/* * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip * * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt> * * Based on w83877f_wdt.c by Scott Jennings, * and wdt977.c by Woody Suwalski * * ----------------------- * * 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. * */ #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> #include <asm/system.h> #define WATCHDOG_VERSION "1.00" #define WATCHDOG_NAME "W83977F WDT" #define PFX WATCHDOG_NAME ": " #define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" #define IO_INDEX_PORT 0x3F0 #define IO_DATA_PORT (IO_INDEX_PORT+1) #define UNLOCK_DATA 0x87 #define LOCK_DATA 0xAA #define DEVICE_REGISTER 0x07 #define DEFAULT_TIMEOUT 45 /* default timeout in seconds */ static int timeout = DEFAULT_TIMEOUT; static int timeoutW; /* timeout in watchdog counter units */ static unsigned long timer_alive; static int testmode; static char expect_close; static DEFINE_SPINLOCK(spinlock); module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")"); module_param(testmode, int, 0); MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); /* * Start the watchdog */ static int wdt_start(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* Unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. * F2 has the timeout in watchdog counter units. * F3 is set to enable watchdog LED blink at timeout. * F4 is used to just clear the TIMEOUT'ed state (bit 0). */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(timeoutW, IO_DATA_PORT); outb_p(0xF3, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF4, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); /* Set device Aux2 active */ outb_p(0x30, IO_INDEX_PORT); outb_p(0x01, IO_DATA_PORT); /* * Select device Aux1 (dev=7) to set GP16 as the watchdog output * (in reg E6) and GP13 as the watchdog LED output (in reg E3). * Map GP16 at pin 119. * In test mode watch the bit 0 on F4 to indicate "triggered" or * check watchdog LED on SBC. */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x07, IO_DATA_PORT); if (!testmode) { unsigned pin_map; outb_p(0xE6, IO_INDEX_PORT); outb_p(0x0A, IO_DATA_PORT); outb_p(0x2C, IO_INDEX_PORT); pin_map = inb_p(IO_DATA_PORT); pin_map |= 0x10; pin_map &= ~(0x20); outb_p(0x2C, IO_INDEX_PORT); outb_p(pin_map, IO_DATA_PORT); } outb_p(0xE3, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); /* Set device Aux1 active */ outb_p(0x30, IO_INDEX_PORT); outb_p(0x01, IO_DATA_PORT); /* Lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); printk(KERN_INFO PFX "activated.\n"); return 0; } /* * Stop the watchdog */ static int wdt_stop(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* Unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. * F2 is reset to its default value (watchdog timer disabled). * F3 is reset to its default state. * F4 clears the TIMEOUT'ed state (bit 0) - back to default. */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(0xFF, IO_DATA_PORT); outb_p(0xF3, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); outb_p(0xF4, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); /* * Select device Aux1 (dev=7) to set GP16 (in reg E6) and * Gp13 (in reg E3) as inputs. */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x07, IO_DATA_PORT); if (!testmode) { outb_p(0xE6, IO_INDEX_PORT); outb_p(0x01, IO_DATA_PORT); } outb_p(0xE3, IO_INDEX_PORT); outb_p(0x01, IO_DATA_PORT); /* Lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); printk(KERN_INFO PFX "shutdown.\n"); return 0; } /* * Send a keepalive ping to the watchdog * This is done by simply re-writing the timeout to reg. 0xF2 */ static int wdt_keepalive(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* Unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* Select device Aux2 (device=8) to kick watchdog reg F2 */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(timeoutW, IO_DATA_PORT); /* Lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); return 0; } /* * Set the watchdog timeout value */ static int wdt_set_timeout(int t) { int tmrval; /* * Convert seconds to watchdog counter time units, rounding up. * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup * value. This information is supplied in the PCM-5335 manual and was * checked by me on a real board. This is a bit strange because W83977f * datasheet says counter unit is in minutes! */ if (t < 15) return -EINVAL; tmrval = ((t + 15) + 29) / 30; if (tmrval > 255) return -EINVAL; /* * timeout is the timeout in seconds, * timeoutW is the timeout in watchdog counter units. */ timeoutW = tmrval; timeout = (timeoutW * 30) - 15; return 0; } /* * Get the watchdog status */ static int wdt_get_status(int *status) { int new_status; unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* Unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* Select device Aux2 (device=8) to read watchdog reg F4 */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF4, IO_INDEX_PORT); new_status = inb_p(IO_DATA_PORT); /* Lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); *status = 0; if (new_status & 1) *status |= WDIOF_CARDRESET; return 0; } /* * /dev/watchdog handling */ static int wdt_open(struct inode *inode, struct file *file) { /* If the watchdog is alive we don't need to start it again */ if (test_and_set_bit(0, &timer_alive)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); wdt_start(); return nonseekable_open(inode, file); } static int wdt_release(struct inode *inode, struct file *file) { /* * Shut off the timer. * Lock it in if it's a module and we set nowayout */ if (expect_close == 42) { wdt_stop(); clear_bit(0, &timer_alive); } else { wdt_keepalive(); printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n"); } expect_close = 0; return 0; } /* * wdt_write: * @file: file handle to the watchdog * @buf: buffer to write (unused as data does not matter here * @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 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { /* See if we got the magic character 'V' and reload the timer */ if (count) { if (!nowayout) { size_t ofs; /* note: just in case someone wrote the magic character long ago */ expect_close = 0; /* scan to see whether or not we got the magic character */ for (ofs = 0; ofs != count; ofs++) { char c; if (get_user(c, buf + ofs)) return -EFAULT; if (c == 'V') expect_close = 42; } } /* someone wrote to us, we should restart timer */ wdt_keepalive(); } return count; } /* * wdt_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 struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .firmware_version = 1, .identity = WATCHDOG_NAME, }; static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int status; int new_options, retval = -EINVAL; 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, &ident, sizeof(ident)) ? -EFAULT : 0; case WDIOC_GETSTATUS: wdt_get_status(&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) { wdt_stop(); retval = 0; } if (new_options & WDIOS_ENABLECARD) { wdt_start(); retval = 0; } return retval; case WDIOC_KEEPALIVE: wdt_keepalive(); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, uarg.i)) return -EFAULT; if (wdt_set_timeout(new_timeout)) return -EINVAL; wdt_keepalive(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(timeout, uarg.i); 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 w83977f_wdt_init(void) { int rc; printk(KERN_INFO PFX DRIVER_VERSION); /* * Check that the timeout value is within it's range; * if not reset to the default */ if (wdt_set_timeout(timeout)) { wdt_set_timeout(DEFAULT_TIMEOUT); printk(KERN_INFO PFX "timeout value must be 15 <= timeout <= 7635, using %d\n", DEFAULT_TIMEOUT); } if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", IO_INDEX_PORT); rc = -EIO; goto err_out; } 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; } printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", timeout, nowayout, testmode); return 0; err_out_reboot: unregister_reboot_notifier(&wdt_notifier); err_out_region: release_region(IO_INDEX_PORT, 2); err_out: return rc; } static void __exit w83977f_wdt_exit(void) { wdt_stop(); misc_deregister(&wdt_miscdev); unregister_reboot_notifier(&wdt_notifier); release_region(IO_INDEX_PORT, 2); } module_init(w83977f_wdt_init); module_exit(w83977f_wdt_exit); MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>"); MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);