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-rw-r--r--drivers/iio/common/hid-sensors/hid-sensor-attributes.c114
-rw-r--r--include/linux/hid-sensor-hub.h4
2 files changed, 118 insertions, 0 deletions
diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
index 75b54730a963..e61b1faa1e06 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -26,6 +26,40 @@
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+struct {
+ u32 usage_id;
+ int unit; /* 0 for default others from HID sensor spec */
+ int scale_val0; /* scale, whole number */
+ int scale_val1; /* scale, fraction in micros */
+} static unit_conversion[] = {
+ {HID_USAGE_SENSOR_ACCEL_3D, 0, 9, 806650},
+ {HID_USAGE_SENSOR_ACCEL_3D,
+ HID_USAGE_SENSOR_UNITS_METERS_PER_SEC_SQRD, 1, 0},
+ {HID_USAGE_SENSOR_ACCEL_3D,
+ HID_USAGE_SENSOR_UNITS_G, 9, 806650},
+
+ {HID_USAGE_SENSOR_GYRO_3D, 0, 0, 17453},
+ {HID_USAGE_SENSOR_GYRO_3D,
+ HID_USAGE_SENSOR_UNITS_RADIANS_PER_SECOND, 1, 0},
+ {HID_USAGE_SENSOR_GYRO_3D,
+ HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND, 0, 17453},
+
+ {HID_USAGE_SENSOR_COMPASS_3D, 0, 0, 1000},
+ {HID_USAGE_SENSOR_COMPASS_3D, HID_USAGE_SENSOR_UNITS_GAUSS, 1, 0},
+
+ {HID_USAGE_SENSOR_INCLINOMETER_3D, 0, 0, 17453},
+ {HID_USAGE_SENSOR_INCLINOMETER_3D,
+ HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453},
+ {HID_USAGE_SENSOR_INCLINOMETER_3D,
+ HID_USAGE_SENSOR_UNITS_RADIANS, 1, 0},
+
+ {HID_USAGE_SENSOR_ALS, 0, 1, 0},
+ {HID_USAGE_SENSOR_ALS, HID_USAGE_SENSOR_UNITS_LUX, 1, 0},
+
+ {HID_USAGE_SENSOR_PRESSURE, 0, 100000, 0},
+ {HID_USAGE_SENSOR_PRESSURE, HID_USAGE_SENSOR_UNITS_PASCAL, 1, 0},
+};
+
static int pow_10(unsigned power)
{
int i;
@@ -209,6 +243,86 @@ int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
}
EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
+/*
+ * This fuction applies the unit exponent to the scale.
+ * For example:
+ * 9.806650 ->exp:2-> val0[980]val1[665000]
+ * 9.000806 ->exp:2-> val0[900]val1[80600]
+ * 0.174535 ->exp:2-> val0[17]val1[453500]
+ * 1.001745 ->exp:0-> val0[1]val1[1745]
+ * 1.001745 ->exp:2-> val0[100]val1[174500]
+ * 1.001745 ->exp:4-> val0[10017]val1[450000]
+ * 9.806650 ->exp:-2-> val0[0]val1[98066]
+ */
+static void adjust_exponent_micro(int *val0, int *val1, int scale0,
+ int scale1, int exp)
+{
+ int i;
+ int x;
+ int res;
+ int rem;
+
+ if (exp > 0) {
+ *val0 = scale0 * pow_10(exp);
+ res = 0;
+ if (exp > 6) {
+ *val1 = 0;
+ return;
+ }
+ for (i = 0; i < exp; ++i) {
+ x = scale1 / pow_10(5 - i);
+ res += (pow_10(exp - 1 - i) * x);
+ scale1 = scale1 % pow_10(5 - i);
+ }
+ *val0 += res;
+ *val1 = scale1 * pow_10(exp);
+ } else if (exp < 0) {
+ exp = abs(exp);
+ if (exp > 6) {
+ *val0 = *val1 = 0;
+ return;
+ }
+ *val0 = scale0 / pow_10(exp);
+ rem = scale0 % pow_10(exp);
+ res = 0;
+ for (i = 0; i < (6 - exp); ++i) {
+ x = scale1 / pow_10(5 - i);
+ res += (pow_10(5 - exp - i) * x);
+ scale1 = scale1 % pow_10(5 - i);
+ }
+ *val1 = rem * pow_10(6 - exp) + res;
+ } else {
+ *val0 = scale0;
+ *val1 = scale1;
+ }
+}
+
+int hid_sensor_format_scale(u32 usage_id,
+ struct hid_sensor_hub_attribute_info *attr_info,
+ int *val0, int *val1)
+{
+ int i;
+ int exp;
+
+ *val0 = 1;
+ *val1 = 0;
+
+ for (i = 0; ARRAY_SIZE(unit_conversion); ++i) {
+ if (unit_conversion[i].usage_id == usage_id &&
+ unit_conversion[i].unit == attr_info->units) {
+ exp = hid_sensor_convert_exponent(
+ attr_info->unit_expo);
+ adjust_exponent_micro(val0, val1,
+ unit_conversion[i].scale_val0,
+ unit_conversion[i].scale_val1, exp);
+ break;
+ }
+ }
+
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+EXPORT_SYMBOL(hid_sensor_format_scale);
+
int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
u32 usage_id,
struct hid_sensor_common *st)
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index b70cfd7ff29c..89626b23c246 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -223,4 +223,8 @@ int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,
int hid_sensor_get_usage_index(struct hid_sensor_hub_device *hsdev,
u32 report_id, int field_index, u32 usage_id);
+int hid_sensor_format_scale(u32 usage_id,
+ struct hid_sensor_hub_attribute_info *attr_info,
+ int *val0, int *val1);
+
#endif