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_WTCNT_MAXCNT    0xffff
  51
  52 #define S3C2410_WTCON_RSTEN     (1 << 0)
  53 #define S3C2410_WTCON_INTEN     (1 << 2)
  54 #define S3C2410_WTCON_ENABLE    (1 << 5)
  55
  56 #define S3C2410_WTCON_DIV16     (0 << 3)
  57 #define S3C2410_WTCON_DIV32     (1 << 3)
  58 #define S3C2410_WTCON_DIV64     (2 << 3)
  59 #define S3C2410_WTCON_DIV128    (3 << 3)
  60
  61 #define S3C2410_WTCON_MAXDIV    0x80
  62
  63 #define S3C2410_WTCON_PRESCALE(x)       ((x) << 8)
  64 #define S3C2410_WTCON_PRESCALE_MASK     (0xff << 8)
  65 #define S3C2410_WTCON_PRESCALE_MAX      0xff
  66
  67 #define CONFIG_S3C2410_WATCHDOG_ATBOOT          (0)
  68 #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME    (15)
  69
  70 #define EXYNOS5_RST_STAT_REG_OFFSET             0x0404
  71 #define EXYNOS5_WDT_DISABLE_REG_OFFSET          0x0408
  72 #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET       0x040c
  73 #define QUIRK_HAS_PMU_CONFIG                    (1 << 0)
  74 #define QUIRK_HAS_RST_STAT                      (1 << 1)
  75
  76 /* These quirks require that we have a PMU register map */
  77 #define QUIRKS_HAVE_PMUREG                      (QUIRK_HAS_PMU_CONFIG | \
  78                                                  QUIRK_HAS_RST_STAT)
  79
  80 static bool nowayout    = WATCHDOG_NOWAYOUT;
  81 static int tmr_margin;
  82 static int tmr_atboot   = CONFIG_S3C2410_WATCHDOG_ATBOOT;
  83 static int soft_noboot;
  84 static int debug;
  85
  86 module_param(tmr_margin,  int, 0);
  87 module_param(tmr_atboot,  int, 0);
  88 module_param(nowayout,   bool, 0);
  89 module_param(soft_noboot, int, 0);
  90 module_param(debug,       int, 0);
  91
  92 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
  93                 __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
  94 MODULE_PARM_DESC(tmr_atboot,
  95                 "Watchdog is started at boot time if set to 1, default="
  96                         __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
  97 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
  98                         __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  99 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
 100                         "0 to reboot (default 0)");
 101 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
 102
 103 /**
 104  * struct s3c2410_wdt_variant - Per-variant config data
 105  *
 106  * @disable_reg: Offset in pmureg for the register that disables the watchdog
 107  * timer reset functionality.
 108  * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
 109  * timer reset functionality.
 110  * @mask_bit: Bit number for the watchdog timer in the disable register and the
 111  * mask reset register.
 112  * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
 113  * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
 114  * reset.
 115  * @quirks: A bitfield of quirks.
 116  */
 117
 118 struct s3c2410_wdt_variant {
 119         int disable_reg;
 120         int mask_reset_reg;
 121         int mask_bit;
 122         int rst_stat_reg;
 123         int rst_stat_bit;
 124         u32 quirks;
 125 };
 126
 127 struct s3c2410_wdt {
 128         struct device           *dev;
 129         struct clk              *clock;
 130         void __iomem            *reg_base;
 131         unsigned int            count;
 132         spinlock_t              lock;
 133         unsigned long           wtcon_save;
 134         unsigned long           wtdat_save;
 135         struct watchdog_device  wdt_device;
 136         struct notifier_block   freq_transition;
 137         struct s3c2410_wdt_variant *drv_data;
 138         struct regmap *pmureg;
 139 };
 140
 141 static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
 142         .quirks = 0
 143 };
 144
 145 #ifdef CONFIG_OF
 146 static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
 147         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 148         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 149         .mask_bit = 20,
 150         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 151         .rst_stat_bit = 20,
 152         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 153 };
 154
 155 static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
 156         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 157         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 158         .mask_bit = 0,
 159         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 160         .rst_stat_bit = 9,
 161         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 162 };
 163
 164 static const struct s3c2410_wdt_variant drv_data_exynos7 = {
 165         .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
 166         .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
 167         .mask_bit = 23,
 168         .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
 169         .rst_stat_bit = 23,     /* A57 WDTRESET */
 170         .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
 171 };
 172
 173 static const struct of_device_id s3c2410_wdt_match[] = {
 174         { .compatible = "samsung,s3c2410-wdt",
 175           .data = &drv_data_s3c2410 },
 176         { .compatible = "samsung,exynos5250-wdt",
 177           .data = &drv_data_exynos5250 },
 178         { .compatible = "samsung,exynos5420-wdt",
 179           .data = &drv_data_exynos5420 },
 180         { .compatible = "samsung,exynos7-wdt",
 181           .data = &drv_data_exynos7 },
 182         {},
 183 };
 184 MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
 185 #endif
 186
 187 static const struct platform_device_id s3c2410_wdt_ids[] = {
 188         {
 189                 .name = "s3c2410-wdt",
 190                 .driver_data = (unsigned long)&drv_data_s3c2410,
 191         },
 192         {}
 193 };
 194 MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
 195
 196 /* watchdog control routines */
 197
 198 #define DBG(fmt, ...)                                   \
 199 do {                                                    \
 200         if (debug)                                      \
 201                 pr_info(fmt, ##__VA_ARGS__);            \
 202 } while (0)
 203
 204 /* functions */
 205
 206 static inline unsigned int s3c2410wdt_max_timeout(struct clk *clock)
 207 {
 208         unsigned long freq = clk_get_rate(clock);
 209
 210         return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1)
 211                                        / S3C2410_WTCON_MAXDIV);
 212 }
 213
 214 static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
 215 {
 216         return container_of(nb, struct s3c2410_wdt, freq_transition);
 217 }
 218
 219 static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
 220 {
 221         int ret;
 222         u32 mask_val = 1 << wdt->drv_data->mask_bit;
 223         u32 val = 0;
 224
 225         /* No need to do anything if no PMU CONFIG needed */
 226         if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
 227                 return 0;
 228
 229         if (mask)
 230                 val = mask_val;
 231
 232         ret = regmap_update_bits(wdt->pmureg,
 233                         wdt->drv_data->disable_reg,
 234                         mask_val, val);
 235         if (ret < 0)
 236                 goto error;
 237
 238         ret = regmap_update_bits(wdt->pmureg,
 239                         wdt->drv_data->mask_reset_reg,
 240                         mask_val, val);
 241  error:
 242         if (ret < 0)
 243                 dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
 244
 245         return ret;
 246 }
 247
 248 static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
 249 {
 250         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 251
 252         spin_lock(&wdt->lock);
 253         writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 254         spin_unlock(&wdt->lock);
 255
 256         return 0;
 257 }
 258
 259 static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
 260 {
 261         unsigned long wtcon;
 262
 263         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 264         wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
 265         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 266 }
 267
 268 static int s3c2410wdt_stop(struct watchdog_device *wdd)
 269 {
 270         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 271
 272         spin_lock(&wdt->lock);
 273         __s3c2410wdt_stop(wdt);
 274         spin_unlock(&wdt->lock);
 275
 276         return 0;
 277 }
 278
 279 static int s3c2410wdt_start(struct watchdog_device *wdd)
 280 {
 281         unsigned long wtcon;
 282         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 283
 284         spin_lock(&wdt->lock);
 285
 286         __s3c2410wdt_stop(wdt);
 287
 288         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 289         wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
 290
 291         if (soft_noboot) {
 292                 wtcon |= S3C2410_WTCON_INTEN;
 293                 wtcon &= ~S3C2410_WTCON_RSTEN;
 294         } else {
 295                 wtcon &= ~S3C2410_WTCON_INTEN;
 296                 wtcon |= S3C2410_WTCON_RSTEN;
 297         }
 298
 299         DBG("%s: count=0x%08x, wtcon=%08lx\n",
 300             __func__, wdt->count, wtcon);
 301
 302         writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
 303         writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
 304         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 305         spin_unlock(&wdt->lock);
 306
 307         return 0;
 308 }
 309
 310 static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
 311 {
 312         return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
 313 }
 314
 315 static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
 316 {
 317         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 318         unsigned long freq = clk_get_rate(wdt->clock);
 319         unsigned int count;
 320         unsigned int divisor = 1;
 321         unsigned long wtcon;
 322
 323         if (timeout < 1)
 324                 return -EINVAL;
 325
 326         freq = DIV_ROUND_UP(freq, 128);
 327         count = timeout * freq;
 328
 329         DBG("%s: count=%d, timeout=%d, freq=%lu\n",
 330             __func__, count, timeout, freq);
 331
 332         /* if the count is bigger than the watchdog register,
 333            then work out what we need to do (and if) we can
 334            actually make this value
 335         */
 336
 337         if (count >= 0x10000) {
 338                 divisor = DIV_ROUND_UP(count, 0xffff);
 339
 340                 if (divisor > 0x100) {
 341                         dev_err(wdt->dev, "timeout %d too big\n", timeout);
 342                         return -EINVAL;
 343                 }
 344         }
 345
 346         DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
 347             __func__, timeout, divisor, count, DIV_ROUND_UP(count, divisor));
 348
 349         count = DIV_ROUND_UP(count, divisor);
 350         wdt->count = count;
 351
 352         /* update the pre-scaler */
 353         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 354         wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
 355         wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
 356
 357         writel(count, wdt->reg_base + S3C2410_WTDAT);
 358         writel(wtcon, wdt->reg_base + S3C2410_WTCON);
 359
 360         wdd->timeout = (count * divisor) / freq;
 361
 362         return 0;
 363 }
 364
 365 static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action,
 366                               void *data)
 367 {
 368         struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
 369         void __iomem *wdt_base = wdt->reg_base;
 370
 371         /* disable watchdog, to be safe  */
 372         writel(0, wdt_base + S3C2410_WTCON);
 373
 374         /* put initial values into count and data */
 375         writel(0x80, wdt_base + S3C2410_WTCNT);
 376         writel(0x80, wdt_base + S3C2410_WTDAT);
 377
 378         /* set the watchdog to go and reset... */
 379         writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
 380                 S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
 381                 wdt_base + S3C2410_WTCON);
 382
 383         /* wait for reset to assert... */
 384         mdelay(500);
 385
 386         return 0;
 387 }
 388
 389 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
 390
 391 static const struct watchdog_info s3c2410_wdt_ident = {
 392         .options          =     OPTIONS,
 393         .firmware_version =     0,
 394         .identity         =     "S3C2410 Watchdog",
 395 };
 396
 397 static struct watchdog_ops s3c2410wdt_ops = {
 398         .owner = THIS_MODULE,
 399         .start = s3c2410wdt_start,
 400         .stop = s3c2410wdt_stop,
 401         .ping = s3c2410wdt_keepalive,
 402         .set_timeout = s3c2410wdt_set_heartbeat,
 403         .restart = s3c2410wdt_restart,
 404 };
 405
 406 static struct watchdog_device s3c2410_wdd = {
 407         .info = &s3c2410_wdt_ident,
 408         .ops = &s3c2410wdt_ops,
 409         .timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME,
 410 };
 411
 412 /* interrupt handler code */
 413
 414 static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
 415 {
 416         struct s3c2410_wdt *wdt = platform_get_drvdata(param);
 417
 418         dev_info(wdt->dev, "watchdog timer expired (irq)\n");
 419
 420         s3c2410wdt_keepalive(&wdt->wdt_device);
 421         return IRQ_HANDLED;
 422 }
 423
 424 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ
 425
 426 static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
 427                                           unsigned long val, void *data)
 428 {
 429         int ret;
 430         struct s3c2410_wdt *wdt = freq_to_wdt(nb);
 431
 432         if (!s3c2410wdt_is_running(wdt))
 433                 goto done;
 434
 435         if (val == CPUFREQ_PRECHANGE) {
 436                 /* To ensure that over the change we don't cause the
 437                  * watchdog to trigger, we perform an keep-alive if
 438                  * the watchdog is running.
 439                  */
 440
 441                 s3c2410wdt_keepalive(&wdt->wdt_device);
 442         } else if (val == CPUFREQ_POSTCHANGE) {
 443                 s3c2410wdt_stop(&wdt->wdt_device);
 444
 445                 ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 446                                                 wdt->wdt_device.timeout);
 447
 448                 if (ret >= 0)
 449                         s3c2410wdt_start(&wdt->wdt_device);
 450                 else
 451                         goto err;
 452         }
 453
 454 done:
 455         return 0;
 456
 457  err:
 458         dev_err(wdt->dev, "cannot set new value for timeout %d\n",
 459                                 wdt->wdt_device.timeout);
 460         return ret;
 461 }
 462
 463 static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 464 {
 465         wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 466
 467         return cpufreq_register_notifier(&wdt->freq_transition,
 468                                          CPUFREQ_TRANSITION_NOTIFIER);
 469 }
 470
 471 static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 472 {
 473         wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
 474
 475         cpufreq_unregister_notifier(&wdt->freq_transition,
 476                                     CPUFREQ_TRANSITION_NOTIFIER);
 477 }
 478
 479 #else
 480
 481 static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
 482 {
 483         return 0;
 484 }
 485
 486 static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
 487 {
 488 }
 489 #endif
 490
 491 static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
 492 {
 493         unsigned int rst_stat;
 494         int ret;
 495
 496         if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
 497                 return 0;
 498
 499         ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
 500         if (ret)
 501                 dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
 502         else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
 503                 return WDIOF_CARDRESET;
 504
 505         return 0;
 506 }
 507
 508 /* s3c2410_get_wdt_driver_data */
 509 static inline struct s3c2410_wdt_variant *
 510 get_wdt_drv_data(struct platform_device *pdev)
 511 {
 512         if (pdev->dev.of_node) {
 513                 const struct of_device_id *match;
 514                 match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
 515                 return (struct s3c2410_wdt_variant *)match->data;
 516         } else {
 517                 return (struct s3c2410_wdt_variant *)
 518                         platform_get_device_id(pdev)->driver_data;
 519         }
 520 }
 521
 522 static int s3c2410wdt_probe(struct platform_device *pdev)
 523 {
 524         struct device *dev;
 525         struct s3c2410_wdt *wdt;
 526         struct resource *wdt_mem;
 527         struct resource *wdt_irq;
 528         unsigned int wtcon;
 529         int started = 0;
 530         int ret;
 531
 532         DBG("%s: probe=%p\n", __func__, pdev);
 533
 534         dev = &pdev->dev;
 535
 536         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 537         if (!wdt)
 538                 return -ENOMEM;
 539
 540         wdt->dev = &pdev->dev;
 541         spin_lock_init(&wdt->lock);
 542         wdt->wdt_device = s3c2410_wdd;
 543
 544         wdt->drv_data = get_wdt_drv_data(pdev);
 545         if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
 546                 wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
 547                                                 "samsung,syscon-phandle");
 548                 if (IS_ERR(wdt->pmureg)) {
 549                         dev_err(dev, "syscon regmap lookup failed.\n");
 550                         return PTR_ERR(wdt->pmureg);
 551                 }
 552         }
 553
 554         wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 555         if (wdt_irq == NULL) {
 556                 dev_err(dev, "no irq resource specified\n");
 557                 ret = -ENOENT;
 558                 goto err;
 559         }
 560
 561         /* get the memory region for the watchdog timer */
 562         wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 563         wdt->reg_base = devm_ioremap_resource(dev, wdt_mem);
 564         if (IS_ERR(wdt->reg_base)) {
 565                 ret = PTR_ERR(wdt->reg_base);
 566                 goto err;
 567         }
 568
 569         DBG("probe: mapped reg_base=%p\n", wdt->reg_base);
 570
 571         wdt->clock = devm_clk_get(dev, "watchdog");
 572         if (IS_ERR(wdt->clock)) {
 573                 dev_err(dev, "failed to find watchdog clock source\n");
 574                 ret = PTR_ERR(wdt->clock);
 575                 goto err;
 576         }
 577
 578         ret = clk_prepare_enable(wdt->clock);
 579         if (ret < 0) {
 580                 dev_err(dev, "failed to enable clock\n");
 581                 return ret;
 582         }
 583
 584         wdt->wdt_device.min_timeout = 1;
 585         wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt->clock);
 586
 587         ret = s3c2410wdt_cpufreq_register(wdt);
 588         if (ret < 0) {
 589                 dev_err(dev, "failed to register cpufreq\n");
 590                 goto err_clk;
 591         }
 592
 593         watchdog_set_drvdata(&wdt->wdt_device, wdt);
 594
 595         /* see if we can actually set the requested timer margin, and if
 596          * not, try the default value */
 597
 598         watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev);
 599         ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 600                                         wdt->wdt_device.timeout);
 601         if (ret) {
 602                 started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
 603                                         CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
 604
 605                 if (started == 0)
 606                         dev_info(dev,
 607                            "tmr_margin value out of range, default %d used\n",
 608                                CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
 609                 else
 610                         dev_info(dev, "default timer value is out of range, "
 611                                                         "cannot start\n");
 612         }
 613
 614         ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
 615                                 pdev->name, pdev);
 616         if (ret != 0) {
 617                 dev_err(dev, "failed to install irq (%d)\n", ret);
 618                 goto err_cpufreq;
 619         }
 620
 621         watchdog_set_nowayout(&wdt->wdt_device, nowayout);
 622         watchdog_set_restart_priority(&wdt->wdt_device, 128);
 623
 624         wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 625         wdt->wdt_device.parent = &pdev->dev;
 626
 627         ret = watchdog_register_device(&wdt->wdt_device);
 628         if (ret) {
 629                 dev_err(dev, "cannot register watchdog (%d)\n", ret);
 630                 goto err_cpufreq;
 631         }
 632
 633         ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 634         if (ret < 0)
 635                 goto err_unregister;
 636
 637         if (tmr_atboot && started == 0) {
 638                 dev_info(dev, "starting watchdog timer\n");
 639                 s3c2410wdt_start(&wdt->wdt_device);
 640         } else if (!tmr_atboot) {
 641                 /* if we're not enabling the watchdog, then ensure it is
 642                  * disabled if it has been left running from the bootloader
 643                  * or other source */
 644
 645                 s3c2410wdt_stop(&wdt->wdt_device);
 646         }
 647
 648         platform_set_drvdata(pdev, wdt);
 649
 650         /* print out a statement of readiness */
 651
 652         wtcon = readl(wdt->reg_base + S3C2410_WTCON);
 653
 654         dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
 655                  (wtcon & S3C2410_WTCON_ENABLE) ?  "" : "in",
 656                  (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
 657                  (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
 658
 659         return 0;
 660
 661  err_unregister:
 662         watchdog_unregister_device(&wdt->wdt_device);
 663
 664  err_cpufreq:
 665         s3c2410wdt_cpufreq_deregister(wdt);
 666
 667  err_clk:
 668         clk_disable_unprepare(wdt->clock);
 669
 670  err:
 671         return ret;
 672 }
 673
 674 static int s3c2410wdt_remove(struct platform_device *dev)
 675 {
 676         int ret;
 677         struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 678
 679         ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 680         if (ret < 0)
 681                 return ret;
 682
 683         watchdog_unregister_device(&wdt->wdt_device);
 684
 685         s3c2410wdt_cpufreq_deregister(wdt);
 686
 687         clk_disable_unprepare(wdt->clock);
 688
 689         return 0;
 690 }
 691
 692 static void s3c2410wdt_shutdown(struct platform_device *dev)
 693 {
 694         struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
 695
 696         s3c2410wdt_mask_and_disable_reset(wdt, true);
 697
 698         s3c2410wdt_stop(&wdt->wdt_device);
 699 }
 700
 701 #ifdef CONFIG_PM_SLEEP
 702
 703 static int s3c2410wdt_suspend(struct device *dev)
 704 {
 705         int ret;
 706         struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 707
 708         /* Save watchdog state, and turn it off. */
 709         wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
 710         wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
 711
 712         ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 713         if (ret < 0)
 714                 return ret;
 715
 716         /* Note that WTCNT doesn't need to be saved. */
 717         s3c2410wdt_stop(&wdt->wdt_device);
 718
 719         return 0;
 720 }
 721
 722 static int s3c2410wdt_resume(struct device *dev)
 723 {
 724         int ret;
 725         struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
 726
 727         /* Restore watchdog state. */
 728         writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
 729         writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
 730         writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
 731
 732         ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
 733         if (ret < 0)
 734                 return ret;
 735
 736         dev_info(dev, "watchdog %sabled\n",
 737                 (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
 738
 739         return 0;
 740 }
 741 #endif
 742
 743 static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
 744                         s3c2410wdt_resume);
 745
 746 static struct platform_driver s3c2410wdt_driver = {
 747         .probe          = s3c2410wdt_probe,
 748         .remove         = s3c2410wdt_remove,
 749         .shutdown       = s3c2410wdt_shutdown,
 750         .id_table       = s3c2410_wdt_ids,
 751         .driver         = {
 752                 .name   = "s3c2410-wdt",
 753                 .pm     = &s3c2410wdt_pm_ops,
 754                 .of_match_table = of_match_ptr(s3c2410_wdt_match),
 755         },
 756 };
 757
 758 module_platform_driver(s3c2410wdt_driver);
 759
 760 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
 761               "Dimitry Andric <dimitry.andric@tomtom.com>");
 762 MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
 763 MODULE_LICENSE("GPL");