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>

1 files changed, 14 insertions, 6 deletions

diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index 60a34277ddf2..4c49b041922d 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/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