[PATCH v2 07/10] iio: magnetometer: bmc150: 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/magnetometer/bmc150_magn.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/iio/magnetometer/bmc150_magn.c 
b/drivers/iio/magnetometer/bmc150_magn.c
index d91cb845e3d6..b0d8b036d9bb 100644
--- a/drivers/iio/magnetometer/bmc150_magn.c
+++ b/drivers/iio/magnetometer/bmc150_magn.c
@@ -143,6 +143,7 @@ struct bmc150_magn_data {
         */
        struct mutex mutex;
        struct regmap *regmap;
+       struct iio_mount_matrix orientation;
        /* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
        s32 buffer[6];
        struct iio_trigger *dready_trig;
@@ -612,6 +613,20 @@ static ssize_t bmc150_magn_show_samp_freq_avail(struct 
device *dev,
        return len;
 }
 
+static const struct iio_mount_matrix *
+bmc150_magn_get_mount_matrix(const struct iio_dev *indio_dev,
+                             const struct iio_chan_spec *chan)
+{
+       struct bmc150_magn_data *data = iio_priv(indio_dev);
+
+       return &data->orientation;
+}
+
+static const struct iio_chan_spec_ext_info bmc150_magn_ext_info[] = {
+       IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bmc150_magn_get_mount_matrix),
+       { }
+};
+
 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(bmc150_magn_show_samp_freq_avail);
 
 static struct attribute *bmc150_magn_attributes[] = {
@@ -638,6 +653,7 @@ static const struct attribute_group bmc150_magn_attrs_group 
= {
                .storagebits = 32,                                      \
                .endianness = IIO_LE                                    \
        },                                                              \
+       .ext_info = bmc150_magn_ext_info,                               \
 }
 
 static const struct iio_chan_spec bmc150_magn_channels[] = {
@@ -861,6 +877,11 @@ int bmc150_magn_probe(struct device *dev, struct regmap 
*regmap,
        data->irq = irq;
        data->dev = dev;
 
+       ret = iio_read_mount_matrix(dev, "mount-matrix",
+                               &data->orientation);
+       if (ret)
+               return ret;
+
        if (!name && ACPI_HANDLE(dev))
                name = bmc150_magn_match_acpi_device(dev);
 
-- 
2.19.1