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