iio: humidity: hts221: remove usage of iio_priv_to_dev()

We may want to get rid of the iio_priv_to_dev() helper. That's a bit
uncertain at this point. The reason is that we will hide some of the
members of the iio_dev structure (to prevent drivers from accessing them
directly), and that will also mean hiding the implementation of the
iio_priv_to_dev() helper inside the IIO core.

Hiding the implementation of iio_priv_to_dev() implies that some fast-paths
may not be fast anymore, so a general idea is to try to get rid of the
iio_priv_to_dev() altogether.

For this driver, removing the iio_priv_to_dev() helper means passing the
iio_dev object on hts221_allocate_buffers() & hts221_allocate_trigger().
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/humidity/hts221.h

@@ -46,7 +46,7 @@ extern const struct dev_pm_ops hts221_pm_ops;
 int hts221_probe(struct device *dev, int irq, const char *name,
 		 struct regmap *regmap);
 int hts221_set_enable(struct hts221_hw *hw, bool enable);
-int hts221_allocate_buffers(struct hts221_hw *hw);
-int hts221_allocate_trigger(struct hts221_hw *hw);
+int hts221_allocate_buffers(struct iio_dev *iio_dev);
+int hts221_allocate_trigger(struct iio_dev *iio_dev);
 
 #endif /* HTS221_H */

drivers/iio/humidity/hts221_buffer.c

@@ -72,10 +72,10 @@ static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
 	return IRQ_HANDLED;
 }
 
-int hts221_allocate_trigger(struct hts221_hw *hw)
+int hts221_allocate_trigger(struct iio_dev *iio_dev)
 {
+	struct hts221_hw *hw = iio_priv(iio_dev);
 	struct st_sensors_platform_data *pdata = dev_get_platdata(hw->dev);
-	struct iio_dev *iio_dev = iio_priv_to_dev(hw);
 	bool irq_active_low = false, open_drain = false;
 	unsigned long irq_type;
 	int err;
@@ -190,9 +190,10 @@ static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
 	return IRQ_HANDLED;
 }
 
-int hts221_allocate_buffers(struct hts221_hw *hw)
+int hts221_allocate_buffers(struct iio_dev *iio_dev)
 {
-	return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
+	struct hts221_hw *hw = iio_priv(iio_dev);
+	return devm_iio_triggered_buffer_setup(hw->dev, iio_dev,
 					NULL, hts221_buffer_handler_thread,
 					&hts221_buffer_ops);
 }

drivers/iio/humidity/hts221_core.c

@@ -621,11 +621,11 @@ int hts221_probe(struct device *dev, int irq, const char *name,
 	}
 
 	if (hw->irq > 0) {
-		err = hts221_allocate_buffers(hw);
+		err = hts221_allocate_buffers(iio_dev);
 		if (err < 0)
 			return err;
 
-		err = hts221_allocate_trigger(hw);
+		err = hts221_allocate_trigger(iio_dev);
 		if (err)
 			return err;
 	}