[PATCH v2 05/10] iio: gyro: bmg160: add mount matrix support

[H. Nikolaus Schaller]

This patch allows to read a mount-matrix device tree
property and report to user-space or in-kernel iio
clients.

Signed-off-by: H. Nikolaus Schaller <h...@goldelico.com>
---
 drivers/iio/gyro/bmg160_core.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/iio/gyro/bmg160_core.c b/drivers/iio/gyro/bmg160_core.c
index 63ca31628a93..e7b38adee39a 100644
--- a/drivers/iio/gyro/bmg160_core.c
+++ b/drivers/iio/gyro/bmg160_core.c
@@ -102,6 +102,7 @@ struct bmg160_data {
        struct regmap *regmap;
        struct iio_trigger *dready_trig;
        struct iio_trigger *motion_trig;
+       struct iio_mount_matrix orientation;
        struct mutex mutex;
        s16 buffer[8];
        u32 dps_range;
@@ -794,6 +795,20 @@ static int bmg160_write_event_config(struct iio_dev 
*indio_dev,
        return 0;
 }
 
+static const struct iio_mount_matrix *
+bmg160_get_mount_matrix(const struct iio_dev *indio_dev,
+                        const struct iio_chan_spec *chan)
+{
+       struct bmg160_data *data = iio_priv(indio_dev);
+
+       return &data->orientation;
+}
+
+static const struct iio_chan_spec_ext_info bmg160_ext_info[] = {
+       IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bmg160_get_mount_matrix),
+       { }
+};
+
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 400 1000 2000");
 
 static IIO_CONST_ATTR(in_anglvel_scale_available,
@@ -831,6 +846,7 @@ static const struct iio_event_spec bmg160_event = {
                .storagebits = 16,                                      \
                .endianness = IIO_LE,                                   \
        },                                                              \
+       .ext_info = bmg160_ext_info,                                    \
        .event_spec = &bmg160_event,                                    \
        .num_event_specs = 1                                            \
 }
@@ -1075,6 +1091,11 @@ int bmg160_core_probe(struct device *dev, struct regmap 
*regmap, int irq,
        data->irq = irq;
        data->regmap = regmap;
 
+       ret = iio_read_mount_matrix(dev, "mount-matrix",
+                               &data->orientation);
+       if (ret)
+               return ret;
+
        ret = bmg160_chip_init(data);
        if (ret < 0)
                return ret;
-- 
2.19.1