/* * Watchdog driver for Broadcom BCM47XX * * Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs> * Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr> * * 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. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/bitops.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/reboot.h> #include <linux/types.h> #include <linux/uaccess.h> #include <linux/watchdog.h> #include <linux/timer.h> #include <linux/jiffies.h> #include <linux/ssb/ssb_embedded.h> #include <asm/mach-bcm47xx/bcm47xx.h> #define DRV_NAME "bcm47xx_wdt" #define WDT_DEFAULT_TIME 30 /* seconds */ #define WDT_MAX_TIME 255 /* seconds */ static int wdt_time = WDT_DEFAULT_TIME; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(wdt_time, int, 0); MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default=" __MODULE_STRING(WDT_DEFAULT_TIME) ")"); #ifdef CONFIG_WATCHDOG_NOWAYOUT module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); #endif static unsigned long bcm47xx_wdt_busy; static char expect_release; static struct timer_list wdt_timer; static atomic_t ticks; static inline void bcm47xx_wdt_hw_start(void) { /* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */ switch (bcm47xx_bus_type) { #ifdef CONFIG_BCM47XX_SSB case BCM47XX_BUS_TYPE_SSB: ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0xfffffff); break; #endif #ifdef CONFIG_BCM47XX_BCMA case BCM47XX_BUS_TYPE_BCMA: bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0xfffffff); break; #endif } } static inline int bcm47xx_wdt_hw_stop(void) { switch (bcm47xx_bus_type) { #ifdef CONFIG_BCM47XX_SSB case BCM47XX_BUS_TYPE_SSB: return ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0); #endif #ifdef CONFIG_BCM47XX_BCMA case BCM47XX_BUS_TYPE_BCMA: bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0); return 0; #endif } return -EINVAL; } static void bcm47xx_timer_tick(unsigned long unused) { if (!atomic_dec_and_test(&ticks)) { bcm47xx_wdt_hw_start(); mod_timer(&wdt_timer, jiffies + HZ); } else { pr_crit("Watchdog will fire soon!!!\n"); } } static inline void bcm47xx_wdt_pet(void) { atomic_set(&ticks, wdt_time); } static void bcm47xx_wdt_start(void) { bcm47xx_wdt_pet(); bcm47xx_timer_tick(0); } static void bcm47xx_wdt_pause(void) { del_timer_sync(&wdt_timer); bcm47xx_wdt_hw_stop(); } static void bcm47xx_wdt_stop(void) { bcm47xx_wdt_pause(); } static int bcm47xx_wdt_settimeout(int new_time) { if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) return -EINVAL; wdt_time = new_time; return 0; } static int bcm47xx_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &bcm47xx_wdt_busy)) return -EBUSY; bcm47xx_wdt_start(); return nonseekable_open(inode, file); } static int bcm47xx_wdt_release(struct inode *inode, struct file *file) { if (expect_release == 42) { bcm47xx_wdt_stop(); } else { pr_crit("Unexpected close, not stopping watchdog!\n"); bcm47xx_wdt_start(); } clear_bit(0, &bcm47xx_wdt_busy); expect_release = 0; return 0; } static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { if (len) { if (!nowayout) { size_t i; expect_release = 0; for (i = 0; i != len; i++) { char c; if (get_user(c, data + i)) return -EFAULT; if (c == 'V') expect_release = 42; } } bcm47xx_wdt_pet(); } return len; } static const struct watchdog_info bcm47xx_wdt_info = { .identity = DRV_NAME, .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static long bcm47xx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int new_value, retval = -EINVAL; switch (cmd) { case WDIOC_GETSUPPORT: return copy_to_user(argp, &bcm47xx_wdt_info, sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_SETOPTIONS: if (get_user(new_value, p)) return -EFAULT; if (new_value & WDIOS_DISABLECARD) { bcm47xx_wdt_stop(); retval = 0; } if (new_value & WDIOS_ENABLECARD) { bcm47xx_wdt_start(); retval = 0; } return retval; case WDIOC_KEEPALIVE: bcm47xx_wdt_pet(); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_value, p)) return -EFAULT; if (bcm47xx_wdt_settimeout(new_value)) return -EINVAL; bcm47xx_wdt_pet(); case WDIOC_GETTIMEOUT: return put_user(wdt_time, p); default: return -ENOTTY; } } static int bcm47xx_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) bcm47xx_wdt_stop(); return NOTIFY_DONE; } static const struct file_operations bcm47xx_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .unlocked_ioctl = bcm47xx_wdt_ioctl, .open = bcm47xx_wdt_open, .release = bcm47xx_wdt_release, .write = bcm47xx_wdt_write, }; static struct miscdevice bcm47xx_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &bcm47xx_wdt_fops, }; static struct notifier_block bcm47xx_wdt_notifier = { .notifier_call = bcm47xx_wdt_notify_sys, }; static int __init bcm47xx_wdt_init(void) { int ret; if (bcm47xx_wdt_hw_stop() < 0) return -ENODEV; setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L); if (bcm47xx_wdt_settimeout(wdt_time)) { bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME); pr_info("wdt_time value must be 0 < wdt_time < %d, using %d\n", (WDT_MAX_TIME + 1), wdt_time); } ret = register_reboot_notifier(&bcm47xx_wdt_notifier); if (ret) return ret; ret = misc_register(&bcm47xx_wdt_miscdev); if (ret) { unregister_reboot_notifier(&bcm47xx_wdt_notifier); return ret; } pr_info("BCM47xx Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : ""); return 0; } static void __exit bcm47xx_wdt_exit(void) { if (!nowayout) bcm47xx_wdt_stop(); misc_deregister(&bcm47xx_wdt_miscdev); unregister_reboot_notifier(&bcm47xx_wdt_notifier); } module_init(bcm47xx_wdt_init); module_exit(bcm47xx_wdt_exit); MODULE_AUTHOR("Aleksandar Radovanovic"); MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);