drivers/char/moxa_watchdog.c.new-05152006

   1 /*\r
   2  * History:\r
   3  * Date         Aurhor                  Comment\r
   4  * 02-23-2006   Victor Yu.              Create it.\r
   5  */\r
   6 //#define __KERNEL_SYSCALLS__\r
   7 #include <linux/config.h>\r
   8 #include <linux/proc_fs.h>\r
   9 #include <linux/devfs_fs_kernel.h>\r
  10 #include <linux/unistd.h>\r
  11 #include <linux/string.h>\r
  12 #include <linux/ctype.h>\r
  13 #include <linux/module.h>\r
  14 #include <linux/kernel.h>\r
  15 #include <linux/miscdevice.h>\r
  16 #include <linux/fcntl.h>\r
  17 #include <linux/init.h>\r
  18 #include <linux/poll.h>\r
  19 #include <linux/spinlock.h>\r
  20 #include <linux/delay.h>\r
  21 #include <linux/timer.h>\r
  22 #include <linux/ioport.h>\r
  23 #include <linux/interrupt.h>\r
  24 #include <linux/sched.h>\r
  25 #include <linux/signal.h>\r
  26 #include <linux/mm.h>\r
  27 #include <linux/kmod.h>\r
  28 #include <asm/io.h>\r
  29 #include <asm/uaccess.h>\r
  30 #include <asm/system.h>\r
  31 #include <asm/irq.h>\r
  32 #include <asm/bitops.h>\r
  33 \r
  34 //#define VICTOR_DEBUG\r
  35 #ifdef VICTOR_DEBUG\r
  36 #define dbg_printk(x...)        printk(x)\r
  37 #else\r
  38 #define dbg_printk(x...)\r
  39 #endif\r
  40 \r
  41 #define MOXA_WATCHDOG_VERSION   "1.0"\r
  42 #define MOXA_WATCHDOG_MINOR     106\r
  43 #define DEFAULT_WATCHDOG_TIME   (30UL*1000UL)   // 30 seconds\r
  44 #define WATCHDOG_MIN_TIME       50UL            // 50 msec\r
  45 #define WATCHDOG_MAX_TIME       (60UL*1000UL)   // 60 seconds\r
  46 #define WATCHDOG_TOL_TIME       (500UL)         // 500 msec, for watchdog timer polling\r
  47 #define WATCHDOG_TOL_COUNT_TIME (1000UL)        // 1 seconds, for watchdog timer count\r
  48 #define WATCHDOG_COUNTER(x)     ((APB_CLK/1000UL)*(x))\r
  49 #define WATCHDOG_JIFFIES(x)     ((((x)+WATCHDOG_TOL_TIME)*HZ)/1000UL)\r
  50 \r
  51 #if 0   // mask by Victor Yu. 05-15-2006\r
  52 static spinlock_t               swtdlock=SPIN_LOCK_UNLOCKED;\r
  53 #endif\r
  54 static int                      opencounts=0;\r
  55 static int                      swtduserenabled=0;\r
  56 static unsigned long            swtdtime=DEFAULT_WATCHDOG_TIME;\r
  57 static struct timer_list        swtdtimer;\r
  58 static struct work_struct       rebootqueue;\r
  59 \r
  60 static void swtd_enable(void)\r
  61 {\r
  62         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+4) = WATCHDOG_COUNTER(swtdtime+WATCHDOG_TOL_COUNT_TIME);\r
  63         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+8) = 0x5ab9;\r
  64         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+12) = 0x03;\r
  65 }\r
  66 \r
  67 static void swtd_disable(void)\r
  68 {\r
  69         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+12) = 0;\r
  70 }\r
  71 \r
  72 #define IOCTL_WATCHDOG_ENABLE           1       // enable watch dog and set time (unint msec)\r
  73 #define IOCTL_WATCHDOG_DISABLE          2       // disable watch dog, kernle do it\r
  74 #define IOCTL_WATCHDOG_GET_SETTING      3       // get now setting about mode and time\r
  75 #define IOCTL_WATCHDOG_ACK              4       // to ack watch dog\r
  76 struct swtd_set_struct {\r
  77         int             mode;\r
  78         unsigned long   time;\r
  79 };\r
  80 static int swtd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)\r
  81 {\r
  82         unsigned long           time;\r
  83         struct swtd_set_struct  nowset;\r
  84         unsigned long           flags;\r
  85 \r
  86         switch ( cmd ) {\r
  87         case IOCTL_WATCHDOG_ENABLE :\r
  88                 if ( copy_from_user(&time, (void *)arg, sizeof(time)) )\r
  89                         return -EFAULT;\r
  90                 if ( time < WATCHDOG_MIN_TIME || time > WATCHDOG_MAX_TIME )\r
  91                         return -EINVAL;\r
  92 #if 0   // mask by Victor Yu. 05-15-2006\r
  93                 spin_lock(&swtdlock);\r
  94                 del_timer(&swtdtimer);\r
  95                 swtd_disable();\r
  96                 swtdtime = time;\r
  97                 swtduserenabled = 1;\r
  98                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
  99                 add_timer(&swtdtimer);\r
 100                 swtd_enable();\r
 101                 spin_unlock(&swtdlock);\r
 102 #else   // add by Victor Yu. 05-15-2006\r
 103                 save_flags(flags);\r
 104                 cli();\r
 105                 if ( swtduserenabled ) {\r
 106                         swtd_disable();\r
 107                         del_timer(&swtdtimer);\r
 108                 }\r
 109                 swtdtime = time;\r
 110                 swtduserenabled = 1;\r
 111                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 112                 add_timer(&swtdtimer);\r
 113                 swtd_enable();\r
 114                 restore_flags(flags);\r
 115 #endif\r
 116                 break;\r
 117         case IOCTL_WATCHDOG_DISABLE :\r
 118 #if 0   // mask by Victor Yu. 05-15-2006\r
 119                 spin_lock(&swtdlock);\r
 120                 if ( swtduserenabled ) {\r
 121                         swtd_disable();\r
 122                         del_timer(&swtdtimer);\r
 123                         swtduserenabled = 0;\r
 124                         swtdtime = DEFAULT_WATCHDOG_TIME;\r
 125                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 126                         add_timer(&swtdtimer);\r
 127                         swtd_enable();\r
 128                 }\r
 129                 spin_unlock(&swtdlock);\r
 130 #else   // add by Victor Yu. 05-15-2006\r
 131                 save_flags(flags);\r
 132                 cli();\r
 133                 if ( swtduserenabled ) {\r
 134                         swtd_disable();\r
 135                         del_timer(&swtdtimer);\r
 136                         swtduserenabled = 0;\r
 137                 }\r
 138                 restore_flags(flags);\r
 139 #endif\r
 140                 break;\r
 141         case IOCTL_WATCHDOG_GET_SETTING :\r
 142                 nowset.mode = swtduserenabled;\r
 143                 nowset.time = swtdtime;\r
 144                 if ( copy_to_user((void *)arg, &nowset, sizeof(nowset)) )\r
 145                         return -EFAULT;\r
 146                 break;\r
 147         case IOCTL_WATCHDOG_ACK :\r
 148 #if 0   // mask by Victor Yu. 05-15-2006\r
 149                 spin_lock(&swtdlock);\r
 150                 if ( swtduserenabled ) {\r
 151                         swtd_disable();\r
 152                         del_timer(&swtdtimer);\r
 153                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 154                         add_timer(&swtdtimer);\r
 155                         swtd_enable();\r
 156                 }\r
 157                 spin_unlock(&swtdlock);\r
 158 #else   // add by Victor Yu. 05-15-2006\r
 159                 save_flags(flags);\r
 160                 cli();\r
 161                 if ( swtduserenabled ) {\r
 162                         swtd_disable();\r
 163                         del_timer(&swtdtimer);\r
 164                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 165                         add_timer(&swtdtimer);\r
 166                         swtd_enable();\r
 167                 }\r
 168                 restore_flags(flags);\r
 169 #endif\r
 170                 break;\r
 171         default:\r
 172                 return -EINVAL;\r
 173         }\r
 174         return 0;\r
 175 }\r
 176 \r
 177 static int swtd_open(struct inode *inode, struct file *file)\r
 178 {\r
 179         unsigned long   flags;\r
 180 \r
 181         if ( MINOR(inode->i_rdev) != MOXA_WATCHDOG_MINOR )\r
 182                 return -ENODEV;\r
 183 #if 0   // mask by Victor Yu. 05-15-2006\r
 184         spin_lock(&swtdlock);\r
 185         opencounts++;\r
 186         spin_unlock(&swtdlock);\r
 187 #else   // add by Victor Yu. 05-15-2006\r
 188         save_flags(flags);\r
 189         cli();\r
 190 #if 0   // mask by Victor Yu. 05-15-2006\r
 191         if ( swtduserenabled == 0 ) {\r
 192                 swtduserenabled = 1;\r
 193                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 194                 add_timer(&swtdtimer);\r
 195                 swtd_enable();\r
 196         }\r
 197 #endif\r
 198         opencounts++;\r
 199         restore_flags(flags);\r
 200 #endif\r
 201         return 0;\r
 202 }\r
 203 \r
 204 static int swtd_release(struct inode *inode, struct file *file)\r
 205 {\r
 206         unsigned long   flags;\r
 207 \r
 208 #if 0   // mask by Victor Yu. 05-15-2006\r
 209         spin_lock(&swtdlock);\r
 210 #else   // add by Victor Yu. 05-15-2006\r
 211         save_flags(flags);\r
 212         cli();\r
 213 #endif\r
 214         dbg_printk("swtd_release entry.\n");\r
 215         opencounts--;\r
 216         if ( opencounts <= 0 ) {\r
 217 #if 0   // mask by Victor Yu. 02-23-2006\r
 218                 if ( signal_pending(current) ) {\r
 219                         dbg_printk("swtd_release has signal pending\n");\r
 220                         dbg_printk("parent signal blocked=0x%x,0x%x, pending=0x%x,0x%x\n", current->parent->blocked.sig[0], current->parent->blocked.sig[1], current->parent->pending.signal.sig[0], current->parent->pending.signal.sig[1]);\r
 221                         dbg_printk("signal blocked=0x%x,0x%x, pending=0x%x,0x%x\n", current->blocked.sig[0], current->blocked.sig[1], current->pending.signal.sig[0], current->pending.signal.sig[1]);\r
 222                         if ( sigismember(&current->parent->blocked, SIGKILL) ) {\r
 223                                 dbg_printk("swtd_release get SIGKILL signal\n");\r
 224                                 goto swtd_release_l1;\r
 225                         }\r
 226                         if ( sigismember(&current->blocked, SIGKILL) ) {\r
 227                                 dbg_printk("swtd_release get SIGKILL signal\n");\r
 228                                 goto swtd_release_l1;\r
 229                         }\r
 230                         if ( sigismember(&current->parent->blocked, SIGCHLD) ) {\r
 231                                 dbg_printk("swtd_release get SIGCHLD signal\n");\r
 232                                 goto swtd_release_l1;\r
 233                         }\r
 234                         if ( sigismember(&current->blocked, SIGCHLD) ) {\r
 235                                 dbg_printk("swtd_release get SIGCHLD signal\n");\r
 236                                 goto swtd_release_l1;\r
 237                         }\r
 238                         if ( sigismember(&current->parent->blocked, SIGTERM) ) {\r
 239                                 dbg_printk("swtd_release get SIGTERM signal\n");\r
 240                                 goto swtd_release_l1;\r
 241                         }\r
 242                         if ( sigismember(&current->blocked, SIGTERM) ) {\r
 243                                 dbg_printk("swtd_release get SIGTERM signal\n");\r
 244                                 goto swtd_release_l1;\r
 245                         }\r
 246                         if ( sigismember(&current->parent->blocked, SIGINT) ) {\r
 247                                 dbg_printk("swtd_release get SIGINT signal\n");\r
 248                                 goto swtd_release_l1;\r
 249                         }\r
 250                         if ( sigismember(&current->blocked, SIGINT) ) {\r
 251                                 dbg_printk("swtd_release get SIGINT signal\n");\r
 252                                 goto swtd_release_l1;\r
 253                         }\r
 254 #ifdef VICTOR_DEBUG     // add by Victor Yu. 02-23-2006\r
 255                         if ( sigismember(&current->parent->blocked, SIGSTOP) ) {\r
 256                                 dbg_printk("swtd_release get SIGSTOP signal\n");\r
 257                         }\r
 258                         if ( sigismember(&current->parent->blocked, SIGHUP) ) {\r
 259                                 dbg_printk("swtd_release get SIGHUP signal\n");\r
 260                         }\r
 261                         if ( sigismember(&current->parent->blocked, SIGQUIT) ) {\r
 262                                 dbg_printk("swtd_release get SIGQUIT signal\n");\r
 263                         }\r
 264                         if ( sigismember(&current->parent->blocked, SIGTSTP) ) {\r
 265                                 dbg_printk("swtd_release get SIGTSTP signal\n");\r
 266                         }\r
 267                         if ( sigismember(&current->parent->blocked, SIGABRT) ) {\r
 268                                 dbg_printk("swtd_release get SIGABRT signal\n");\r
 269                         }\r
 270                         if ( sigismember(&current->parent->blocked, SIGSEGV) ) {\r
 271                                 dbg_printk("swtd_release get SIGSEGV signal\n");\r
 272                         }\r
 273 #endif\r
 274                 } else {        // normal close the file handle\r
 275 swtd_release_l1:\r
 276 #endif\r
 277                         if ( swtduserenabled ) {\r
 278                                 swtd_disable();\r
 279                                 del_timer(&swtdtimer);\r
 280                                 swtduserenabled = 0;\r
 281 #if 0   // mask by Victor Yu. 05-15-2006\r
 282                                 swtdtime = DEFAULT_WATCHDOG_TIME;\r
 283                                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 284                                 add_timer(&swtdtimer);\r
 285                                 swtd_enable();\r
 286 #endif\r
 287                         }\r
 288 #if 0   // mask by Victor Yu. 02-23-2006\r
 289                 }\r
 290 #endif\r
 291                 opencounts = 0;\r
 292         }\r
 293 #if 0   // mask by Victor Yu. 05-15-1006\r
 294         spin_unlock(&swtdlock);\r
 295 #else   // add by Victor Yu. 05-15-2006\r
 296         restore_flags(flags);\r
 297 #endif\r
 298         return 0;\r
 299 }\r
 300 \r
 301 static void swtd_reboot(void *unused)\r
 302 {\r
 303         char    *argv[2], *envp[5];\r
 304 \r
 305         if ( in_interrupt() )\r
 306                 return;\r
 307         if ( !current->fs->root )\r
 308                 return;\r
 309         argv[0] = "/sbin/reboot";\r
 310         argv[1] = 0;\r
 311         envp[0] = "HOME=/";\r
 312         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";\r
 313         envp[2] = 0;\r
 314         call_usermodehelper(argv[0], argv, envp, 0);\r
 315 }\r
 316 \r
 317 static void swtd_poll(unsigned long ignore)\r
 318 {\r
 319         unsigned long   flags;\r
 320 \r
 321 #if 0   // mask by Victor Yu. 05-15-2006\r
 322         spin_lock(&swtdlock);\r
 323 #else   // add by Victor Yu. 05-15-2006\r
 324         save_flags(flags);\r
 325         cli();\r
 326 #endif\r
 327         swtd_disable();\r
 328         del_timer(&swtdtimer);\r
 329 #if 0   // mask by Victor Yu. 05-15-2006\r
 330         if ( swtduserenabled ) {\r
 331                 dbg_printk("Now reboot the system.\n");\r
 332                 schedule_work(&rebootqueue);\r
 333         } else {\r
 334                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 335                 add_timer(&swtdtimer);\r
 336                 swtd_enable();\r
 337         }\r
 338         spin_unlock(&swtdlock);\r
 339 #else   // add by Victor Yu. 05-15-2006\r
 340         dbg_printk("Now reboot the system.\n");\r
 341         schedule_work(&rebootqueue);\r
 342         restore_flags(flags);\r
 343 #endif\r
 344 }\r
 345 \r
 346 static int swtd_proc_output(char *buf)\r
 347 {\r
 348         char    *p;\r
 349 \r
 350         p = buf;\r
 351         p += sprintf(p,\r
 352                      "user enable\t: %d\n"\r
 353                      "ack time\t: %d msec\n",\r
 354                      swtduserenabled, (int)swtdtime);\r
 355         return p - buf;\r
 356 }\r
 357 \r
 358 static int swtd_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)\r
 359 {\r
 360         int     len=swtd_proc_output(page);\r
 361 \r
 362         if ( len <= off + count )\r
 363                 *eof = 1;\r
 364         *start = page + off;\r
 365         len -= off;\r
 366         if ( len > count )\r
 367                 len = count;\r
 368         if ( len < 0 )\r
 369                 len = 0;\r
 370         return len;\r
 371 }\r
 372 \r
 373 static struct file_operations swtd_fops = {\r
 374         owner:THIS_MODULE,\r
 375         llseek:NULL,\r
 376         ioctl:swtd_ioctl,\r
 377         open:swtd_open,\r
 378         release:swtd_release,\r
 379 };\r
 380 static struct miscdevice swtd_dev = {\r
 381         MOXA_WATCHDOG_MINOR,\r
 382         "swtd",\r
 383         &swtd_fops\r
 384 };\r
 385 \r
 386 static void __exit moxa_swtd_exit(void)\r
 387 {\r
 388         unsigned long   flags;\r
 389 \r
 390 #if 0   // mask by Victor Yu. 05-15-2006\r
 391         spin_lock(&swtdlock);\r
 392 #else   // add by Victor Yu. 05-15-2006\r
 393         save_flags(flags);\r
 394         cli();\r
 395 #endif\r
 396         if ( swtduserenabled ) {\r
 397                 swtd_disable();\r
 398                 del_timer(&swtdtimer);\r
 399                 swtduserenabled = 0;\r
 400                 opencounts = 0;\r
 401         }\r
 402 #if 0   // mask by Victor Yu. 05-15-2006\r
 403         spin_unlock(&swtdlock);\r
 404 #else   // add by Victor Yu. 05-15-2006\r
 405         restore_flags(flags);\r
 406 #endif\r
 407         misc_deregister(&swtd_dev);\r
 408 }\r
 409 \r
 410 static int __init moxa_swtd_init(void)\r
 411 {\r
 412         // register misc\r
 413         if ( misc_register(&swtd_dev) ) {\r
 414                 printk("Moxa ART CPU WatchDog: Register misc fail !\n");\r
 415                 goto moxa_swtd_init_err;\r
 416         }\r
 417         INIT_WORK(&rebootqueue, swtd_reboot, NULL);\r
 418 #if 0   // mask by Victor Yu. 05-15-2006\r
 419         spin_lock(&swtdlock);\r
 420 #endif\r
 421         init_timer(&swtdtimer);\r
 422         swtdtimer.function = swtd_poll;\r
 423 #if 0   // mask by Victor Yu. 05-15-2006\r
 424         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 425         add_timer(&swtdtimer);\r
 426         swtd_enable();\r
 427         spin_unlock(&swtdlock);\r
 428 #endif\r
 429         create_proc_read_entry("driver/swtd", 0, 0, swtd_read_proc, NULL);\r
 430         printk("Moxa ART CPU WatchDog driver v" MOXA_WATCHDOG_VERSION "\n");\r
 431 \r
 432         return 0;\r
 433 \r
 434 moxa_swtd_init_err:\r
 435         misc_deregister(&swtd_dev);\r
 436         return -ENOMEM;\r
 437 }\r
 438 \r
 439 module_init(moxa_swtd_init);\r
 440 module_exit(moxa_swtd_exit);\r
 441 \r
 442 MODULE_AUTHOR("Victor Yu");\r
 443 MODULE_LICENSE("GPL");\r