hwrng: omap - Convert release_resource to release_region/release_mem_…

…region

Request_region should be used with release_region, not release_resource.

The local variable mem, storing the result of request_mem_region, is
dropped and instead the pointer res is stored in the drvdata field of the
platform device.  This information is retrieved in omap_rng_remove to
release the region.  The drvdata field is not used elsewhere.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,E;
@@
(
*x = request_region(...)
|
*x = request_mem_region(...)
)
... when != release_region(x)
    when != x = E
* release_resource(x);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/omap-rng.c

@@ -91,7 +91,7 @@ static struct hwrng omap_rng_ops = {
 
 static int __devinit omap_rng_probe(struct platform_device *pdev)
 {
-	struct resource *res, *mem;
+	struct resource *res;
 	int ret;
 
 	/*
@@ -116,14 +116,12 @@ static int __devinit omap_rng_probe(struct platform_device *pdev)
 	if (!res)
 		return -ENOENT;
 
-	mem = request_mem_region(res->start, resource_size(res),
-				 pdev->name);
-	if (mem == NULL) {
+	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
 		ret = -EBUSY;
 		goto err_region;
 	}
 
-	dev_set_drvdata(&pdev->dev, mem);
+	dev_set_drvdata(&pdev->dev, res);
 	rng_base = ioremap(res->start, resource_size(res));
 	if (!rng_base) {
 		ret = -ENOMEM;
@@ -146,7 +144,7 @@ static int __devinit omap_rng_probe(struct platform_device *pdev)
 	iounmap(rng_base);
 	rng_base = NULL;
 err_ioremap:
-	release_resource(mem);
+	release_mem_region(res->start, resource_size(res));
 err_region:
 	if (cpu_is_omap24xx()) {
 		clk_disable(rng_ick);
@@ -157,7 +155,7 @@ static int __devinit omap_rng_probe(struct platform_device *pdev)
 
 static int __exit omap_rng_remove(struct platform_device *pdev)
 {
-	struct resource *mem = dev_get_drvdata(&pdev->dev);
+	struct resource *res = dev_get_drvdata(&pdev->dev);
 
 	hwrng_unregister(&omap_rng_ops);
 
@@ -170,7 +168,7 @@ static int __exit omap_rng_remove(struct platform_device *pdev)
 		clk_put(rng_ick);
 	}
 
-	release_resource(mem);
+	release_mem_region(res->start, resource_size(res));
 	rng_base = NULL;
 
 	return 0;