Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / watchdog / s3c2410_wdt.c
diff --git a/kernel/drivers/watchdog/s3c2410_wdt.c b/kernel/drivers/watchdog/s3c2410_wdt.c
new file mode 100644 (file)
index 0000000..e89ae02
--- /dev/null
@@ -0,0 +1,755 @@
+/* linux/drivers/char/watchdog/s3c2410_wdt.c
+ *
+ * Copyright (c) 2004 Simtec Electronics
+ *     Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2410 Watchdog Timer Support
+ *
+ * Based on, softdog.c by Alan Cox,
+ *     (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+
+#define S3C2410_WTCON          0x00
+#define S3C2410_WTDAT          0x04
+#define S3C2410_WTCNT          0x08
+
+#define S3C2410_WTCON_RSTEN    (1 << 0)
+#define S3C2410_WTCON_INTEN    (1 << 2)
+#define S3C2410_WTCON_ENABLE   (1 << 5)
+
+#define S3C2410_WTCON_DIV16    (0 << 3)
+#define S3C2410_WTCON_DIV32    (1 << 3)
+#define S3C2410_WTCON_DIV64    (2 << 3)
+#define S3C2410_WTCON_DIV128   (3 << 3)
+
+#define S3C2410_WTCON_PRESCALE(x)      ((x) << 8)
+#define S3C2410_WTCON_PRESCALE_MASK    (0xff << 8)
+
+#define CONFIG_S3C2410_WATCHDOG_ATBOOT         (0)
+#define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME   (15)
+
+#define EXYNOS5_RST_STAT_REG_OFFSET            0x0404
+#define EXYNOS5_WDT_DISABLE_REG_OFFSET         0x0408
+#define EXYNOS5_WDT_MASK_RESET_REG_OFFSET      0x040c
+#define QUIRK_HAS_PMU_CONFIG                   (1 << 0)
+#define QUIRK_HAS_RST_STAT                     (1 << 1)
+
+/* These quirks require that we have a PMU register map */
+#define QUIRKS_HAVE_PMUREG                     (QUIRK_HAS_PMU_CONFIG | \
+                                                QUIRK_HAS_RST_STAT)
+
+static bool nowayout   = WATCHDOG_NOWAYOUT;
+static int tmr_margin;
+static int tmr_atboot  = CONFIG_S3C2410_WATCHDOG_ATBOOT;
+static int soft_noboot;
+static int debug;
+
+module_param(tmr_margin,  int, 0);
+module_param(tmr_atboot,  int, 0);
+module_param(nowayout,   bool, 0);
+module_param(soft_noboot, int, 0);
+module_param(debug,      int, 0);
+
+MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
+               __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")");
+MODULE_PARM_DESC(tmr_atboot,
+               "Watchdog is started at boot time if set to 1, default="
+                       __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT));
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+                       __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
+                       "0 to reboot (default 0)");
+MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
+
+/**
+ * struct s3c2410_wdt_variant - Per-variant config data
+ *
+ * @disable_reg: Offset in pmureg for the register that disables the watchdog
+ * timer reset functionality.
+ * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
+ * timer reset functionality.
+ * @mask_bit: Bit number for the watchdog timer in the disable register and the
+ * mask reset register.
+ * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
+ * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
+ * reset.
+ * @quirks: A bitfield of quirks.
+ */
+
+struct s3c2410_wdt_variant {
+       int disable_reg;
+       int mask_reset_reg;
+       int mask_bit;
+       int rst_stat_reg;
+       int rst_stat_bit;
+       u32 quirks;
+};
+
+struct s3c2410_wdt {
+       struct device           *dev;
+       struct clk              *clock;
+       void __iomem            *reg_base;
+       unsigned int            count;
+       spinlock_t              lock;
+       unsigned long           wtcon_save;
+       unsigned long           wtdat_save;
+       struct watchdog_device  wdt_device;
+       struct notifier_block   freq_transition;
+       struct notifier_block   restart_handler;
+       struct s3c2410_wdt_variant *drv_data;
+       struct regmap *pmureg;
+};
+
+static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
+       .quirks = 0
+};
+
+#ifdef CONFIG_OF
+static const struct s3c2410_wdt_variant drv_data_exynos5250  = {
+       .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
+       .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
+       .mask_bit = 20,
+       .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+       .rst_stat_bit = 20,
+       .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
+};
+
+static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
+       .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
+       .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
+       .mask_bit = 0,
+       .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+       .rst_stat_bit = 9,
+       .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
+};
+
+static const struct s3c2410_wdt_variant drv_data_exynos7 = {
+       .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
+       .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
+       .mask_bit = 23,
+       .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+       .rst_stat_bit = 23,     /* A57 WDTRESET */
+       .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT,
+};
+
+static const struct of_device_id s3c2410_wdt_match[] = {
+       { .compatible = "samsung,s3c2410-wdt",
+         .data = &drv_data_s3c2410 },
+       { .compatible = "samsung,exynos5250-wdt",
+         .data = &drv_data_exynos5250 },
+       { .compatible = "samsung,exynos5420-wdt",
+         .data = &drv_data_exynos5420 },
+       { .compatible = "samsung,exynos7-wdt",
+         .data = &drv_data_exynos7 },
+       {},
+};
+MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
+#endif
+
+static const struct platform_device_id s3c2410_wdt_ids[] = {
+       {
+               .name = "s3c2410-wdt",
+               .driver_data = (unsigned long)&drv_data_s3c2410,
+       },
+       {}
+};
+MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
+
+/* watchdog control routines */
+
+#define DBG(fmt, ...)                                  \
+do {                                                   \
+       if (debug)                                      \
+               pr_info(fmt, ##__VA_ARGS__);            \
+} while (0)
+
+/* functions */
+
+static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
+{
+       return container_of(nb, struct s3c2410_wdt, freq_transition);
+}
+
+static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask)
+{
+       int ret;
+       u32 mask_val = 1 << wdt->drv_data->mask_bit;
+       u32 val = 0;
+
+       /* No need to do anything if no PMU CONFIG needed */
+       if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG))
+               return 0;
+
+       if (mask)
+               val = mask_val;
+
+       ret = regmap_update_bits(wdt->pmureg,
+                       wdt->drv_data->disable_reg,
+                       mask_val, val);
+       if (ret < 0)
+               goto error;
+
+       ret = regmap_update_bits(wdt->pmureg,
+                       wdt->drv_data->mask_reset_reg,
+                       mask_val, val);
+ error:
+       if (ret < 0)
+               dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
+
+       return ret;
+}
+
+static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
+{
+       struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
+
+       spin_lock(&wdt->lock);
+       writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
+       spin_unlock(&wdt->lock);
+
+       return 0;
+}
+
+static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
+{
+       unsigned long wtcon;
+
+       wtcon = readl(wdt->reg_base + S3C2410_WTCON);
+       wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
+       writel(wtcon, wdt->reg_base + S3C2410_WTCON);
+}
+
+static int s3c2410wdt_stop(struct watchdog_device *wdd)
+{
+       struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
+
+       spin_lock(&wdt->lock);
+       __s3c2410wdt_stop(wdt);
+       spin_unlock(&wdt->lock);
+
+       return 0;
+}
+
+static int s3c2410wdt_start(struct watchdog_device *wdd)
+{
+       unsigned long wtcon;
+       struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
+
+       spin_lock(&wdt->lock);
+
+       __s3c2410wdt_stop(wdt);
+
+       wtcon = readl(wdt->reg_base + S3C2410_WTCON);
+       wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
+
+       if (soft_noboot) {
+               wtcon |= S3C2410_WTCON_INTEN;
+               wtcon &= ~S3C2410_WTCON_RSTEN;
+       } else {
+               wtcon &= ~S3C2410_WTCON_INTEN;
+               wtcon |= S3C2410_WTCON_RSTEN;
+       }
+
+       DBG("%s: count=0x%08x, wtcon=%08lx\n",
+           __func__, wdt->count, wtcon);
+
+       writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
+       writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
+       writel(wtcon, wdt->reg_base + S3C2410_WTCON);
+       spin_unlock(&wdt->lock);
+
+       return 0;
+}
+
+static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
+{
+       return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
+}
+
+static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout)
+{
+       struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
+       unsigned long freq = clk_get_rate(wdt->clock);
+       unsigned int count;
+       unsigned int divisor = 1;
+       unsigned long wtcon;
+
+       if (timeout < 1)
+               return -EINVAL;
+
+       freq = DIV_ROUND_UP(freq, 128);
+       count = timeout * freq;
+
+       DBG("%s: count=%d, timeout=%d, freq=%lu\n",
+           __func__, count, timeout, freq);
+
+       /* if the count is bigger than the watchdog register,
+          then work out what we need to do (and if) we can
+          actually make this value
+       */
+
+       if (count >= 0x10000) {
+               divisor = DIV_ROUND_UP(count, 0xffff);
+
+               if (divisor > 0x100) {
+                       dev_err(wdt->dev, "timeout %d too big\n", timeout);
+                       return -EINVAL;
+               }
+       }
+
+       DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n",
+           __func__, timeout, divisor, count, DIV_ROUND_UP(count, divisor));
+
+       count = DIV_ROUND_UP(count, divisor);
+       wdt->count = count;
+
+       /* update the pre-scaler */
+       wtcon = readl(wdt->reg_base + S3C2410_WTCON);
+       wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
+       wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
+
+       writel(count, wdt->reg_base + S3C2410_WTDAT);
+       writel(wtcon, wdt->reg_base + S3C2410_WTCON);
+
+       wdd->timeout = (count * divisor) / freq;
+
+       return 0;
+}
+
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+
+static const struct watchdog_info s3c2410_wdt_ident = {
+       .options          =     OPTIONS,
+       .firmware_version =     0,
+       .identity         =     "S3C2410 Watchdog",
+};
+
+static struct watchdog_ops s3c2410wdt_ops = {
+       .owner = THIS_MODULE,
+       .start = s3c2410wdt_start,
+       .stop = s3c2410wdt_stop,
+       .ping = s3c2410wdt_keepalive,
+       .set_timeout = s3c2410wdt_set_heartbeat,
+};
+
+static struct watchdog_device s3c2410_wdd = {
+       .info = &s3c2410_wdt_ident,
+       .ops = &s3c2410wdt_ops,
+       .timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME,
+};
+
+/* interrupt handler code */
+
+static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
+{
+       struct s3c2410_wdt *wdt = platform_get_drvdata(param);
+
+       dev_info(wdt->dev, "watchdog timer expired (irq)\n");
+
+       s3c2410wdt_keepalive(&wdt->wdt_device);
+       return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
+
+static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
+                                         unsigned long val, void *data)
+{
+       int ret;
+       struct s3c2410_wdt *wdt = freq_to_wdt(nb);
+
+       if (!s3c2410wdt_is_running(wdt))
+               goto done;
+
+       if (val == CPUFREQ_PRECHANGE) {
+               /* To ensure that over the change we don't cause the
+                * watchdog to trigger, we perform an keep-alive if
+                * the watchdog is running.
+                */
+
+               s3c2410wdt_keepalive(&wdt->wdt_device);
+       } else if (val == CPUFREQ_POSTCHANGE) {
+               s3c2410wdt_stop(&wdt->wdt_device);
+
+               ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
+                                               wdt->wdt_device.timeout);
+
+               if (ret >= 0)
+                       s3c2410wdt_start(&wdt->wdt_device);
+               else
+                       goto err;
+       }
+
+done:
+       return 0;
+
+ err:
+       dev_err(wdt->dev, "cannot set new value for timeout %d\n",
+                               wdt->wdt_device.timeout);
+       return ret;
+}
+
+static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
+{
+       wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
+
+       return cpufreq_register_notifier(&wdt->freq_transition,
+                                        CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
+{
+       wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
+
+       cpufreq_unregister_notifier(&wdt->freq_transition,
+                                   CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+#else
+
+static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
+{
+       return 0;
+}
+
+static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
+{
+}
+#endif
+
+static int s3c2410wdt_restart(struct notifier_block *this,
+                             unsigned long mode, void *cmd)
+{
+       struct s3c2410_wdt *wdt = container_of(this, struct s3c2410_wdt,
+                                              restart_handler);
+       void __iomem *wdt_base = wdt->reg_base;
+
+       /* disable watchdog, to be safe  */
+       writel(0, wdt_base + S3C2410_WTCON);
+
+       /* put initial values into count and data */
+       writel(0x80, wdt_base + S3C2410_WTCNT);
+       writel(0x80, wdt_base + S3C2410_WTDAT);
+
+       /* set the watchdog to go and reset... */
+       writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
+               S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
+               wdt_base + S3C2410_WTCON);
+
+       /* wait for reset to assert... */
+       mdelay(500);
+
+       return NOTIFY_DONE;
+}
+
+static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
+{
+       unsigned int rst_stat;
+       int ret;
+
+       if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT))
+               return 0;
+
+       ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
+       if (ret)
+               dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
+       else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
+               return WDIOF_CARDRESET;
+
+       return 0;
+}
+
+/* s3c2410_get_wdt_driver_data */
+static inline struct s3c2410_wdt_variant *
+get_wdt_drv_data(struct platform_device *pdev)
+{
+       if (pdev->dev.of_node) {
+               const struct of_device_id *match;
+               match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
+               return (struct s3c2410_wdt_variant *)match->data;
+       } else {
+               return (struct s3c2410_wdt_variant *)
+                       platform_get_device_id(pdev)->driver_data;
+       }
+}
+
+static int s3c2410wdt_probe(struct platform_device *pdev)
+{
+       struct device *dev;
+       struct s3c2410_wdt *wdt;
+       struct resource *wdt_mem;
+       struct resource *wdt_irq;
+       unsigned int wtcon;
+       int started = 0;
+       int ret;
+
+       DBG("%s: probe=%p\n", __func__, pdev);
+
+       dev = &pdev->dev;
+
+       wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+       if (!wdt)
+               return -ENOMEM;
+
+       wdt->dev = &pdev->dev;
+       spin_lock_init(&wdt->lock);
+       wdt->wdt_device = s3c2410_wdd;
+
+       wdt->drv_data = get_wdt_drv_data(pdev);
+       if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
+               wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
+                                               "samsung,syscon-phandle");
+               if (IS_ERR(wdt->pmureg)) {
+                       dev_err(dev, "syscon regmap lookup failed.\n");
+                       return PTR_ERR(wdt->pmureg);
+               }
+       }
+
+       wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+       if (wdt_irq == NULL) {
+               dev_err(dev, "no irq resource specified\n");
+               ret = -ENOENT;
+               goto err;
+       }
+
+       /* get the memory region for the watchdog timer */
+       wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       wdt->reg_base = devm_ioremap_resource(dev, wdt_mem);
+       if (IS_ERR(wdt->reg_base)) {
+               ret = PTR_ERR(wdt->reg_base);
+               goto err;
+       }
+
+       DBG("probe: mapped reg_base=%p\n", wdt->reg_base);
+
+       wdt->clock = devm_clk_get(dev, "watchdog");
+       if (IS_ERR(wdt->clock)) {
+               dev_err(dev, "failed to find watchdog clock source\n");
+               ret = PTR_ERR(wdt->clock);
+               goto err;
+       }
+
+       ret = clk_prepare_enable(wdt->clock);
+       if (ret < 0) {
+               dev_err(dev, "failed to enable clock\n");
+               return ret;
+       }
+
+       ret = s3c2410wdt_cpufreq_register(wdt);
+       if (ret < 0) {
+               dev_err(dev, "failed to register cpufreq\n");
+               goto err_clk;
+       }
+
+       watchdog_set_drvdata(&wdt->wdt_device, wdt);
+
+       /* see if we can actually set the requested timer margin, and if
+        * not, try the default value */
+
+       watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev);
+       ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
+                                       wdt->wdt_device.timeout);
+       if (ret) {
+               started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
+                                       CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
+
+               if (started == 0)
+                       dev_info(dev,
+                          "tmr_margin value out of range, default %d used\n",
+                              CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME);
+               else
+                       dev_info(dev, "default timer value is out of range, "
+                                                       "cannot start\n");
+       }
+
+       ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
+                               pdev->name, pdev);
+       if (ret != 0) {
+               dev_err(dev, "failed to install irq (%d)\n", ret);
+               goto err_cpufreq;
+       }
+
+       watchdog_set_nowayout(&wdt->wdt_device, nowayout);
+
+       wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
+
+       ret = watchdog_register_device(&wdt->wdt_device);
+       if (ret) {
+               dev_err(dev, "cannot register watchdog (%d)\n", ret);
+               goto err_cpufreq;
+       }
+
+       ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+       if (ret < 0)
+               goto err_unregister;
+
+       if (tmr_atboot && started == 0) {
+               dev_info(dev, "starting watchdog timer\n");
+               s3c2410wdt_start(&wdt->wdt_device);
+       } else if (!tmr_atboot) {
+               /* if we're not enabling the watchdog, then ensure it is
+                * disabled if it has been left running from the bootloader
+                * or other source */
+
+               s3c2410wdt_stop(&wdt->wdt_device);
+       }
+
+       platform_set_drvdata(pdev, wdt);
+
+       wdt->restart_handler.notifier_call = s3c2410wdt_restart;
+       wdt->restart_handler.priority = 128;
+       ret = register_restart_handler(&wdt->restart_handler);
+       if (ret)
+               pr_err("cannot register restart handler, %d\n", ret);
+
+       /* print out a statement of readiness */
+
+       wtcon = readl(wdt->reg_base + S3C2410_WTCON);
+
+       dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
+                (wtcon & S3C2410_WTCON_ENABLE) ?  "" : "in",
+                (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
+                (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
+
+       return 0;
+
+ err_unregister:
+       watchdog_unregister_device(&wdt->wdt_device);
+
+ err_cpufreq:
+       s3c2410wdt_cpufreq_deregister(wdt);
+
+ err_clk:
+       clk_disable_unprepare(wdt->clock);
+
+ err:
+       return ret;
+}
+
+static int s3c2410wdt_remove(struct platform_device *dev)
+{
+       int ret;
+       struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
+
+       unregister_restart_handler(&wdt->restart_handler);
+
+       ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+       if (ret < 0)
+               return ret;
+
+       watchdog_unregister_device(&wdt->wdt_device);
+
+       s3c2410wdt_cpufreq_deregister(wdt);
+
+       clk_disable_unprepare(wdt->clock);
+
+       return 0;
+}
+
+static void s3c2410wdt_shutdown(struct platform_device *dev)
+{
+       struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
+
+       s3c2410wdt_mask_and_disable_reset(wdt, true);
+
+       s3c2410wdt_stop(&wdt->wdt_device);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int s3c2410wdt_suspend(struct device *dev)
+{
+       int ret;
+       struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
+
+       /* Save watchdog state, and turn it off. */
+       wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
+       wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
+
+       ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+       if (ret < 0)
+               return ret;
+
+       /* Note that WTCNT doesn't need to be saved. */
+       s3c2410wdt_stop(&wdt->wdt_device);
+
+       return 0;
+}
+
+static int s3c2410wdt_resume(struct device *dev)
+{
+       int ret;
+       struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
+
+       /* Restore watchdog state. */
+       writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
+       writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
+       writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
+
+       ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+       if (ret < 0)
+               return ret;
+
+       dev_info(dev, "watchdog %sabled\n",
+               (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
+
+       return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
+                       s3c2410wdt_resume);
+
+static struct platform_driver s3c2410wdt_driver = {
+       .probe          = s3c2410wdt_probe,
+       .remove         = s3c2410wdt_remove,
+       .shutdown       = s3c2410wdt_shutdown,
+       .id_table       = s3c2410_wdt_ids,
+       .driver         = {
+               .name   = "s3c2410-wdt",
+               .pm     = &s3c2410wdt_pm_ops,
+               .of_match_table = of_match_ptr(s3c2410_wdt_match),
+       },
+};
+
+module_platform_driver(s3c2410wdt_driver);
+
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, "
+             "Dimitry Andric <dimitry.andric@tomtom.com>");
+MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
+MODULE_LICENSE("GPL");