drivers/watchdog/cpu5wdt.c

   1 /*
   2  * sma cpu5 watchdog driver
   3  *
   4  * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/types.h>
  25 #include <linux/errno.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/fs.h>
  28 #include <linux/init.h>
  29 #include <linux/ioport.h>
  30 #include <linux/timer.h>
  31 #include <linux/completion.h>
  32 #include <linux/jiffies.h>
  33 #include <asm/io.h>
  34 #include <asm/uaccess.h>
  35
  36 #include <linux/watchdog.h>
  37
  38 /* adjustable parameters */
  39
  40 static int verbose = 0;
  41 static int port = 0x91;
  42 static int ticks = 10000;
  43
  44 #define PFX                     "cpu5wdt: "
  45
  46 #define CPU5WDT_EXTENT          0x0A
  47
  48 #define CPU5WDT_STATUS_REG      0x00
  49 #define CPU5WDT_TIME_A_REG      0x02
  50 #define CPU5WDT_TIME_B_REG      0x03
  51 #define CPU5WDT_MODE_REG        0x04
  52 #define CPU5WDT_TRIGGER_REG     0x07
  53 #define CPU5WDT_ENABLE_REG      0x08
  54 #define CPU5WDT_RESET_REG       0x09
  55
  56 #define CPU5WDT_INTERVAL        (HZ/10+1)
  57
  58 /* some device data */
  59
  60 static struct {
  61         struct completion stop;
  62 <<<<<<< HEAD:drivers/watchdog/cpu5wdt.c
  63         volatile int running;
  64 =======
  65         int running;
  66 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/watchdog/cpu5wdt.c
  67         struct timer_list timer;
  68 <<<<<<< HEAD:drivers/watchdog/cpu5wdt.c
  69         volatile int queue;
  70 =======
  71         int queue;
  72 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/watchdog/cpu5wdt.c
  73         int default_ticks;
  74         unsigned long inuse;
  75 } cpu5wdt_device;
  76
  77 /* generic helper functions */
  78
  79 static void cpu5wdt_trigger(unsigned long unused)
  80 {
  81         if ( verbose > 2 )
  82                 printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);
  83
  84         if( cpu5wdt_device.running )
  85                 ticks--;
  86
  87         /* keep watchdog alive */
  88         outb(1, port + CPU5WDT_TRIGGER_REG);
  89
  90         /* requeue?? */
  91         if (cpu5wdt_device.queue && ticks)
  92                 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
  93         else {
  94                 /* ticks doesn't matter anyway */
  95                 complete(&cpu5wdt_device.stop);
  96         }
  97
  98 }
  99
 100 static void cpu5wdt_reset(void)
 101 {
 102         ticks = cpu5wdt_device.default_ticks;
 103
 104         if ( verbose )
 105                 printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);
 106
 107 }
 108
 109 static void cpu5wdt_start(void)
 110 {
 111         if ( !cpu5wdt_device.queue ) {
 112                 cpu5wdt_device.queue = 1;
 113                 outb(0, port + CPU5WDT_TIME_A_REG);
 114                 outb(0, port + CPU5WDT_TIME_B_REG);
 115                 outb(1, port + CPU5WDT_MODE_REG);
 116                 outb(0, port + CPU5WDT_RESET_REG);
 117                 outb(0, port + CPU5WDT_ENABLE_REG);
 118                 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
 119         }
 120         /* if process dies, counter is not decremented */
 121         cpu5wdt_device.running++;
 122 }
 123
 124 static int cpu5wdt_stop(void)
 125 {
 126         if ( cpu5wdt_device.running )
 127                 cpu5wdt_device.running = 0;
 128
 129         ticks = cpu5wdt_device.default_ticks;
 130
 131         if ( verbose )
 132                 printk(KERN_CRIT PFX "stop not possible\n");
 133
 134         return -EIO;
 135 }
 136
 137 /* filesystem operations */
 138
 139 static int cpu5wdt_open(struct inode *inode, struct file *file)
 140 {
 141         if ( test_and_set_bit(0, &cpu5wdt_device.inuse) )
 142                 return -EBUSY;
 143
 144         return nonseekable_open(inode, file);
 145 }
 146
 147 static int cpu5wdt_release(struct inode *inode, struct file *file)
 148 {
 149         clear_bit(0, &cpu5wdt_device.inuse);
 150         return 0;
 151 }
 152
 153 static int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 154 {
 155         void __user *argp = (void __user *)arg;
 156         unsigned int value;
 157         static struct watchdog_info ident =
 158         {
 159                 .options = WDIOF_CARDRESET,
 160                 .identity = "CPU5 WDT",
 161         };
 162
 163         switch(cmd) {
 164                 case WDIOC_KEEPALIVE:
 165                         cpu5wdt_reset();
 166                         break;
 167                 case WDIOC_GETSTATUS:
 168                         value = inb(port + CPU5WDT_STATUS_REG);
 169                         value = (value >> 2) & 1;
 170                         if ( copy_to_user(argp, &value, sizeof(int)) )
 171                                 return -EFAULT;
 172                         break;
 173                 case WDIOC_GETBOOTSTATUS:
 174                         if ( copy_to_user(argp, &value, sizeof(int)) )
 175                                 return -EFAULT;
 176                         break;
 177                 case WDIOC_GETSUPPORT:
 178                         if ( copy_to_user(argp, &ident, sizeof(ident)) )
 179                                 return -EFAULT;
 180                         break;
 181                 case WDIOC_SETOPTIONS:
 182                         if ( copy_from_user(&value, argp, sizeof(int)) )
 183                                 return -EFAULT;
 184                         switch(value) {
 185                                 case WDIOS_ENABLECARD:
 186                                         cpu5wdt_start();
 187                                         break;
 188                                 case WDIOS_DISABLECARD:
 189                                         return cpu5wdt_stop();
 190                                 default:
 191                                         return -EINVAL;
 192                         }
 193                         break;
 194                 default:
 195                         return -ENOTTY;
 196         }
 197         return 0;
 198 }
 199
 200 static ssize_t cpu5wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 201 {
 202         if ( !count )
 203                 return -EIO;
 204
 205         cpu5wdt_reset();
 206
 207         return count;
 208 }
 209
 210 static const struct file_operations cpu5wdt_fops = {
 211         .owner          = THIS_MODULE,
 212         .llseek         = no_llseek,
 213         .ioctl          = cpu5wdt_ioctl,
 214         .open           = cpu5wdt_open,
 215         .write          = cpu5wdt_write,
 216         .release        = cpu5wdt_release,
 217 };
 218
 219 static struct miscdevice cpu5wdt_misc = {
 220         .minor  = WATCHDOG_MINOR,
 221         .name   = "watchdog",
 222         .fops   = &cpu5wdt_fops,
 223 };
 224
 225 /* init/exit function */
 226
 227 static int __devinit cpu5wdt_init(void)
 228 {
 229         unsigned int val;
 230         int err;
 231
 232         if ( verbose )
 233                 printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);
 234
 235         if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {
 236                 printk(KERN_ERR PFX "request_region failed\n");
 237                 err = -EBUSY;
 238                 goto no_port;
 239         }
 240
 241         if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {
 242                 printk(KERN_ERR PFX "misc_register failed\n");
 243                 goto no_misc;
 244         }
 245
 246         /* watchdog reboot? */
 247         val = inb(port + CPU5WDT_STATUS_REG);
 248         val = (val >> 2) & 1;
 249         if ( !val )
 250                 printk(KERN_INFO PFX "sorry, was my fault\n");
 251
 252         init_completion(&cpu5wdt_device.stop);
 253         cpu5wdt_device.queue = 0;
 254
 255         clear_bit(0, &cpu5wdt_device.inuse);
 256
 257         setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
 258
 259         cpu5wdt_device.default_ticks = ticks;
 260
 261         printk(KERN_INFO PFX "init success\n");
 262
 263         return 0;
 264
 265 no_misc:
 266         release_region(port, CPU5WDT_EXTENT);
 267 no_port:
 268         return err;
 269 }
 270
 271 static int __devinit cpu5wdt_init_module(void)
 272 {
 273         return cpu5wdt_init();
 274 }
 275
 276 static void __devexit cpu5wdt_exit(void)
 277 {
 278         if ( cpu5wdt_device.queue ) {
 279                 cpu5wdt_device.queue = 0;
 280                 wait_for_completion(&cpu5wdt_device.stop);
 281         }
 282
 283         misc_deregister(&cpu5wdt_misc);
 284
 285         release_region(port, CPU5WDT_EXTENT);
 286
 287 }
 288
 289 static void __devexit cpu5wdt_exit_module(void)
 290 {
 291         cpu5wdt_exit();
 292 }
 293
 294 /* module entry points */
 295
 296 module_init(cpu5wdt_init_module);
 297 module_exit(cpu5wdt_exit_module);
 298
 299 MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
 300 MODULE_DESCRIPTION("sma cpu5 watchdog driver");
 301 MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
 302 MODULE_LICENSE("GPL");
 303 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 304
 305 module_param(port, int, 0);
 306 MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
 307
 308 module_param(verbose, int, 0);
 309 MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
 310
 311 module_param(ticks, int, 0);
 312 MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");