HID: sensor-hub: Add sensor_hub_input_attr_read_values() for multi-byte reads

sensor_hub_input_attr_get_raw_value() is limited to returning a single
32-bit value, which is insufficient for sensors that report data larger
than 32 bits, such as a quaternion with four s16 elements.

Add sensor_hub_input_attr_read_values() that accepts a caller-provided
buffer and accumulates incoming data until the buffer is full. The two
paths are distinguished in sensor_hub_raw_event() by pending.max_raw_size
being non-zero, preserving backward compatibility.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Co-developed-by: Zhang Lixu <lixu.zhang@intel.com>
Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Jiri Kosina <jkosina@suse.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index e71056553108..ab5cc8db3fbb 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -43,6 +43,8 @@ struct hid_sensor_hub_attribute_info {
  * @attr_usage_id:	Usage Id of a field, e.g. X-axis for a gyro.
  * @raw_size:		Response size for a read request.
  * @raw_data:		Place holder for received response.
+ * @index:		Current write index into raw_data for multi-byte reads.
+ * @max_raw_size:	Total buffer size for multi-byte reads; 0 for single-value reads.
  */
 struct sensor_hub_pending {
 	bool status;
@@ -51,6 +53,8 @@ struct sensor_hub_pending {
 	u32 attr_usage_id;
 	int raw_size;
 	u8  *raw_data;
+	u32 index;
+	u32 max_raw_size;
 };
 
 /**
@@ -184,6 +188,27 @@ int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
 );
 
 /**
+ * sensor_hub_input_attr_read_values() - Synchronous multi-byte read request
+ * @hsdev:		Hub device instance.
+ * @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
+ * @buffer_size:	Size of the buffer in bytes
+ * @buffer:		Buffer to store the read data
+ *
+ * Issues a synchronous or asynchronous read request for an input attribute,
+ * accumulating data into the provided buffer until it is full.
+ * Return: 0 on success, -ETIMEDOUT if the device did not respond, or a
+ * negative error code.
+ */
+int sensor_hub_input_attr_read_values(struct hid_sensor_hub_device *hsdev,
+				      u32 usage_id, u32 attr_usage_id,
+				      u32 report_id,
+				      enum sensor_hub_read_flags flag,
+				      u32 buffer_size, u8 *buffer);
+
+/**
 * sensor_hub_set_feature() - Feature set request
 * @hsdev:	Hub device instance.
 * @report_id:	Report id to look for