iio:trigger: Introduce iio_tigger_{set,get}_drvdata

Introduce iio_tigger_{set,get}_drvdata which allows to attach driver specific
data to a trigger. The functions wrap access to the triggers private_data field
and all current users are updated to use iio_tigger_{set,get}_drvdata instead of
directly accessing the private_data field. This is the first step towards
removing the private_data field from the iio_trigger struct.

The following coccinelle script has been used to update the drivers:
<smpl>
@@
struct iio_trigger *trigger;
expression priv;
@@
-trigger->private_data = priv
+iio_trigger_set_drv_data(trigger, priv)

@@
struct iio_trigger *trigger;
@@
-trigger->private_data
+iio_trigger_get_drv_data(trigger)
</smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/imu/adis_trigger.c b/drivers/iio/imu/adis_trigger.c
index 5a24c9c..e0017c2 100644
--- a/drivers/iio/imu/adis_trigger.c
+++ b/drivers/iio/imu/adis_trigger.c
@@ -19,7 +19,7 @@
 static int adis_data_rdy_trigger_set_state(struct iio_trigger *trig,
 						bool state)
 {
-	struct adis *adis = trig->private_data;
+	struct adis *adis = iio_trigger_get_drvdata(trig);
 
 	return adis_enable_irq(adis, state);
 }
@@ -57,7 +57,7 @@
 
 	adis->trig->dev.parent = &adis->spi->dev;
 	adis->trig->ops = &adis_trigger_ops;
-	adis->trig->private_data = adis;
+	iio_trigger_set_drvdata(adis->trig, adis);
 	ret = iio_trigger_register(adis->trig);
 
 	indio_dev->trig = adis->trig;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
index e1d0869..03b9372 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
@@ -103,7 +103,7 @@
 static int inv_mpu_data_rdy_trigger_set_state(struct iio_trigger *trig,
 						bool state)
 {
-	return inv_mpu6050_set_enable(trig->private_data, state);
+	return inv_mpu6050_set_enable(iio_trigger_get_drvdata(trig), state);
 }
 
 static const struct iio_trigger_ops inv_mpu_trigger_ops = {
@@ -130,8 +130,8 @@
 	if (ret)
 		goto error_free_trig;
 	st->trig->dev.parent = &st->client->dev;
-	st->trig->private_data = indio_dev;
 	st->trig->ops = &inv_mpu_trigger_ops;
+	iio_trigger_set_drvdata(st->trig, indio_dev);
 	ret = iio_trigger_register(st->trig);
 	if (ret)
 		goto error_free_irq;