staging:iio:magnetometer:ak8975: set power-down mode after reading fuse ROM data

Fuse ROM data access mode is the only mode which does not
transition to power-down mode automatically.

As per the AK8975 data sheet, it is recomended to set the
power-down mode first before attempting to change into
another mode.

Signed-off-by: Leed Aguilar <leed.aguilar@ti.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c
index 7562cafb26b..001b3bff476 100644
--- a/drivers/staging/iio/magnetometer/ak8975.c
+++ b/drivers/staging/iio/magnetometer/ak8975.c
@@ -194,6 +194,17 @@ static int ak8975_setup(struct i2c_client *client)
                 return ret;
         }
 
+        /* After reading fuse ROM data set power-down mode */
+        ret = ak8975_write_data(client,
+                                AK8975_REG_CNTL,
+                                AK8975_REG_CNTL_MODE_POWER_DOWN,
+                                AK8975_REG_CNTL_MODE_MASK,
+                                AK8975_REG_CNTL_MODE_SHIFT);
+        if (ret < 0) {
+                dev_err(&client->dev, "Error in setting power-down mode\n");
+                return ret;
+        }
+
 /*
  * Precalculate scale factor (in Gauss units) for each axis and
  * store in the device data.