| /* |
| * sma cpu5 watchdog driver |
| * |
| * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de> |
| * |
| * 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. |
| * |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #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/ioport.h> |
| #include <linux/timer.h> |
| #include <linux/completion.h> |
| #include <linux/jiffies.h> |
| #include <linux/io.h> |
| #include <linux/uaccess.h> |
| #include <linux/watchdog.h> |
| |
| /* adjustable parameters */ |
| |
| static int verbose; |
| static int port = 0x91; |
| static int ticks = 10000; |
| static DEFINE_SPINLOCK(cpu5wdt_lock); |
| |
| #define PFX "cpu5wdt: " |
| |
| #define CPU5WDT_EXTENT 0x0A |
| |
| #define CPU5WDT_STATUS_REG 0x00 |
| #define CPU5WDT_TIME_A_REG 0x02 |
| #define CPU5WDT_TIME_B_REG 0x03 |
| #define CPU5WDT_MODE_REG 0x04 |
| #define CPU5WDT_TRIGGER_REG 0x07 |
| #define CPU5WDT_ENABLE_REG 0x08 |
| #define CPU5WDT_RESET_REG 0x09 |
| |
| #define CPU5WDT_INTERVAL (HZ/10+1) |
| |
| /* some device data */ |
| |
| static struct { |
| struct completion stop; |
| int running; |
| struct timer_list timer; |
| int queue; |
| int default_ticks; |
| unsigned long inuse; |
| } cpu5wdt_device; |
| |
| /* generic helper functions */ |
| |
| static void cpu5wdt_trigger(struct timer_list *unused) |
| { |
| if (verbose > 2) |
| pr_debug("trigger at %i ticks\n", ticks); |
| |
| if (cpu5wdt_device.running) |
| ticks--; |
| |
| spin_lock(&cpu5wdt_lock); |
| /* keep watchdog alive */ |
| outb(1, port + CPU5WDT_TRIGGER_REG); |
| |
| /* requeue?? */ |
| if (cpu5wdt_device.queue && ticks) |
| mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL); |
| else { |
| /* ticks doesn't matter anyway */ |
| complete(&cpu5wdt_device.stop); |
| } |
| spin_unlock(&cpu5wdt_lock); |
| |
| } |
| |
| static void cpu5wdt_reset(void) |
| { |
| ticks = cpu5wdt_device.default_ticks; |
| |
| if (verbose) |
| pr_debug("reset (%i ticks)\n", (int) ticks); |
| |
| } |
| |
| static void cpu5wdt_start(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&cpu5wdt_lock, flags); |
| if (!cpu5wdt_device.queue) { |
| cpu5wdt_device.queue = 1; |
| outb(0, port + CPU5WDT_TIME_A_REG); |
| outb(0, port + CPU5WDT_TIME_B_REG); |
| outb(1, port + CPU5WDT_MODE_REG); |
| outb(0, port + CPU5WDT_RESET_REG); |
| outb(0, port + CPU5WDT_ENABLE_REG); |
| mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL); |
| } |
| /* if process dies, counter is not decremented */ |
| cpu5wdt_device.running++; |
| spin_unlock_irqrestore(&cpu5wdt_lock, flags); |
| } |
| |
| static int cpu5wdt_stop(void) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&cpu5wdt_lock, flags); |
| if (cpu5wdt_device.running) |
| cpu5wdt_device.running = 0; |
| ticks = cpu5wdt_device.default_ticks; |
| spin_unlock_irqrestore(&cpu5wdt_lock, flags); |
| if (verbose) |
| pr_crit("stop not possible\n"); |
| return -EIO; |
| } |
| |
| /* filesystem operations */ |
| |
| static int cpu5wdt_open(struct inode *inode, struct file *file) |
| { |
| if (test_and_set_bit(0, &cpu5wdt_device.inuse)) |
| return -EBUSY; |
| return nonseekable_open(inode, file); |
| } |
| |
| static int cpu5wdt_release(struct inode *inode, struct file *file) |
| { |
| clear_bit(0, &cpu5wdt_device.inuse); |
| return 0; |
| } |
| |
| static long cpu5wdt_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| unsigned int value; |
| static const struct watchdog_info ident = { |
| .options = WDIOF_CARDRESET, |
| .identity = "CPU5 WDT", |
| }; |
| |
| switch (cmd) { |
| case WDIOC_GETSUPPORT: |
| if (copy_to_user(argp, &ident, sizeof(ident))) |
| return -EFAULT; |
| break; |
| case WDIOC_GETSTATUS: |
| value = inb(port + CPU5WDT_STATUS_REG); |
| value = (value >> 2) & 1; |
| return put_user(value, p); |
| case WDIOC_GETBOOTSTATUS: |
| return put_user(0, p); |
| case WDIOC_SETOPTIONS: |
| if (get_user(value, p)) |
| return -EFAULT; |
| if (value & WDIOS_ENABLECARD) |
| cpu5wdt_start(); |
| if (value & WDIOS_DISABLECARD) |
| cpu5wdt_stop(); |
| break; |
| case WDIOC_KEEPALIVE: |
| cpu5wdt_reset(); |
| break; |
| default: |
| return -ENOTTY; |
| } |
| return 0; |
| } |
| |
| static ssize_t cpu5wdt_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| if (!count) |
| return -EIO; |
| cpu5wdt_reset(); |
| return count; |
| } |
| |
| static const struct file_operations cpu5wdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .unlocked_ioctl = cpu5wdt_ioctl, |
| .open = cpu5wdt_open, |
| .write = cpu5wdt_write, |
| .release = cpu5wdt_release, |
| }; |
| |
| static struct miscdevice cpu5wdt_misc = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &cpu5wdt_fops, |
| }; |
| |
| /* init/exit function */ |
| |
| static int cpu5wdt_init(void) |
| { |
| unsigned int val; |
| int err; |
| |
| if (verbose) |
| pr_debug("port=0x%x, verbose=%i\n", port, verbose); |
| |
| init_completion(&cpu5wdt_device.stop); |
| cpu5wdt_device.queue = 0; |
| timer_setup(&cpu5wdt_device.timer, cpu5wdt_trigger, 0); |
| cpu5wdt_device.default_ticks = ticks; |
| |
| if (!request_region(port, CPU5WDT_EXTENT, PFX)) { |
| pr_err("request_region failed\n"); |
| err = -EBUSY; |
| goto no_port; |
| } |
| |
| /* watchdog reboot? */ |
| val = inb(port + CPU5WDT_STATUS_REG); |
| val = (val >> 2) & 1; |
| if (!val) |
| pr_info("sorry, was my fault\n"); |
| |
| err = misc_register(&cpu5wdt_misc); |
| if (err < 0) { |
| pr_err("misc_register failed\n"); |
| goto no_misc; |
| } |
| |
| |
| pr_info("init success\n"); |
| return 0; |
| |
| no_misc: |
| release_region(port, CPU5WDT_EXTENT); |
| no_port: |
| return err; |
| } |
| |
| static int cpu5wdt_init_module(void) |
| { |
| return cpu5wdt_init(); |
| } |
| |
| static void cpu5wdt_exit(void) |
| { |
| if (cpu5wdt_device.queue) { |
| cpu5wdt_device.queue = 0; |
| wait_for_completion(&cpu5wdt_device.stop); |
| del_timer(&cpu5wdt_device.timer); |
| } |
| |
| misc_deregister(&cpu5wdt_misc); |
| |
| release_region(port, CPU5WDT_EXTENT); |
| |
| } |
| |
| static void cpu5wdt_exit_module(void) |
| { |
| cpu5wdt_exit(); |
| } |
| |
| /* module entry points */ |
| |
| module_init(cpu5wdt_init_module); |
| module_exit(cpu5wdt_exit_module); |
| |
| MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>"); |
| MODULE_DESCRIPTION("sma cpu5 watchdog driver"); |
| MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog"); |
| MODULE_LICENSE("GPL"); |
| |
| module_param_hw(port, int, ioport, 0); |
| MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91"); |
| |
| module_param(verbose, int, 0); |
| MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)"); |
| |
| module_param(ticks, int, 0); |
| MODULE_PARM_DESC(ticks, "count down ticks, default is 10000"); |