diff options
Diffstat (limited to 'drivers/watchdog/rdc321x_wdt.c')
| -rw-r--r-- | drivers/watchdog/rdc321x_wdt.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c new file mode 100644 index 000000000000..9108efa73e7d --- /dev/null +++ b/drivers/watchdog/rdc321x_wdt.c @@ -0,0 +1,285 @@ +/* + * RDC321x watchdog driver + * + * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org> + * + * 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 <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/timer.h> +#include <linux/completion.h> +#include <linux/jiffies.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> +#include <linux/io.h> +#include <linux/uaccess.h> + +#include <asm/mach-rdc321x/rdc321x_defs.h> + +#define RDC_WDT_MASK 0x80000000 /* Mask */ +#define RDC_WDT_EN 0x00800000 /* Enable bit */ +#define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */ +#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) + +static int ticks = 1000; + +/* some device data */ + +static struct { + struct completion stop; + int running; + struct timer_list timer; + int queue; + int default_ticks; + unsigned long inuse; + spinlock_t lock; +} rdc321x_wdt_device; + +/* generic helper functions */ + +static void rdc321x_wdt_trigger(unsigned long unused) +{ + unsigned long flags; + + if (rdc321x_wdt_device.running) + ticks--; + + /* keep watchdog alive */ + spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); + outl(RDC_WDT_EN | inl(RDC3210_CFGREG_DATA), + RDC3210_CFGREG_DATA); + spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); + + /* 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) +{ + unsigned long flags; + + if (!rdc321x_wdt_device.queue) { + rdc321x_wdt_device.queue = 1; + + /* Clear the timer */ + spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); + 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); + spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); + + 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", + }; + unsigned long flags; + + switch (cmd) { + case WDIOC_KEEPALIVE: + rdc321x_wdt_reset(); + break; + case WDIOC_GETSTATUS: + /* Read the value from the DATA register */ + spin_lock_irqsave(&rdc321x_wdt_device.lock, flags); + value = inl(RDC3210_CFGREG_DATA); + spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags); + 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; + + err = misc_register(&rdc321x_wdt_misc); + if (err < 0) { + printk(KERN_ERR PFX "watchdog misc_register failed\n"); + return err; + } + + spin_lock_init(&rdc321x_wdt_device.lock); + + /* 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 "watchdog 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 <florian@openwrt.org>"); +MODULE_DESCRIPTION("RDC321x watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |