rtc: rtc-s3c: Updates RTC driver for clock enabling support

This Patch updates existing Samsung RTC driver for clock enabling support.
Signed-off-by: Atul Dahiya <atul.dahiya@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>

drivers/rtc/rtc-s3c.c

 /* drivers/rtc/rtc-s3c.c
+ *
+ * Copyright (c) 2010 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
  *
  * Copyright (c) 2004,2006 Simtec Electronics
  *	Ben Dooks, <ben@simtec.co.uk>
@@ -39,6 +42,7 @@ enum s3c_cpu_type {
 
 static struct resource *s3c_rtc_mem;
 
+static struct clk *rtc_clk;
 static void __iomem *s3c_rtc_base;
 static int s3c_rtc_alarmno = NO_IRQ;
 static int s3c_rtc_tickno  = NO_IRQ;
@@ -431,6 +435,10 @@ static int __devexit s3c_rtc_remove(struct platform_device *dev)
 	s3c_rtc_setpie(&dev->dev, 0);
 	s3c_rtc_setaie(0);
 
+	clk_disable(rtc_clk);
+	clk_put(rtc_clk);
+	rtc_clk = NULL;
+
 	iounmap(s3c_rtc_base);
 	release_resource(s3c_rtc_mem);
 	kfree(s3c_rtc_mem);
@@ -488,6 +496,16 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 		goto err_nomap;
 	}
 
+	rtc_clk = clk_get(&pdev->dev, "rtc");
+	if (IS_ERR(rtc_clk)) {
+		dev_err(&pdev->dev, "failed to find rtc clock source\n");
+		ret = PTR_ERR(rtc_clk);
+		rtc_clk = NULL;
+		goto err_clk;
+	}
+
+	clk_enable(rtc_clk);
+
 	/* check to see if everything is setup correctly */
 
 	s3c_rtc_enable(pdev, 1);
@@ -523,6 +541,10 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 
  err_nortc:
 	s3c_rtc_enable(pdev, 0);
+	clk_disable(rtc_clk);
+	clk_put(rtc_clk);
+
+ err_clk:
 	iounmap(s3c_rtc_base);
 
  err_nomap: