rtc: at91sam9: properly handle error case

In case of a probe error, it is possible to abort after issuing
clk_prepare_enable(). Ensure the clock is disabled and unprepared in that
case.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

drivers/rtc/rtc-at91sam9.c

@@ -451,8 +451,10 @@ static int at91_rtc_probe(struct platform_device *pdev)
 
 	rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
 					&at91_rtc_ops, THIS_MODULE);
-	if (IS_ERR(rtc->rtcdev))
-		return PTR_ERR(rtc->rtcdev);
+	if (IS_ERR(rtc->rtcdev)) {
+		ret = PTR_ERR(rtc->rtcdev);
+		goto err_clk;
+	}
 
 	/* register irq handler after we know what name we'll use */
 	ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt,
@@ -460,7 +462,7 @@ static int at91_rtc_probe(struct platform_device *pdev)
 			       dev_name(&rtc->rtcdev->dev), rtc);
 	if (ret) {
 		dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
-		return ret;
+		goto err_clk;
 	}
 
 	/* NOTE:  sam9260 rev A silicon has a ROM bug which resets the
@@ -474,6 +476,11 @@ static int at91_rtc_probe(struct platform_device *pdev)
 				dev_name(&rtc->rtcdev->dev));
 
 	return 0;
+
+err_clk:
+	clk_disable_unprepare(rtc->sclk);
+
+	return ret;
 }
 
 /*