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