diff options
Diffstat (limited to 'drivers/watchdog/bcm47xx_wdt.c')
| -rw-r--r-- | drivers/watchdog/bcm47xx_wdt.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/watchdog/bcm47xx_wdt.c b/drivers/watchdog/bcm47xx_wdt.c new file mode 100644 index 00000000000..751c003864a --- /dev/null +++ b/drivers/watchdog/bcm47xx_wdt.c @@ -0,0 +1,286 @@ +/* + * 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. + */ + +#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 int 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, int, 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 */ + ssb_watchdog_timer_set(&ssb_bcm47xx, 0xfffffff); +} + +static inline int bcm47xx_wdt_hw_stop(void) +{ + return ssb_watchdog_timer_set(&ssb_bcm47xx, 0); +} + +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 { + printk(KERN_CRIT DRV_NAME "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 { + printk(KERN_CRIT DRV_NAME + ": 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 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); + printk(KERN_INFO DRV_NAME ": " + "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; + } + + printk(KERN_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); |