watchdog: ar7_wdt.c: use devm_request_and_ioremap

Combine request_region and ioremap into devm_request_and_ioremap. This has
the effect of fixing a missing iounmap on the failure of clk_get.

This also introduces a call to clk_put and clears the vbus_clk variable in
the case of failure or device removal.

Signed-off-by: Julia Lawall <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/ar7_wdt.c

···
 		platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
 	if (!ar7_regs_wdt) {
 		pr_err("could not get registers resource\n");
-		rc = -ENODEV;
-		goto out;
+		return -ENODEV;
 	}
 
-	if (!request_mem_region(ar7_regs_wdt->start,
-				resource_size(ar7_regs_wdt), LONGNAME)) {
-		pr_warn("watchdog I/O region busy\n");
-		rc = -EBUSY;
-		goto out;
-	}
-
-	ar7_wdt = ioremap(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
+	ar7_wdt = devm_request_and_ioremap(&pdev->dev, ar7_regs_wdt);
 	if (!ar7_wdt) {
 		pr_err("could not ioremap registers\n");
-		rc = -ENXIO;
-		goto out_mem_region;
+		return -ENXIO;
 	}
 
 	vbus_clk = clk_get(NULL, "vbus");
 	if (IS_ERR(vbus_clk)) {
 		pr_err("could not get vbus clock\n");
-		rc = PTR_ERR(vbus_clk);
-		goto out_mem_region;
+		return PTR_ERR(vbus_clk);
 	}
 
 	ar7_wdt_disable_wdt();
···
 	rc = misc_register(&ar7_wdt_miscdev);
 	if (rc) {
 		pr_err("unable to register misc device\n");
-		goto out_alloc;
+		goto out;
 	}
-	goto out;
+	return 0;
 
-out_alloc:
-	iounmap(ar7_wdt);
-out_mem_region:
-	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
 out:
+	clk_put(vbus_clk);
+	vbus_clk = NULL;
 	return rc;
 }
 
 static int __devexit ar7_wdt_remove(struct platform_device *pdev)
 {
 	misc_deregister(&ar7_wdt_miscdev);
-	iounmap(ar7_wdt);
-	release_mem_region(ar7_regs_wdt->start, resource_size(ar7_regs_wdt));
-
+	clk_put(vbus_clk);
+	vbus_clk = NULL;
 	return 0;
 }