iio: hid-sensor-temperature: Fix issues of timestamp channel

This patch fixes 2 issues of timestamp channel:
1. This patch ensures that there is sufficient space and correct
alignment for the timestamp.
2. Correct the timestamp channel scan index.

Fixes: 59d0f2da35 ("iio: hid: Add temperature sensor support")
Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210303063615.12130-4-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/temperature/hid-sensor-temperature.c

@@ -15,7 +15,10 @@
 struct temperature_state {
 	struct hid_sensor_common common_attributes;
 	struct hid_sensor_hub_attribute_info temperature_attr;
-	s32 temperature_data;
+	struct {
+		s32 temperature_data;
+		u64 timestamp __aligned(8);
+	} scan;
 	int scale_pre_decml;
 	int scale_post_decml;
 	int scale_precision;
@@ -32,7 +35,7 @@ static const struct iio_chan_spec temperature_channels[] = {
 			BIT(IIO_CHAN_INFO_SAMP_FREQ) |
 			BIT(IIO_CHAN_INFO_HYSTERESIS),
 	},
-	IIO_CHAN_SOFT_TIMESTAMP(3),
+	IIO_CHAN_SOFT_TIMESTAMP(1),
 };
 
 /* Adjust channel real bits based on report descriptor */
@@ -123,9 +126,8 @@ static int temperature_proc_event(struct hid_sensor_hub_device *hsdev,
 	struct temperature_state *temp_st = iio_priv(indio_dev);
 
 	if (atomic_read(&temp_st->common_attributes.data_ready))
-		iio_push_to_buffers_with_timestamp(indio_dev,
-				&temp_st->temperature_data,
-				iio_get_time_ns(indio_dev));
+		iio_push_to_buffers_with_timestamp(indio_dev, &temp_st->scan,
+						   iio_get_time_ns(indio_dev));
 
 	return 0;
 }
@@ -140,7 +142,7 @@ static int temperature_capture_sample(struct hid_sensor_hub_device *hsdev,
 
 	switch (usage_id) {
 	case HID_USAGE_SENSOR_DATA_ENVIRONMENTAL_TEMPERATURE:
-		temp_st->temperature_data = *(s32 *)raw_data;
+		temp_st->scan.temperature_data = *(s32 *)raw_data;
 		return 0;
 	default:
 		return -EINVAL;