[PATCH] iio: hid-sensor: Store restore poll and hysteresis on S3

[Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>]

This change undo the change done by 'commit 3bec24747446
("iio: hid-sensor-trigger: Change get poll value function order to avoid
sensor properties losing after resume from S3")' as this breaks some
USB/i2c sensor hubs.

Instead of relying on HW for restoring poll and hysteresis, driver stores
and restores on resume (S3). In this way user space modified settings are
not lost for any kind of sensor hub behavior.

In this change, whenever user space modifies sampling frequency or
hysteresis driver will get the feature value from the hub and store in the
per device hid_sensor_common data structure. On resume callback from S3,
system will set the feature to sensor hub, if user space ever modified the
feature value.

Fixes: 3bec24747446 ("iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3")
Reported-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Ritesh Raj Sarraf <rrs@researchut.com>
Tested-by: Song, Hongyan <hongyan.song@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 .../iio/common/hid-sensors/hid-sensor-attributes.c | 26 ++++++++++++++++++++--
 .../iio/common/hid-sensors/hid-sensor-trigger.c    | 20 ++++++++++++++---
 include/linux/hid-sensor-hub.h                     |  2 ++
 3 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
index 7afdac42..efd3151 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -221,7 +221,15 @@ int hid_sensor_write_samp_freq_value(struct hid_sensor_common *st,
 	if (ret < 0 || value < 0)
 		ret = -EINVAL;
 
-	return ret;
+	ret = sensor_hub_get_feature(st->hsdev,
+				     st->poll.report_id,
+				     st->poll.index, sizeof(value), &value);
+	if (ret < 0 || value < 0)
+		return -EINVAL;
+
+	st->poll_interval = value;
+
+	return 0;
 }
 EXPORT_SYMBOL(hid_sensor_write_samp_freq_value);
 
@@ -266,7 +274,16 @@ int hid_sensor_write_raw_hyst_value(struct hid_sensor_common *st,
 	if (ret < 0 || value < 0)
 		ret = -EINVAL;
 
-	return ret;
+	ret = sensor_hub_get_feature(st->hsdev,
+				     st->sensitivity.report_id,
+				     st->sensitivity.index, sizeof(value),
+				     &value);
+	if (ret < 0 || value < 0)
+		return -EINVAL;
+
+	st->raw_hystersis = value;
+
+	return 0;
 }
 EXPORT_SYMBOL(hid_sensor_write_raw_hyst_value);
 
@@ -369,6 +386,9 @@ int hid_sensor_get_reporting_interval(struct hid_sensor_hub_device *hsdev,
 	/* Default unit of measure is milliseconds */
 	if (st->poll.units == 0)
 		st->poll.units = HID_USAGE_SENSOR_UNITS_MILLISECOND;
+
+	st->poll_interval = -1;
+
 	return 0;
 
 }
@@ -397,6 +417,8 @@ int hid_sensor_parse_common_attributes(struct hid_sensor_hub_device *hsdev,
 			HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS,
 			 &st->sensitivity);
 
+	st->raw_hystersis = -1;
+
 	sensor_hub_input_get_attribute_info(hsdev,
 					    HID_INPUT_REPORT, usage_id,
 					    HID_USAGE_SENSOR_TIME_TIMESTAMP,
diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
index ecf592d..6082934 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
@@ -51,6 +51,8 @@ static int _hid_sensor_power_state(struct hid_sensor_common *st, bool state)
 			st->report_state.report_id,
 			st->report_state.index,
 			HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM);
+
+		poll_value = hid_sensor_read_poll_value(st);
 	} else {
 		int val;
 
@@ -87,9 +89,7 @@ static int _hid_sensor_power_state(struct hid_sensor_common *st, bool state)
 	sensor_hub_get_feature(st->hsdev, st->power_state.report_id,
 			       st->power_state.index,
 			       sizeof(state_val), &state_val);
-	if (state)
-		poll_value = hid_sensor_read_poll_value(st);
-	if (poll_value > 0)
+	if (state && poll_value)
 		msleep_interruptible(poll_value * 2);
 
 	return 0;
@@ -127,6 +127,20 @@ static void hid_sensor_set_power_work(struct work_struct *work)
 	struct hid_sensor_common *attrb = container_of(work,
 						       struct hid_sensor_common,
 						       work);
+
+	if (attrb->poll_interval >= 0)
+		sensor_hub_set_feature(attrb->hsdev, attrb->poll.report_id,
+				       attrb->poll.index,
+				       sizeof(attrb->poll_interval),
+				       &attrb->poll_interval);
+
+	if (attrb->raw_hystersis >= 0)
+		sensor_hub_set_feature(attrb->hsdev,
+				       attrb->sensitivity.report_id,
+				       attrb->sensitivity.index,
+				       sizeof(attrb->raw_hystersis),
+				       &attrb->raw_hystersis);
+
 	_hid_sensor_power_state(attrb, true);
 }
 
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index 7ef111d..f32d7c3 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -231,6 +231,8 @@ struct hid_sensor_common {
 	unsigned usage_id;
 	atomic_t data_ready;
 	atomic_t user_requested_state;
+	int poll_interval;
+	int raw_hystersis;
 	struct iio_trigger *trigger;
 	int timestamp_ns_scale;
 	struct hid_sensor_hub_attribute_info poll;
-- 
2.9.3