[PATCH RFT V2 3/3] iio: mxs-lradc: implement suspend/resume support

[Stefan Wahren <stefan.wahren@i2se.com>]

This patch implements suspend/resume support for mxs-lradc.
It's possible to use the touchscreen as wakeup source.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/iio/adc/mxs-lradc.c |   61 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
index cfc558f..6bd387f 100644
--- a/drivers/iio/adc/mxs-lradc.c
+++ b/drivers/iio/adc/mxs-lradc.c
@@ -29,6 +29,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/stmp_device.h>
 #include <linux/sysfs.h>
@@ -1745,10 +1746,70 @@ static int mxs_lradc_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int __maybe_unused mxs_lradc_suspend(struct device *dev)
+{
+	struct iio_dev *iio = dev_get_drvdata(dev);
+	struct mxs_lradc *lradc = iio_priv(iio);
+	struct input_dev *input = lradc->ts_input;
+	int ret = 0;
+
+	if (input) {
+		mutex_lock(&input->mutex);
+
+		/* Enable touchscreen wakeup irq */
+		if (input->users && device_may_wakeup(dev))
+			ret = enable_irq_wake(lradc->irq[0]);
+		else
+			mxs_lradc_disable_ts(lradc);
+
+		mutex_unlock(&input->mutex);
+	}
+
+	if (ret)
+		return ret;
+
+	mxs_lradc_hw_stop(lradc);
+
+	clk_disable_unprepare(lradc->clk);
+
+	return ret;
+}
+
+static int __maybe_unused mxs_lradc_resume(struct device *dev)
+{
+	struct iio_dev *iio = dev_get_drvdata(dev);
+	struct mxs_lradc *lradc = iio_priv(iio);
+	struct input_dev *input = lradc->ts_input;
+	int ret;
+
+	ret = clk_prepare_enable(lradc->clk);
+	if (ret)
+		return ret;
+
+	mxs_lradc_hw_init(lradc);
+
+	if (input) {
+		mutex_lock(&input->mutex);
+
+		/* Disable touchscreen wakeup irq */
+		if (input->users && device_may_wakeup(dev))
+			ret = disable_irq_wake(lradc->irq[0]);
+		else
+			mxs_lradc_enable_touch_detection(lradc);
+
+		mutex_unlock(&input->mutex);
+	}
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(mxs_lradc_pm_ops, mxs_lradc_suspend, mxs_lradc_resume);
+
 static struct platform_driver mxs_lradc_driver = {
 	.driver	= {
 		.name	= DRIVER_NAME,
 		.of_match_table = mxs_lradc_dt_ids,
+		.pm	= &mxs_lradc_pm_ops,
 	},
 	.probe	= mxs_lradc_probe,
 	.remove	= mxs_lradc_remove,
-- 
1.7.9.5