drivers/watchdog/sch311x_wdt.c

   1 /*
   2  *      sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
   3  *                      integrated watchdog.
   4  *
   5  *      (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  *
  12  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
  13  *      provide warranty for any of this software. This material is
  14  *      provided "AS-IS" and at no charge.
  15  */
  16
  17 /*
  18  *      Includes, defines, variables, module parameters, ...
  19  */
  20
  21 /* Includes */
  22 #include <linux/module.h>               /* For module specific items */
  23 #include <linux/moduleparam.h>          /* For new moduleparam's */
  24 #include <linux/types.h>                /* For standard types (like size_t) */
  25 #include <linux/errno.h>                /* For the -ENODEV/... values */
  26 #include <linux/kernel.h>               /* For printk/... */
  27 #include <linux/miscdevice.h>           /* For MODULE_ALIAS_MISCDEV
  28                                                         (WATCHDOG_MINOR) */
  29 #include <linux/watchdog.h>             /* For the watchdog specific items */
  30 #include <linux/init.h>                 /* For __init/__exit/... */
  31 #include <linux/fs.h>                   /* For file operations */
  32 #include <linux/platform_device.h>      /* For platform_driver framework */
  33 #include <linux/ioport.h>               /* For io-port access */
  34 #include <linux/spinlock.h>             /* For spin_lock/spin_unlock/... */
  35 #include <linux/uaccess.h>              /* For copy_to_user/put_user/... */
  36 #include <linux/io.h>                   /* For inb/outb/... */
  37
  38 /* Module and version information */
  39 #define DRV_NAME        "sch311x_wdt"
  40 #define PFX             DRV_NAME ": "
  41
  42 /* Runtime registers */
  43 #define RESGEN                  0x1d
  44 #define GP60                    0x47
  45 #define WDT_TIME_OUT            0x65
  46 #define WDT_VAL                 0x66
  47 #define WDT_CFG                 0x67
  48 #define WDT_CTRL                0x68
  49
  50 /* internal variables */
  51 static unsigned long sch311x_wdt_is_open;
  52 static char sch311x_wdt_expect_close;
  53 static struct platform_device *sch311x_wdt_pdev;
  54
  55 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
  56
  57 static struct { /* The devices private data */
  58         /* the Runtime Register base address */
  59         unsigned short runtime_reg;
  60         /* The card's boot status */
  61         int boot_status;
  62         /* the lock for io operations */
  63         spinlock_t io_lock;
  64 } sch311x_wdt_data;
  65
  66 /* Module load parameters */
  67 static unsigned short force_id;
  68 module_param(force_id, ushort, 0);
  69 MODULE_PARM_DESC(force_id, "Override the detected device ID");
  70
  71 static unsigned short therm_trip;
  72 module_param(therm_trip, ushort, 0);
  73 MODULE_PARM_DESC(therm_trip, "Should a ThermTrip trigger the reset generator");
  74
  75 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  76 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
  77 module_param(timeout, int, 0);
  78 MODULE_PARM_DESC(timeout,
  79         "Watchdog timeout in seconds. 1<= timeout <=15300, default="
  80                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  81
  82 static int nowayout = WATCHDOG_NOWAYOUT;
  83 module_param(nowayout, int, 0);
  84 MODULE_PARM_DESC(nowayout,
  85         "Watchdog cannot be stopped once started (default="
  86                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  87
  88 /*
  89  *      Super-IO functions
  90  */
  91
  92 static inline void sch311x_sio_enter(int sio_config_port)
  93 {
  94         outb(0x55, sio_config_port);
  95 }
  96
  97 static inline void sch311x_sio_exit(int sio_config_port)
  98 {
  99         outb(0xaa, sio_config_port);
 100 }
 101
 102 static inline int sch311x_sio_inb(int sio_config_port, int reg)
 103 {
 104         outb(reg, sio_config_port);
 105         return inb(sio_config_port + 1);
 106 }
 107
 108 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
 109 {
 110         outb(reg, sio_config_port);
 111         outb(val, sio_config_port + 1);
 112 }
 113
 114 /*
 115  *      Watchdog Operations
 116  */
 117
 118 static void sch311x_wdt_set_timeout(int t)
 119 {
 120         unsigned char timeout_unit = 0x80;
 121
 122         /* When new timeout is bigger then 255 seconds, we will use minutes */
 123         if (t > 255) {
 124                 timeout_unit = 0;
 125                 t /= 60;
 126         }
 127
 128         /* -- Watchdog Timeout --
 129          * Bit 0-6 (Reserved)
 130          * Bit 7   WDT Time-out Value Units Select
 131          *         (0 = Minutes, 1 = Seconds)
 132          */
 133         outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
 134
 135         /* -- Watchdog Timer Time-out Value --
 136          * Bit 0-7 Binary coded units (0=Disabled, 1..255)
 137          */
 138         outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
 139 }
 140
 141 static void sch311x_wdt_start(void)
 142 {
 143         spin_lock(&sch311x_wdt_data.io_lock);
 144
 145         /* set watchdog's timeout */
 146         sch311x_wdt_set_timeout(timeout);
 147         /* enable the watchdog */
 148         /* -- General Purpose I/O Bit 6.0 --
 149          * Bit 0,   In/Out: 0 = Output, 1 = Input
 150          * Bit 1,   Polarity: 0 = No Invert, 1 = Invert
 151          * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
 152          *                           10 = Either Edge Triggered Intr.4
 153          * Bit 4-6  (Reserved)
 154          * Bit 7,   Output Type: 0 = Push Pull Bit, 1 = Open Drain
 155          */
 156         outb(0x0e, sch311x_wdt_data.runtime_reg + GP60);
 157
 158         spin_unlock(&sch311x_wdt_data.io_lock);
 159
 160 }
 161
 162 static void sch311x_wdt_stop(void)
 163 {
 164         spin_lock(&sch311x_wdt_data.io_lock);
 165
 166         /* stop the watchdog */
 167         outb(0x01, sch311x_wdt_data.runtime_reg + GP60);
 168         /* disable timeout by setting it to 0 */
 169         sch311x_wdt_set_timeout(0);
 170
 171         spin_unlock(&sch311x_wdt_data.io_lock);
 172 }
 173
 174 static void sch311x_wdt_keepalive(void)
 175 {
 176         spin_lock(&sch311x_wdt_data.io_lock);
 177         sch311x_wdt_set_timeout(timeout);
 178         spin_unlock(&sch311x_wdt_data.io_lock);
 179 }
 180
 181 static int sch311x_wdt_set_heartbeat(int t)
 182 {
 183         if (t < 1 || t > (255*60))
 184                 return -EINVAL;
 185
 186         /* When new timeout is bigger then 255 seconds,
 187          * we will round up to minutes (with a max of 255) */
 188         if (t > 255)
 189                 t = (((t - 1) / 60) + 1) * 60;
 190
 191         timeout = t;
 192         return 0;
 193 }
 194
 195 static void sch311x_wdt_get_status(int *status)
 196 {
 197         unsigned char new_status;
 198
 199         *status = 0;
 200
 201         spin_lock(&sch311x_wdt_data.io_lock);
 202
 203         /* -- Watchdog timer control --
 204          * Bit 0   Status Bit: 0 = Timer counting, 1 = Timeout occured
 205          * Bit 1   Reserved
 206          * Bit 2   Force Timeout: 1 = Forces WD timeout event (self-cleaning)
 207          * Bit 3   P20 Force Timeout enabled:
 208          *          0 = P20 activity does not generate the WD timeout event
 209          *          1 = P20 Allows rising edge of P20, from the keyboard
 210          *              controller, to force the WD timeout event.
 211          * Bit 4-7 Reserved
 212          */
 213         new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
 214         if (new_status & 0x01)
 215                 *status |= WDIOF_CARDRESET;
 216
 217         spin_unlock(&sch311x_wdt_data.io_lock);
 218 }
 219
 220 /*
 221  *      /dev/watchdog handling
 222  */
 223
 224 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
 225                                                 size_t count, loff_t *ppos)
 226 {
 227         if (count) {
 228                 if (!nowayout) {
 229                         size_t i;
 230
 231                         sch311x_wdt_expect_close = 0;
 232
 233                         for (i = 0; i != count; i++) {
 234                                 char c;
 235                                 if (get_user(c, buf + i))
 236                                         return -EFAULT;
 237                                 if (c == 'V')
 238                                         sch311x_wdt_expect_close = 42;
 239                         }
 240                 }
 241                 sch311x_wdt_keepalive();
 242         }
 243         return count;
 244 }
 245
 246 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
 247                                                         unsigned long arg)
 248 {
 249         int status;
 250         int new_timeout;
 251         void __user *argp = (void __user *)arg;
 252         int __user *p = argp;
 253         static struct watchdog_info ident = {
 254                 .options                = WDIOF_KEEPALIVEPING |
 255                                           WDIOF_SETTIMEOUT |
 256                                           WDIOF_MAGICCLOSE,
 257                 .firmware_version       = 1,
 258                 .identity               = DRV_NAME,
 259         };
 260
 261         switch (cmd) {
 262         case WDIOC_GETSUPPORT:
 263                 if (copy_to_user(argp, &ident, sizeof(ident)))
 264                         return -EFAULT;
 265                 break;
 266
 267         case WDIOC_GETSTATUS:
 268         {
 269                 sch311x_wdt_get_status(&status);
 270                 return put_user(status, p);
 271         }
 272         case WDIOC_GETBOOTSTATUS:
 273                 return put_user(sch311x_wdt_data.boot_status, p);
 274
 275         case WDIOC_SETOPTIONS:
 276         {
 277                 int options, retval = -EINVAL;
 278
 279                 if (get_user(options, p))
 280                         return -EFAULT;
 281                 if (options & WDIOS_DISABLECARD) {
 282                         sch311x_wdt_stop();
 283                         retval = 0;
 284                 }
 285                 if (options & WDIOS_ENABLECARD) {
 286                         sch311x_wdt_start();
 287                         retval = 0;
 288                 }
 289                 return retval;
 290         }
 291         case WDIOC_KEEPALIVE:
 292                 sch311x_wdt_keepalive();
 293                 break;
 294
 295         case WDIOC_SETTIMEOUT:
 296                 if (get_user(new_timeout, p))
 297                         return -EFAULT;
 298                 if (sch311x_wdt_set_heartbeat(new_timeout))
 299                         return -EINVAL;
 300                 sch311x_wdt_keepalive();
 301                 /* Fall */
 302         case WDIOC_GETTIMEOUT:
 303                 return put_user(timeout, p);
 304         default:
 305                 return -ENOTTY;
 306         }
 307         return 0;
 308 }
 309
 310 static int sch311x_wdt_open(struct inode *inode, struct file *file)
 311 {
 312         if (test_and_set_bit(0, &sch311x_wdt_is_open))
 313                 return -EBUSY;
 314         /*
 315          *      Activate
 316          */
 317         sch311x_wdt_start();
 318         return nonseekable_open(inode, file);
 319 }
 320
 321 static int sch311x_wdt_close(struct inode *inode, struct file *file)
 322 {
 323         if (sch311x_wdt_expect_close == 42) {
 324                 sch311x_wdt_stop();
 325         } else {
 326                 printk(KERN_CRIT PFX
 327                                 "Unexpected close, not stopping watchdog!\n");
 328                 sch311x_wdt_keepalive();
 329         }
 330         clear_bit(0, &sch311x_wdt_is_open);
 331         sch311x_wdt_expect_close = 0;
 332         return 0;
 333 }
 334
 335 /*
 336  *      Kernel Interfaces
 337  */
 338
 339 static const struct file_operations sch311x_wdt_fops = {
 340         .owner          = THIS_MODULE,
 341         .llseek         = no_llseek,
 342         .write          = sch311x_wdt_write,
 343         .unlocked_ioctl = sch311x_wdt_ioctl,
 344         .open           = sch311x_wdt_open,
 345         .release        = sch311x_wdt_close,
 346 };
 347
 348 static struct miscdevice sch311x_wdt_miscdev = {
 349         .minor  = WATCHDOG_MINOR,
 350         .name   = "watchdog",
 351         .fops   = &sch311x_wdt_fops,
 352 };
 353
 354 /*
 355  *      Init & exit routines
 356  */
 357
 358 static int __devinit sch311x_wdt_probe(struct platform_device *pdev)
 359 {
 360         struct device *dev = &pdev->dev;
 361         unsigned char val;
 362         int err;
 363
 364         spin_lock_init(&sch311x_wdt_data.io_lock);
 365
 366         if (!request_region(sch311x_wdt_data.runtime_reg + RESGEN, 1,
 367                                                                 DRV_NAME)) {
 368                 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
 369                         sch311x_wdt_data.runtime_reg + RESGEN,
 370                         sch311x_wdt_data.runtime_reg + RESGEN);
 371                 err = -EBUSY;
 372                 goto exit;
 373         }
 374
 375         if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
 376                 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
 377                         sch311x_wdt_data.runtime_reg + GP60,
 378                         sch311x_wdt_data.runtime_reg + GP60);
 379                 err = -EBUSY;
 380                 goto exit_release_region;
 381         }
 382
 383         if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
 384                                                                 DRV_NAME)) {
 385                 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
 386                         sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
 387                         sch311x_wdt_data.runtime_reg + WDT_CTRL);
 388                 err = -EBUSY;
 389                 goto exit_release_region2;
 390         }
 391
 392         /* Make sure that the watchdog is not running */
 393         sch311x_wdt_stop();
 394
 395         /* Disable keyboard and mouse interaction and interrupt */
 396         /* -- Watchdog timer configuration --
 397          * Bit 0   Reserved
 398          * Bit 1   Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
 399          * Bit 2   Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
 400          * Bit 3   Reserved
 401          * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
 402          *            0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
 403          */
 404         outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
 405
 406         /* Check that the heartbeat value is within it's range ;
 407          * if not reset to the default */
 408         if (sch311x_wdt_set_heartbeat(timeout)) {
 409                 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 410                 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
 411                         timeout);
 412         }
 413
 414         /* Get status at boot */
 415         sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
 416
 417         /* enable watchdog */
 418         /* -- Reset Generator --
 419          * Bit 0   Enable Watchdog Timer Generation: 0* = Enabled, 1 = Disabled
 420          * Bit 1   Thermtrip Source Select: O* = No Source, 1 = Source
 421          * Bit 2   WDT2_CTL: WDT input bit
 422          * Bit 3-7 Reserved
 423          */
 424         outb(0, sch311x_wdt_data.runtime_reg + RESGEN);
 425         val = therm_trip ? 0x06 : 0x04;
 426         outb(val, sch311x_wdt_data.runtime_reg + RESGEN);
 427
 428         err = misc_register(&sch311x_wdt_miscdev);
 429         if (err != 0) {
 430                 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
 431                                                         WATCHDOG_MINOR, err);
 432                 goto exit_release_region3;
 433         }
 434
 435         sch311x_wdt_miscdev.parent = dev;
 436
 437         dev_info(dev,
 438                 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
 439                 timeout, nowayout);
 440
 441         return 0;
 442
 443 exit_release_region3:
 444         release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
 445 exit_release_region2:
 446         release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
 447 exit_release_region:
 448         release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
 449         sch311x_wdt_data.runtime_reg = 0;
 450 exit:
 451         return err;
 452 }
 453
 454 static int __devexit sch311x_wdt_remove(struct platform_device *pdev)
 455 {
 456         /* Stop the timer before we leave */
 457         if (!nowayout)
 458                 sch311x_wdt_stop();
 459
 460         /* Deregister */
 461         misc_deregister(&sch311x_wdt_miscdev);
 462         release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
 463         release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
 464         release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
 465         sch311x_wdt_data.runtime_reg = 0;
 466         return 0;
 467 }
 468
 469 static void sch311x_wdt_shutdown(struct platform_device *dev)
 470 {
 471         /* Turn the WDT off if we have a soft shutdown */
 472         sch311x_wdt_stop();
 473 }
 474
 475 #define sch311x_wdt_suspend NULL
 476 #define sch311x_wdt_resume  NULL
 477
 478 static struct platform_driver sch311x_wdt_driver = {
 479         .probe          = sch311x_wdt_probe,
 480         .remove         = __devexit_p(sch311x_wdt_remove),
 481         .shutdown       = sch311x_wdt_shutdown,
 482         .suspend        = sch311x_wdt_suspend,
 483         .resume         = sch311x_wdt_resume,
 484         .driver         = {
 485                 .owner = THIS_MODULE,
 486                 .name = DRV_NAME,
 487         },
 488 };
 489
 490 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
 491 {
 492         int err = 0, reg;
 493         unsigned short base_addr;
 494         unsigned char dev_id;
 495
 496         sch311x_sio_enter(sio_config_port);
 497
 498         /* Check device ID. We currently know about:
 499          * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
 500         reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
 501         if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
 502                 err = -ENODEV;
 503                 goto exit;
 504         }
 505         dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
 506
 507         /* Select logical device A (runtime registers) */
 508         sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
 509
 510         /* Check if Logical Device Register is currently active */
 511         if (sch311x_sio_inb(sio_config_port, 0x30) && 0x01 == 0)
 512                 printk(KERN_INFO PFX "Seems that LDN 0x0a is not active...\n");
 513
 514         /* Get the base address of the runtime registers */
 515         base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
 516                            sch311x_sio_inb(sio_config_port, 0x61);
 517         if (!base_addr) {
 518                 printk(KERN_ERR PFX "Base address not set.\n");
 519                 err = -ENODEV;
 520                 goto exit;
 521         }
 522         *addr = base_addr;
 523
 524         printk(KERN_INFO PFX "Found an SMSC SCH311%d chip at 0x%04x\n",
 525                 dev_id, base_addr);
 526
 527 exit:
 528         sch311x_sio_exit(sio_config_port);
 529         return err;
 530 }
 531
 532 static int __init sch311x_wdt_init(void)
 533 {
 534         int err, i, found = 0;
 535         unsigned short addr = 0;
 536
 537         for (i = 0; !found && sch311x_ioports[i]; i++)
 538                 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
 539                         found++;
 540
 541         if (!found)
 542                 return -ENODEV;
 543
 544         sch311x_wdt_data.runtime_reg = addr;
 545
 546         err = platform_driver_register(&sch311x_wdt_driver);
 547         if (err)
 548                 return err;
 549
 550         sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
 551                                                                 NULL, 0);
 552
 553         if (IS_ERR(sch311x_wdt_pdev)) {
 554                 err = PTR_ERR(sch311x_wdt_pdev);
 555                 goto unreg_platform_driver;
 556         }
 557
 558         return 0;
 559
 560 unreg_platform_driver:
 561         platform_driver_unregister(&sch311x_wdt_driver);
 562         return err;
 563 }
 564
 565 static void __exit sch311x_wdt_exit(void)
 566 {
 567         platform_device_unregister(sch311x_wdt_pdev);
 568         platform_driver_unregister(&sch311x_wdt_driver);
 569 }
 570
 571 module_init(sch311x_wdt_init);
 572 module_exit(sch311x_wdt_exit);
 573
 574 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
 575 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
 576 MODULE_LICENSE("GPL");
 577 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 578