/* * 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 * * 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. */ #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(); /* Fall through */ 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 ret; /* only allow one at a time */ if (test_and_set_bit(0, &wdt_open)) return -EBUSY; ret = it8712f_wdt_enable(); if (ret) return ret; return nonseekable_open(inode, file); } static int it8712f_wdt_release(struct inode *inode, struct file *file) { if (expect_close != 42) { pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n"); } else if (!nowayout) { if (it8712f_wdt_disable()) pr_warn("Watchdog disable failed\n"); } expect_close = 0; clear_bit(0, &wdt_open); return 0; } static const struct file_operations it8712f_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = it8712f_wdt_write, .unlocked_ioctl = it8712f_wdt_ioctl, .open = it8712f_wdt_open, .release = it8712f_wdt_release, }; static struct miscdevice it8712f_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &it8712f_wdt_fops, }; static int __init it8712f_wdt_find(unsigned short *address) { int err = -ENODEV; int chip_type; int ret = superio_enter(); if (ret) return ret; chip_type = superio_inw(DEVID); if (chip_type != IT8712F_DEVID) goto exit; superio_select(LDN_GAME); superio_outb(1, ACT_REG); if (!(superio_inb(ACT_REG) & 0x01)) { pr_err("Device not activated, skipping\n"); goto exit; } *address = superio_inw(BASE_REG); if (*address == 0) { pr_err("Base address not set, skipping\n"); goto exit; } err = 0; revision = superio_inb(DEVREV) & 0x0f; /* Later revisions have 16-bit values per datasheet 0.9.1 */ if (revision >= 0x08) max_units = 65535; if (margin > (max_units * 60)) margin = (max_units * 60); pr_info("Found IT%04xF chip revision %d - using DogFood address 0x%x\n", chip_type, revision, *address); exit: superio_exit(); return err; } static int __init it8712f_wdt_init(void) { int err = 0; if (it8712f_wdt_find(&address)) return -ENODEV; if (!request_region(address, 1, "IT8712F Watchdog")) { pr_warn("watchdog I/O region busy\n"); return -EBUSY; } err = it8712f_wdt_disable(); if (err) { pr_err("unable to disable watchdog timer\n"); goto out; } err = register_reboot_notifier(&it8712f_wdt_notifier); if (err) { pr_err("unable to register reboot notifier\n"); goto out; } err = misc_register(&it8712f_wdt_miscdev); if (err) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, err); goto reboot_out; } return 0; reboot_out: unregister_reboot_notifier(&it8712f_wdt_notifier); out: release_region(address, 1); return err; } static void __exit it8712f_wdt_exit(void) { misc_deregister(&it8712f_wdt_miscdev); unregister_reboot_notifier(&it8712f_wdt_notifier); release_region(address, 1); } module_init(it8712f_wdt_init); module_exit(it8712f_wdt_exit);