[PATCH v9 4/5] iio: magnetometer: ak8975: add scan mask index enum

[Joshua Crofts <joshua.crofts1@gmail.com>]

Add an enum to explicitly define scan mask indexes for the X, Y, Z and
timestamp channels. Also, update the struct iio_chan_spec to use said
enum for the .scan_index parameter.

This prevents magic numbers from obscuring the hardware channel mapping
and improves code style.

No functional change.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
---
 drivers/iio/magnetometer/ak8975.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 42f6892f4efd..ac556644b02d 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -237,6 +237,13 @@ enum ak_ctrl_mode {
 	MODE_END,
 };
 
+enum ak_chan_index {
+	AK8975_CHAN_X,
+	AK8975_CHAN_Y,
+	AK8975_CHAN_Z,
+	AK8975_CHAN_TS,
+};
+
 struct ak_def {
 	enum asahi_compass_chipset type;
 	long (*raw_to_gauss)(u16 data);
@@ -851,8 +858,10 @@ static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
 	}
 
 static const struct iio_chan_spec ak8975_channels[] = {
-	AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
-	IIO_CHAN_SOFT_TIMESTAMP(3),
+	AK8975_CHANNEL(X, AK8975_CHAN_X),
+	AK8975_CHANNEL(Y, AK8975_CHAN_Y),
+	AK8975_CHANNEL(Z, AK8975_CHAN_Z),
+	IIO_CHAN_SOFT_TIMESTAMP(AK8975_CHAN_TS),
 };
 
 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };

-- 
2.55.0