[PATCH v3 1/2] watchdog: add WDIOC_SETPRETIMEOUT and WDIOC_GETPRETIMEOUT

[PATCH v3 1/2] watchdog: add WDIOC_SETPRETIMEOUT and WDIOC_GETPRETIMEOUT

[Robin Gong]

Since the watchdog common framework centrialize the IOCTL interfaces of
device driver now, the SETPRETIMEOUT and GETPRETIMEOUT need to be added
in the common code.

Signed-off-by: Robin Gong <b38343@freescale.com>
---
 Documentation/watchdog/watchdog-kernel-api.txt | 12 +++++++++
 drivers/watchdog/watchdog_dev.c                | 37 ++++++++++++++++++++++++++
 include/linux/watchdog.h                       | 11 ++++++++
 3 files changed, 60 insertions(+)

diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index d8b0d33..20aa841 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -51,6 +51,7 @@ struct watchdog_device {
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;
 	unsigned int timeout;
+	unsigned int pretimeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
 	void *driver_data;
@@ -73,6 +74,7 @@ It contains following fields:
   additional information about the watchdog timer itself. (Like it's unique name)
 * ops: a pointer to the list of watchdog operations that the watchdog supports.
 * timeout: the watchdog timer's timeout value (in seconds).
+* pretimeout:	The watchdog devices pre_timeout value.
 * min_timeout: the watchdog timer's minimum timeout value (in seconds).
 * max_timeout: the watchdog timer's maximum timeout value (in seconds).
 * bootstatus: status of the device after booting (reported with watchdog
@@ -99,6 +101,7 @@ struct watchdog_ops {
 	int (*ping)(struct watchdog_device *);
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
+	int (*set_pretimeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
 	void (*ref)(struct watchdog_device *);
 	void (*unref)(struct watchdog_device *);
@@ -163,6 +166,15 @@ they are supported. These optional routines/operations are:
   because the watchdog does not necessarily has a 1 second resolution).
   (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
   watchdog's info structure).
+* set_pretimeout: this routine check and changes the pre_timeout value of
+  the watchdog, because some watchdog device can trigger the pre_timeout
+  interrupt before watchdog timeout event happened, so that we have chance
+  to save some critical information or something else before watchdog
+  triggered. The pre_timeout value means the number of seconds before
+  watchdog timeout.It returns 0 on success, -EINVAL for "parameter out
+  of range" and and -EIO for "could not write value to the watchdog".
+  (Note: the WDIOF_SETPRETIMEOUT needs to be set in the options field of the
+  watchdog's info structure).
 * get_timeleft: this routines returns the time that's left before a reset.
 * ref: the operation that calls kref_get on the kref of a dynamically
   allocated watchdog_device struct.
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..f4a02e5 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -218,6 +218,37 @@ out_timeout:
 }
 
 /*
+ *	watchdog_set_pretimeout: set the watchdog timer pretimeout
+ *	@wddev: the watchdog device to set the timeout for
+ *	@timeout: pretimeout to set in seconds
+ */
+
+static int watchdog_set_pretimeout(struct watchdog_device *wddev,
+				   unsigned int timeout)
+{
+	int err;
+
+	if (!wddev->ops->set_pretimeout ||
+	    !(wddev->info->options & WDIOF_PRETIMEOUT))
+		return -EOPNOTSUPP;
+	if (watchdog_pretimeout_invalid(wddev, timeout))
+		return -EINVAL;
+
+	mutex_lock(&wddev->lock);
+
+	if (test_bit(WDOG_UNREGISTERED, &wddev->status)) {
+		err = -ENODEV;
+		goto out_timeout;
+	}
+
+	err = wddev->ops->set_pretimeout(wddev, timeout);
+
+out_timeout:
+	mutex_unlock(&wddev->lock);
+	return err;
+}
+
+/*
  *	watchdog_get_timeleft: wrapper to get the time left before a reboot
  *	@wddev: the watchdog device to get the remaining time from
  *	@timeleft: the time that's left
@@ -393,6 +424,12 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 		if (err)
 			return err;
 		return put_user(val, p);
+	case WDIOC_SETPRETIMEOUT:
+		if (get_user(val, p))
+			return -EFAULT;
+		return watchdog_set_pretimeout(wdd, val);
+	case WDIOC_GETPRETIMEOUT:
+		return put_user(wdd->pretimeout, p);
 	default:
 		return -ENOTTY;
 	}
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index d74a0e9..281b949 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -25,6 +25,7 @@ struct watchdog_device;
  * @ping:	The routine that sends a keepalive ping to the watchdog device.
  * @status:	The routine that shows the status of the watchdog device.
  * @set_timeout:The routine for setting the watchdog devices timeout value.
+ * @set_pretimeout:The routine for setting the watchdog devices pretimeout.
  * @get_timeleft:The routine that get's the time that's left before a reset.
  * @ref:	The ref operation for dyn. allocated watchdog_device structs
  * @unref:	The unref operation for dyn. allocated watchdog_device structs
@@ -44,6 +45,7 @@ struct watchdog_ops {
 	int (*ping)(struct watchdog_device *);
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
+	int (*set_pretimeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
 	void (*ref)(struct watchdog_device *);
 	void (*unref)(struct watchdog_device *);
@@ -60,6 +62,7 @@ struct watchdog_ops {
  * @ops:	Pointer to the list of watchdog operations.
  * @bootstatus:	Status of the watchdog device at boot.
  * @timeout:	The watchdog devices timeout value.
+ * @pretimeout: The watchdog devices pre_timeout value.
  * @min_timeout:The watchdog devices minimum timeout value.
  * @max_timeout:The watchdog devices maximum timeout value.
  * @driver-data:Pointer to the drivers private data.
@@ -86,6 +89,7 @@ struct watchdog_device {
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;
 	unsigned int timeout;
+	unsigned int pretimeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
 	void *driver_data;
@@ -123,6 +127,13 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
 		(t < wdd->min_timeout || t > wdd->max_timeout));
 }
 
+/* Use the following function to check if a pretimeout value is invalid */
+static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd,
+					       unsigned int t)
+{
+	return wdd->timeout && t >= wdd->timeout;
+}
+
 /* Use the following functions to manipulate watchdog driver specific data */
 static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
 {
-- 
1.9.1

[PATCH v3 2/2] watchdog: imx2_wdt: add set_pretimeout interface

[Robin Gong]

Enable set_pretimeout interface and trigger the pretimeout interrupt before
watchdog timeout event happen.

Signed-off-by: Robin Gong <b38343@freescale.com>
---
 drivers/watchdog/imx2_wdt.c | 58 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 0bb1a1d..06631cf 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -24,6 +24,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
@@ -52,12 +53,18 @@
 #define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
 #define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */
 
+#define IMX2_WDT_WICR		0x06		/*Interrupt Control Register*/
+#define IMX2_WDT_WICR_WIE	(1 << 15)	/* -> Interrupt Enable */
+#define IMX2_WDT_WICR_WTIS	(1 << 14)	/* -> Interrupt Status */
+#define IMX2_WDT_WICR_WICT	0xFF	/* Watchdog Interrupt Timeout */
+
 #define IMX2_WDT_WMCR		0x08		/* Misc Register */
 
 #define IMX2_WDT_MAX_TIME	128
 #define IMX2_WDT_DEFAULT_TIME	60		/* in seconds */
 
 #define WDOG_SEC_TO_COUNT(s)	((s * 2 - 1) << 8)
+#define WDOG_SEC_TO_PRECOUNT(s)	((s) * 2)	/* set WDOG pre timeout count*/
 
 struct imx2_wdt_device {
 	struct clk *clk;
@@ -80,7 +87,8 @@ MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
 
 static const struct watchdog_info imx2_wdt_info = {
 	.identity = "imx2+ watchdog",
-	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE
+		   | WDIOF_PRETIMEOUT,
 };
 
 static int imx2_restart_handler(struct notifier_block *this, unsigned long mode,
@@ -207,12 +215,49 @@ static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
 	}
 }
 
+static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog,
+				   unsigned int new_timeout)
+{
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+	u32 val;
+
+	regmap_read(wdev->regmap, IMX2_WDT_WICR, &val);
+	/* set the new pre-timeout value in the WSR */
+	val &= ~IMX2_WDT_WICR_WICT;
+	val |= WDOG_SEC_TO_PRECOUNT(new_timeout);
+
+	regmap_write(wdev->regmap, IMX2_WDT_WICR, val | IMX2_WDT_WICR_WIE);
+
+	wdog->pretimeout = new_timeout;
+
+	return 0;
+}
+
+static irqreturn_t imx2_wdt_isr(int irq, void *dev_id)
+{
+	struct platform_device *pdev = dev_id;
+	struct watchdog_device *wdog = platform_get_drvdata(pdev);
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+	u32 val;
+
+	regmap_read(wdev->regmap, IMX2_WDT_WICR, &val);
+	if (val & IMX2_WDT_WICR_WTIS) {
+		/*clear interrupt status bit*/
+		regmap_write(wdev->regmap, IMX2_WDT_WICR, val);
+		panic("pre-timeout:%d, %d seconds remained\n", wdog->pretimeout,
+		      wdog->timeout - wdog->pretimeout);
+	}
+
+	return IRQ_HANDLED;
+}
+
 static const struct watchdog_ops imx2_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = imx2_wdt_start,
 	.stop = imx2_wdt_stop,
 	.ping = imx2_wdt_ping,
 	.set_timeout = imx2_wdt_set_timeout,
+	.set_pretimeout = imx2_wdt_set_pretimeout,
 };
 
 static const struct regmap_config imx2_wdt_regmap_config = {
@@ -229,6 +274,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	int ret;
+	int irq;
 	u32 val;
 
 	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
@@ -294,6 +340,16 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq > 0) {
+		ret = devm_request_irq(&pdev->dev, irq, imx2_wdt_isr, 0,
+				       dev_name(&pdev->dev), pdev);
+		if (ret) {
+			dev_err(&pdev->dev, "can't get irq %d\n", irq);
+			goto disable_clk;
+		}
+	}
+
 	wdev->restart_handler.notifier_call = imx2_restart_handler;
 	wdev->restart_handler.priority = 128;
 	ret = register_restart_handler(&wdev->restart_handler);
-- 
1.9.1

[PATCH v3 2/2] watchdog: imx2_wdt: add set_pretimeout interface

[Robin Gong]

Enable set_pretimeout interface and trigger the pretimeout interrupt before
watchdog timeout event happen.

Signed-off-by: Robin Gong <b38343@freescale.com>
---
 drivers/watchdog/imx2_wdt.c | 58 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 0bb1a1d..06631cf 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -24,6 +24,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
@@ -52,12 +53,18 @@
 #define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
 #define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */
 
+#define IMX2_WDT_WICR		0x06		/*Interrupt Control Register*/
+#define IMX2_WDT_WICR_WIE	(1 << 15)	/* -> Interrupt Enable */
+#define IMX2_WDT_WICR_WTIS	(1 << 14)	/* -> Interrupt Status */
+#define IMX2_WDT_WICR_WICT	0xFF	/* Watchdog Interrupt Timeout */
+
 #define IMX2_WDT_WMCR		0x08		/* Misc Register */
 
 #define IMX2_WDT_MAX_TIME	128
 #define IMX2_WDT_DEFAULT_TIME	60		/* in seconds */
 
 #define WDOG_SEC_TO_COUNT(s)	((s * 2 - 1) << 8)
+#define WDOG_SEC_TO_PRECOUNT(s)	((s) * 2)	/* set WDOG pre timeout count*/
 
 struct imx2_wdt_device {
 	struct clk *clk;
@@ -80,7 +87,8 @@ MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
 
 static const struct watchdog_info imx2_wdt_info = {
 	.identity = "imx2+ watchdog",
-	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE
+		   | WDIOF_PRETIMEOUT,
 };
 
 static int imx2_restart_handler(struct notifier_block *this, unsigned long mode,
@@ -207,12 +215,49 @@ static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
 	}
 }
 
+static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog,
+				   unsigned int new_timeout)
+{
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+	u32 val;
+
+	regmap_read(wdev->regmap, IMX2_WDT_WICR, &val);
+	/* set the new pre-timeout value in the WSR */
+	val &= ~IMX2_WDT_WICR_WICT;
+	val |= WDOG_SEC_TO_PRECOUNT(new_timeout);
+
+	regmap_write(wdev->regmap, IMX2_WDT_WICR, val | IMX2_WDT_WICR_WIE);
+
+	wdog->pretimeout = new_timeout;
+
+	return 0;
+}
+
+static irqreturn_t imx2_wdt_isr(int irq, void *dev_id)
+{
+	struct platform_device *pdev = dev_id;
+	struct watchdog_device *wdog = platform_get_drvdata(pdev);
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+	u32 val;
+
+	regmap_read(wdev->regmap, IMX2_WDT_WICR, &val);
+	if (val & IMX2_WDT_WICR_WTIS) {
+		/*clear interrupt status bit*/
+		regmap_write(wdev->regmap, IMX2_WDT_WICR, val);
+		panic("pre-timeout:%d, %d seconds remained\n", wdog->pretimeout,
+		      wdog->timeout - wdog->pretimeout);
+	}
+
+	return IRQ_HANDLED;
+}
+
 static const struct watchdog_ops imx2_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = imx2_wdt_start,
 	.stop = imx2_wdt_stop,
 	.ping = imx2_wdt_ping,
 	.set_timeout = imx2_wdt_set_timeout,
+	.set_pretimeout = imx2_wdt_set_pretimeout,
 };
 
 static const struct regmap_config imx2_wdt_regmap_config = {
@@ -229,6 +274,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	int ret;
+	int irq;
 	u32 val;
 
 	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
@@ -294,6 +340,16 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 		goto disable_clk;
 	}
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq > 0) {
+		ret = devm_request_irq(&pdev->dev, irq, imx2_wdt_isr, 0,
+				       dev_name(&pdev->dev), pdev);
+		if (ret) {
+			dev_err(&pdev->dev, "can't get irq %d\n", irq);
+			goto disable_clk;
+		}
+	}
+
 	wdev->restart_handler.notifier_call = imx2_restart_handler;
 	wdev->restart_handler.priority = 128;
 	ret = register_restart_handler(&wdev->restart_handler);
-- 
1.9.1