watchdog: imx2_wdt: allow setting timeout in devicetree

By following best practice described in
Documentation/watchdog/watchdog-kernel-api.txt, it also let us to set
timout-sec property in devicetree.
Signed-off-by: NMarcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.txt

@@ -11,6 +11,7 @@ Optional properties:
   detail please see: Documentation/devicetree/bindings/regmap/regmap.txt.
 - fsl,ext-reset-output: If present the watchdog device is configured to
   assert its external reset (WDOG_B) instead of issuing a software reset.
+- timeout-sec : Contains the watchdog timeout in seconds
 
 Examples:
 
@@ -19,4 +20,5 @@ wdt@73f98000 {
 	reg = <0x73f98000 0x4000>;
 	interrupts = <58>;
 	big-endian;
+	timeout-sec = <20>;
 };

drivers/watchdog/imx2_wdt.c

@@ -76,7 +76,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
 
-static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
+static unsigned timeout;
 module_param(timeout, uint, 0);
 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
 				__MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");
@@ -281,6 +281,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 	wdog->info		= &imx2_wdt_info;
 	wdog->ops		= &imx2_wdt_ops;
 	wdog->min_timeout	= 1;
+	wdog->timeout		= IMX2_WDT_DEFAULT_TIME;
 	wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
 	wdog->parent		= &pdev->dev;
 
@@ -299,11 +300,6 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 
 	wdev->ext_reset = of_property_read_bool(pdev->dev.of_node,
 						"fsl,ext-reset-output");
-	wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
-	if (wdog->timeout != timeout)
-		dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
-			 timeout, wdog->timeout);
-
 	platform_set_drvdata(pdev, wdog);
 	watchdog_set_drvdata(wdog, wdev);
 	watchdog_set_nowayout(wdog, nowayout);