/* * RDC321x watchdog driver * * Copyright (C) 2007-2010 Florian Fainelli * * 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 extern int rdc321x_pci_write(int reg, u32 val); extern int rdc321x_pci_read(int reg, u32 *val); #define RDC321X_WDT_REG 0x00000044 #define RDC_WDT_EN 0x00800000 /* Enable bit */ #define RDC_WDT_WDTIRQ 0x00400000 /* Create WDT IRQ before CPU reset */ #define RDC_WDT_NMIIRQ 0x00200000 /* Create NMI IRQ before CPU reset */ #define RDC_WDT_RST 0x00100000 /* Reset wdt */ #define RDC_WDT_NIF 0x00080000 /* NMI interrupt occured */ #define RDC_WDT_WIF 0x00040000 /* WDT interrupt occured */ #define RDC_WDT_IRT 0x00000700 /* IRQ Routing table */ #define RDC_WDT_CNT 0x0000007F /* WDT count */ /* default counter value (2.34 s) */ #define RDC_WDT_DFLT_CNT 0x00000040 #define RDC_WDT_SETUP (RDC_WDT_EN | RDC_WDT_NMIIRQ | RDC_WDT_RST | RDC_WDT_DFLT_CNT) /* some device data */ static struct { struct timer_list timer; int seconds_left; int total_seconds; bool inuse; bool running; bool close_expected; } rdc321x_wdt_dev; static struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .identity = "RDC321x WDT", }; /* generic helper functions */ static void rdc321x_wdt_timer(unsigned long unused) { if (!rdc321x_wdt_dev.running) { rdc321x_pci_write(RDC321X_WDT_REG, 0); return; } rdc321x_wdt_dev.seconds_left--; if (rdc321x_wdt_dev.seconds_left < 1) return; rdc321x_pci_write(RDC321X_WDT_REG, RDC_WDT_SETUP); mod_timer(&rdc321x_wdt_dev.timer, HZ * 2 + jiffies); } static void rdc321x_wdt_reset(void) { rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds; } static void rdc321x_wdt_start(void) { if (rdc321x_wdt_dev.running) return; rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds; rdc321x_wdt_dev.running = true; rdc321x_wdt_timer(0); return; } static int rdc321x_wdt_stop(void) { if (WATCHDOG_NOWAYOUT) return -ENOSYS; rdc321x_wdt_dev.running = false; return 0; } /* filesystem operations */ static int rdc321x_wdt_open(struct inode *inode, struct file *file) { if (xchg(&rdc321x_wdt_dev.inuse, true)) return -EBUSY; return nonseekable_open(inode, file); } static int rdc321x_wdt_release(struct inode *inode, struct file *file) { int res; if (rdc321x_wdt_dev.close_expected) { res = rdc321x_wdt_stop(); if (res) return res; } rdc321x_wdt_dev.inuse = false; return 0; } static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int value; switch (cmd) { case WDIOC_KEEPALIVE: rdc321x_wdt_reset(); break; case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_SETTIMEOUT: if (copy_from_user(&rdc321x_wdt_dev.total_seconds, argp, sizeof(int))) return -EFAULT; rdc321x_wdt_dev.seconds_left = rdc321x_wdt_dev.total_seconds; break; case WDIOC_GETTIMEOUT: if (copy_to_user(argp, &rdc321x_wdt_dev.total_seconds, sizeof(int))) return -EFAULT; break; case WDIOC_GETTIMELEFT: if (copy_to_user(argp, &rdc321x_wdt_dev.seconds_left, sizeof(int))) 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 -EINVAL; } return 0; } static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { size_t i; if (!count) return -EIO; rdc321x_wdt_dev.close_expected = false; for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') { rdc321x_wdt_dev.close_expected = true; break; } } rdc321x_wdt_reset(); return count; } static const struct file_operations rdc321x_wdt_fops = { .llseek = no_llseek, .unlocked_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 __init rdc321x_wdt_probe(struct platform_device *pdev) { int err; err = rdc321x_pci_write(RDC321X_WDT_REG, 0); if (err) return err; rdc321x_wdt_dev.running = false; rdc321x_wdt_dev.close_expected = false; rdc321x_wdt_dev.inuse = 0; setup_timer(&rdc321x_wdt_dev.timer, rdc321x_wdt_timer, 0); rdc321x_wdt_dev.total_seconds = 100; err = misc_register(&rdc321x_wdt_misc); if (err < 0) { printk(KERN_ERR PFX "watchdog: misc_register failed\n"); return err; } dev_info(&pdev->dev, "watchdog init success\n"); return 0; } static int __devexit rdc321x_wdt_remove(struct platform_device *pdev) { if (rdc321x_wdt_dev.inuse) rdc321x_wdt_dev.inuse = 0; while (timer_pending(&rdc321x_wdt_dev.timer)) msleep(100); misc_deregister(&rdc321x_wdt_misc); return 0; } static struct platform_driver rdc321x_wdt_driver = { .driver.name = "rdc321x-wdt", .driver.owner = THIS_MODULE, .probe = rdc321x_wdt_probe, .remove = __devexit_p(rdc321x_wdt_remove), }; 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("platform:rdc321x-wdt");