/* * Watchdog Timer Driver * for ITE IT87xx Environment Control - Low Pin Count Input / Output * * (c) Copyright 2007 Oliver Schuster * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define WATCHDOG_VERSION "1.14" #define WATCHDOG_NAME "IT87 WDT" #define PFX WATCHDOG_NAME ": " #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 int 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, int, 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(); printk(KERN_CRIT PFX "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: printk(KERN_ERR PFX "Unsupported Chip found, Chip %04x Revision %02x\n", chip_type, chip_rev); return -ENODEV; case NO_DEV_ID: printk(KERN_ERR PFX "no device\n"); return -ENODEV; default: printk(KERN_ERR PFX "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) printk(KERN_ERR PFX "I/O Address 0x%04x and 0x%04x" " already in use\n", base, CIR_BASE); else printk(KERN_ERR PFX "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; printk(KERN_WARNING PFX "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) { printk(KERN_ERR PFX "Cannot register reboot notifier (err=%d)\n", rc); goto err_out_region; } rc = misc_register(&wdt_miscdev); if (rc) { printk(KERN_ERR PFX "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)); } printk(KERN_INFO PFX "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);