On 2/23/23 23:42, Xingyu Wu wrote:
On 2023/2/24 2:23, Guenter Roeck wrote:
On Mon, Feb 20, 2023 at 04:19:26PM +0800, Xingyu Wu wrote:
Add watchdog driver for the StarFive JH7110 SoC.
Signed-off-by: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/watchdog/Kconfig | 9 +
drivers/watchdog/Makefile | 2 +
drivers/watchdog/starfive-wdt.c | 651 ++++++++++++++++++++++++++++++++
4 files changed, 669 insertions(+)
create mode 100644 drivers/watchdog/starfive-wdt.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 135d93368d36..6cbcf08fa76a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19933,6 +19933,13 @@ F: Documentation/devicetree/bindings/reset/starfive,jh7100-reset.yaml
F: drivers/reset/reset-starfive-jh7100.c
F: include/dt-bindings/reset/starfive-jh7100.h
+STARFIVE JH7110 WATCHDOG DRIVER
+M: Xingyu Wu <xingyu.wu@xxxxxxxxxxxxxxxx>
+M: Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
+S: Supported
+F: Documentation/devicetree/bindings/watchdog/starfive*
+F: drivers/watchdog/starfive-wdt.c
+
STATIC BRANCH/CALL
M: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
M: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0bc40b763b06..4608eb5c9501 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -2089,6 +2089,15 @@ config UML_WATCHDOG
tristate "UML watchdog"
depends on UML || COMPILE_TEST
+config STARFIVE_WATCHDOG
+ tristate "StarFive Watchdog support"
+ depends on RISCV
+ select WATCHDOG_CORE
+ default SOC_STARFIVE
+ help
+ Say Y here to support the watchdog of StarFive JH7110 SoC.
+ This driver can also be built as a module if choose M.
+
#
# ISA-based Watchdog Cards
#
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 9cbf6580f16c..4c0bd377e92a 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -211,6 +211,8 @@ obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o
# Xen
obj-$(CONFIG_XEN_WDT) += xen_wdt.o
+obj-$(CONFIG_STARFIVE_WATCHDOG) += starfive-wdt.o
+
# Architecture Independent
obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o
obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
diff --git a/drivers/watchdog/starfive-wdt.c b/drivers/watchdog/starfive-wdt.c
new file mode 100644
index 000000000000..dfbb80406076
--- /dev/null
+++ b/drivers/watchdog/starfive-wdt.c
@@ -0,0 +1,651 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Starfive Watchdog driver
+ *
+ * Copyright (C) 2022 StarFive Technology Co., Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/watchdog.h>
+
+/* JH7110 WatchDog register define */
+#define STARFIVE_WDT_JH7110_LOAD 0x000 /* RW: Watchdog load register */
+#define STARFIVE_WDT_JH7110_VALUE 0x004 /* RO: The current value for the watchdog counter */
+#define STARFIVE_WDT_JH7110_CONTROL 0x008 /*
+ * RW:
+ * [0]: reset enable;
+ * [1]: int enable/wdt enable/reload counter;
+ * [31:2]: reserve.
reserved
Will fix.
+ */
+#define STARFIVE_WDT_JH7110_INTCLR 0x00c /* WO: clear intterupt && reload the counter */
+#define STARFIVE_WDT_JH7110_RIS 0x010 /* RO: Raw interrupt status from the counter */
+#define STARFIVE_WDT_JH7110_IMS 0x014 /* RO: Enabled interrupt status from the counter */
+#define STARFIVE_WDT_JH7110_LOCK 0xc00 /*
+ * RO: Enable write access to all other registers
+ * by writing 0x1ACCE551.
+ */
"RO" contradicts itself against the rest of the comment. The register is
written to, so it can't bew RO.
Change to 'RW'.
+
+/* WDOGCONTROL */
+#define STARFIVE_WDT_ENABLE 0x1
+#define STARFIVE_WDT_JH7110_EN_SHIFT 0
+#define STARFIVE_WDT_RESET_EN 0x1
+#define STARFIVE_WDT_JH7110_RESEN_SHIFT 1
+
+/* WDOGLOCK */
+#define STARFIVE_WDT_LOCKED BIT(0)
+#define STARFIVE_WDT_JH7110_UNLOCK_KEY 0x1acce551
+
+/* WDOGINTCLR */
+#define STARFIVE_WDT_INTCLR 0x1
+
+#define STARFIVE_WDT_MAXCNT 0xffffffff
+#define STARFIVE_WDT_DEFAULT_TIME (15)
+#define STARFIVE_WDT_DELAY_US 0
+#define STARFIVE_WDT_TIMEOUT_US 10000
+
+/* module parameter */
+#define STARFIVE_WDT_EARLY_ENA 0
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat;
+static int early_enable = STARFIVE_WDT_EARLY_ENA;
+
+module_param(heartbeat, int, 0);
+module_param(early_enable, int, 0);
+module_param(nowayout, bool, 0);
+
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
+ __MODULE_STRING(STARFIVE_WDT_DEFAULT_TIME) ")");
+MODULE_PARM_DESC(early_enable,
+ "Watchdog is started at boot time if set to 1, default="
+ __MODULE_STRING(STARFIVE_WDT_EARLY_ENA));
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct starfive_wdt_variant {
+ u32 control;
+ u32 load;
+ u32 enable;
+ u32 value;
+ u32 int_clr;
+ u32 unlock;
+ u32 unlock_key;
+ u32 irq_is_raise;
+ u8 enrst_shift;
+ u8 en_shift;
+};
+
+struct starfive_wdt {
+ unsigned long freq;
+ struct device *dev;
+ struct watchdog_device wdt_device;
+ struct clk *core_clk;
+ struct clk *apb_clk;
+ struct reset_control *rsts;
+ const struct starfive_wdt_variant *drv_data;
+ u32 count; /*count of timeout*/
+ u32 reload; /*restore the count*/
+ void __iomem *base;
+ spinlock_t lock; /* spinlock for register handling */
+};
+
+/* Register bias in JH7110 */
+static const struct starfive_wdt_variant drv_data_jh7110 = {
+ .control = STARFIVE_WDT_JH7110_CONTROL,
+ .load = STARFIVE_WDT_JH7110_LOAD,
+ .enable = STARFIVE_WDT_JH7110_CONTROL,
+ .value = STARFIVE_WDT_JH7110_VALUE,
+ .int_clr = STARFIVE_WDT_JH7110_INTCLR,
+ .unlock = STARFIVE_WDT_JH7110_LOCK,
+ .unlock_key = STARFIVE_WDT_JH7110_UNLOCK_KEY,
+ .irq_is_raise = STARFIVE_WDT_JH7110_IMS,
+ .enrst_shift = STARFIVE_WDT_JH7110_RESEN_SHIFT,
+ .en_shift = STARFIVE_WDT_JH7110_EN_SHIFT,
+};
+
+static const struct of_device_id starfive_wdt_match[] = {
+ { .compatible = "starfive,jh7110-wdt", .data = &drv_data_jh7110 },
+ {}
+};
+MODULE_DEVICE_TABLE(of, starfive_wdt_match);
+
+static const struct platform_device_id starfive_wdt_ids[] = {
+ {
+ .name = "starfive-jh7110-wdt",
+ .driver_data = (unsigned long)&drv_data_jh7110,
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(platform, starfive_wdt_ids);
+
+static int starfive_wdt_get_clock_rate(struct starfive_wdt *wdt)
+{
+ wdt->freq = clk_get_rate(wdt->core_clk);
+ /* The clock rate should not be 0.*/
This is obvious and not worth a comment.
Will drop.
+ if (wdt->freq)
+ return 0;
+
+ dev_err(wdt->dev, "get clock rate failed.\n");
+ return -ENOENT;
Error handling should come first
if (!wdt->freq) {
dev_err(wdt->dev, "get clock rate failed.\n");
return -EINVAL;
}
return 0;
This is not "No such file or directory" (yes, I see that other drivers
do that, but that doesn't make it better). Use -EINVAL instead.
Will fix.
+}
+
+static int starfive_wdt_get_clock(struct starfive_wdt *wdt)
+{
+ wdt->apb_clk = devm_clk_get(wdt->dev, "apb");
+ if (IS_ERR(wdt->apb_clk)) {
+ dev_err(wdt->dev, "failed to get apb clock.\n");
+ return PTR_ERR(wdt->apb_clk);
+ }
+
+ wdt->core_clk = devm_clk_get(wdt->dev, "core");
+ if (IS_ERR(wdt->core_clk)) {
+ dev_err(wdt->dev, "failed to get core clock.\n");
+ return PTR_ERR(wdt->core_clk);
+ }
+
+ return 0;
+}
+
+static int starfive_wdt_reset_init(struct starfive_wdt *wdt)
+{
+ int ret = 0;
+
+ wdt->rsts = devm_reset_control_array_get_exclusive(wdt->dev);
+ if (IS_ERR(wdt->rsts)) {
+ dev_err(wdt->dev, "failed to get rsts error.\n");
I don't think this message is understandable. "failed to get reset
control", maybe. Also, the call may return -EPROBE_DEFER,
which should not generate an error message. Either drop the message
or use dev_err_probe().
Thanks you for reminding me. I will drop this.
So is the devm_clk_get() and also drop the error message?
Yes, actually. It can indeed also return -EPROBE_DEFER.
+ ret = PTR_ERR(wdt->rsts);
+ } else {
+ ret = reset_control_deassert(wdt->rsts);
+ if (ret)
+ dev_err(wdt->dev, "failed to deassert rsts.\n");
+ }
+
+ return ret;
+}
+
+static u32 starfive_wdt_ticks_to_sec(struct starfive_wdt *wdt, u32 ticks)
+{
+ return DIV_ROUND_CLOSEST(ticks, wdt->freq);
+}
+
+/*
+ * Write unlock-key to unlock. Write other value to lock. When lock bit is 1,
+ * external accesses to other watchdog registers are ignored.
+ */
+static bool starfive_wdt_is_locked(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->unlock);
+ return !!(val & STARFIVE_WDT_LOCKED);
+}
+
+static void starfive_wdt_unlock(struct starfive_wdt *wdt)
+{
+ if (starfive_wdt_is_locked(wdt))
+ writel(wdt->drv_data->unlock_key,
+ wdt->base + wdt->drv_data->unlock);
+}
+
+static void starfive_wdt_lock(struct starfive_wdt *wdt)
+{
+ if (!starfive_wdt_is_locked(wdt))
+ writel(~wdt->drv_data->unlock_key,
+ wdt->base + wdt->drv_data->unlock);
+}
+
+/* enable watchdog interrupt to reset/reboot */
+static void starfive_wdt_enable_reset(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->control);
+ val |= STARFIVE_WDT_RESET_EN << wdt->drv_data->enrst_shift;
+ writel(val, wdt->base + wdt->drv_data->control);
+}
+
+/* disable watchdog interrupt to reset/reboot */
+static void starfive_wdt_disable_reset(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->control);
+ val &= ~(STARFIVE_WDT_RESET_EN << wdt->drv_data->enrst_shift);
+ writel(val, wdt->base + wdt->drv_data->control);
+}
+
+/* interrupt status whether has been raised from the counter */
+static bool starfive_wdt_raise_irq_status(struct starfive_wdt *wdt)
+{
+ return !!readl(wdt->base + wdt->drv_data->irq_is_raise);
+}
+
+/* clear interrupt signal before initialization or reload */
+static void starfive_wdt_int_clr(struct starfive_wdt *wdt)
+{
+ writel(STARFIVE_WDT_INTCLR, wdt->base + wdt->drv_data->int_clr);
+}
+
+static inline void starfive_wdt_set_count(struct starfive_wdt *wdt, u32 val)
+{
+ writel(val, wdt->base + wdt->drv_data->load);
+}
+
+static inline u32 starfive_wdt_get_count(struct starfive_wdt *wdt)
+{
+ return readl(wdt->base + wdt->drv_data->value);
+}
+
+/* enable watchdog */
+static inline void starfive_wdt_enable(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->enable);
+ val |= STARFIVE_WDT_ENABLE << wdt->drv_data->en_shift;
+ writel(val, wdt->base + wdt->drv_data->enable);
+}
+
+/* disable watchdog */
+static inline void starfive_wdt_disable(struct starfive_wdt *wdt)
+{
+ u32 val;
+
+ val = readl(wdt->base + wdt->drv_data->enable);
+ val &= ~(STARFIVE_WDT_ENABLE << wdt->drv_data->en_shift);
+ writel(val, wdt->base + wdt->drv_data->enable);
+}
+
+static inline void starfive_wdt_set_reload_count(struct starfive_wdt *wdt, u32 count)
+{
+ starfive_wdt_set_count(wdt, count);
+ /* need enable controller to reload counter */
+ starfive_wdt_enable(wdt);
+}
+
+static unsigned int starfive_wdt_max_timeout(struct starfive_wdt *wdt)
+{
+ return DIV_ROUND_UP(STARFIVE_WDT_MAXCNT, (wdt->freq / 2)) - 1;
+}
+
+static unsigned int starfive_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+ u32 count;
+
+ starfive_wdt_unlock(wdt);
+ /*
+ * Because set half count value,
+ * timeleft value should add the count value before first timeout.
+ */
+ count = starfive_wdt_get_count(wdt);
+ if (!starfive_wdt_raise_irq_status(wdt))
+ count += wdt->count;
+
+ starfive_wdt_lock(wdt);
+
+ return starfive_wdt_ticks_to_sec(wdt, count);
+}
+
+static int starfive_wdt_keepalive(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ spin_lock(&wdt->lock);
+
+ starfive_wdt_unlock(wdt);
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_set_reload_count(wdt, wdt->count);
+ starfive_wdt_lock(wdt);
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+static int starfive_wdt_stop(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ spin_lock(&wdt->lock);
+
+ starfive_wdt_unlock(wdt);
+ starfive_wdt_disable_reset(wdt);
Is that necessary ? The watchdog is going to be stopped, after all.
It doesn't seem necessary. Drop this. And drop this entire function
because no one use it.
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_disable(wdt);
+ starfive_wdt_lock(wdt);
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+static int starfive_wdt_pm_stop(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ starfive_wdt_stop(wdd);
+ pm_runtime_put_sync(wdt->dev);
+
+ return 0;
+}
+
+static int starfive_wdt_start(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ spin_lock(&wdt->lock);
+ starfive_wdt_unlock(wdt);
+ /* disable watchdog, to be safe */
+ starfive_wdt_disable(wdt);
+
+ starfive_wdt_enable_reset(wdt);
+ starfive_wdt_int_clr(wdt);
+ starfive_wdt_set_count(wdt, wdt->count);
+ starfive_wdt_enable(wdt);
+
+ starfive_wdt_lock(wdt);
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+static int starfive_wdt_pm_start(struct watchdog_device *wdd)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ pm_runtime_get_sync(wdt->dev);
+
+ return starfive_wdt_start(wdd);
+}
+
+static int starfive_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct starfive_wdt *wdt = watchdog_get_drvdata(wdd);
+ unsigned long freq = wdt->freq;
+
+ spin_lock(&wdt->lock);
+
+ /*
+ * This watchdog takes twice timeouts to reset.
+ * In order to reduce time to reset, should set half count value.
+ */
+ wdt->count = timeout * freq / 2;
+ wdd->timeout = timeout;
+
+ starfive_wdt_unlock(wdt);
+ starfive_wdt_disable(wdt);
+ starfive_wdt_set_reload_count(wdt, wdt->count);
+ starfive_wdt_enable(wdt);
+ starfive_wdt_lock(wdt);
+
+ spin_unlock(&wdt->lock);
+
+ return 0;
+}
+
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+
+static const struct watchdog_info starfive_wdt_ident = {
+ .options = OPTIONS,
+ .identity = "StarFive Watchdog",
+};
+
+static const struct watchdog_ops starfive_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = starfive_wdt_pm_start,
+ .stop = starfive_wdt_pm_stop,
+ .ping = starfive_wdt_keepalive,
+ .set_timeout = starfive_wdt_set_timeout,
+ .get_timeleft = starfive_wdt_get_timeleft,
+};
+
+static const struct watchdog_device starfive_wdd = {
+ .info = &starfive_wdt_ident,
+ .ops = &starfive_wdt_ops,
+ .timeout = STARFIVE_WDT_DEFAULT_TIME,
+};
+
+static inline const struct starfive_wdt_variant *
+starfive_wdt_get_drv_data(struct platform_device *pdev)
+{
+ const struct starfive_wdt_variant *variant;
+
+ variant = of_device_get_match_data(&pdev->dev);
+ if (!variant) {
+ /* Device matched by platform_device_id */
+ variant = (struct starfive_wdt_variant *)
+ platform_get_device_id(pdev)->driver_data;
+ }
+
+ return variant;
+}
+
+static int starfive_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct starfive_wdt *wdt;
+ int ret;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->dev = dev;
+ spin_lock_init(&wdt->lock);
+ wdt->wdt_device = starfive_wdd;
+
+ wdt->drv_data = starfive_wdt_get_drv_data(pdev);
+
+ /* get the memory region for the watchdog timer */
+ wdt->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(wdt->base)) {
+ ret = PTR_ERR(wdt->base);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, wdt);
+ pm_runtime_enable(wdt->dev);
+
+ ret = starfive_wdt_get_clock(wdt);
+ if (ret)
+ return ret;
+
+ if (pm_runtime_enabled(wdt->dev)) {
+ ret = pm_runtime_get_sync(wdt->dev);
+ if (ret < 0)
+ return ret;
+ } else {
+ /* runtime PM is disabled but clocks need to be enabled */
+ ret = clk_prepare_enable(wdt->apb_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable apb_clk.\n");
+ return ret;
+ }
+ ret = clk_prepare_enable(wdt->core_clk);
+ if (ret) {
+ dev_err(wdt->dev, "failed to enable core_clk.\n");
+ goto err_apb_clk_disable;
+ }
+ }
+
+ ret = starfive_wdt_get_clock_rate(wdt);
+ if (ret)
+ goto err_clk_disable;
+
+ ret = starfive_wdt_reset_init(wdt);
+ if (ret)
+ goto err_clk_disable;
+
+ wdt->wdt_device.min_timeout = 1;
+ wdt->wdt_device.max_timeout = starfive_wdt_max_timeout(wdt);
wdt->wdt_device.timeout = STARFIVE_WDT_DEFAULT_TIME;
should be set here. Otherwise the warning below would always be seen
if the module parameter is not set.
+
+ watchdog_set_drvdata(&wdt->wdt_device, wdt);
+
+ /*
+ * see if we can actually set the requested heartbeat,
+ * and if not, try the default value.
+ */
+ watchdog_init_timeout(&wdt->wdt_device, heartbeat, dev);
+ if (wdt->wdt_device.timeout == 0 ||
If wdt->wdt_device.timeout is pre-initialized, it will never be 0 here.
+ wdt->wdt_device.timeout > wdt->wdt_device.max_timeout) {
That won't happen because watchdog_init_timeout() validates it and does
not update the value if it is out of range.
+ dev_warn(dev, "heartbeat value out of range, default %d used\n",
+ STARFIVE_WDT_DEFAULT_TIME);
+ wdt->wdt_device.timeout = STARFIVE_WDT_DEFAULT_TIME;
And this is then unnecessary. wdt->wdt_device.timeout will always be
valid if it was pre-initialized.
It is changed to be this at beginning of the driver:
static int heartbeat = STARFIVE_WDT_DEFAULT_TIME;
No, this is wrong. The static variable should be set to 0 to indicate
"use default".
and it is changed to be this here:
ret = watchdog_init_timeout(&wdt->wdt_device, heartbeat, dev);
if (ret)
return ret;
Would that be better?
No, it is worse, because it would not instantiate the watchdog at all
if a bad heartbeat is provided.
+ }
+ starfive_wdt_set_timeout(&wdt->wdt_device, wdt->wdt_device.timeout);
+
+ watchdog_set_nowayout(&wdt->wdt_device, nowayout);
+ watchdog_stop_on_reboot(&wdt->wdt_device);
+ watchdog_stop_on_unregister(&wdt->wdt_device);
+
+ wdt->wdt_device.parent = dev;
+
+ ret = watchdog_register_device(&wdt->wdt_device);
+ if (ret)
+ goto err_clk_disable;
+
+ if (early_enable) {
+ starfive_wdt_start(&wdt->wdt_device);
+ set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
Is it correct to call pm_runtime_put_sync() below if the watchdog
is running ? Doesn't that stop the clock ?
Add a check of 'early_enable' to pm_runtime_put_sync() or
move it after starfive_wdt_stop() immediately.
+ } else {
+ starfive_wdt_stop(&wdt->wdt_device);
+ }
Wrong order. This has to be done _before_ the watchdog device is registered
to make sure that the watchdog core knows about WDOG_HW_RUNNING.
So move this before watchdog_register_device().
Best regards,
Xingyu Wu
