- 根目录:
- drivers
- watchdog
- it87_wdt.c
/*
* Watchdog Timer Driver
* for ITE IT87xx Environment Control - Low Pin Count Input / Output
*
* (c) Copyright 2007 Oliver Schuster <olivers137@aol.com>
*
* Based on softdog.c by Alan Cox,
* 83977f_wdt.c by Jose Goncalves,
* it87.c by Chris Gauthron, Jean Delvare
*
* Data-sheets: Publicly available at the ITE website
* http://www.ite.com.tw/
*
* Support of the watchdog timers, which are available on
* IT8702, IT8712, IT8716, IT8718, IT8720, IT8721 and IT8726.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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 "1.14"
#define WATCHDOG_NAME "IT87 WDT"
#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
#define WD_MAGIC 'V'
/* Defaults for Module Parameter */
#define DEFAULT_NOGAMEPORT 0
#define DEFAULT_EXCLUSIVE 1
#define DEFAULT_TIMEOUT 60
#define DEFAULT_TESTMODE 0
#define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT
/* IO Ports */
#define REG 0x2e
#define VAL 0x2f
/* Logical device Numbers LDN */
#define GPIO 0x07
#define GAMEPORT 0x09
#define CIR 0x0a
/* Configuration Registers and Functions */
#define LDNREG 0x07
#define CHIPID 0x20
#define CHIPREV 0x22
#define ACTREG 0x30
#define BASEREG 0x60
/* Chip Id numbers */
#define NO_DEV_ID 0xffff
#define IT8702_ID 0x8702
#define IT8705_ID 0x8705
#define IT8712_ID 0x8712
#define IT8716_ID 0x8716
#define IT8718_ID 0x8718
#define IT8720_ID 0x8720
#define IT8721_ID 0x8721
#define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */
/* GPIO Configuration Registers LDN=0x07 */
#define WDTCTRL 0x71
#define WDTCFG 0x72
#define WDTVALLSB 0x73
#define WDTVALMSB 0x74
/* GPIO Bits WDTCTRL */
#define WDT_CIRINT 0x80
#define WDT_MOUSEINT 0x40
#define WDT_KYBINT 0x20
#define WDT_GAMEPORT 0x10 /* not in it8718, it8720, it8721 */
#define WDT_FORCE 0x02
#define WDT_ZERO 0x01
/* GPIO Bits WDTCFG */
#define WDT_TOV1 0x80
#define WDT_KRST 0x40
#define WDT_TOVE 0x20
#define WDT_PWROK 0x10 /* not in it8721 */
#define WDT_INT_MASK 0x0f
/* CIR Configuration Register LDN=0x0a */
#define CIR_ILS 0x70
/* The default Base address is not always available, we use this */
#define CIR_BASE 0x0208
/* CIR Controller */
#define CIR_DR(b) (b)
#define CIR_IER(b) (b + 1)
#define CIR_RCR(b) (b + 2)
#define CIR_TCR1(b) (b + 3)
#define CIR_TCR2(b) (b + 4)
#define CIR_TSR(b) (b + 5)
#define CIR_RSR(b) (b + 6)
#define CIR_BDLR(b) (b + 5)
#define CIR_BDHR(b) (b + 6)
#define CIR_IIR(b) (b + 7)
/* Default Base address of Game port */
#define GP_BASE_DEFAULT 0x0201
/* wdt_status */
#define WDTS_TIMER_RUN 0
#define WDTS_DEV_OPEN 1
#define WDTS_KEEPALIVE 2
#define WDTS_LOCKED 3
#define WDTS_USE_GP 4
#define WDTS_EXPECTED 5
static unsigned int base, gpact, ciract, max_units, chip_type;
static unsigned long wdt_status;
static int nogameport = DEFAULT_NOGAMEPORT;
static int exclusive = DEFAULT_EXCLUSIVE;
static int timeout = DEFAULT_TIMEOUT;
static int testmode = DEFAULT_TESTMODE;
static bool nowayout = DEFAULT_NOWAYOUT;
module_param(nogameport, int, 0);
MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
__MODULE_STRING(DEFAULT_NOGAMEPORT));
module_param(exclusive, int, 0);
MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
__MODULE_STRING(DEFAULT_EXCLUSIVE));
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
__MODULE_STRING(DEFAULT_TIMEOUT));
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
__MODULE_STRING(DEFAULT_TESTMODE));
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
__MODULE_STRING(WATCHDOG_NOWAYOUT));
/* Superio Chip */
static inline int superio_enter(void)
{
/*
* Try to reserve REG and REG + 1 for exclusive access.
*/
if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
return -EBUSY;
outb(0x87, REG);
outb(0x01, REG);
outb(0x55, REG);
outb(0x55, REG);
return 0;
}
static inline void superio_exit(void)
{
outb(0x02, REG);
outb(0x02, VAL);
release_region(REG, 2);
}
static inline void superio_select(int ldn)
{
outb(LDNREG, REG);
outb(ldn, VAL);
}
static inline int superio_inb(int reg)
{
outb(reg, REG);
return inb(VAL);
}
static inline void superio_outb(int val, int reg)
{
outb(reg, REG);
outb(val, VAL);
}
static inline int superio_inw(int reg)
{
int val;
outb(reg++, REG);
val = inb(VAL) << 8;
outb(reg, REG);
val |= inb(VAL);
return val;
}
static inline void superio_outw(int val, int reg)
{
outb(reg++, REG);
outb(val >> 8, VAL);
outb(reg, REG);
outb(val, VAL);
}
/* Internal function, should be called after superio_select(GPIO) */
static void wdt_update_timeout(void)
{
unsigned char cfg = WDT_KRST;
int tm = timeout;
if (testmode)
cfg = 0;
if (tm <= max_units)
cfg |= WDT_TOV1;
else
tm /= 60;
if (chip_type != IT8721_ID)
cfg |= WDT_PWROK;
superio_outb(cfg, WDTCFG);
superio_outb(tm, WDTVALLSB);
if (max_units > 255)
superio_outb(tm>>8, WDTVALMSB);
}
static int wdt_round_time(int t)
{
t += 59;
t -= t % 60;
return t;
}
/* watchdog timer handling */
static void wdt_keepalive(void)
{
if (test_bit(WDTS_USE_GP, &wdt_status))
inb(base);
else
/* The timer reloads with around 5 msec delay */
outb(0x55, CIR_DR(base));
set_bit(WDTS_KEEPALIVE, &wdt_status);
}
static int wdt_start(void)
{
int ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
if (test_bit(WDTS_USE_GP, &wdt_status))
superio_outb(WDT_GAMEPORT, WDTCTRL);
else
superio_outb(WDT_CIRINT, WDTCTRL);
wdt_update_timeout();
superio_exit();
return 0;
}
static int wdt_stop(void)
{
int ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
superio_outb(0x00, WDTCTRL);
superio_outb(WDT_TOV1, WDTCFG);
superio_outb(0x00, WDTVALLSB);
if (max_units > 255)
superio_outb(0x00, WDTVALMSB);
superio_exit();
return 0;
}
/**
* wdt_set_timeout - set a new timeout value with watchdog ioctl
* @t: timeout value in seconds
*
* The hardware device has a 8 or 16 bit watchdog timer (depends on
* chip version) that can be configured to count seconds or minutes.
*
* Used within WDIOC_SETTIMEOUT watchdog device ioctl.
*/
static int wdt_set_timeout(int t)
{
if (t < 1 || t > max_units * 60)
return -EINVAL;
if (t > max_units)
timeout = wdt_round_time(t);
else
timeout = t;
if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
int ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
wdt_update_timeout();
superio_exit();
}
return 0;
}
/**
* wdt_get_status - determines the status supported by watchdog ioctl
* @status: status returned to user space
*
* The status bit of the device does not allow to distinguish
* between a regular system reset and a watchdog forced reset.
* But, in test mode it is useful, so it is supported through
* WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
* reports the keepalive signal and the acception of the magic.
*
* Used within WDIOC_GETSTATUS watchdog device ioctl.
*/
static int wdt_get_status(int *status)
{
*status = 0;
if (testmode) {
int ret = superio_enter();
if (ret)
return ret;
superio_select(GPIO);
if (superio_inb(WDTCTRL) & WDT_ZERO) {
superio_outb(0x00, WDTCTRL);
clear_bit(WDTS_TIMER_RUN, &wdt_status);
*status |= WDIOF_CARDRESET;
}
superio_exit();
}
if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
*status |= WDIOF_KEEPALIVEPING;
if (test_bit(WDTS_EXPECTED, &wdt_status))
*status |= WDIOF_MAGICCLOSE;
return 0;
}
/* /dev/watchdog handling */
/**
* wdt_open - watchdog file_operations .open
* @inode: inode of the device
* @file: file handle to the device
*
* The watchdog timer starts by opening the device.
*
* Used within the file operation of the watchdog device.
*/
static int wdt_open(struct inode *inode, struct file *file)
{
if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
return -EBUSY;
if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
int ret;
if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
__module_get(THIS_MODULE);
ret = wdt_start();
if (ret) {
clear_bit(WDTS_LOCKED, &wdt_status);
clear_bit(WDTS_TIMER_RUN, &wdt_status);
clear_bit(WDTS_DEV_OPEN, &wdt_status);
return ret;
}
}
return nonseekable_open(inode, file);
}
/**
* wdt_release - watchdog file_operations .release
* @inode: inode of the device
* @file: file handle to the device
*
* Closing the watchdog device either stops the watchdog timer
* or in the case, that nowayout is set or the magic character
* wasn't written, a critical warning about an running watchdog
* timer is given.
*
* Used within the file operation of the watchdog device.
*/
static int wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
int ret = wdt_stop();
if (ret) {
/*
* Stop failed. Just keep the watchdog alive
* and hope nothing bad happens.
*/
set_bit(WDTS_EXPECTED, &wdt_status);
wdt_keepalive();
return ret;
}
clear_bit(WDTS_TIMER_RUN, &wdt_status);
} else {
wdt_keepalive();
pr_crit("unexpected close, not stopping watchdog!\n");
}
}
clear_bit(WDTS_DEV_OPEN, &wdt_status);
return 0;
}
/**
* wdt_write - watchdog file_operations .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 don't define content meaning.
*
* Used within the file operation of the watchdog device.
*/
static ssize_t wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
clear_bit(WDTS_EXPECTED, &wdt_status);
wdt_keepalive();
}
if (!nowayout) {
size_t ofs;
/* note: just in case someone wrote the magic character long ago */
for (ofs = 0; ofs != count; ofs++) {
char c;
if (get_user(c, buf + ofs))
return -EFAULT;
if (c == WD_MAGIC)
set_bit(WDTS_EXPECTED, &wdt_status);
}
}
return count;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
/**
* wdt_ioctl - watchdog file_operations .unlocked_ioctl
* @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.
*
* Used within the file operation of the watchdog device.
*/
static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int rc = 0, status, new_options, 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,
&ident, sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
rc = wdt_get_status(&status);
if (rc)
return rc;
return put_user(status, uarg.i);
case WDIOC_GETBOOTSTATUS:
return put_user(0, uarg.i);
case WDIOC_KEEPALIVE:
wdt_keepalive();
return 0;
case WDIOC_SETOPTIONS:
if (get_user(new_options, uarg.i))
return -EFAULT;
switch (new_options) {
case WDIOS_DISABLECARD:
if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
rc = wdt_stop();
if (rc)
return rc;
}
clear_bit(WDTS_TIMER_RUN, &wdt_status);
return 0;
case WDIOS_ENABLECARD:
if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
rc = wdt_start();
if (rc) {
clear_bit(WDTS_TIMER_RUN, &wdt_status);
return rc;
}
}
return 0;
default:
return -EFAULT;
}
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, uarg.i))
return -EFAULT;
rc = wdt_set_timeout(new_timeout);
case WDIOC_GETTIMEOUT:
if (put_user(timeout, uarg.i))
return -EFAULT;
return rc;
default:
return -ENOTTY;
}
}
static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdt_stop();
return NOTIFY_DONE;
}
static const struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdt_write,
.unlocked_ioctl = wdt_ioctl,
.open = wdt_open,
.release = wdt_release,
};
static struct miscdevice wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdt_fops,
};
static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
static int __init it87_wdt_init(void)
{
int rc = 0;
int try_gameport = !nogameport;
u8 chip_rev;
int gp_rreq_fail = 0;
wdt_status = 0;
rc = superio_enter();
if (rc)
return rc;
chip_type = superio_inw(CHIPID);
chip_rev = superio_inb(CHIPREV) & 0x0f;
superio_exit();
switch (chip_type) {
case IT8702_ID:
max_units = 255;
break;
case IT8712_ID:
max_units = (chip_rev < 8) ? 255 : 65535;
break;
case IT8716_ID:
case IT8726_ID:
max_units = 65535;
break;
case IT8718_ID:
case IT8720_ID:
case IT8721_ID:
max_units = 65535;
try_gameport = 0;
break;
case IT8705_ID:
pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
chip_type, chip_rev);
return -ENODEV;
case NO_DEV_ID:
pr_err("no device\n");
return -ENODEV;
default:
pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
chip_type, chip_rev);
return -ENODEV;
}
rc = superio_enter();
if (rc)
return rc;
superio_select(GPIO);
superio_outb(WDT_TOV1, WDTCFG);
superio_outb(0x00, WDTCTRL);
/* First try to get Gameport support */
if (try_gameport) {
superio_select(GAMEPORT);
base = superio_inw(BASEREG);
if (!base) {
base = GP_BASE_DEFAULT;
superio_outw(base, BASEREG);
}
gpact = superio_inb(ACTREG);
superio_outb(0x01, ACTREG);
if (request_region(base, 1, WATCHDOG_NAME))
set_bit(WDTS_USE_GP, &wdt_status);
else
gp_rreq_fail = 1;
}
/* If we haven't Gameport support, try to get CIR support */
if (!test_bit(WDTS_USE_GP, &wdt_status)) {
if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
if (gp_rreq_fail)
pr_err("I/O Address 0x%04x and 0x%04x already in use\n",
base, CIR_BASE);
else
pr_err("I/O Address 0x%04x already in use\n",
CIR_BASE);
rc = -EIO;
goto err_out;
}
base = CIR_BASE;
superio_select(CIR);
superio_outw(base, BASEREG);
superio_outb(0x00, CIR_ILS);
ciract = superio_inb(ACTREG);
superio_outb(0x01, ACTREG);
if (gp_rreq_fail) {
superio_select(GAMEPORT);
superio_outb(gpact, ACTREG);
}
}
if (timeout < 1 || timeout > max_units * 60) {
timeout = DEFAULT_TIMEOUT;
pr_warn("Timeout value out of range, use default %d sec\n",
DEFAULT_TIMEOUT);
}
if (timeout > max_units)
timeout = wdt_round_time(timeout);
rc = register_reboot_notifier(&wdt_notifier);
if (rc) {
pr_err("Cannot register reboot notifier (err=%d)\n", rc);
goto err_out_region;
}
rc = misc_register(&wdt_miscdev);
if (rc) {
pr_err("Cannot register miscdev on minor=%d (err=%d)\n",
wdt_miscdev.minor, rc);
goto err_out_reboot;
}
/* Initialize CIR to use it as keepalive source */
if (!test_bit(WDTS_USE_GP, &wdt_status)) {
outb(0x00, CIR_RCR(base));
outb(0xc0, CIR_TCR1(base));
outb(0x5c, CIR_TCR2(base));
outb(0x10, CIR_IER(base));
outb(0x00, CIR_BDHR(base));
outb(0x01, CIR_BDLR(base));
outb(0x09, CIR_IER(base));
}
pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d)\n",
chip_type, chip_rev, timeout,
nowayout, testmode, exclusive, nogameport);
superio_exit();
return 0;
err_out_reboot:
unregister_reboot_notifier(&wdt_notifier);
err_out_region:
release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
if (!test_bit(WDTS_USE_GP, &wdt_status)) {
superio_select(CIR);
superio_outb(ciract, ACTREG);
}
err_out:
if (try_gameport) {
superio_select(GAMEPORT);
superio_outb(gpact, ACTREG);
}
superio_exit();
return rc;
}
static void __exit it87_wdt_exit(void)
{
if (superio_enter() == 0) {
superio_select(GPIO);
superio_outb(0x00, WDTCTRL);
superio_outb(0x00, WDTCFG);
superio_outb(0x00, WDTVALLSB);
if (max_units > 255)
superio_outb(0x00, WDTVALMSB);
if (test_bit(WDTS_USE_GP, &wdt_status)) {
superio_select(GAMEPORT);
superio_outb(gpact, ACTREG);
} else {
superio_select(CIR);
superio_outb(ciract, ACTREG);
}
superio_exit();
}
misc_deregister(&wdt_miscdev);
unregister_reboot_notifier(&wdt_notifier);
release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
}
module_init(it87_wdt_init);
module_exit(it87_wdt_exit);
MODULE_AUTHOR("Oliver Schuster");
MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);