ENGR00215489-1 WDOG:add WDIOC_SETPRETIMEOUT and WDIOC_GETPRETIMEOUT interface

Add these two interface, so than user can set and get pre-timeout value to save
some important data before watchdog reboot.

Signed-off-by: Robin Gong <B38343@freescale.com>
(cherry picked from commit 36d2c03e30f18a34439fdb928ad5bad8d66a1b64)
(cherry picked from commit 19b8c1ed3997e01c108c9b22f5541a28f2b23923)

1 files changed, 68 insertions, 2 deletions

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index dd51d9539b33..11bda8079b12 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -2,7 +2,7 @@
  * Watchdog driver for IMX2 and later processors
  *
  *  Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
- *  Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *  Copyright (C) 2015 Freescale Semiconductor, Inc.
  *
  * some parts adapted by similar drivers from Darius Augulis and Vladimir
  * Zapolskiy, additional improvements by Wim Van Sebroeck.
@@ -22,6 +22,8 @@
  */
 
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
@@ -43,17 +45,23 @@
 #define IMX2_WDT_WCR_WDE	(1 << 2)	/* -> Watchdog Enable */
 #define IMX2_WDT_WCR_WDZST	(1 << 0)	/* -> Watchdog timer Suspend */
 
+
 #define IMX2_WDT_WSR		0x02		/* Service Register */
 #define IMX2_WDT_SEQ1		0x5555		/* -> service sequence 1 */
 #define IMX2_WDT_SEQ2		0xAAAA		/* -> service sequence 2 */
 
 #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 << 0)	/* -> Watchdog Interrupt Timeout Field */
 
 #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*/
 
 #define IMX2_WDT_STATUS_OPEN	0
 #define IMX2_WDT_STATUS_STARTED	1
@@ -63,6 +71,7 @@ static struct {
 	struct clk *clk;
 	void __iomem *base;
 	unsigned timeout;
+	unsigned pretimeout;
 	unsigned long status;
 	struct timer_list timer;	/* Pings the watchdog when closed */
 } imx2_wdt;
@@ -82,7 +91,7 @@ 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 inline void imx2_wdt_setup(void)
@@ -151,6 +160,38 @@ static void imx2_wdt_set_timeout(int new_timeout)
 	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
 }
 
+
+static int imx2_wdt_check_pretimeout_set(void)
+{
+	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WICR);
+	return (val & IMX2_WDT_WICR_WIE) ? 1 : 0;
+}
+
+static void imx2_wdt_set_pretimeout(int new_timeout)
+{
+	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WICR);
+
+	/* set the new pre-timeout value in the WSR */
+	val &= ~IMX2_WDT_WICR_WICT;
+	val |= WDOG_SEC_TO_PRECOUNT(new_timeout);
+
+	if (!imx2_wdt_check_pretimeout_set())
+		val |= IMX2_WDT_WICR_WIE;	/*enable*/
+	__raw_writew(val, imx2_wdt.base + IMX2_WDT_WICR);
+}
+
+static irqreturn_t imx2_wdt_isr(int irq, void *dev_id)
+{
+	u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WICR);
+	if (val & IMX2_WDT_WICR_WTIS) {
+		/*clear interrupt status bit*/
+		__raw_writew(val, imx2_wdt.base + IMX2_WDT_WICR);
+		printk(KERN_INFO "watchdog pre-timeout:%d, %d Seconds remained\n", \
+			imx2_wdt.pretimeout, imx2_wdt.timeout-imx2_wdt.pretimeout);
+	}
+	return IRQ_HANDLED;
+}
+
 static int imx2_wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
@@ -213,6 +254,17 @@ static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
 	case WDIOC_GETTIMEOUT:
 		return put_user(imx2_wdt.timeout, p);
 
+	case WDIOC_SETPRETIMEOUT:
+		if (get_user(new_value, p))
+			return -EFAULT;
+		if ((new_value < 0) || (new_value >= imx2_wdt.timeout))
+			return -EINVAL;
+		imx2_wdt_set_pretimeout(new_value);
+		imx2_wdt.pretimeout = new_value;
+
+	case WDIOC_GETPRETIMEOUT:
+		return put_user(imx2_wdt.pretimeout, p);
+
 	default:
 		return -ENOTTY;
 	}
@@ -258,6 +310,7 @@ static struct miscdevice imx2_wdt_miscdev = {
 static int __init imx2_wdt_probe(struct platform_device *pdev)
 {
 	int ret;
+	int irq;
 	struct resource *res;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -271,6 +324,19 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 		return PTR_ERR(imx2_wdt.clk);
 	}
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = irq;
+		goto fail;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, imx2_wdt_isr, 0,
+			       dev_name(&pdev->dev), NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "can't get irq %d\n", irq);
+		goto fail;
+	}
+
 	imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
 	if (imx2_wdt.timeout != timeout)
 		dev_warn(&pdev->dev, "Initial timeout out of range! "