Merge tag 'linux-watchdog-5.5-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - support for NCT6116D

 - several small fixes and improvements

* tag 'linux-watchdog-5.5-rc1' of git://www.linux-watchdog.org/linux-watchdog: (24 commits)
  watchdog: jz4740: Drop dependency on MACH_JZ47xx
  watchdog: jz4740: Use regmap provided by TCU driver
  watchdog: jz4740: Use WDT clock provided by TCU driver
  dt-bindings: watchdog: sama5d4_wdt: add microchip,sam9x60-wdt compatible
  watchdog: sama5d4_wdt: cleanup the bit definitions
  watchdog: sprd: Fix the incorrect pointer getting from driver data
  watchdog: aspeed: Fix clock behaviour for ast2600
  watchdog: imx7ulp: Fix reboot hang
  watchdog: make nowayout sysfs file writable
  watchdog: prevent deferral of watchdogd wakeup on RT
  watchdog: imx7ulp: Use definitions instead of magic values
  watchdog: imx7ulp: Remove inline annotations
  watchdog: imx7ulp: Remove unused structure member
  watchdog: imx7ulp: Pass the wdog instance inimx7ulp_wdt_enable()
  watchdog: wdat_wdt: Spelling s/configrable/configurable/
  watchdog: bd70528: Trivial function documentation fix
  watchdog: cadence: Do not show error in case of deferred probe
  watchdog: Fix the race between the release of watchdog_core_data and cdev
  watchdog: sbc7240_wdt: Fix yet another -Wimplicit-fallthrough warning
  watchdog: intel-mid_wdt: Add WATCHDOG_NOWAYOUT support
  ...

1 files changed, 58 insertions, 43 deletions

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3858094ca6ba..4b2a85438478 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -34,7 +34,6 @@
 #include <linux/init.h>		/* For __init/__exit/... */
 #include <linux/hrtimer.h>	/* For hrtimers */
 #include <linux/kernel.h>	/* For printk/panic/... */
-#include <linux/kref.h>		/* For data references */
 #include <linux/kthread.h>	/* For kthread_work */
 #include <linux/miscdevice.h>	/* For handling misc devices */
 #include <linux/module.h>	/* For module stuff/... */
@@ -52,14 +51,14 @@
 
 /*
  * struct watchdog_core_data - watchdog core internal data
- * @kref:	Reference count.
+ * @dev:	The watchdog's internal device
  * @cdev:	The watchdog's Character device.
  * @wdd:	Pointer to watchdog device.
  * @lock:	Lock for watchdog core.
  * @status:	Watchdog core internal status bits.
  */
 struct watchdog_core_data {
-	struct kref kref;
+	struct device dev;
 	struct cdev cdev;
 	struct watchdog_device *wdd;
 	struct mutex lock;
@@ -158,7 +157,8 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd)
 		ktime_t t = watchdog_next_keepalive(wdd);
 
 		if (t > 0)
-			hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL);
+			hrtimer_start(&wd_data->timer, t,
+				      HRTIMER_MODE_REL_HARD);
 	} else {
 		hrtimer_cancel(&wd_data->timer);
 	}
@@ -177,7 +177,7 @@ static int __watchdog_ping(struct watchdog_device *wdd)
 	if (ktime_after(earliest_keepalive, now)) {
 		hrtimer_start(&wd_data->timer,
 			      ktime_sub(earliest_keepalive, now),
-			      HRTIMER_MODE_REL);
+			      HRTIMER_MODE_REL_HARD);
 		return 0;
 	}
 
@@ -452,7 +452,26 @@ static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
 
 	return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
 }
-static DEVICE_ATTR_RO(nowayout);
+
+static ssize_t nowayout_store(struct device *dev, struct device_attribute *attr,
+				const char *buf, size_t len)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	unsigned int value;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &value);
+	if (ret)
+		return ret;
+	if (value > 1)
+		return -EINVAL;
+	/* nowayout cannot be disabled once set */
+	if (test_bit(WDOG_NO_WAY_OUT, &wdd->status) && !value)
+		return -EPERM;
+	watchdog_set_nowayout(wdd, value);
+	return len;
+}
+static DEVICE_ATTR_RW(nowayout);
 
 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 				char *buf)
@@ -839,7 +858,7 @@ static int watchdog_open(struct inode *inode, struct file *file)
 	file->private_data = wd_data;
 
 	if (!hw_running)
-		kref_get(&wd_data->kref);
+		get_device(&wd_data->dev);
 
 	/*
 	 * open_timeout only applies for the first open from
@@ -860,11 +879,11 @@ out_clear:
 	return err;
 }
 
-static void watchdog_core_data_release(struct kref *kref)
+static void watchdog_core_data_release(struct device *dev)
 {
 	struct watchdog_core_data *wd_data;
 
-	wd_data = container_of(kref, struct watchdog_core_data, kref);
+	wd_data = container_of(dev, struct watchdog_core_data, dev);
 
 	kfree(wd_data);
 }
@@ -924,7 +943,7 @@ done:
 	 */
 	if (!running) {
 		module_put(wd_data->cdev.owner);
-		kref_put(&wd_data->kref, watchdog_core_data_release);
+		put_device(&wd_data->dev);
 	}
 	return 0;
 }
@@ -944,17 +963,22 @@ static struct miscdevice watchdog_miscdev = {
 	.fops		= &watchdog_fops,
 };
 
+static struct class watchdog_class = {
+	.name =		"watchdog",
+	.owner =	THIS_MODULE,
+	.dev_groups =	wdt_groups,
+};
+
 /*
  *	watchdog_cdev_register: register watchdog character device
  *	@wdd: watchdog device
- *	@devno: character device number
  *
  *	Register a watchdog character device including handling the legacy
  *	/dev/watchdog node. /dev/watchdog is actually a miscdevice and
  *	thus we set it up like that.
  */
 
-static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
+static int watchdog_cdev_register(struct watchdog_device *wdd)
 {
 	struct watchdog_core_data *wd_data;
 	int err;
@@ -962,7 +986,6 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
 	wd_data = kzalloc(sizeof(struct watchdog_core_data), GFP_KERNEL);
 	if (!wd_data)
 		return -ENOMEM;
-	kref_init(&wd_data->kref);
 	mutex_init(&wd_data->lock);
 
 	wd_data->wdd = wdd;
@@ -972,7 +995,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
 		return -ENODEV;
 
 	kthread_init_work(&wd_data->work, watchdog_ping_work);
-	hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	wd_data->timer.function = watchdog_timer_expired;
 
 	if (wdd->id == 0) {
@@ -991,23 +1014,33 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
 		}
 	}
 
+	device_initialize(&wd_data->dev);
+	wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id);
+	wd_data->dev.class = &watchdog_class;
+	wd_data->dev.parent = wdd->parent;
+	wd_data->dev.groups = wdd->groups;
+	wd_data->dev.release = watchdog_core_data_release;
+	dev_set_drvdata(&wd_data->dev, wdd);
+	dev_set_name(&wd_data->dev, "watchdog%d", wdd->id);
+
 	/* Fill in the data structures */
 	cdev_init(&wd_data->cdev, &watchdog_fops);
-	wd_data->cdev.owner = wdd->ops->owner;
 
 	/* Add the device */
-	err = cdev_add(&wd_data->cdev, devno, 1);
+	err = cdev_device_add(&wd_data->cdev, &wd_data->dev);
 	if (err) {
 		pr_err("watchdog%d unable to add device %d:%d\n",
 			wdd->id,  MAJOR(watchdog_devt), wdd->id);
 		if (wdd->id == 0) {
 			misc_deregister(&watchdog_miscdev);
 			old_wd_data = NULL;
-			kref_put(&wd_data->kref, watchdog_core_data_release);
+			put_device(&wd_data->dev);
 		}
 		return err;
 	}
 
+	wd_data->cdev.owner = wdd->ops->owner;
+
 	/* Record time of most recent heartbeat as 'just before now'. */
 	wd_data->last_hw_keepalive = ktime_sub(ktime_get(), 1);
 	watchdog_set_open_deadline(wd_data);
@@ -1018,9 +1051,10 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
 	 */
 	if (watchdog_hw_running(wdd)) {
 		__module_get(wdd->ops->owner);
-		kref_get(&wd_data->kref);
+		get_device(&wd_data->dev);
 		if (handle_boot_enabled)
-			hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL);
+			hrtimer_start(&wd_data->timer, 0,
+				      HRTIMER_MODE_REL_HARD);
 		else
 			pr_info("watchdog%d running and kernel based pre-userspace handler disabled\n",
 				wdd->id);
@@ -1041,7 +1075,7 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 {
 	struct watchdog_core_data *wd_data = wdd->wd_data;
 
-	cdev_del(&wd_data->cdev);
+	cdev_device_del(&wd_data->cdev, &wd_data->dev);
 	if (wdd->id == 0) {
 		misc_deregister(&watchdog_miscdev);
 		old_wd_data = NULL;
@@ -1060,15 +1094,9 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 	hrtimer_cancel(&wd_data->timer);
 	kthread_cancel_work_sync(&wd_data->work);
 
-	kref_put(&wd_data->kref, watchdog_core_data_release);
+	put_device(&wd_data->dev);
 }
 
-static struct class watchdog_class = {
-	.name =		"watchdog",
-	.owner =	THIS_MODULE,
-	.dev_groups =	wdt_groups,
-};
-
 static int watchdog_reboot_notifier(struct notifier_block *nb,
 				    unsigned long code, void *data)
 {
@@ -1099,27 +1127,14 @@ static int watchdog_reboot_notifier(struct notifier_block *nb,
 
 int watchdog_dev_register(struct watchdog_device *wdd)
 {
-	struct device *dev;
-	dev_t devno;
 	int ret;
 
-	devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
-
-	ret = watchdog_cdev_register(wdd, devno);
+	ret = watchdog_cdev_register(wdd);
 	if (ret)
 		return ret;
 
-	dev = device_create_with_groups(&watchdog_class, wdd->parent,
-					devno, wdd, wdd->groups,
-					"watchdog%d", wdd->id);
-	if (IS_ERR(dev)) {
-		watchdog_cdev_unregister(wdd);
-		return PTR_ERR(dev);
-	}
-
 	ret = watchdog_register_pretimeout(wdd);
 	if (ret) {
-		device_destroy(&watchdog_class, devno);
 		watchdog_cdev_unregister(wdd);
 		return ret;
 	}
@@ -1127,7 +1142,8 @@ int watchdog_dev_register(struct watchdog_device *wdd)
 	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
 		wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
 
-		ret = devm_register_reboot_notifier(dev, &wdd->reboot_nb);
+		ret = devm_register_reboot_notifier(&wdd->wd_data->dev,
+						    &wdd->reboot_nb);
 		if (ret) {
 			pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",
 			       wdd->id, ret);
@@ -1149,7 +1165,6 @@ int watchdog_dev_register(struct watchdog_device *wdd)
 void watchdog_dev_unregister(struct watchdog_device *wdd)
 {
 	watchdog_unregister_pretimeout(wdd);
-	device_destroy(&watchdog_class, wdd->wd_data->cdev.dev);
 	watchdog_cdev_unregister(wdd);
 }