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|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IT8712F "Smart Guardian" Watchdog support
*
* Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
*
* Based on info and code taken from:
*
* drivers/char/watchdog/scx200_wdt.c
* drivers/hwmon/it87.c
* IT8712F EC-LPC I/O Preliminary Specification 0.8.2
* IT8712F EC-LPC I/O Preliminary Specification 0.9.3
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/ioport.h>
#define DEBUG
#define NAME "it8712f_wdt"
MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
MODULE_DESCRIPTION("IT8712F Watchdog Driver");
MODULE_LICENSE("GPL");
static int max_units = 255;
static int margin = 60; /* in seconds */
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
static unsigned long wdt_open;
static unsigned expect_close;
static unsigned char revision;
/* Dog Food address - We use the game port address */
static unsigned short address;
#define REG 0x2e /* The register to read/write */
#define VAL 0x2f /* The value to read/write */
#define LDN 0x07 /* Register: Logical device select */
#define DEVID 0x20 /* Register: Device ID */
#define DEVREV 0x22 /* Register: Device Revision */
#define ACT_REG 0x30 /* LDN Register: Activation */
#define BASE_REG 0x60 /* LDN Register: Base address */
#define IT8712F_DEVID 0x8712
#define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
#define LDN_GAME 0x09 /* Game Port */
#define WDT_CONTROL 0x71 /* WDT Register: Control */
#define WDT_CONFIG 0x72 /* WDT Register: Configuration */
#define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */
#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
static int wdt_control_reg = WDT_RESET_GAME;
module_param(wdt_control_reg, int, 0);
MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
"register. The default WDT_RESET_GAME resets the timer on "
"game port reads that this driver generates. You can also "
"use KBD, MOUSE or CIR if you have some external way to "
"generate those interrupts.");
static int superio_inb(int reg)
{
outb(reg, REG);
return inb(VAL);
}
static void superio_outb(int val, int reg)
{
outb(reg, REG);
outb(val, VAL);
}
static 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_select(int ldn)
{
outb(LDN, REG);
outb(ldn, VAL);
}
static inline int superio_enter(void)
{
/*
* Try to reserve REG and REG + 1 for exclusive access.
*/
if (!request_muxed_region(REG, 2, 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 it8712f_wdt_ping(void)
{
if (wdt_control_reg & WDT_RESET_GAME)
inb(address);
}
static void it8712f_wdt_update_margin(void)
{
int config = WDT_OUT_KRST | WDT_OUT_PWROK;
int units = margin;
/* Switch to minutes precision if the configured margin
* value does not fit within the register width.
*/
if (units <= max_units) {
config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */
pr_info("timer margin %d seconds\n", units);
} else {
units /= 60;
pr_info("timer margin %d minutes\n", units);
}
superio_outb(config, WDT_CONFIG);
if (revision >= 0x08)
superio_outb(units >> 8, WDT_TIMEOUT + 1);
superio_outb(units, WDT_TIMEOUT);
}
static int it8712f_wdt_get_status(void)
{
if (superio_inb(WDT_CONTROL) & 0x01)
return WDIOF_CARDRESET;
else
return 0;
}
static int it8712f_wdt_enable(void)
{
int ret = superio_enter();
if (ret)
return ret;
pr_debug("enabling watchdog timer\n");
superio_select(LDN_GPIO);
superio_outb(wdt_control_reg, WDT_CONTROL);
it8712f_wdt_update_margin();
superio_exit();
it8712f_wdt_ping();
return 0;
}
static int it8712f_wdt_disable(void)
{
int ret = superio_enter();
if (ret)
return ret;
pr_debug("disabling watchdog timer\n");
superio_select(LDN_GPIO);
superio_outb(0, WDT_CONFIG);
superio_outb(0, WDT_CONTROL);
if (revision >= 0x08)
superio_outb(0, WDT_TIMEOUT + 1);
superio_outb(0, WDT_TIMEOUT);
superio_exit();
return 0;
}
static int it8712f_wdt_notify(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_HALT || code == SYS_POWER_OFF)
if (!nowayout)
it8712f_wdt_disable();
return NOTIFY_DONE;
}
static struct notifier_block it8712f_wdt_notifier = {
.notifier_call = it8712f_wdt_notify,
};
static ssize_t it8712f_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* check for a magic close character */
if (len) {
size_t i;
it8712f_wdt_ping();
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;
}
}
return len;
}
static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.identity = "IT8712F Watchdog",
.firmware_version = 1,
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
int value;
int ret;
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
ret = superio_enter();
if (ret)
return ret;
superio_select(LDN_GPIO);
value = it8712f_wdt_get_status();
superio_exit();
return put_user(value, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
it8712f_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(value, p))
return -EFAULT;
if (value < 1)
return -EINVAL;
if (value > (max_units * 60))
return -EINVAL;
margin = value;
ret = superio_enter();
if (ret)
return ret;
superio_select(LDN_GPIO);
it8712f_wdt_update_margin();
superio_exit();
it8712f_wdt_ping();
fallthrough;
case WDIOC_GETTIMEOUT:
if (put_user(margin, p))
return -EFAULT;
return 0;
default:
return -ENOTTY;
}
}
static int it8712f_wdt_open(struct inode *inode, struct file *file)
{
int
|