drivers/char/moxa_watchdog.c-09032718

   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 #if 1   // add by Jared Wu. 03-10-2009 Ack the watchdog instead of disable it.\r
  61         // this means that if the kernel crashed, the hardware watchdog will\r
  62         // reset in 5 sec.\r
  63 static void swtd_enable_with_time(unsigned long swtd_time)\r
  64 {\r
  65         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+4) = WATCHDOG_COUNTER(swtd_time+WATCHDOG_TOL_COUNT_TIME);\r
  66         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+8) = 0x5ab9;\r
  67         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+12) = 0x03;\r
  68 \r
  69 }\r
  70 #endif\r
  71 \r
  72 static void swtd_enable(void)\r
  73 {\r
  74         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+4) = WATCHDOG_COUNTER(swtdtime+WATCHDOG_TOL_COUNT_TIME);\r
  75         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+8) = 0x5ab9;\r
  76         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+12) = 0x03;\r
  77 }\r
  78 \r
  79 static void swtd_disable(void)\r
  80 {\r
  81         *(unsigned int *)(CPE_WATCHDOG_VA_BASE+12) = 0;\r
  82 }\r
  83 \r
  84 #define IOCTL_WATCHDOG_ENABLE           1       // enable watch dog and set time (unint msec)\r
  85 #define IOCTL_WATCHDOG_DISABLE          2       // disable watch dog, kernle do it\r
  86 #define IOCTL_WATCHDOG_GET_SETTING      3       // get now setting about mode and time\r
  87 #define IOCTL_WATCHDOG_ACK              4       // to ack watch dog\r
  88 struct swtd_set_struct {\r
  89         int             mode;\r
  90         unsigned long   time;\r
  91 };\r
  92 static int swtd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)\r
  93 {\r
  94         unsigned long           time;\r
  95         struct swtd_set_struct  nowset;\r
  96         unsigned long           flags;\r
  97 \r
  98         switch ( cmd ) {\r
  99         case IOCTL_WATCHDOG_ENABLE :\r
 100                 if ( copy_from_user(&time, (void *)arg, sizeof(time)) )\r
 101                         return -EFAULT;\r
 102                 if ( time < WATCHDOG_MIN_TIME || time > WATCHDOG_MAX_TIME )\r
 103                         return -EINVAL;\r
 104 #if 0   // mask by Victor Yu. 05-15-2006\r
 105                 spin_lock(&swtdlock);\r
 106                 del_timer(&swtdtimer);\r
 107                 swtd_disable();\r
 108                 swtdtime = time;\r
 109                 swtduserenabled = 1;\r
 110                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 111                 add_timer(&swtdtimer);\r
 112                 swtd_enable();\r
 113                 spin_unlock(&swtdlock);\r
 114 #else   // add by Victor Yu. 05-15-2006\r
 115                 save_flags(flags);\r
 116                 cli();\r
 117                 if ( swtduserenabled ) {\r
 118                         swtd_disable();\r
 119                         del_timer(&swtdtimer);\r
 120                 }\r
 121                 swtdtime = time;\r
 122                 swtduserenabled = 1;\r
 123                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 124                 add_timer(&swtdtimer);\r
 125                 swtd_enable();\r
 126                 restore_flags(flags);\r
 127 #endif\r
 128                 break;\r
 129         case IOCTL_WATCHDOG_DISABLE :\r
 130 #if 0   // mask by Victor Yu. 05-15-2006\r
 131                 spin_lock(&swtdlock);\r
 132                 if ( swtduserenabled ) {\r
 133                         swtd_disable();\r
 134                         del_timer(&swtdtimer);\r
 135                         swtduserenabled = 0;\r
 136                         swtdtime = DEFAULT_WATCHDOG_TIME;\r
 137                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 138                         add_timer(&swtdtimer);\r
 139                         swtd_enable();\r
 140                 }\r
 141                 spin_unlock(&swtdlock);\r
 142 #else   // add by Victor Yu. 05-15-2006\r
 143                 save_flags(flags);\r
 144                 cli();\r
 145                 if ( swtduserenabled ) {\r
 146                         swtd_disable();\r
 147                         del_timer(&swtdtimer);\r
 148                         swtduserenabled = 0;\r
 149                 }\r
 150                 restore_flags(flags);\r
 151 #endif\r
 152                 break;\r
 153         case IOCTL_WATCHDOG_GET_SETTING :\r
 154                 nowset.mode = swtduserenabled;\r
 155                 nowset.time = swtdtime;\r
 156                 if ( copy_to_user((void *)arg, &nowset, sizeof(nowset)) )\r
 157                         return -EFAULT;\r
 158                 break;\r
 159         case IOCTL_WATCHDOG_ACK :\r
 160 #if 0   // mask by Victor Yu. 05-15-2006\r
 161                 spin_lock(&swtdlock);\r
 162                 if ( swtduserenabled ) {\r
 163                         swtd_disable();\r
 164                         del_timer(&swtdtimer);\r
 165                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 166                         add_timer(&swtdtimer);\r
 167                         swtd_enable();\r
 168                 }\r
 169                 spin_unlock(&swtdlock);\r
 170 #else   // add by Victor Yu. 05-15-2006\r
 171                 save_flags(flags);\r
 172                 cli();\r
 173                 if ( swtduserenabled ) {\r
 174                         swtd_disable();\r
 175                         del_timer(&swtdtimer);\r
 176                         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 177                         add_timer(&swtdtimer);\r
 178                         swtd_enable();\r
 179                 }\r
 180                 restore_flags(flags);\r
 181 #endif\r
 182                 break;\r
 183         default:\r
 184                 return -EINVAL;\r
 185         }\r
 186         return 0;\r
 187 }\r
 188 \r
 189 static int swtd_open(struct inode *inode, struct file *file)\r
 190 {\r
 191         unsigned long   flags;\r
 192 \r
 193         if ( MINOR(inode->i_rdev) != MOXA_WATCHDOG_MINOR )\r
 194                 return -ENODEV;\r
 195 #if 0   // mask by Victor Yu. 05-15-2006\r
 196         spin_lock(&swtdlock);\r
 197         opencounts++;\r
 198         spin_unlock(&swtdlock);\r
 199 #else   // add by Victor Yu. 05-15-2006\r
 200         save_flags(flags);\r
 201         cli();\r
 202 #if 0   // mask by Victor Yu. 05-15-2006\r
 203         if ( swtduserenabled == 0 ) {\r
 204                 swtduserenabled = 1;\r
 205                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 206                 add_timer(&swtdtimer);\r
 207                 swtd_enable();\r
 208         }\r
 209 #endif\r
 210         opencounts++;\r
 211         restore_flags(flags);\r
 212 #endif\r
 213         return 0;\r
 214 }\r
 215 \r
 216 static int swtd_release(struct inode *inode, struct file *file)\r
 217 {\r
 218         unsigned long   flags;\r
 219 \r
 220 #if 0   // mask by Victor Yu. 05-15-2006\r
 221         spin_lock(&swtdlock);\r
 222 #else   // add by Victor Yu. 05-15-2006\r
 223         save_flags(flags);\r
 224         cli();\r
 225 #endif\r
 226         dbg_printk("swtd_release entry.\n");\r
 227         opencounts--;\r
 228         if ( opencounts <= 0 ) {\r
 229 #if 0   // mask by Victor Yu. 02-23-2006\r
 230                 if ( signal_pending(current) ) {\r
 231                         dbg_printk("swtd_release has signal pending\n");\r
 232                         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
 233                         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
 234                         if ( sigismember(&current->parent->blocked, SIGKILL) ) {\r
 235                                 dbg_printk("swtd_release get SIGKILL signal\n");\r
 236                                 goto swtd_release_l1;\r
 237                         }\r
 238                         if ( sigismember(&current->blocked, SIGKILL) ) {\r
 239                                 dbg_printk("swtd_release get SIGKILL signal\n");\r
 240                                 goto swtd_release_l1;\r
 241                         }\r
 242                         if ( sigismember(&current->parent->blocked, SIGCHLD) ) {\r
 243                                 dbg_printk("swtd_release get SIGCHLD signal\n");\r
 244                                 goto swtd_release_l1;\r
 245                         }\r
 246                         if ( sigismember(&current->blocked, SIGCHLD) ) {\r
 247                                 dbg_printk("swtd_release get SIGCHLD signal\n");\r
 248                                 goto swtd_release_l1;\r
 249                         }\r
 250                         if ( sigismember(&current->parent->blocked, SIGTERM) ) {\r
 251                                 dbg_printk("swtd_release get SIGTERM signal\n");\r
 252                                 goto swtd_release_l1;\r
 253                         }\r
 254                         if ( sigismember(&current->blocked, SIGTERM) ) {\r
 255                                 dbg_printk("swtd_release get SIGTERM signal\n");\r
 256                                 goto swtd_release_l1;\r
 257                         }\r
 258                         if ( sigismember(&current->parent->blocked, SIGINT) ) {\r
 259                                 dbg_printk("swtd_release get SIGINT signal\n");\r
 260                                 goto swtd_release_l1;\r
 261                         }\r
 262                         if ( sigismember(&current->blocked, SIGINT) ) {\r
 263                                 dbg_printk("swtd_release get SIGINT signal\n");\r
 264                                 goto swtd_release_l1;\r
 265                         }\r
 266 #ifdef VICTOR_DEBUG     // add by Victor Yu. 02-23-2006\r
 267                         if ( sigismember(&current->parent->blocked, SIGSTOP) ) {\r
 268                                 dbg_printk("swtd_release get SIGSTOP signal\n");\r
 269                         }\r
 270                         if ( sigismember(&current->parent->blocked, SIGHUP) ) {\r
 271                                 dbg_printk("swtd_release get SIGHUP signal\n");\r
 272                         }\r
 273                         if ( sigismember(&current->parent->blocked, SIGQUIT) ) {\r
 274                                 dbg_printk("swtd_release get SIGQUIT signal\n");\r
 275                         }\r
 276                         if ( sigismember(&current->parent->blocked, SIGTSTP) ) {\r
 277                                 dbg_printk("swtd_release get SIGTSTP signal\n");\r
 278                         }\r
 279                         if ( sigismember(&current->parent->blocked, SIGABRT) ) {\r
 280                                 dbg_printk("swtd_release get SIGABRT signal\n");\r
 281                         }\r
 282                         if ( sigismember(&current->parent->blocked, SIGSEGV) ) {\r
 283                                 dbg_printk("swtd_release get SIGSEGV signal\n");\r
 284                         }\r
 285 #endif\r
 286                 } else {        // normal close the file handle\r
 287 swtd_release_l1:\r
 288 #endif\r
 289                         if ( swtduserenabled ) {\r
 290                                 //swtd_disable(); //Johnson Liu remark 2009-03-27\r
 291                                 del_timer(&swtdtimer);\r
 292                                 swtduserenabled = 0;\r
 293 #if 0   // mask by Victor Yu. 05-15-2006\r
 294                                 swtdtime = DEFAULT_WATCHDOG_TIME;\r
 295                                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 296                                 add_timer(&swtdtimer);\r
 297                                 swtd_enable();\r
 298 #endif\r
 299                         }\r
 300 #if 0   // mask by Victor Yu. 02-23-2006\r
 301                 }\r
 302 #endif\r
 303                 opencounts = 0;\r
 304         }\r
 305 #if 0   // mask by Victor Yu. 05-15-1006\r
 306         spin_unlock(&swtdlock);\r
 307 #else   // add by Victor Yu. 05-15-2006\r
 308         restore_flags(flags);\r
 309 #endif\r
 310         return 0;\r
 311 }\r
 312 \r
 313 static void swtd_reboot(void *unused)\r
 314 {\r
 315         char    *argv[2], *envp[5];\r
 316 \r
 317         if ( in_interrupt() )\r
 318                 return;\r
 319         if ( !current->fs->root )\r
 320                 return;\r
 321         argv[0] = "/sbin/reboot";\r
 322         argv[1] = 0;\r
 323         envp[0] = "HOME=/";\r
 324         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";\r
 325         envp[2] = 0;\r
 326         call_usermodehelper(argv[0], argv, envp, 0);\r
 327 }\r
 328 \r
 329 static void swtd_poll(unsigned long ignore)\r
 330 {\r
 331         unsigned long   flags;\r
 332 \r
 333 #if 0   // mask by Victor Yu. 05-15-2006\r
 334         spin_lock(&swtdlock);\r
 335 #else   // add by Victor Yu. 05-15-2006\r
 336         save_flags(flags);\r
 337         cli();\r
 338 #endif\r
 339 \r
 340 #if 0   // add by Victor Yu. 08-31-2006\r
 341         swtd_disable();\r
 342 #else   // add by Jared Wu. 03-10-2009 Ack the watchdog instead of disable it.\r
 343         // this means that if the kernel crashed, the hardware watchdog will\r
 344         // reset in 5 sec.\r
 345         swtd_enable_with_time(50000);\r
 346 #endif\r
 347         del_timer(&swtdtimer);\r
 348 #if 0   // mask by Victor Yu. 05-15-2006\r
 349         if ( swtduserenabled ) {\r
 350                 dbg_printk("Now reboot the system.\n");\r
 351                 schedule_work(&rebootqueue);\r
 352         } else {\r
 353                 swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 354                 add_timer(&swtdtimer);\r
 355                 swtd_enable();\r
 356         }\r
 357         spin_unlock(&swtdlock);\r
 358 #else   // add by Victor Yu. 05-15-2006\r
 359         dbg_printk("Now reboot the system.\n");\r
 360         schedule_work(&rebootqueue);\r
 361         restore_flags(flags);\r
 362 #endif\r
 363 }\r
 364 \r
 365 static int swtd_proc_output(char *buf)\r
 366 {\r
 367         char    *p;\r
 368 \r
 369         p = buf;\r
 370         p += sprintf(p,\r
 371                      "user enable\t: %d\n"\r
 372                      "ack time\t: %d msec\n",\r
 373                      swtduserenabled, (int)swtdtime);\r
 374         return p - buf;\r
 375 }\r
 376 \r
 377 static int swtd_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)\r
 378 {\r
 379         int     len=swtd_proc_output(page);\r
 380 \r
 381         if ( len <= off + count )\r
 382                 *eof = 1;\r
 383         *start = page + off;\r
 384         len -= off;\r
 385         if ( len > count )\r
 386                 len = count;\r
 387         if ( len < 0 )\r
 388                 len = 0;\r
 389         return len;\r
 390 }\r
 391 \r
 392 static struct file_operations swtd_fops = {\r
 393         owner:THIS_MODULE,\r
 394         llseek:NULL,\r
 395         ioctl:swtd_ioctl,\r
 396         open:swtd_open,\r
 397         release:swtd_release,\r
 398 };\r
 399 static struct miscdevice swtd_dev = {\r
 400         MOXA_WATCHDOG_MINOR,\r
 401         "swtd",\r
 402         &swtd_fops\r
 403 };\r
 404 \r
 405 static void __exit moxa_swtd_exit(void)\r
 406 {\r
 407         unsigned long   flags;\r
 408 \r
 409 #if 0   // mask by Victor Yu. 05-15-2006\r
 410         spin_lock(&swtdlock);\r
 411 #else   // add by Victor Yu. 05-15-2006\r
 412         save_flags(flags);\r
 413         cli();\r
 414 #endif\r
 415         if ( swtduserenabled ) {\r
 416                 swtd_disable();\r
 417                 del_timer(&swtdtimer);\r
 418                 swtduserenabled = 0;\r
 419                 opencounts = 0;\r
 420         }\r
 421 #if 0   // mask by Victor Yu. 05-15-2006\r
 422         spin_unlock(&swtdlock);\r
 423 #else   // add by Victor Yu. 05-15-2006\r
 424         restore_flags(flags);\r
 425 #endif\r
 426         misc_deregister(&swtd_dev);\r
 427 }\r
 428 \r
 429 static int __init moxa_swtd_init(void)\r
 430 {\r
 431         // register misc\r
 432         if ( misc_register(&swtd_dev) ) {\r
 433                 printk("Moxa ART CPU WatchDog: Register misc fail !\n");\r
 434                 goto moxa_swtd_init_err;\r
 435         }\r
 436         INIT_WORK(&rebootqueue, swtd_reboot, NULL);\r
 437 #if 0   // mask by Victor Yu. 05-15-2006\r
 438         spin_lock(&swtdlock);\r
 439 #endif\r
 440         init_timer(&swtdtimer);\r
 441         swtdtimer.function = swtd_poll;\r
 442 #if 0   // mask by Victor Yu. 05-15-2006\r
 443         swtdtimer.expires = jiffies + WATCHDOG_JIFFIES(swtdtime);\r
 444         add_timer(&swtdtimer);\r
 445         swtd_enable();\r
 446         spin_unlock(&swtdlock);\r
 447 #endif\r
 448         create_proc_read_entry("driver/swtd", 0, 0, swtd_read_proc, NULL);\r
 449         printk("Moxa ART CPU WatchDog driver v" MOXA_WATCHDOG_VERSION "\n");\r
 450 \r
 451         return 0;\r
 452 \r
 453 moxa_swtd_init_err:\r
 454         misc_deregister(&swtd_dev);\r
 455         return -ENOMEM;\r
 456 }\r
 457 \r
 458 module_init(moxa_swtd_init);\r
 459 module_exit(moxa_swtd_exit);\r
 460 \r
 461 MODULE_AUTHOR("Victor Yu");\r
 462 MODULE_LICENSE("GPL");\r