[PATCH v2 13/17] iio: light: apds9960: Discard pm_runtime_put_autosuspend() return values

[Brian Norris]

This driver propagates the return value of pm_runtime_put_autosuspend(),
which is not particularly useful.

Returning an error code from pm_runtime_put_autosuspend() merely means
that it has not queued up a timer or work item to check whether or not
the device can be suspended and there are many perfectly valid
situations in which that can happen, like after writing "on" to the
device's runtime PM "control" attribute in sysfs for one example.

For this reason, modify this driver to simply discard the
pm_runtime_put_autosuspend() return value. Inline the "off" helper, as
it's trivial now, and rename to apds9960_power_on().

This will facilitate a planned change of the
pm_runtime_put_autosuspend() return type to void in the future, similar
to commit 3afd8df02433 ("PM: runtime: Change pm_runtime_put() return
type to void").

Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
---
I'm not sure if apds9960_write_event_config()'s existing logic is
correct, but I don't want to mess with it.

Changes in v2:
 * Split iio patch into per-driver patches
 * Inline the put() helper

 drivers/iio/light/apds9960.c | 48 ++++++++++++++----------------------
 1 file changed, 18 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/light/apds9960.c b/drivers/iio/light/apds9960.c
index afe520de60e2..0e084ffba1a6 100644
--- a/drivers/iio/light/apds9960.c
+++ b/drivers/iio/light/apds9960.c
@@ -476,38 +476,23 @@ static int apds9960_set_als_gain(struct apds9960_data *data, int val)
 	return ret;
 }
 
-#ifdef CONFIG_PM
-static int apds9960_set_power_state(struct apds9960_data *data, bool on)
+static void apds9960_power_on(struct apds9960_data *data)
 {
 	struct device *dev = &data->client->dev;
-	int ret = 0;
+	int suspended;
 
 	mutex_lock(&data->lock);
 
-	if (on) {
-		int suspended;
-
-		suspended = pm_runtime_suspended(dev);
-		ret = pm_runtime_get_sync(dev);
+	suspended = pm_runtime_suspended(dev);
+	pm_runtime_get_sync(dev);
 
-		/* Allow one integration cycle before allowing a reading */
-		if (suspended)
-			usleep_range(data->als_adc_int_us,
-				     APDS9960_MAX_INT_TIME_IN_US);
-	} else {
-		ret = pm_runtime_put_autosuspend(dev);
-	}
+	/* Allow one integration cycle before allowing a reading */
+	if (suspended)
+		usleep_range(data->als_adc_int_us,
+			     APDS9960_MAX_INT_TIME_IN_US);
 
 	mutex_unlock(&data->lock);
-
-	return ret;
 }
-#else
-static int apds9960_set_power_state(struct apds9960_data *data, bool on)
-{
-	return 0;
-}
-#endif
 
 static int apds9960_read_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
@@ -522,7 +507,7 @@ static int apds9960_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		apds9960_set_power_state(data, true);
+		apds9960_power_on(data);
 		switch (chan->type) {
 		case IIO_PROXIMITY:
 			ret = regmap_read(data->regmap, chan->address, val);
@@ -540,7 +525,7 @@ static int apds9960_read_raw(struct iio_dev *indio_dev,
 		default:
 			ret = -EINVAL;
 		}
-		apds9960_set_power_state(data, false);
+		pm_runtime_put_autosuspend(&data->client->dev);
 		break;
 	case IIO_CHAN_INFO_INT_TIME:
 		/* RGB + ALS sensors only have integration time */
@@ -767,7 +752,6 @@ static int apds9960_write_event_config(struct iio_dev *indio_dev,
 		if (ret)
 			return ret;
 		data->pxs_int = state;
-		apds9960_set_power_state(data, state);
 		break;
 	case IIO_INTENSITY:
 		if (data->als_int == state)
@@ -777,12 +761,16 @@ static int apds9960_write_event_config(struct iio_dev *indio_dev,
 		if (ret)
 			return ret;
 		data->als_int = state;
-		apds9960_set_power_state(data, state);
 		break;
 	default:
 		return -EINVAL;
 	}
 
+	if (state)
+		apds9960_power_on(data);
+	else
+		pm_runtime_put_autosuspend(&data->client->dev);
+
 	return 0;
 }
 
@@ -1078,7 +1066,7 @@ static int apds9960_probe(struct i2c_client *client)
 	pm_runtime_set_autosuspend_delay(&client->dev, 5000);
 	pm_runtime_use_autosuspend(&client->dev);
 
-	apds9960_set_power_state(data, true);
+	apds9960_power_on(data);
 
 	ret = apds9960_regfield_init(data);
 	if (ret)
@@ -1105,12 +1093,12 @@ static int apds9960_probe(struct i2c_client *client)
 	if (ret)
 		goto error_power_down;
 
-	apds9960_set_power_state(data, false);
+	pm_runtime_put_autosuspend(&client->dev);
 
 	return 0;
 
 error_power_down:
-	apds9960_set_power_state(data, false);
+	pm_runtime_put_autosuspend(&client->dev);
 
 	return ret;
 }
-- 
2.56.0.218.g1ec904b173-goog