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>

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index ad2a40fefc6cb491807e39845bfdcec344c97b0f..e4de28b4284899f1b76ab69c2e75f4a9286021a3 100644 (file)
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -33,7 +33,9 @@
 #include <linux/uaccess.h>
 #include <linux/timer.h>
 #include <linux/jiffies.h>
+#include <linux/interrupt.h>
 #include <mach/hardware.h>
+#include <mach/irqs.h>
 
 #define DRIVER_NAME "imx2-wdt"
 
@@ -43,14 +45,21 @@
 #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_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
@@ -60,6 +69,7 @@ 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;
@@ -79,7 +89,7 @@ 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)
@@ -148,6 +158,38 @@ 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))
@@ -205,6 +247,17 @@ 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;
        }
@@ -251,6 +304,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 {
        int ret;
        int res_size;
+       int irq;
        struct resource *res;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -259,6 +313,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "can't get device irq number\n");
+               return -ENODEV;
+       }
+
        res_size = resource_size(res);
        if (!devm_request_mem_region(&pdev->dev, res->start, res_size,
                res->name)) {
@@ -279,6 +339,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
                return PTR_ERR(imx2_wdt.clk);
        }
 
+       ret = request_irq(irq, imx2_wdt_isr, 0, pdev->name, NULL);
+       if (ret) {
+               dev_err(&pdev->dev, "can't claim 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! "