[PATCH 5/5] iio: accel: adxl345: Add timestamp to FIFO data

[Md Shofiqul Islam]

The driver pushes FIFO samples using iio_push_to_buffers() which does
not attach a hardware timestamp to the data.  Add a scan buffer struct
with an aligned_s64 timestamp field to struct adxl345_state, capture a
timestamp with iio_get_time_ns() at the start of adxl345_fifo_push(),
and switch the push loop to iio_push_to_buffers_with_timestamp().  The
ADXL345 always scans all three axes together so the scan buffer layout
is fixed.

Signed-off-by: Md Shofiqul Islam <shofiqtest@xxxxxxxxx>
---
 drivers/iio/accel/adxl345_core.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 6c9080d88c..2b121bed89 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -204,6 +204,10 @@ struct adxl345_state {
 	u32 tap_window_us;
 
 	__le16 fifo_buf[ADXL345_DIRS * ADXL345_FIFO_SIZE + 1] __aligned(IIO_DMA_MINALIGN);
+	struct {
+		__le16 channels[ADXL345_DIRS];
+		aligned_s64 ts;
+	} scan;
 };
 
 static const struct iio_event_spec adxl345_events[] = {
@@ -1657,6 +1661,7 @@ static int adxl345_fifo_push(struct iio_dev *indio_dev,
 			     int samples)
 {
 	struct adxl345_state *st = iio_priv(indio_dev);
+	s64 ts = iio_get_time_ns(indio_dev);
 	int i, ret;
 
 	if (samples <= 0)
@@ -1666,8 +1671,11 @@ static int adxl345_fifo_push(struct iio_dev *indio_dev,
 	if (ret)
 		return ret;
 
-	for (i = 0; i < ADXL345_DIRS * samples; i += ADXL345_DIRS)
-		iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
+	for (i = 0; i < ADXL345_DIRS * samples; i += ADXL345_DIRS) {
+		memcpy(st->scan.channels, &st->fifo_buf[i],
+		       sizeof(st->scan.channels));
+		iio_push_to_buffers_with_timestamp(indio_dev, &st->scan, ts);
+	}
 
 	return 0;
 }
-- 
2.54.0.windows.1