drivers/watchdog/s3c2410_wdt.c

   1 /* linux/drivers/char/watchdog/s3c2410_wdt.c
   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  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24 */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/moduleparam.h>
  30 #include <linux/types.h>
  31 #include <linux/timer.h>
  32 #include <linux/watchdog.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/clk.h>
  36 #include <linux/uaccess.h>
  37 #include <linux/io.h>
  38 #include <linux/cpufreq.h>
  39 #include <linux/slab.h>
  40 #include <linux/err.h>
  41 #include <linux/of.h>
  42 #include <linux/mfd/syscon.h>
  43 #include <linux/regmap.h>
  44 #include <linux/delay.h>
  45
  46 #define S3C2410_WTCON           0x00
  47 #define S3C2410_WTDAT           0x04
  48 #define S3C2410_WTCNT           0x08
  49
  50 #define S3C2410_WTCON_RSTEN     (1 << 0)
  51 #define S3C2410_WTCON_INTEN     (1 << 2)
  52 #define S3C2410_WTCON_ENABLE    (1 << 5)
  53
  54 #define S3C2410_WTCON_DIV16     (0 << 3)
  55 #define S3C2410_WTCON_DIV32     (1 << 3)
  56 #define S3C2410_WTCON_DIV64     (2 << 3)
  57 #define S3C2410_WTCON_DIV128    (3 << 3)
  58
  59 #define S3C2410_WTCON_PRESCALE(x)       ((x) << 8)
  60 #define S3C2410_WTCON_PRESCALE_MASK     (0xff << 8)
  61
  62 #define CONFIG_S3C2410_WATCHDOG_ATBOOT          (0)
  63 #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME    (15)
  64
  65 #define EXYNOS5_RST_STAT_REG_OFFSET             0x0404
  66 #define EXYNOS5_WDT_DISABLE_REG_OFFSET          0x0408
  67 #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET       0x040c
  68 #define QUIRK_HAS_PMU_CONFIG                    (1 << 0)
  69 #define QUIRK_HAS_RST_STAT                      (1 << 1)
  70
  71 /* These quirks require that we have a PMU register map */
  72 #define QUIRKS_HAVE_PMUREG                      (QUIRK_HAS_PMU_CONFIG | \
  73                                                  QUIRK_HAS_RST_STAT)
  74
  75 static bool nowayout    = WATCHDOG_NOWAYOUT;
  76 static int tmr_margin;
  77 static int tmr_atboot   = CONFIG_S3C2410_WATCHDOG_ATBOOT;
  78 static int soft_noboot;
  79 static int debug;
  80
  81 module_param(tmr_margin,  int, 0);
  82 module_param(tmr_atboot,  int, 0);
  83 module_param(nowayout,   bool, 0);
  84 module_param(soft_noboot, int, 0);
  85 module_param(debug,       int, 0);
  86
  87 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
  88                 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
  89 MODULE_PARM_DESC(tmr_atboot,
  90                 "Watchdog is started at boot time if set to 1, default="
  91                         __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
  92 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  93                         __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  94 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
  95                         "0 to reboot (default 0)");
  96 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
  97
  98 /**
  99  * struct s3c2410_wdt_variant - Per-variant config data
 100  *
 101  * @disable_reg: Offset in pmureg for the register that disables the watchdog
 102  * timer reset functionality.
 103  * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
 104  * timer reset functionality.
 105  * @mask_bit: Bit number for the watchdog timer in the disable register and the
 106  * mask reset register.
 107  * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
 108  * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
 109  * reset.
 110  * @quirks: A bitfield of quirks.
 111  */
 112
 113 struct s3c2410_wdt_variant {
 114         int disable_reg;
 115         int mask_reset_reg;
 116         int mask_bit;
 117         int rst_stat_reg;
 118         int rst_stat_bit;
 119         u32 quirks;
 120 };
 121
 122 struct s3c2410_wdt {
 123         struct device           *dev;
 124         struct clk              *clock;
 125         void __iomem            *reg_base;
 126         unsigned int            count;
 127         spinlock_t              lock;
 128         unsigned long           wtcon_save;
 129         unsigned long           wtdat_save;
 130         struct watchdog_device  wdt_device;
 131         struct notifier_block   freq_transition;
 132         struct s3c2410_wdt_variant *drv_data;
 133         struct regmap *pmureg;
 134 };
 135
 136 static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
 137         .quirks = 0
 138 };
 139
 140 #ifdef CONFIG_OF
 141 static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
 142         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 143         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 144         .mask_bit = 20,
 145         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 146         .rst_stat_bit = 20,
 147         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 148 };
 149
 150 static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
 151         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 152         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 153         .mask_bit = 0,
 154         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 155         .rst_stat_bit = 9,
 156         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 157 };
 158
 159 static const struct s3c2410_wdt_variant drv_data_exynos7 = {
 160         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 161         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 162         .mask_bit = 23,
 163         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 164         .rst_stat_bit = 23,     /* A57 WDTRESET */
 165         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 166 };
 167
 168 static const struct of_device_id s3c2410_wdt_match[] = {
 169         { .compatible = "samsung,s3c2410-wdt",
 170           .data = &drv_data_s3c2410 },
 171         { .compatible = "samsung,exynos5250-wdt",
 172           .data = &drv_data_exynos5250 },
 173         { .compatible = "samsung,exynos5420-wdt",
 174           .data = &drv_data_exynos5420 },
 175         { .compatible = "samsung,exynos7-wdt",
 176           .data = &drv_data_exynos7 },
 177         {},
 178 };
 179 MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
 180 #endif
 181
 182 static const struct platform_device_id s3c2410_wdt_ids[] = {
 183         {
 184                 .name = "s3c2410-wdt",
 185                 .driver_data = (unsigned long)&drv_data_s3c2410,
 186         },
 187         {}
 188 };
 189 MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
 190
 191 /* watchdog control routines */
 192
 193 #define DBG(fmt, ...)                                   \
 194 do {                                                    \
 195         if (debug)                                      \
 196                 pr_info(fmt, ##__VA_ARGS__);            \
 197 } while (0)
 198
 199 /* functions */
 200
 201 static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
 202 {
 203         return container_of(nb, struct s3c2410_wdt, freq_transition);
 204 }
 205
 206 static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
 207 {
 208         int ret;
 209         u32 mask_val = 1 << wdt->drv_data->mask_bit;
 210         u32 val = 0;
 211
 212         /* No need to do anything if no PMU CONFIG needed */
 213         if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
 214                 return 0;
 215
 216         if (mask)
 217                 val = mask_val;
 218
 219         ret = regmap_update_bits(wdt->pmureg,
 220                         wdt->drv_data->disable_reg,
 221                         mask_val, val);
 222         if (ret < 0)
 223                 goto error;
 224
 225         ret = regmap_update_bits(wdt->pmureg,
 226                         wdt->drv_data->mask_reset_reg,
 227                         mask_val, val);
 228  error:
 229         if (ret < 0)
 230                 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
 231
 232         return ret;
 233 }
 234
 235 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 236 {
 237         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 238
 239         spin_lock(&wdt->lock);
 240         writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 241         spin_unlock(&wdt->lock);
 242
 243         return 0;
 244 }
 245
 246 static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
 247 {
 248         unsigned long wtcon;
 249
 250         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 251         wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
 252         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 253 }
 254
 255 static int s3c2410wdt_stop(struct watchdog_device *wdd)
 256 {
 257         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 258
 259         spin_lock(&wdt->lock);
 260         __s3c2410wdt_stop(wdt);
 261         spin_unlock(&wdt->lock);
 262
 263         return 0;
 264 }
 265
 266 static int s3c2410wdt_start(struct watchdog_device *wdd)
 267 {
 268         unsigned long wtcon;
 269         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 270
 271         spin_lock(&wdt->lock);
 272
 273         __s3c2410wdt_stop(wdt);
 274
 275         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 276         wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
 277
 278         if (soft_noboot) {
 279                 wtcon |= S3C2410_WTCON_INTEN;
 280                 wtcon &= ~S3C2410_WTCON_RSTEN;
 281         } else {
 282                 wtcon &= ~S3C2410_WTCON_INTEN;
 283                 wtcon |= S3C2410_WTCON_RSTEN;
 284         }
 285
 286         DBG("%s: count=0x%08x, wtcon=%08lx\n",
 287             __func__, wdt->count, wtcon);
 288
 289         writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
 290         writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 291         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 292         spin_unlock(&wdt->lock);
 293
 294         return 0;
 295 }
 296
 297 static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
 298 {
 299         return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
 300 }
 301
 302 static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
 303 {
 304         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 305         unsigned long freq = clk_get_rate(wdt->clock);
 306         unsigned int count;
 307         unsigned int divisor = 1;
 308         unsigned long wtcon;
 309
 310         if (timeout < 1)
 311                 return -EINVAL;
 312
 313         freq = DIV_ROUND_UP(freq, 128);
 314         count = timeout * freq;
 315
 316         DBG("%s: count=%d, timeout=%d, freq=%lu\n",
 317             __func__, count, timeout, freq);
 318
 319         /* if the count is bigger than the watchdog register,
 320            then work out what we need to do (and if) we can
 321            actually make this value
 322         */
 323
 324         if (count >= 0x10000) {
 325                 divisor = DIV_ROUND_UP(count, 0xffff);
 326
 327                 if (divisor > 0x100) {
 328                         dev_err(wdt->dev, "timeout %d too big\n", timeout);
 329                         return -EINVAL;
 330                 }
 331         }
 332
 333         DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
 334             __func__, timeout, divisor, count, DIV_ROUND_UP(count, divisor));
 335
 336         count = DIV_ROUND_UP(count, divisor);
 337         wdt->count = count;
 338
 339         /* update the pre-scaler */
 340         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 341         wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
 342         wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
 343
 344         writel(count, wdt->reg_base + S3C2410_WTDAT);
 345         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 346
 347         wdd->timeout = (count * divisor) / freq;
 348
 349         return 0;
 350 }
 351
 352 static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action,
 353                               void *data)
 354 {
 355         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 356         void __iomem *wdt_base = wdt->reg_base;
 357
 358         /* disable watchdog, to be safe  */
 359         writel(0, wdt_base + S3C2410_WTCON);
 360
 361         /* put initial values into count and data */
 362         writel(0x80, wdt_base + S3C2410_WTCNT);
 363         writel(0x80, wdt_base + S3C2410_WTDAT);
 364
 365         /* set the watchdog to go and reset... */
 366         writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
 367                 S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
 368                 wdt_base + S3C2410_WTCON);
 369
 370         /* wait for reset to assert... */
 371         mdelay(500);
 372
 373         return 0;
 374 }
 375
 376 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
 377
 378 static const struct watchdog_info s3c2410_wdt_ident = {
 379         .options          =     OPTIONS,
 380         .firmware_version =     0,
 381         .identity         =     "S3C2410 Watchdog",
 382 };
 383
 384 static struct watchdog_ops s3c2410wdt_ops = {
 385         .owner = THIS_MODULE,
 386         .start = s3c2410wdt_start,
 387         .stop = s3c2410wdt_stop,
 388         .ping = s3c2410wdt_keepalive,
 389         .set_timeout = s3c2410wdt_set_heartbeat,
 390         .restart = s3c2410wdt_restart,
 391 };
 392
 393 static struct watchdog_device s3c2410_wdd = {
 394         .info = &s3c2410_wdt_ident,
 395         .ops = &s3c2410wdt_ops,
 396         .timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME,
 397 };
 398
 399 /* interrupt handler code */
 400
 401 static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
 402 {
 403         struct s3c2410_wdt *wdt = platform_get_drvdata(param);
 404
 405         dev_info(wdt->dev, "watchdog timer expired (irq)\n");
 406
 407         s3c2410wdt_keepalive(&wdt->wdt_device);
 408         return IRQ_HANDLED;
 409 }
 410
 411 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
 412
 413 static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
 414                                           unsigned long val, void *data)
 415 {
 416         int ret;
 417         struct s3c2410_wdt *wdt = freq_to_wdt(nb);
 418
 419         if (!s3c2410wdt_is_running(wdt))
 420                 goto done;
 421
 422         if (val == CPUFREQ_PRECHANGE) {
 423                 /* To ensure that over the change we don't cause the
 424                  * watchdog to trigger, we perform an keep-alive if
 425                  * the watchdog is running.
 426                  */
 427
 428                 s3c2410wdt_keepalive(&wdt->wdt_device);
 429         } else if (val == CPUFREQ_POSTCHANGE) {
 430                 s3c2410wdt_stop(&wdt->wdt_device);
 431
 432                 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 433                                                 wdt->wdt_device.timeout);
 434
 435                 if (ret >= 0)
 436                         s3c2410wdt_start(&wdt->wdt_device);
 437                 else
 438                         goto err;
 439         }
 440
 441 done:
 442         return 0;
 443
 444  err:
 445         dev_err(wdt->dev, "cannot set new value for timeout %d\n",
 446                                 wdt->wdt_device.timeout);
 447         return ret;
 448 }
 449
 450 static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 451 {
 452         wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 453
 454         return cpufreq_register_notifier(&wdt->freq_transition,
 455                                          CPUFREQ_TRANSITION_NOTIFIER);
 456 }
 457
 458 static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 459 {
 460         wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 461
 462         cpufreq_unregister_notifier(&wdt->freq_transition,
 463                                     CPUFREQ_TRANSITION_NOTIFIER);
 464 }
 465
 466 #else
 467
 468 static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 469 {
 470         return 0;
 471 }
 472
 473 static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 474 {
 475 }
 476 #endif
 477
 478 static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
 479 {
 480         unsigned int rst_stat;
 481         int ret;
 482
 483         if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
 484                 return 0;
 485
 486         ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
 487         if (ret)
 488                 dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
 489         else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
 490                 return WDIOF_CARDRESET;
 491
 492         return 0;
 493 }
 494
 495 /* s3c2410_get_wdt_driver_data */
 496 static inline struct s3c2410_wdt_variant *
 497 get_wdt_drv_data(struct platform_device *pdev)
 498 {
 499         if (pdev->dev.of_node) {
 500                 const struct of_device_id *match;
 501                 match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
 502                 return (struct s3c2410_wdt_variant *)match->data;
 503         } else {
 504                 return (struct s3c2410_wdt_variant *)
 505                         platform_get_device_id(pdev)->driver_data;
 506         }
 507 }
 508
 509 static int s3c2410wdt_probe(struct platform_device *pdev)
 510 {
 511         struct device *dev;
 512         struct s3c2410_wdt *wdt;
 513         struct resource *wdt_mem;
 514         struct resource *wdt_irq;
 515         unsigned int wtcon;
 516         int started = 0;
 517         int ret;
 518
 519         DBG("%s: probe=%p\n", __func__, pdev);
 520
 521         dev = &pdev->dev;
 522
 523         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 524         if (!wdt)
 525                 return -ENOMEM;
 526
 527         wdt->dev = &pdev->dev;
 528         spin_lock_init(&wdt->lock);
 529         wdt->wdt_device = s3c2410_wdd;
 530
 531         wdt->drv_data = get_wdt_drv_data(pdev);
 532         if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
 533                 wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
 534                                                 "samsung,syscon-phandle");
 535                 if (IS_ERR(wdt->pmureg)) {
 536                         dev_err(dev, "syscon regmap lookup failed.\n");
 537                         return PTR_ERR(wdt->pmureg);
 538                 }
 539         }
 540
 541         wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 542         if (wdt_irq == NULL) {
 543                 dev_err(dev, "no irq resource specified\n");
 544                 ret = -ENOENT;
 545                 goto err;
 546         }
 547
 548         /* get the memory region for the watchdog timer */
 549         wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 550         wdt->reg_base = devm_ioremap_resource(dev, wdt_mem);
 551         if (IS_ERR(wdt->reg_base)) {
 552                 ret = PTR_ERR(wdt->reg_base);
 553                 goto err;
 554         }
 555
 556         DBG("probe: mapped reg_base=%p\n", wdt->reg_base);
 557
 558         wdt->clock = devm_clk_get(dev, "watchdog");
 559         if (IS_ERR(wdt->clock)) {
 560                 dev_err(dev, "failed to find watchdog clock source\n");
 561                 ret = PTR_ERR(wdt->clock);
 562                 goto err;
 563         }
 564
 565         ret = clk_prepare_enable(wdt->clock);
 566         if (ret < 0) {
 567                 dev_err(dev, "failed to enable clock\n");
 568                 return ret;
 569         }
 570
 571         ret = s3c2410wdt_cpufreq_register(wdt);
 572         if (ret < 0) {
 573                 dev_err(dev, "failed to register cpufreq\n");
 574                 goto err_clk;
 575         }
 576
 577         watchdog_set_drvdata(&wdt->wdt_device, wdt);
 578
 579         /* see if we can actually set the requested timer margin, and if
 580          * not, try the default value */
 581
 582         watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev);
 583         ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 584                                         wdt->wdt_device.timeout);
 585         if (ret) {
 586                 started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 587                                         CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
 588
 589                 if (started == 0)
 590                         dev_info(dev,
 591                            "tmr_margin value out of range, default %d used\n",
 592                                CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
 593                 else
 594                         dev_info(dev, "default timer value is out of range, "
 595                                                         "cannot start\n");
 596         }
 597
 598         ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
 599                                 pdev->name, pdev);
 600         if (ret != 0) {
 601                 dev_err(dev, "failed to install irq (%d)\n", ret);
 602                 goto err_cpufreq;
 603         }
 604
 605         watchdog_set_nowayout(&wdt->wdt_device, nowayout);
 606         watchdog_set_restart_priority(&wdt->wdt_device, 128);
 607
 608         wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 609         wdt->wdt_device.parent = &pdev->dev;
 610
 611         ret = watchdog_register_device(&wdt->wdt_device);
 612         if (ret) {
 613                 dev_err(dev, "cannot register watchdog (%d)\n", ret);
 614                 goto err_cpufreq;
 615         }
 616
 617         ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 618         if (ret < 0)
 619                 goto err_unregister;
 620
 621         if (tmr_atboot && started == 0) {
 622                 dev_info(dev, "starting watchdog timer\n");
 623                 s3c2410wdt_start(&wdt->wdt_device);
 624         } else if (!tmr_atboot) {
 625                 /* if we're not enabling the watchdog, then ensure it is
 626                  * disabled if it has been left running from the bootloader
 627                  * or other source */
 628
 629                 s3c2410wdt_stop(&wdt->wdt_device);
 630         }
 631
 632         platform_set_drvdata(pdev, wdt);
 633
 634         /* print out a statement of readiness */
 635
 636         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 637
 638         dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
 639                  (wtcon & S3C2410_WTCON_ENABLE) ?  "" : "in",
 640                  (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
 641                  (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
 642
 643         return 0;
 644
 645  err_unregister:
 646         watchdog_unregister_device(&wdt->wdt_device);
 647
 648  err_cpufreq:
 649         s3c2410wdt_cpufreq_deregister(wdt);
 650
 651  err_clk:
 652         clk_disable_unprepare(wdt->clock);
 653
 654  err:
 655         return ret;
 656 }
 657
 658 static int s3c2410wdt_remove(struct platform_device *dev)
 659 {
 660         int ret;
 661         struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 662
 663         ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 664         if (ret < 0)
 665                 return ret;
 666
 667         watchdog_unregister_device(&wdt->wdt_device);
 668
 669         s3c2410wdt_cpufreq_deregister(wdt);
 670
 671         clk_disable_unprepare(wdt->clock);
 672
 673         return 0;
 674 }
 675
 676 static void s3c2410wdt_shutdown(struct platform_device *dev)
 677 {
 678         struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 679
 680         s3c2410wdt_mask_and_disable_reset(wdt, true);
 681
 682         s3c2410wdt_stop(&wdt->wdt_device);
 683 }
 684
 685 #ifdef CONFIG_PM_SLEEP
 686
 687 static int s3c2410wdt_suspend(struct device *dev)
 688 {
 689         int ret;
 690         struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 691
 692         /* Save watchdog state, and turn it off. */
 693         wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
 694         wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
 695
 696         ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 697         if (ret < 0)
 698                 return ret;
 699
 700         /* Note that WTCNT doesn't need to be saved. */
 701         s3c2410wdt_stop(&wdt->wdt_device);
 702
 703         return 0;
 704 }
 705
 706 static int s3c2410wdt_resume(struct device *dev)
 707 {
 708         int ret;
 709         struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 710
 711         /* Restore watchdog state. */
 712         writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
 713         writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
 714         writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
 715
 716         ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 717         if (ret < 0)
 718                 return ret;
 719
 720         dev_info(dev, "watchdog %sabled\n",
 721                 (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
 722
 723         return 0;
 724 }
 725 #endif
 726
 727 static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
 728                         s3c2410wdt_resume);
 729
 730 static struct platform_driver s3c2410wdt_driver = {
 731         .probe          = s3c2410wdt_probe,
 732         .remove         = s3c2410wdt_remove,
 733         .shutdown       = s3c2410wdt_shutdown,
 734         .id_table       = s3c2410_wdt_ids,
 735         .driver         = {
 736                 .name   = "s3c2410-wdt",
 737                 .pm     = &s3c2410wdt_pm_ops,
 738                 .of_match_table = of_match_ptr(s3c2410_wdt_match),
 739         },
 740 };
 741
 742 module_platform_driver(s3c2410wdt_driver);
 743
 744 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
 745               "Dimitry Andric <dimitry.andric@tomtom.com>");
 746 MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
 747 MODULE_LICENSE("GPL");