linux/drivers/watchdog/sch311x_wdt.c
<<
>>
Prefs
   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 */
  51static unsigned long sch311x_wdt_is_open;
  52static char sch311x_wdt_expect_close;
  53static struct platform_device *sch311x_wdt_pdev;
  54
  55static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
  56
  57static 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 */
  67static unsigned short force_id;
  68module_param(force_id, ushort, 0);
  69MODULE_PARM_DESC(force_id, "Override the detected device ID");
  70
  71#define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  72static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
  73module_param(timeout, int, 0);
  74MODULE_PARM_DESC(timeout,
  75        "Watchdog timeout in seconds. 1<= timeout <=15300, default="
  76                __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  77
  78static bool nowayout = WATCHDOG_NOWAYOUT;
  79module_param(nowayout, bool, 0);
  80MODULE_PARM_DESC(nowayout,
  81        "Watchdog cannot be stopped once started (default="
  82                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  83
  84/*
  85 *      Super-IO functions
  86 */
  87
  88static inline void sch311x_sio_enter(int sio_config_port)
  89{
  90        outb(0x55, sio_config_port);
  91}
  92
  93static inline void sch311x_sio_exit(int sio_config_port)
  94{
  95        outb(0xaa, sio_config_port);
  96}
  97
  98static 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
 104static 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
 114static 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
 137static 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
 161static 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
 176static 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
 183static 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
 197static 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
 226static 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
 248static 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
 312static 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
 323static 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
 340static 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
 349static 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
 359static int __devinit 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
 423exit_release_region2:
 424        release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
 425exit_release_region:
 426        release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
 427        sch311x_wdt_data.runtime_reg = 0;
 428exit:
 429        return err;
 430}
 431
 432static int __devexit 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
 446static 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
 452static struct platform_driver sch311x_wdt_driver = {
 453        .probe          = sch311x_wdt_probe,
 454        .remove         = __devexit_p(sch311x_wdt_remove),
 455        .shutdown       = sch311x_wdt_shutdown,
 456        .driver         = {
 457                .owner = THIS_MODULE,
 458                .name = DRV_NAME,
 459        },
 460};
 461
 462static 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
 498exit:
 499        sch311x_sio_exit(sio_config_port);
 500        return err;
 501}
 502
 503static 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
 531unreg_platform_driver:
 532        platform_driver_unregister(&sch311x_wdt_driver);
 533        return err;
 534}
 535
 536static void __exit sch311x_wdt_exit(void)
 537{
 538        platform_device_unregister(sch311x_wdt_pdev);
 539        platform_driver_unregister(&sch311x_wdt_driver);
 540}
 541
 542module_init(sch311x_wdt_init);
 543module_exit(sch311x_wdt_exit);
 544
 545MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
 546MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
 547MODULE_LICENSE("GPL");
 548MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 549
 550
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.