iio_sensors: Remove hard coded exponent and data bytes

The current implementation used hard coded exponent and
data bytes for the data transformation macros inside
transform_sample_ISH function. These values were not
correct for all implementations and were resulting in
large invalid values.

These can be calculated from the SysFs attributes exported
by the driver. This patch changes the calculation to use these
and was tested on BDW Wilson Beach (running Intel FW) and
BDW RVP Y (running STM FW).

Change-Id: Ie66ee5a5b9692cee3a48d4027f795b16c6b5e8d0
Signed-off-by: Archana Patni <archana.patni@intel.com>
Signed-off-by: Subramony Sesha <subramony.sesha@intel.com>

diff --git a/transform.c b/transform.c
index eb4e783..4c7a24b 100644 (file)
--- a/transform.c
+++ b/transform.c
@@ -118,12 +118,6 @@ inline float convert_from_vtf_format(int size, int exponent, unsigned int value)
 #define CONVERT_M_MG_VTF16E14_Y(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 #define CONVERT_M_MG_VTF16E14_Z(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 
-#define DATA_BYTES     2
-#define ACC_EXPONENT   -2
-#define GYRO_EXPONENT  -1
-#define MAGN_EXPONENT  0
-#define INC_EXPONENT   -1
-#define ROT_EXPONENT   -8
 
 /*----------------------------------------------------------------------------*/
 
@@ -272,6 +266,8 @@ static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
        int i           = sensor_info[s].catalog_index;
        int sensor_type = sensor_catalog[i].type;
        float correction;
+       int data_bytes  = (sample_type->realbits)/8;
+       int exponent    = sensor_info[s].offset;
 
        /* In case correction has been requested using properties, apply it */
        correction = sensor_info[s].channel[c].opt_scale;
@@ -282,17 +278,17 @@ static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
                                case 0:
                                        return  correction *
                                                CONVERT_A_G_VTF16E14_X(
-                                               DATA_BYTES, ACC_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 1:
                                        return  correction *
                                                CONVERT_A_G_VTF16E14_Y(
-                                               DATA_BYTES, ACC_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 2:
                                        return  correction *
                                                CONVERT_A_G_VTF16E14_Z(
-                                               DATA_BYTES, ACC_EXPONENT, val);
+                                               data_bytes, exponent, val);
                        }
                        break;
 
@@ -302,17 +298,17 @@ static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
                                case 0:
                                        return  correction *
                                                CONVERT_G_D_VTF16E14_X(
-                                               DATA_BYTES, GYRO_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 1:
                                        return  correction *
                                                CONVERT_G_D_VTF16E14_Y(
-                                               DATA_BYTES, GYRO_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 2:
                                        return  correction *
                                                CONVERT_G_D_VTF16E14_Z(
-                                               DATA_BYTES, GYRO_EXPONENT, val);
+                                               data_bytes, exponent, val);
                        }
                        break;
 
@@ -321,27 +317,27 @@ static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
                                case 0:
                                        return  correction *
                                                CONVERT_M_MG_VTF16E14_X(
-                                               DATA_BYTES, MAGN_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 1:
                                        return  correction *
                                                CONVERT_M_MG_VTF16E14_Y(
-                                               DATA_BYTES, MAGN_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                                case 2:
                                        return  correction *
                                                CONVERT_M_MG_VTF16E14_Z(
-                                               DATA_BYTES, MAGN_EXPONENT, val);
+                                               data_bytes, exponent, val);
                        }
                        break;
 
                case SENSOR_TYPE_ORIENTATION:
                        return  correction * convert_from_vtf_format(
-                                               DATA_BYTES, INC_EXPONENT, val);
+                                               data_bytes, exponent, val);
 
                case SENSOR_TYPE_ROTATION_VECTOR:
                        return  correction * convert_from_vtf_format(
-                                               DATA_BYTES, ROT_EXPONENT, val);
+                                               data_bytes, exponent, val);
        }
 
        return 0;