iio: Add relative sensitivity support

Some hid sensors may use relative sensitivity such as als sensor.
This patch adds relative sensitivity checking for all hid sensors.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Link: https://lore.kernel.org/r/20210207070048.23935-2-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/common/hid-sensors/hid-sensor-attributes.c

@@ -263,6 +263,29 @@ int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
 }
 EXPORT_SYMBOL(hid_sensor_read_raw_hyst_value);
 
+int hid_sensor_read_raw_hyst_rel_value(struct hid_sensor_common *st, int *val1,
+				       int *val2)
+{
+	s32 value;
+	int ret;
+
+	ret = sensor_hub_get_feature(st->hsdev,
+				     st->sensitivity_rel.report_id,
+				     st->sensitivity_rel.index, sizeof(value),
+				     &value);
+	if (ret < 0 || value < 0) {
+		*val1 = *val2 = 0;
+		return -EINVAL;
+	}
+
+	convert_from_vtf_format(value, st->sensitivity_rel.size,
+				st->sensitivity_rel.unit_expo, val1, val2);
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+EXPORT_SYMBOL(hid_sensor_read_raw_hyst_rel_value);
+
+
 int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 					int val1, int val2)
 {
@@ -294,6 +317,37 @@ int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 }
 EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
 
+int hid_sensor_write_raw_hyst_rel_value(struct hid_sensor_common *st,
+					int val1, int val2)
+{
+	s32 value;
+	int ret;
+
+	if (val1 < 0 || val2 < 0)
+		return -EINVAL;
+
+	value = convert_to_vtf_format(st->sensitivity_rel.size,
+				st->sensitivity_rel.unit_expo,
+				val1, val2);
+	ret = sensor_hub_set_feature(st->hsdev, st->sensitivity_rel.report_id,
+				     st->sensitivity_rel.index, sizeof(value),
+				     &value);
+	if (ret < 0 || value < 0)
+		return -EINVAL;
+
+	ret = sensor_hub_get_feature(st->hsdev,
+				     st->sensitivity_rel.report_id,
+				     st->sensitivity_rel.index, sizeof(value),
+				     &value);
+	if (ret < 0 || value < 0)
+		return -EINVAL;
+
+	st->raw_hystersis = value;
+
+	return 0;
+}
+EXPORT_SYMBOL(hid_sensor_write_raw_hyst_rel_value);
+
 /*
  * This fuction applies the unit exponent to the scale.
  * For example:
@@ -478,16 +532,28 @@ int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 			HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
 			 &st->sensitivity);
 
+	sensor_hub_input_get_attribute_info(hsdev,
+			HID_FEATURE_REPORT, usage_id,
+			HID_USAGE_SENSOR_PROP_SENSITIVITY_REL_PCT,
+			&st->sensitivity_rel);
 	/*
 	 * Set Sensitivity field ids, when there is no individual modifier, will
-	 * check absolute sensitivity of data field
+	 * check absolute sensitivity and relative sensitivity of data field
 	 */
-	for (i = 0; i < sensitivity_addresses_len && st->sensitivity.index < 0; i++) {
-		sensor_hub_input_get_attribute_info(hsdev,
-				HID_FEATURE_REPORT, usage_id,
+	for (i = 0; i < sensitivity_addresses_len; i++) {
+		if (st->sensitivity.index < 0)
+			sensor_hub_input_get_attribute_info(
+				hsdev, HID_FEATURE_REPORT, usage_id,
 				HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
 					sensitivity_addresses[i],
 				&st->sensitivity);
+
+		if (st->sensitivity_rel.index < 0)
+			sensor_hub_input_get_attribute_info(
+				hsdev, HID_FEATURE_REPORT, usage_id,
+				HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_REL_PCT |
+					sensitivity_addresses[i],
+				&st->sensitivity_rel);
 	}
 
 	st->raw_hystersis = -1;

drivers/iio/industrialio-core.c

@@ -157,6 +157,7 @@ static const char * const iio_chan_info_postfix[] = {
 	[IIO_CHAN_INFO_PHASE] = "phase",
 	[IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 	[IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
+	[IIO_CHAN_INFO_HYSTERESIS_RELATIVE] = "hysteresis_relative",
 	[IIO_CHAN_INFO_INT_TIME] = "integration_time",
 	[IIO_CHAN_INFO_ENABLE] = "en",
 	[IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",

include/linux/hid-sensor-hub.h

@@ -231,6 +231,7 @@ struct hid_sensor_common {
 	struct hid_sensor_hub_attribute_info report_state;
 	struct hid_sensor_hub_attribute_info power_state;
 	struct hid_sensor_hub_attribute_info sensitivity;
+	struct hid_sensor_hub_attribute_info sensitivity_rel;
 	struct hid_sensor_hub_attribute_info report_latency;
 	struct work_struct work;
 };
@@ -253,8 +254,12 @@ int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 					u32 sensitivity_addresses_len);
 int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 					int val1, int val2);
+int hid_sensor_write_raw_hyst_rel_value(struct hid_sensor_common *st, int val1,
+					int val2);
 int hid_sensor_read_raw_hyst_value(struct hid_sensor_common *st,
 					int *val1, int *val2);
+int hid_sensor_read_raw_hyst_rel_value(struct hid_sensor_common *st,
+				       int *val1, int *val2);
 int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
 					int val1, int val2);
 int hid_sensor_read_samp_freq_value(struct hid_sensor_common *st,

include/linux/hid-sensor-ids.h

@@ -149,6 +149,7 @@
 /* Per data field properties */
 #define HID_USAGE_SENSOR_DATA_MOD_NONE					0x00
 #define HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS		0x1000
+#define HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_REL_PCT            0xE000
 
 /* Power state enumerations */
 #define HID_USAGE_SENSOR_PROP_POWER_STATE_UNDEFINED_ENUM	0x200850

include/linux/iio/types.h

@@ -50,6 +50,7 @@ enum iio_chan_info_enum {
 	IIO_CHAN_INFO_PHASE,
 	IIO_CHAN_INFO_HARDWAREGAIN,
 	IIO_CHAN_INFO_HYSTERESIS,
+	IIO_CHAN_INFO_HYSTERESIS_RELATIVE,
 	IIO_CHAN_INFO_INT_TIME,
 	IIO_CHAN_INFO_ENABLE,
 	IIO_CHAN_INFO_CALIBHEIGHT,