linux/drivers/watchdog/s3c2410_wdt.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) 2004 Simtec Electronics
   4 *      Ben Dooks <ben@simtec.co.uk>
   5 *
   6 * S3C2410 Watchdog Timer Support
   7 *
   8 * Based on, softdog.c by Alan Cox,
   9 *     (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/moduleparam.h>
  14#include <linux/types.h>
  15#include <linux/timer.h>
  16#include <linux/watchdog.h>
  17#include <linux/platform_device.h>
  18#include <linux/interrupt.h>
  19#include <linux/clk.h>
  20#include <linux/uaccess.h>
  21#include <linux/io.h>
  22#include <linux/cpufreq.h>
  23#include <linux/slab.h>
  24#include <linux/err.h>
  25#include <linux/of.h>
  26#include <linux/of_device.h>
  27#include <linux/mfd/syscon.h>
  28#include <linux/regmap.h>
  29#include <linux/delay.h>
  30
  31#define S3C2410_WTCON           0x00
  32#define S3C2410_WTDAT           0x04
  33#define S3C2410_WTCNT           0x08
  34#define S3C2410_WTCLRINT        0x0c
  35
  36#define S3C2410_WTCNT_MAXCNT    0xffff
  37
  38#define S3C2410_WTCON_RSTEN     (1 << 0)
  39#define S3C2410_WTCON_INTEN     (1 << 2)
  40#define S3C2410_WTCON_ENABLE    (1 << 5)
  41
  42#define S3C2410_WTCON_DIV16     (0 << 3)
  43#define S3C2410_WTCON_DIV32     (1 << 3)
  44#define S3C2410_WTCON_DIV64     (2 << 3)
  45#define S3C2410_WTCON_DIV128    (3 << 3)
  46
  47#define S3C2410_WTCON_MAXDIV    0x80
  48
  49#define S3C2410_WTCON_PRESCALE(x)       ((x) << 8)
  50#define S3C2410_WTCON_PRESCALE_MASK     (0xff << 8)
  51#define S3C2410_WTCON_PRESCALE_MAX      0xff
  52
  53#define S3C2410_WATCHDOG_ATBOOT         (0)
  54#define S3C2410_WATCHDOG_DEFAULT_TIME   (15)
  55
  56#define EXYNOS5_RST_STAT_REG_OFFSET             0x0404
  57#define EXYNOS5_WDT_DISABLE_REG_OFFSET          0x0408
  58#define EXYNOS5_WDT_MASK_RESET_REG_OFFSET       0x040c
  59#define QUIRK_HAS_PMU_CONFIG                    (1 << 0)
  60#define QUIRK_HAS_RST_STAT                      (1 << 1)
  61#define QUIRK_HAS_WTCLRINT_REG                  (1 << 2)
  62
  63/* These quirks require that we have a PMU register map */
  64#define QUIRKS_HAVE_PMUREG                      (QUIRK_HAS_PMU_CONFIG | \
  65                                                 QUIRK_HAS_RST_STAT)
  66
  67static bool nowayout    = WATCHDOG_NOWAYOUT;
  68static int tmr_margin;
  69static int tmr_atboot   = S3C2410_WATCHDOG_ATBOOT;
  70static int soft_noboot;
  71
  72module_param(tmr_margin,  int, 0);
  73module_param(tmr_atboot,  int, 0);
  74module_param(nowayout,   bool, 0);
  75module_param(soft_noboot, int, 0);
  76
  77MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
  78                __MODULE_STRING(S3C2410_WATCHDOG_DEFAULT_TIME) ")");
  79MODULE_PARM_DESC(tmr_atboot,
  80                "Watchdog is started at boot time if set to 1, default="
  81                        __MODULE_STRING(S3C2410_WATCHDOG_ATBOOT));
  82MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  83                        __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  84MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default 0)");
  85
  86/**
  87 * struct s3c2410_wdt_variant - Per-variant config data
  88 *
  89 * @disable_reg: Offset in pmureg for the register that disables the watchdog
  90 * timer reset functionality.
  91 * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
  92 * timer reset functionality.
  93 * @mask_bit: Bit number for the watchdog timer in the disable register and the
  94 * mask reset register.
  95 * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
  96 * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
  97 * reset.
  98 * @quirks: A bitfield of quirks.
  99 */
 100
 101struct s3c2410_wdt_variant {
 102        int disable_reg;
 103        int mask_reset_reg;
 104        int mask_bit;
 105        int rst_stat_reg;
 106        int rst_stat_bit;
 107        u32 quirks;
 108};
 109
 110struct s3c2410_wdt {
 111        struct device           *dev;
 112        struct clk              *clock;
 113        void __iomem            *reg_base;
 114        unsigned int            count;
 115        spinlock_t              lock;
 116        unsigned long           wtcon_save;
 117        unsigned long           wtdat_save;
 118        struct watchdog_device  wdt_device;
 119        struct notifier_block   freq_transition;
 120        const struct s3c2410_wdt_variant *drv_data;
 121        struct regmap *pmureg;
 122};
 123
 124static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
 125        .quirks = 0
 126};
 127
 128#ifdef CONFIG_OF
 129static const struct s3c2410_wdt_variant drv_data_s3c6410 = {
 130        .quirks = QUIRK_HAS_WTCLRINT_REG,
 131};
 132
 133static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
 134        .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 135        .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 136        .mask_bit = 20,
 137        .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 138        .rst_stat_bit = 20,
 139        .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
 140                  | QUIRK_HAS_WTCLRINT_REG,
 141};
 142
 143static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
 144        .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 145        .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 146        .mask_bit = 0,
 147        .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 148        .rst_stat_bit = 9,
 149        .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
 150                  | QUIRK_HAS_WTCLRINT_REG,
 151};
 152
 153static const struct s3c2410_wdt_variant drv_data_exynos7 = {
 154        .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 155        .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 156        .mask_bit = 23,
 157        .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 158        .rst_stat_bit = 23,     /* A57 WDTRESET */
 159        .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT \
 160                  | QUIRK_HAS_WTCLRINT_REG,
 161};
 162
 163static const struct of_device_id s3c2410_wdt_match[] = {
 164        { .compatible = "samsung,s3c2410-wdt",
 165          .data = &drv_data_s3c2410 },
 166        { .compatible = "samsung,s3c6410-wdt",
 167          .data = &drv_data_s3c6410 },
 168        { .compatible = "samsung,exynos5250-wdt",
 169          .data = &drv_data_exynos5250 },
 170        { .compatible = "samsung,exynos5420-wdt",
 171          .data = &drv_data_exynos5420 },
 172        { .compatible = "samsung,exynos7-wdt",
 173          .data = &drv_data_exynos7 },
 174        {},
 175};
 176MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
 177#endif
 178
 179static const struct platform_device_id s3c2410_wdt_ids[] = {
 180        {
 181                .name = "s3c2410-wdt",
 182                .driver_data = (unsigned long)&drv_data_s3c2410,
 183        },
 184        {}
 185};
 186MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
 187
 188/* functions */
 189
 190static inline unsigned int s3c2410wdt_max_timeout(struct clk *clock)
 191{
 192        unsigned long freq = clk_get_rate(clock);
 193
 194        return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1)
 195                                       / S3C2410_WTCON_MAXDIV);
 196}
 197
 198static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
 199{
 200        return container_of(nb, struct s3c2410_wdt, freq_transition);
 201}
 202
 203static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
 204{
 205        int ret;
 206        u32 mask_val = 1 << wdt->drv_data->mask_bit;
 207        u32 val = 0;
 208
 209        /* No need to do anything if no PMU CONFIG needed */
 210        if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
 211                return 0;
 212
 213        if (mask)
 214                val = mask_val;
 215
 216        ret = regmap_update_bits(wdt->pmureg,
 217                        wdt->drv_data->disable_reg,
 218                        mask_val, val);
 219        if (ret < 0)
 220                goto error;
 221
 222        ret = regmap_update_bits(wdt->pmureg,
 223                        wdt->drv_data->mask_reset_reg,
 224                        mask_val, val);
 225 error:
 226        if (ret < 0)
 227                dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
 228
 229        return ret;
 230}
 231
 232static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 233{
 234        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 235
 236        spin_lock(&wdt->lock);
 237        writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 238        spin_unlock(&wdt->lock);
 239
 240        return 0;
 241}
 242
 243static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
 244{
 245        unsigned long wtcon;
 246
 247        wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 248        wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
 249        writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 250}
 251
 252static int s3c2410wdt_stop(struct watchdog_device *wdd)
 253{
 254        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 255
 256        spin_lock(&wdt->lock);
 257        __s3c2410wdt_stop(wdt);
 258        spin_unlock(&wdt->lock);
 259
 260        return 0;
 261}
 262
 263static int s3c2410wdt_start(struct watchdog_device *wdd)
 264{
 265        unsigned long wtcon;
 266        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 267
 268        spin_lock(&wdt->lock);
 269
 270        __s3c2410wdt_stop(wdt);
 271
 272        wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 273        wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
 274
 275        if (soft_noboot) {
 276                wtcon |= S3C2410_WTCON_INTEN;
 277                wtcon &= ~S3C2410_WTCON_RSTEN;
 278        } else {
 279                wtcon &= ~S3C2410_WTCON_INTEN;
 280                wtcon |= S3C2410_WTCON_RSTEN;
 281        }
 282
 283        dev_dbg(wdt->dev, "Starting watchdog: count=0x%08x, wtcon=%08lx\n",
 284                wdt->count, wtcon);
 285
 286        writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
 287        writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 288        writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 289        spin_unlock(&wdt->lock);
 290
 291        return 0;
 292}
 293
 294static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
 295{
 296        return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
 297}
 298
 299static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd,
 300                                    unsigned int timeout)
 301{
 302        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 303        unsigned long freq = clk_get_rate(wdt->clock);
 304        unsigned int count;
 305        unsigned int divisor = 1;
 306        unsigned long wtcon;
 307
 308        if (timeout < 1)
 309                return -EINVAL;
 310
 311        freq = DIV_ROUND_UP(freq, 128);
 312        count = timeout * freq;
 313
 314        dev_dbg(wdt->dev, "Heartbeat: count=%d, timeout=%d, freq=%lu\n",
 315                count, timeout, freq);
 316
 317        /* if the count is bigger than the watchdog register,
 318           then work out what we need to do (and if) we can
 319           actually make this value
 320        */
 321
 322        if (count >= 0x10000) {
 323                divisor = DIV_ROUND_UP(count, 0xffff);
 324
 325                if (divisor > 0x100) {
 326                        dev_err(wdt->dev, "timeout %d too big\n", timeout);
 327                        return -EINVAL;
 328                }
 329        }
 330
 331        dev_dbg(wdt->dev, "Heartbeat: timeout=%d, divisor=%d, count=%d (%08x)\n",
 332                timeout, divisor, count, DIV_ROUND_UP(count, divisor));
 333
 334        count = DIV_ROUND_UP(count, divisor);
 335        wdt->count = count;
 336
 337        /* update the pre-scaler */
 338        wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 339        wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
 340        wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
 341
 342        writel(count, wdt->reg_base + S3C2410_WTDAT);
 343        writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 344
 345        wdd->timeout = (count * divisor) / freq;
 346
 347        return 0;
 348}
 349
 350static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action,
 351                              void *data)
 352{
 353        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 354        void __iomem *wdt_base = wdt->reg_base;
 355
 356        /* disable watchdog, to be safe  */
 357        writel(0, wdt_base + S3C2410_WTCON);
 358
 359        /* put initial values into count and data */
 360        writel(0x80, wdt_base + S3C2410_WTCNT);
 361        writel(0x80, wdt_base + S3C2410_WTDAT);
 362
 363        /* set the watchdog to go and reset... */
 364        writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
 365                S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
 366                wdt_base + S3C2410_WTCON);
 367
 368        /* wait for reset to assert... */
 369        mdelay(500);
 370
 371        return 0;
 372}
 373
 374#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
 375
 376static const struct watchdog_info s3c2410_wdt_ident = {
 377        .options          =     OPTIONS,
 378        .firmware_version =     0,
 379        .identity         =     "S3C2410 Watchdog",
 380};
 381
 382static const struct watchdog_ops s3c2410wdt_ops = {
 383        .owner = THIS_MODULE,
 384        .start = s3c2410wdt_start,
 385        .stop = s3c2410wdt_stop,
 386        .ping = s3c2410wdt_keepalive,
 387        .set_timeout = s3c2410wdt_set_heartbeat,
 388        .restart = s3c2410wdt_restart,
 389};
 390
 391static const struct watchdog_device s3c2410_wdd = {
 392        .info = &s3c2410_wdt_ident,
 393        .ops = &s3c2410wdt_ops,
 394        .timeout = S3C2410_WATCHDOG_DEFAULT_TIME,
 395};
 396
 397/* interrupt handler code */
 398
 399static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
 400{
 401        struct s3c2410_wdt *wdt = platform_get_drvdata(param);
 402
 403        dev_info(wdt->dev, "watchdog timer expired (irq)\n");
 404
 405        s3c2410wdt_keepalive(&wdt->wdt_device);
 406
 407        if (wdt->drv_data->quirks & QUIRK_HAS_WTCLRINT_REG)
 408                writel(0x1, wdt->reg_base + S3C2410_WTCLRINT);
 409
 410        return IRQ_HANDLED;
 411}
 412
 413#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
 414
 415static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
 416                                          unsigned long val, void *data)
 417{
 418        int ret;
 419        struct s3c2410_wdt *wdt = freq_to_wdt(nb);
 420
 421        if (!s3c2410wdt_is_running(wdt))
 422                goto done;
 423
 424        if (val == CPUFREQ_PRECHANGE) {
 425                /* To ensure that over the change we don't cause the
 426                 * watchdog to trigger, we perform an keep-alive if
 427                 * the watchdog is running.
 428                 */
 429
 430                s3c2410wdt_keepalive(&wdt->wdt_device);
 431        } else if (val == CPUFREQ_POSTCHANGE) {
 432                s3c2410wdt_stop(&wdt->wdt_device);
 433
 434                ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 435                                                wdt->wdt_device.timeout);
 436
 437                if (ret >= 0)
 438                        s3c2410wdt_start(&wdt->wdt_device);
 439                else
 440                        goto err;
 441        }
 442
 443done:
 444        return 0;
 445
 446 err:
 447        dev_err(wdt->dev, "cannot set new value for timeout %d\n",
 448                                wdt->wdt_device.timeout);
 449        return ret;
 450}
 451
 452static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 453{
 454        wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 455
 456        return cpufreq_register_notifier(&wdt->freq_transition,
 457                                         CPUFREQ_TRANSITION_NOTIFIER);
 458}
 459
 460static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 461{
 462        wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 463
 464        cpufreq_unregister_notifier(&wdt->freq_transition,
 465                                    CPUFREQ_TRANSITION_NOTIFIER);
 466}
 467
 468#else
 469
 470static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 471{
 472        return 0;
 473}
 474
 475static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 476{
 477}
 478#endif
 479
 480static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
 481{
 482        unsigned int rst_stat;
 483        int ret;
 484
 485        if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
 486                return 0;
 487
 488        ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
 489        if (ret)
 490                dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
 491        else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
 492                return WDIOF_CARDRESET;
 493
 494        return 0;
 495}
 496
 497static inline const struct s3c2410_wdt_variant *
 498s3c2410_get_wdt_drv_data(struct platform_device *pdev)
 499{
 500        const struct s3c2410_wdt_variant *variant;
 501
 502        variant = of_device_get_match_data(&pdev->dev);
 503        if (!variant) {
 504                /* Device matched by platform_device_id */
 505                variant = (struct s3c2410_wdt_variant *)
 506                           platform_get_device_id(pdev)->driver_data;
 507        }
 508
 509        return variant;
 510}
 511
 512static int s3c2410wdt_probe(struct platform_device *pdev)
 513{
 514        struct device *dev = &pdev->dev;
 515        struct s3c2410_wdt *wdt;
 516        struct resource *wdt_irq;
 517        unsigned int wtcon;
 518        int started = 0;
 519        int ret;
 520
 521        wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 522        if (!wdt)
 523                return -ENOMEM;
 524
 525        wdt->dev = dev;
 526        spin_lock_init(&wdt->lock);
 527        wdt->wdt_device = s3c2410_wdd;
 528
 529        wdt->drv_data = s3c2410_get_wdt_drv_data(pdev);
 530        if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
 531                wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
 532                                                "samsung,syscon-phandle");
 533                if (IS_ERR(wdt->pmureg)) {
 534                        dev_err(dev, "syscon regmap lookup failed.\n");
 535                        return PTR_ERR(wdt->pmureg);
 536                }
 537        }
 538
 539        wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 540        if (wdt_irq == NULL) {
 541                dev_err(dev, "no irq resource specified\n");
 542                ret = -ENOENT;
 543                goto err;
 544        }
 545
 546        /* get the memory region for the watchdog timer */
 547        wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
 548        if (IS_ERR(wdt->reg_base)) {
 549                ret = PTR_ERR(wdt->reg_base);
 550                goto err;
 551        }
 552
 553        wdt->clock = devm_clk_get(dev, "watchdog");
 554        if (IS_ERR(wdt->clock)) {
 555                dev_err(dev, "failed to find watchdog clock source\n");
 556                ret = PTR_ERR(wdt->clock);
 557                goto err;
 558        }
 559
 560        ret = clk_prepare_enable(wdt->clock);
 561        if (ret < 0) {
 562                dev_err(dev, "failed to enable clock\n");
 563                return ret;
 564        }
 565
 566        wdt->wdt_device.min_timeout = 1;
 567        wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt->clock);
 568
 569        ret = s3c2410wdt_cpufreq_register(wdt);
 570        if (ret < 0) {
 571                dev_err(dev, "failed to register cpufreq\n");
 572                goto err_clk;
 573        }
 574
 575        watchdog_set_drvdata(&wdt->wdt_device, wdt);
 576
 577        /* see if we can actually set the requested timer margin, and if
 578         * not, try the default value */
 579
 580        watchdog_init_timeout(&wdt->wdt_device, tmr_margin, dev);
 581        ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 582                                        wdt->wdt_device.timeout);
 583        if (ret) {
 584                started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 585                                        S3C2410_WATCHDOG_DEFAULT_TIME);
 586
 587                if (started == 0)
 588                        dev_info(dev,
 589                                 "tmr_margin value out of range, default %d used\n",
 590                                 S3C2410_WATCHDOG_DEFAULT_TIME);
 591                else
 592                        dev_info(dev, "default timer value is out of range, cannot start\n");
 593        }
 594
 595        ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
 596                                pdev->name, pdev);
 597        if (ret != 0) {
 598                dev_err(dev, "failed to install irq (%d)\n", ret);
 599                goto err_cpufreq;
 600        }
 601
 602        watchdog_set_nowayout(&wdt->wdt_device, nowayout);
 603        watchdog_set_restart_priority(&wdt->wdt_device, 128);
 604
 605        wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 606        wdt->wdt_device.parent = dev;
 607
 608        ret = watchdog_register_device(&wdt->wdt_device);
 609        if (ret)
 610                goto err_cpufreq;
 611
 612        ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 613        if (ret < 0)
 614                goto err_unregister;
 615
 616        if (tmr_atboot && started == 0) {
 617                dev_info(dev, "starting watchdog timer\n");
 618                s3c2410wdt_start(&wdt->wdt_device);
 619        } else if (!tmr_atboot) {
 620                /* if we're not enabling the watchdog, then ensure it is
 621                 * disabled if it has been left running from the bootloader
 622                 * or other source */
 623
 624                s3c2410wdt_stop(&wdt->wdt_device);
 625        }
 626
 627        platform_set_drvdata(pdev, wdt);
 628
 629        /* print out a statement of readiness */
 630
 631        wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 632
 633        dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
 634                 (wtcon & S3C2410_WTCON_ENABLE) ?  "" : "in",
 635                 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
 636                 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
 637
 638        return 0;
 639
 640 err_unregister:
 641        watchdog_unregister_device(&wdt->wdt_device);
 642
 643 err_cpufreq:
 644        s3c2410wdt_cpufreq_deregister(wdt);
 645
 646 err_clk:
 647        clk_disable_unprepare(wdt->clock);
 648
 649 err:
 650        return ret;
 651}
 652
 653static int s3c2410wdt_remove(struct platform_device *dev)
 654{
 655        int ret;
 656        struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 657
 658        ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 659        if (ret < 0)
 660                return ret;
 661
 662        watchdog_unregister_device(&wdt->wdt_device);
 663
 664        s3c2410wdt_cpufreq_deregister(wdt);
 665
 666        clk_disable_unprepare(wdt->clock);
 667
 668        return 0;
 669}
 670
 671static void s3c2410wdt_shutdown(struct platform_device *dev)
 672{
 673        struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 674
 675        s3c2410wdt_mask_and_disable_reset(wdt, true);
 676
 677        s3c2410wdt_stop(&wdt->wdt_device);
 678}
 679
 680#ifdef CONFIG_PM_SLEEP
 681
 682static int s3c2410wdt_suspend(struct device *dev)
 683{
 684        int ret;
 685        struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 686
 687        /* Save watchdog state, and turn it off. */
 688        wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
 689        wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
 690
 691        ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 692        if (ret < 0)
 693                return ret;
 694
 695        /* Note that WTCNT doesn't need to be saved. */
 696        s3c2410wdt_stop(&wdt->wdt_device);
 697
 698        return 0;
 699}
 700
 701static int s3c2410wdt_resume(struct device *dev)
 702{
 703        int ret;
 704        struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 705
 706        /* Restore watchdog state. */
 707        writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
 708        writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
 709        writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
 710
 711        ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 712        if (ret < 0)
 713                return ret;
 714
 715        dev_info(dev, "watchdog %sabled\n",
 716                (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
 717
 718        return 0;
 719}
 720#endif
 721
 722static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
 723                        s3c2410wdt_resume);
 724
 725static struct platform_driver s3c2410wdt_driver = {
 726        .probe          = s3c2410wdt_probe,
 727        .remove         = s3c2410wdt_remove,
 728        .shutdown       = s3c2410wdt_shutdown,
 729        .id_table       = s3c2410_wdt_ids,
 730        .driver         = {
 731                .name   = "s3c2410-wdt",
 732                .pm     = &s3c2410wdt_pm_ops,
 733                .of_match_table = of_match_ptr(s3c2410_wdt_match),
 734        },
 735};
 736
 737module_platform_driver(s3c2410wdt_driver);
 738
 739MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, Dimitry Andric <dimitry.andric@tomtom.com>");
 740MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
 741MODULE_LICENSE("GPL");
 742