HID: hid-sensor-hub: Extend API for async reads

Add additional flag to read in async mode. In this mode the caller will get
reply via registered callback for capture_sample. Callbacks can be registered
using sensor_hub_register_callback function. The usage id parameter of the
capture_sample can be matched with the usage id of the requested attribute.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-sensor-hub.c

@@ -250,48 +250,53 @@ EXPORT_SYMBOL_GPL(sensor_hub_get_feature);
 
 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
 					u32 usage_id,
-					u32 attr_usage_id, u32 report_id)
+					u32 attr_usage_id, u32 report_id,
+					enum sensor_hub_read_flags flag)
 {
 	struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
 	unsigned long flags;
 	struct hid_report *report;
 	int ret_val = 0;
 
-	mutex_lock(&hsdev->mutex);
-	memset(&hsdev->pending, 0, sizeof(hsdev->pending));
-	init_completion(&hsdev->pending.ready);
-	hsdev->pending.usage_id = usage_id;
-	hsdev->pending.attr_usage_id = attr_usage_id;
-	hsdev->pending.raw_size = 0;
-
-	spin_lock_irqsave(&data->lock, flags);
-	hsdev->pending.status = true;
-	spin_unlock_irqrestore(&data->lock, flags);
-	report = sensor_hub_report(report_id, hsdev->hdev, HID_INPUT_REPORT);
+	report = sensor_hub_report(report_id, hsdev->hdev,
+				   HID_INPUT_REPORT);
 	if (!report)
-		goto err_free;
+		return -EINVAL;
 
+	mutex_lock(&hsdev->mutex);
+	if (flag == SENSOR_HUB_SYNC) {
+		memset(&hsdev->pending, 0, sizeof(hsdev->pending));
+		init_completion(&hsdev->pending.ready);
+		hsdev->pending.usage_id = usage_id;
+		hsdev->pending.attr_usage_id = attr_usage_id;
+		hsdev->pending.raw_size = 0;
+
+		spin_lock_irqsave(&data->lock, flags);
+		hsdev->pending.status = true;
+		spin_unlock_irqrestore(&data->lock, flags);
+	}
 	mutex_lock(&data->mutex);
 	hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
 	mutex_unlock(&data->mutex);
-	wait_for_completion_interruptible_timeout(&hsdev->pending.ready, HZ*5);
-	switch (hsdev->pending.raw_size) {
-	case 1:
-		ret_val = *(u8 *)hsdev->pending.raw_data;
-		break;
-	case 2:
-		ret_val = *(u16 *)hsdev->pending.raw_data;
-		break;
-	case 4:
-		ret_val = *(u32 *)hsdev->pending.raw_data;
-		break;
-	default:
-		ret_val = 0;
+	if (flag == SENSOR_HUB_SYNC) {
+		wait_for_completion_interruptible_timeout(
+						&hsdev->pending.ready, HZ*5);
+		switch (hsdev->pending.raw_size) {
+		case 1:
+			ret_val = *(u8 *)hsdev->pending.raw_data;
+			break;
+		case 2:
+			ret_val = *(u16 *)hsdev->pending.raw_data;
+			break;
+		case 4:
+			ret_val = *(u32 *)hsdev->pending.raw_data;
+			break;
+		default:
+			ret_val = 0;
+		}
+		kfree(hsdev->pending.raw_data);
+		hsdev->pending.status = false;
 	}
-	kfree(hsdev->pending.raw_data);
-
-err_free:
-	hsdev->pending.status = false;
 	mutex_unlock(&hsdev->mutex);
 
 	return ret_val;

drivers/iio/accel/hid-sensor-accel-3d.c

@@ -130,7 +130,8 @@ static int accel_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					accel_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_ACCEL_3D, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&accel_state->common_attributes,

drivers/iio/gyro/hid-sensor-gyro-3d.c

@@ -130,7 +130,8 @@ static int gyro_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					gyro_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_GYRO_3D, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&gyro_state->common_attributes,

drivers/iio/light/hid-sensor-als.c

@@ -109,7 +109,8 @@ static int als_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 					als_state->common_attributes.hsdev,
 					HID_USAGE_SENSOR_ALS, address,
-					report_id);
+					report_id,
+					SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&als_state->common_attributes,
 						false);
 		} else {

drivers/iio/light/hid-sensor-prox.c

@@ -105,7 +105,8 @@ static int prox_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				prox_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_PROX, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&prox_state->common_attributes,
 						false);
 		} else {

drivers/iio/magnetometer/hid-sensor-magn-3d.c

@@ -178,7 +178,8 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				magn_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_COMPASS_3D, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 		else {
 			*val = 0;
 			hid_sensor_power_state(&magn_state->common_attributes,

drivers/iio/orientation/hid-sensor-incl-3d.c

@@ -132,7 +132,8 @@ static int incl_3d_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				incl_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_INCLINOMETER_3D, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 		else {
 			hid_sensor_power_state(&incl_state->common_attributes,
 						false);

drivers/iio/pressure/hid-sensor-press.c

@@ -108,7 +108,8 @@ static int press_read_raw(struct iio_dev *indio_dev,
 			*val = sensor_hub_input_attr_get_raw_value(
 				press_state->common_attributes.hsdev,
 				HID_USAGE_SENSOR_PRESSURE, address,
-				report_id);
+				report_id,
+				SENSOR_HUB_SYNC);
 			hid_sensor_power_state(&press_state->common_attributes,
 						false);
 		} else {

drivers/rtc/rtc-hid-sensor-time.c

@@ -213,7 +213,7 @@ static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	/* get a report with all values through requesting one value */
 	sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
 			HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
-			time_state->info[0].report_id);
+			time_state->info[0].report_id, SENSOR_HUB_SYNC);
 	/* wait for all values (event) */
 	ret = wait_for_completion_killable_timeout(
 			&time_state->comp_last_time, HZ*6);

include/linux/hid-sensor-hub.h

@@ -169,19 +169,27 @@ int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
 			struct hid_sensor_hub_attribute_info *info);
 
 /**
-* sensor_hub_input_attr_get_raw_value() - Synchronous read request
+* sensor_hub_input_attr_get_raw_value() - Attribute read request
 * @usage_id:	Attribute usage id of parent physical device as per spec
 * @attr_usage_id:	Attribute usage id as per spec
 * @report_id:	Report id to look for
+* @flag:      Synchronous or asynchronous read
 *
-* Issues a synchronous read request for an input attribute. Returns
-* data upto 32 bits. Since client can get events, so this call should
-* not be used for data paths, this will impact performance.
+* Issues a synchronous or asynchronous read request for an input attribute.
+* Returns data upto 32 bits.
 */
 
+enum sensor_hub_read_flags {
+	SENSOR_HUB_SYNC,
+	SENSOR_HUB_ASYNC,
+};
+
 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
-			u32 usage_id,
-			u32 attr_usage_id, u32 report_id);
+ 					u32 usage_id,
+ 					u32 attr_usage_id, u32 report_id,
+ 					enum sensor_hub_read_flags flag
+);
+
 /**
 * sensor_hub_set_feature() - Feature set request
 * @report_id:	Report id to look for