drivers/rtc/rtc-ds1742.c: use devm_ioremap_resource()

Replace devm_request_mem_region() and devm_ioremap() with
devm_ioremap_resource().
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ds1742.c

@@ -56,7 +56,6 @@ struct rtc_plat_data {
 	void __iomem *ioaddr_nvram;
 	void __iomem *ioaddr_rtc;
 	size_t size_nvram;
-	size_t size;
 	unsigned long last_jiffies;
 	struct bin_attribute nvram_attr;
 };
@@ -168,22 +167,17 @@ static int ds1742_rtc_probe(struct platform_device *pdev)
 	void __iomem *ioaddr;
 	int ret = 0;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -ENODEV;
 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
-	pdata->size = resource_size(res);
-	if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
-		pdev->name))
-		return -EBUSY;
-	ioaddr = devm_ioremap(&pdev->dev, res->start, pdata->size);
-	if (!ioaddr)
-		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ioaddr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ioaddr))
+		return PTR_ERR(ioaddr);
 
 	pdata->ioaddr_nvram = ioaddr;
-	pdata->size_nvram = pdata->size - RTC_SIZE;
+	pdata->size_nvram = resource_size(res) - RTC_SIZE;
 	pdata->ioaddr_rtc = ioaddr + pdata->size_nvram;
 
 	sysfs_bin_attr_init(&pdata->nvram_attr);