rtc-mxc: multiple fixes in rtc-mxc probe method

On exit paths in mxc_rtc_probe() method some resources are not freed
correctly.

This patch fixes:
* unrequested memory region containing imx RTC registers
* iounmap() isn't called on exit_free_pdata branch
* clock get rate is called for freed clock source
* clock isn't disabled on exit_put_clk branch

To simplify the fix managed device resources are used.

[[e-mail]: coding-style fixes]
Signed-off-by: Vladimir Zapolskiy <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Cc: Daniel Mack <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/rtc/rtc-mxc.c

···
 	struct rtc_device *rtc;
 	struct rtc_plat_data *pdata = NULL;
 	u32 reg;
-	int ret, rate;
+	unsigned long rate;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;
 
-	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
 
-	pdata->ioaddr = ioremap(res->start, resource_size(res));
+	if (!devm_request_mem_region(&pdev->dev, res->start,
+				     resource_size(res), pdev->name))
+		return -EBUSY;
+
+	pdata->ioaddr = devm_ioremap(&pdev->dev, res->start,
+				     resource_size(res));
 
 	clk = clk_get(&pdev->dev, "ckil");
 	if (IS_ERR(clk)) {
-		iounmap(pdata->ioaddr);
 		ret = PTR_ERR(clk);
 		goto exit_free_pdata;
 	}
···
 	else if (rate == 38400)
 		reg = RTC_INPUT_CLK_38400HZ;
 	else {
-		dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n",
-			clk_get_rate(clk));
+		dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
 		ret = -EINVAL;
 		goto exit_free_pdata;
 	}
···
 	pdata->irq = platform_get_irq(pdev, 0);
 
 	if (pdata->irq >= 0 &&
-	    request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED,
-			pdev->name, pdev) < 0) {
+	    devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
+			     IRQF_SHARED, pdev->name, pdev) < 0) {
 		dev_warn(&pdev->dev, "interrupt not available.\n");
 		pdata->irq = -1;
 	}
···
 	return 0;
 
 exit_put_clk:
+	clk_disable(pdata->clk);
 	clk_put(pdata->clk);
 
 exit_free_pdata:
-	kfree(pdata);
 
 	return ret;
 }
···
 
 	rtc_device_unregister(pdata->rtc);
 
-	if (pdata->irq >= 0)
-		free_irq(pdata->irq, pdev);
-
 	clk_disable(pdata->clk);
 	clk_put(pdata->clk);
-	kfree(pdata);
 	platform_set_drvdata(pdev, NULL);
 
 	return 0;