rtc: mxc_v2: use dev_pm_set_wake_irq() to simplify code

With calling dev_pm_set_wake_irq() to set MXC_V2 RTC as wakeup source
for suspend, generic wake irq mechanism will automatically enable
it as wakeup source when suspend, then the suspend/resume callback
which are ONLY for enabling/disabling irq wake can be removed, it
simplifies the code.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-mxc_v2.c

@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
 #include <linux/rtc.h>
 
 #define SRTC_LPPDR_INIT       0x41736166	/* init for glitch detect */
@@ -305,6 +306,9 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 		return pdata->irq;
 
 	device_init_wakeup(&pdev->dev, 1);
+	ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
+	if (ret)
+		dev_err(&pdev->dev, "failed to enable irq wake\n");
 
 	ret = clk_prepare_enable(pdata->clk);
 	if (ret)
@@ -367,30 +371,6 @@ static int mxc_rtc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int mxc_rtc_suspend(struct device *dev)
-{
-	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
-
-	if (device_may_wakeup(dev))
-		enable_irq_wake(pdata->irq);
-
-	return 0;
-}
-
-static int mxc_rtc_resume(struct device *dev)
-{
-	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
-
-	if (device_may_wakeup(dev))
-		disable_irq_wake(pdata->irq);
-
-	return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops, mxc_rtc_suspend, mxc_rtc_resume);
-
 static const struct of_device_id mxc_ids[] = {
 	{ .compatible = "fsl,imx53-rtc", },
 	{}
@@ -400,7 +380,6 @@ static struct platform_driver mxc_rtc_driver = {
 	.driver = {
 		.name = "mxc_rtc_v2",
 		.of_match_table = mxc_ids,
-		.pm = &mxc_rtc_pm_ops,
 	},
 	.probe = mxc_rtc_probe,
 	.remove = mxc_rtc_remove,