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         unsigned char t;
 140
 141         spin_lock(&sch311x_wdt_data.io_lock);
 142
 143         /* set watchdog's timeout */
 144         sch311x_wdt_set_timeout(timeout);
 145         /* enable the watchdog */
 146         /* -- General Purpose I/O Bit 6.0 --
 147          * Bit 0,   In/Out: 0 = Output, 1 = Input
 148          * Bit 1,   Polarity: 0 = No Invert, 1 = Invert
 149          * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
 150          *                           10 = Either Edge Triggered Intr.4
 151          * Bit 4-6  (Reserved)
 152          * Bit 7,   Output Type: 0 = Push Pull Bit, 1 = Open Drain
 153          */
 154         t = inb(sch311x_wdt_data.runtime_reg + GP60);
 155         outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);
 156
 157         spin_unlock(&sch311x_wdt_data.io_lock);
 158
 159 }
 160
 161 static void sch311x_wdt_stop(void)
 162 {
 163         unsigned char t;
 164
 165         spin_lock(&sch311x_wdt_data.io_lock);
 166
 167         /* stop the watchdog */
 168         t = inb(sch311x_wdt_data.runtime_reg + GP60);
 169         outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);
 170         /* disable timeout by setting it to 0 */
 171         sch311x_wdt_set_timeout(0);
 172
 173         spin_unlock(&sch311x_wdt_data.io_lock);
 174 }
 175
 176 static void sch311x_wdt_keepalive(void)
 177 {
 178         spin_lock(&sch311x_wdt_data.io_lock);
 179         sch311x_wdt_set_timeout(timeout);
 180         spin_unlock(&sch311x_wdt_data.io_lock);
 181 }
 182
 183 static int sch311x_wdt_set_heartbeat(int t)
 184 {
 185         if (t < 1 || t > (255*60))
 186                 return -EINVAL;
 187
 188         /* When new timeout is bigger then 255 seconds,
 189          * we will round up to minutes (with a max of 255) */
 190         if (t > 255)
 191                 t = (((t - 1) / 60) + 1) * 60;
 192
 193         timeout = t;
 194         return 0;
 195 }
 196
 197 static void sch311x_wdt_get_status(int *status)
 198 {
 199         unsigned char new_status;
 200
 201         *status = 0;
 202
 203         spin_lock(&sch311x_wdt_data.io_lock);
 204
 205         /* -- Watchdog timer control --
 206          * Bit 0   Status Bit: 0 = Timer counting, 1 = Timeout occurred
 207          * Bit 1   Reserved
 208          * Bit 2   Force Timeout: 1 = Forces WD timeout event (self-cleaning)
 209          * Bit 3   P20 Force Timeout enabled:
 210          *          0 = P20 activity does not generate the WD timeout event
 211          *          1 = P20 Allows rising edge of P20, from the keyboard
 212          *              controller, to force the WD timeout event.
 213          * Bit 4-7 Reserved
 214          */
 215         new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
 216         if (new_status & 0x01)
 217                 *status |= WDIOF_CARDRESET;
 218
 219         spin_unlock(&sch311x_wdt_data.io_lock);
 220 }
 221
 222 /*
 223  *      /dev/watchdog handling
 224  */
 225
 226 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
 227                                                 size_t count, loff_t *ppos)
 228 {
 229         if (count) {
 230                 if (!nowayout) {
 231                         size_t i;
 232
 233                         sch311x_wdt_expect_close = 0;
 234
 235                         for (i = 0; i != count; i++) {
 236                                 char c;
 237                                 if (get_user(c, buf + i))
 238                                         return -EFAULT;
 239                                 if (c == 'V')
 240                                         sch311x_wdt_expect_close = 42;
 241                         }
 242                 }
 243                 sch311x_wdt_keepalive();
 244         }
 245         return count;
 246 }
 247
 248 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
 249                                                         unsigned long arg)
 250 {
 251         int status;
 252         int new_timeout;
 253         void __user *argp = (void __user *)arg;
 254         int __user *p = argp;
 255         static const struct watchdog_info ident = {
 256                 .options                = WDIOF_KEEPALIVEPING |
 257                                           WDIOF_SETTIMEOUT |
 258                                           WDIOF_MAGICCLOSE,
 259                 .firmware_version       = 1,
 260                 .identity               = DRV_NAME,
 261         };
 262
 263         switch (cmd) {
 264         case WDIOC_GETSUPPORT:
 265                 if (copy_to_user(argp, &ident, sizeof(ident)))
 266                         return -EFAULT;
 267                 break;
 268
 269         case WDIOC_GETSTATUS:
 270         {
 271                 sch311x_wdt_get_status(&status);
 272                 return put_user(status, p);
 273         }
 274         case WDIOC_GETBOOTSTATUS:
 275                 return put_user(sch311x_wdt_data.boot_status, p);
 276
 277         case WDIOC_SETOPTIONS:
 278         {
 279                 int options, retval = -EINVAL;
 280
 281                 if (get_user(options, p))
 282                         return -EFAULT;
 283                 if (options & WDIOS_DISABLECARD) {
 284                         sch311x_wdt_stop();
 285                         retval = 0;
 286                 }
 287                 if (options & WDIOS_ENABLECARD) {
 288                         sch311x_wdt_start();
 289                         retval = 0;
 290                 }
 291                 return retval;
 292         }
 293         case WDIOC_KEEPALIVE:
 294                 sch311x_wdt_keepalive();
 295                 break;
 296
 297         case WDIOC_SETTIMEOUT:
 298                 if (get_user(new_timeout, p))
 299                         return -EFAULT;
 300                 if (sch311x_wdt_set_heartbeat(new_timeout))
 301                         return -EINVAL;
 302                 sch311x_wdt_keepalive();
 303                 /* Fall */
 304         case WDIOC_GETTIMEOUT:
 305                 return put_user(timeout, p);
 306         default:
 307                 return -ENOTTY;
 308         }
 309         return 0;
 310 }
 311
 312 static int sch311x_wdt_open(struct inode *inode, struct file *file)
 313 {
 314         if (test_and_set_bit(0, &sch311x_wdt_is_open))
 315                 return -EBUSY;
 316         /*
 317          *      Activate
 318          */
 319         sch311x_wdt_start();
 320         return nonseekable_open(inode, file);
 321 }
 322
 323 static int sch311x_wdt_close(struct inode *inode, struct file *file)
 324 {
 325         if (sch311x_wdt_expect_close == 42) {
 326                 sch311x_wdt_stop();
 327         } else {
 328                 pr_crit("Unexpected close, not stopping watchdog!\n");
 329                 sch311x_wdt_keepalive();
 330         }
 331         clear_bit(0, &sch311x_wdt_is_open);
 332         sch311x_wdt_expect_close = 0;
 333         return 0;
 334 }
 335
 336 /*
 337  *      Kernel Interfaces
 338  */
 339
 340 static const struct file_operations sch311x_wdt_fops = {
 341         .owner          = THIS_MODULE,
 342         .llseek         = no_llseek,
 343         .write          = sch311x_wdt_write,
 344         .unlocked_ioctl = sch311x_wdt_ioctl,
 345         .open           = sch311x_wdt_open,
 346         .release        = sch311x_wdt_close,
 347 };
 348
 349 static struct miscdevice sch311x_wdt_miscdev = {
 350         .minor  = WATCHDOG_MINOR,
 351         .name   = "watchdog",
 352         .fops   = &sch311x_wdt_fops,
 353 };
 354
 355 /*
 356  *      Init & exit routines
 357  */
 358
 359 static int sch311x_wdt_probe(struct platform_device *pdev)
 360 {
 361         struct device *dev = &pdev->dev;
 362         int err;
 363
 364         spin_lock_init(&sch311x_wdt_data.io_lock);
 365
 366         if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
 367                 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
 368                         sch311x_wdt_data.runtime_reg + GP60,
 369                         sch311x_wdt_data.runtime_reg + GP60);
 370                 err = -EBUSY;
 371                 goto exit;
 372         }
 373
 374         if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
 375                                                                 DRV_NAME)) {
 376                 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
 377                         sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
 378                         sch311x_wdt_data.runtime_reg + WDT_CTRL);
 379                 err = -EBUSY;
 380                 goto exit_release_region;
 381         }
 382
 383         /* Make sure that the watchdog is not running */
 384         sch311x_wdt_stop();
 385
 386         /* Disable keyboard and mouse interaction and interrupt */
 387         /* -- Watchdog timer configuration --
 388          * Bit 0   Reserved
 389          * Bit 1   Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
 390          * Bit 2   Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
 391          * Bit 3   Reserved
 392          * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
 393          *            0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
 394          */
 395         outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
 396
 397         /* Check that the heartbeat value is within it's range ;
 398          * if not reset to the default */
 399         if (sch311x_wdt_set_heartbeat(timeout)) {
 400                 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 401                 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
 402                         timeout);
 403         }
 404
 405         /* Get status at boot */
 406         sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
 407
 408         sch311x_wdt_miscdev.parent = dev;
 409
 410         err = misc_register(&sch311x_wdt_miscdev);
 411         if (err != 0) {
 412                 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
 413                                                         WATCHDOG_MINOR, err);
 414                 goto exit_release_region2;
 415         }
 416
 417         dev_info(dev,
 418                 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
 419                 timeout, nowayout);
 420
 421         return 0;
 422
 423 exit_release_region2:
 424         release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
 425 exit_release_region:
 426         release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
 427         sch311x_wdt_data.runtime_reg = 0;
 428 exit:
 429         return err;
 430 }
 431
 432 static int sch311x_wdt_remove(struct platform_device *pdev)
 433 {
 434         /* Stop the timer before we leave */
 435         if (!nowayout)
 436                 sch311x_wdt_stop();
 437
 438         /* Deregister */
 439         misc_deregister(&sch311x_wdt_miscdev);
 440         release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
 441         release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
 442         sch311x_wdt_data.runtime_reg = 0;
 443         return 0;
 444 }
 445
 446 static void sch311x_wdt_shutdown(struct platform_device *dev)
 447 {
 448         /* Turn the WDT off if we have a soft shutdown */
 449         sch311x_wdt_stop();
 450 }
 451
 452 static struct platform_driver sch311x_wdt_driver = {
 453         .probe          = sch311x_wdt_probe,
 454         .remove         = sch311x_wdt_remove,
 455         .shutdown       = sch311x_wdt_shutdown,
 456         .driver         = {
 457                 .owner = THIS_MODULE,
 458                 .name = DRV_NAME,
 459         },
 460 };
 461
 462 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
 463 {
 464         int err = 0, reg;
 465         unsigned short base_addr;
 466         unsigned char dev_id;
 467
 468         sch311x_sio_enter(sio_config_port);
 469
 470         /* Check device ID. We currently know about:
 471          * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
 472         reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
 473         if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
 474                 err = -ENODEV;
 475                 goto exit;
 476         }
 477         dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
 478
 479         /* Select logical device A (runtime registers) */
 480         sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
 481
 482         /* Check if Logical Device Register is currently active */
 483         if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
 484                 pr_info("Seems that LDN 0x0a is not active...\n");
 485
 486         /* Get the base address of the runtime registers */
 487         base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
 488                            sch311x_sio_inb(sio_config_port, 0x61);
 489         if (!base_addr) {
 490                 pr_err("Base address not set\n");
 491                 err = -ENODEV;
 492                 goto exit;
 493         }
 494         *addr = base_addr;
 495
 496         pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
 497
 498 exit:
 499         sch311x_sio_exit(sio_config_port);
 500         return err;
 501 }
 502
 503 static int __init sch311x_wdt_init(void)
 504 {
 505         int err, i, found = 0;
 506         unsigned short addr = 0;
 507
 508         for (i = 0; !found && sch311x_ioports[i]; i++)
 509                 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
 510                         found++;
 511
 512         if (!found)
 513                 return -ENODEV;
 514
 515         sch311x_wdt_data.runtime_reg = addr;
 516
 517         err = platform_driver_register(&sch311x_wdt_driver);
 518         if (err)
 519                 return err;
 520
 521         sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
 522                                                                 NULL, 0);
 523
 524         if (IS_ERR(sch311x_wdt_pdev)) {
 525                 err = PTR_ERR(sch311x_wdt_pdev);
 526                 goto unreg_platform_driver;
 527         }
 528
 529         return 0;
 530
 531 unreg_platform_driver:
 532         platform_driver_unregister(&sch311x_wdt_driver);
 533         return err;
 534 }
 535
 536 static void __exit sch311x_wdt_exit(void)
 537 {
 538         platform_device_unregister(sch311x_wdt_pdev);
 539         platform_driver_unregister(&sch311x_wdt_driver);
 540 }
 541
 542 module_init(sch311x_wdt_init);
 543 module_exit(sch311x_wdt_exit);
 544
 545 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
 546 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
 547 MODULE_LICENSE("GPL");
 548 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 549