/* * RDC321x watchdog driver * * Copyright (C) 2007 Florian Fainelli * * This driver is highly inspired from the cpu5_wdt driver * * 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 #include #include #define RDC_WDT_MASK 0x80000000 /* Mask */ #define RDC_WDT_EN 0x00800000 /* Enable bit */ #define RDC_WDT_WTI 0x00200000 /* Generate a CPU reset/NMI/WDT irq when WDT timeout is reached */ #define RDC_WDT_RST 0x00100000 /* Reset bit */ #define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */ #define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */ #define RDC_WDT_CNT 0x00000001 /* WDT count */ #define RDC_CLS_TMR 0x80003844 /* Clear timer */ #define RDC_WDT_INTERVAL (HZ/10+1) int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static int ticks = 1000; /* some device data */ static struct { struct completion stop; volatile int running; struct timer_list timer; volatile int queue; int default_ticks; unsigned long inuse; } rdc321x_wdt_device; /* generic helper functions */ static void rdc321x_wdt_trigger(unsigned long unused) { if( rdc321x_wdt_device.running ) ticks--; /* keep watchdog alive */ outl(RDC_WDT_EN|inl(RDC3210_CFGREG_DATA), RDC3210_CFGREG_DATA); /* requeue?? */ if (rdc321x_wdt_device.queue && ticks) mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL); else { /* ticks doesn't matter anyway */ complete(&rdc321x_wdt_device.stop); } } static void rdc321x_wdt_reset(void) { ticks = rdc321x_wdt_device.default_ticks; } static void rdc321x_wdt_start(void) { if (!rdc321x_wdt_device.queue) { rdc321x_wdt_device.queue = 1; /* Clear the timer */ outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR); /* Enable watchdog and set the timeout to 81.92 us */ outl(RDC_WDT_EN|RDC_WDT_CNT, RDC3210_CFGREG_DATA); mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL); } /* if process dies, counter is not decremented */ rdc321x_wdt_device.running++; } static int rdc321x_wdt_stop(void) { if (rdc321x_wdt_device.running) rdc321x_wdt_device.running = 0; ticks = rdc321x_wdt_device.default_ticks; return -EIO; } /* filesystem operations */ static int rdc321x_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &rdc321x_wdt_device.inuse)) return -EBUSY; return nonseekable_open(inode, file); } static int rdc321x_wdt_release(struct inode *inode, struct file *file) { clear_bit(0, &rdc321x_wdt_device.inuse); return 0; } static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; unsigned int value; static struct watchdog_info ident = { .options = WDIOF_CARDRESET, .identity = "RDC321x WDT", }; switch(cmd) { case WDIOC_KEEPALIVE: rdc321x_wdt_reset(); break; case WDIOC_GETSTATUS: /* Read the value from the DATA register */ value = inl(RDC3210_CFGREG_DATA); if ( copy_to_user(argp, &value, sizeof(int)) ) return -EFAULT; break; case WDIOC_GETSUPPORT: if ( copy_to_user(argp, &ident, sizeof(ident)) ) return -EFAULT; break; case WDIOC_SETOPTIONS: if ( copy_from_user(&value, argp, sizeof(int)) ) return -EFAULT; switch(value) { case WDIOS_ENABLECARD: rdc321x_wdt_start(); break; case WDIOS_DISABLECARD: return rdc321x_wdt_stop(); default: return -EINVAL; } break; default: return -ENOTTY; } return 0; } static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if ( !count ) return -EIO; rdc321x_wdt_reset(); return count; } static const struct file_operations rdc321x_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .ioctl = rdc321x_wdt_ioctl, .open = rdc321x_wdt_open, .write = rdc321x_wdt_write, .release = rdc321x_wdt_release, }; static struct miscdevice rdc321x_wdt_misc = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &rdc321x_wdt_fops, }; static int __devinit rdc321x_wdt_probe(struct platform_device *pdev) { int err; if ( (err = misc_register(&rdc321x_wdt_misc)) < 0 ) { printk(KERN_ERR PFX "misc_register failed\n"); return err; } /* Reset the watchdog */ outl(RDC_WDT_RST, RDC3210_CFGREG_DATA); init_completion(&rdc321x_wdt_device.stop); rdc321x_wdt_device.queue = 0; clear_bit(0, &rdc321x_wdt_device.inuse); setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0); rdc321x_wdt_device.default_ticks = ticks; printk(KERN_INFO PFX "init success\n"); return 0; } static int rdc321x_wdt_remove(struct platform_device *pdev) { if (rdc321x_wdt_device.queue) { rdc321x_wdt_device.queue = 0; wait_for_completion(&rdc321x_wdt_device.stop); } misc_deregister(&rdc321x_wdt_misc); return 0; } static struct platform_driver rdc321x_wdt_driver = { .probe = rdc321x_wdt_probe, .remove = rdc321x_wdt_remove, .driver = { .owner = THIS_MODULE, .name = "rdc321x-wdt", }, }; static int __init rdc321x_wdt_init(void) { return platform_driver_register(&rdc321x_wdt_driver); } static void __exit rdc321x_wdt_exit(void) { platform_driver_unregister(&rdc321x_wdt_driver); } module_init(rdc321x_wdt_init); module_exit(rdc321x_wdt_exit); MODULE_AUTHOR("Florian Fainelli "); MODULE_DESCRIPTION("RDC321x watchdog driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);