rtc: simplify use of devm_ioremap_resource

Remove unneeded error handling on the result of a call to
platform_get_resource when the value is passed to devm_ioremap_resource.

Move the call to platform_get_resource adjacent to the call to
devm_ioremap_resource to make the connection between them more clear.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression pdev,res,n,e,e1;
expression ret != 0;
identifier l;
@@

- res = platform_get_resource(pdev, IORESOURCE_MEM, n);
  ... when != res
- if (res == NULL) { ... \(goto l;\|return ret;\) }
  ... when != res
+ res = platform_get_resource(pdev, IORESOURCE_MEM, n);
  e = devm_ioremap_resource(e1, res);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[viresh.kumar@linaro.org: acked rtc-spear]
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/rtc-ds1216.c

@@ -144,15 +144,13 @@ static int __init ds1216_rtc_probe(struct platform_device *pdev)
 	struct ds1216_priv *priv;
 	u8 dummy[8];
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -ENODEV;
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
 	platform_set_drvdata(pdev, priv);
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	priv->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(priv->ioaddr))
 		return PTR_ERR(priv->ioaddr);

drivers/rtc/rtc-ds1286.c

@@ -332,13 +332,11 @@ static int ds1286_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct ds1286_priv *priv;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -ENODEV;
 	priv = devm_kzalloc(&pdev->dev, sizeof(struct ds1286_priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	priv->rtcregs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(priv->rtcregs))
 		return PTR_ERR(priv->rtcregs);

drivers/rtc/rtc-spear.c

@@ -358,12 +358,6 @@ static int spear_rtc_probe(struct platform_device *pdev)
 	int status = 0;
 	int irq;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "no resource defined\n");
-		return -EBUSY;
-	}
-
 	config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
 	if (!config)
 		return -ENOMEM;
@@ -383,6 +377,7 @@ static int spear_rtc_probe(struct platform_device *pdev)
 		return status;
 	}
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	config->ioaddr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(config->ioaddr))
 		return PTR_ERR(config->ioaddr);