UP(start_withtimeout, 60));
} else {
/* select seconds for timer units */
superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
F71808FG_FLAG_WD_UNIT);
superio_outb(sioaddr, F71808FG_REG_WD_TIME,
start_withtimeout);
}
superio_exit(sioaddr);
mutex_unlock(&watchdog.lock);
if (nowayout)
__module_get(THIS_MODULE);
pr_info("watchdog started with initial timeout of %u sec\n",
start_withtimeout);
}
return 0;
exit_unlock:
mutex_unlock(&watchdog.lock);
exit_miscdev:
misc_deregister(&watchdog_miscdev);
exit_reboot:
unregister_reboot_notifier(&watchdog_notifier);
return err;
}
static int __init f71808e_find(int sioaddr)
{
u16 devid;
int err = superio_enter(sioaddr);
if (err)
return err;
devid = superio_inw(sioaddr, SIO_REG_MANID);
if (devid != SIO_FINTEK_ID) {
pr_debug("Not a Fintek device\n");
err = -ENODEV;
goto exit;
}
devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
switch (devid) {
case SIO_F71808_ID:
watchdog.type = f71808fg;
break;
case SIO_F71862_ID:
watchdog.type = f71862fg;
err = f71862fg_pin_configure(0); /* validate module parameter */
break;
case SIO_F71869_ID:
watchdog.type = f71869;
break;
case SIO_F71882_ID:
watchdog.type = f71882fg;
break;
case SIO_F71889_ID:
watchdog.type = f71889fg;
break;
case SIO_F71858_ID:
/* Confirmed (by datasheet) not to have a watchdog. */
err = -ENODEV;
goto exit;
default:
pr_info("Unrecognized Fintek device: %04x\n",
(unsigned int)devid);
err = -ENODEV;
goto exit;
}
pr_info("Found %s watchdog chip, revision %d\n",
f71808e_names[watchdog.type],
(int)superio_inb(sioaddr, SIO_REG_DEVREV));
exit:
superio_exit(sioaddr);
return err;
}
static int __init f71808e_init(void)
{
static const unsigned short addrs[] = { 0x2e, 0x4e };
int err = -ENODEV;
int i;
for (i = 0; i < ARRAY_SIZE(addrs); i++) {
err = f71808e_find(addrs[i]);
if (err == 0)
break;
}
if (i == ARRAY_SIZE(addrs))
return err;
return watchdog_init(addrs[i]);
}
static void __exit f71808e_exit(void)
{
if (watchdog_is_running()) {
pr_warn("Watchdog timer still running, stopping it\n");
watchdog_stop();
}
misc_deregister(&watchdog_miscdev);
unregister_reboot_notifier(&watchdog_notifier);
}
MODULE_DESCRIPTION("F71808E Watchdog Driver");
MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
MODULE_LICENSE("GPL");
module_init(f71808e_init);
module_exit(f71808e_exit);