[media] davinci: vpif: Add suspend/resume callbacks to vpif driver

add clock enable and disable in probe and remove functions.
Probe will succeed only if the device clock is provided instead of
assuming that the clock is always enabled. VPIF clock has to be
dealt with during suspend and resume. Implement power management
callbacks to VPIF driver to disable/enable clock on suspend/resume
respectively.

Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/davinci/vpif.c

@@ -23,6 +23,8 @@
 #include <linux/spinlock.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 #include <mach/hardware.h>
 
 #include "vpif.h"
@@ -40,6 +42,7 @@ static struct resource	*res;
 spinlock_t vpif_lock;
 
 void __iomem *vpif_base;
+struct clk *vpif_clk;
 
 /**
  * ch_params: video standard configuration parameters for vpif
@@ -434,10 +437,19 @@ static int __init vpif_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	vpif_clk = clk_get(&pdev->dev, "vpif");
+	if (IS_ERR(vpif_clk)) {
+		status = PTR_ERR(vpif_clk);
+		goto clk_fail;
+	}
+	clk_enable(vpif_clk);
+
 	spin_lock_init(&vpif_lock);
 	dev_info(&pdev->dev, "vpif probe success\n");
 	return 0;
 
+clk_fail:
+	iounmap(vpif_base);
 fail:
 	release_mem_region(res->start, res_len);
 	return status;
@@ -445,15 +457,44 @@ fail:
 
 static int __devexit vpif_remove(struct platform_device *pdev)
 {
+	if (vpif_clk) {
+		clk_disable(vpif_clk);
+		clk_put(vpif_clk);
+	}
+
 	iounmap(vpif_base);
 	release_mem_region(res->start, res_len);
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int vpif_suspend(struct device *dev)
+{
+	clk_disable(vpif_clk);
+	return 0;
+}
+
+static int vpif_resume(struct device *dev)
+{
+	clk_enable(vpif_clk);
+	return 0;
+}
+
+static const struct dev_pm_ops vpif_pm = {
+	.suspend        = vpif_suspend,
+	.resume         = vpif_resume,
+};
+
+#define vpif_pm_ops (&vpif_pm)
+#else
+#define vpif_pm_ops NULL
+#endif
+
 static struct platform_driver vpif_driver = {
 	.driver = {
 		.name	= "vpif",
 		.owner = THIS_MODULE,
+		.pm	= vpif_pm_ops,
 	},
 	.remove = __devexit_p(vpif_remove),
 	.probe = vpif_probe,