| /* |
| * 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); |