Re: [PATCH 1/5] iio: accel: adxl372: Add timestamp to FIFO data

[David Lechner <dlechner@baylibre.com>]

On 5/10/26 3:25 AM, Md Shofiqul Islam wrote:
> 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 the driver state, capture a
> single timestamp per IRQ with iio_get_time_ns(), and switch the FIFO
> push loop to iio_push_to_buffers_with_timestamp().  The same timestamp
> is reused for the event push call in the same handler, replacing the
> duplicate iio_get_time_ns() invocation there.
> 
> Signed-off-by: Md Shofiqul Islam <shofiqtest@gmail.com>
> ---
>  drivers/iio/accel/adxl372.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/accel/adxl372.c b/drivers/iio/accel/adxl372.c
> index 545a21e5a3..521e8313b1 100644
> --- a/drivers/iio/accel/adxl372.c
> +++ b/drivers/iio/accel/adxl372.c
> @@ -367,6 +367,10 @@ struct adxl372_state {
>  	u16				watermark;


>  	__be16				fifo_buf[ADXL372_FIFO_SIZE];

I would just change this line to:

	IIO_DECLARE_BUFFER_WITH_TS(__be16, fifo_buf, ADXL372_FIFO_SIZE);

>  	bool				peak_fifo_mode_en;
> +	struct {
> +		__be16 channels[3];
> +		aligned_s64 ts;
> +	} scan;

Then we don't need the extra struct and memcpy().

If we really do need the memcpy() for some reason, this struct
can be declared on the stack instead of here.

>  	struct mutex			threshold_m; /* lock for threshold */
>  };
>  
> @@ -703,13 +707,15 @@ static irqreturn_t adxl372_trigger_handler(int irq, void  *p)
>  	struct adxl372_state *st = iio_priv(indio_dev);
>  	u8 status1, status2;
>  	u16 fifo_entries;
> +	s64 ts;
>  	int i, ret;
>  
>  	ret = adxl372_get_status(st, &status1, &status2, &fifo_entries);
>  	if (ret < 0)
>  		goto err;
>  
> -	adxl372_push_event(indio_dev, iio_get_time_ns(indio_dev), status2);
> +	ts = iio_get_time_ns(indio_dev);
> +	adxl372_push_event(indio_dev, ts, status2);
>  
>  	if (st->fifo_mode != ADXL372_FIFO_BYPASSED &&
>  	    ADXL372_STATUS_1_FIFO_FULL(status1)) {
> @@ -733,7 +739,10 @@ static irqreturn_t adxl372_trigger_handler(int irq, void  *p)
>  			/* filter peak detection data */
>  			if (st->peak_fifo_mode_en)
>  				adxl372_arrange_axis_data(st, &st->fifo_buf[i]);
> -			iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
> +			memcpy(st->scan.channels, &st->fifo_buf[i],
> +			       st->fifo_set_size * sizeof(__be16));
> +			iio_push_to_buffers_with_timestamp(indio_dev,
> +							   &st->scan, ts);
>  		}
>  	}
>  err: