Hi,
On Wed, Jan 08, 2020 at 04:58:52PM +0100, Tomas Novotny wrote:
> Vishay has published a new version of "Designing the VCNL4200 Into an
> Application" application note in October 2019. The new version specifies
> that there is +-20% of part to part tolerance. Although the application
> note is related to vcnl4200, according to support the vcnl4040's "ASIC
> is quite similar to that one for the VCNL4200".
>
> So update the sampling rates (and comment), including the correct
> sampling rate for proximity. Both sampling rates are lower. Users
> relying on the blocking behaviour of reading will get proximity
> measurements much earlier.
>
> Fixes: 5a441aade5b3 ("iio: light: vcnl4000 add support for the VCNL4040 proximity and light sensor")
> Signed-off-by: Tomas Novotny <tomas@xxxxxxxxxx>
> ---
> drivers/iio/light/vcnl4000.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> index 98428bf430bd..e5b00a6611ac 100644
> --- a/drivers/iio/light/vcnl4000.c
> +++ b/drivers/iio/light/vcnl4000.c
> @@ -174,9 +174,10 @@ static int vcnl4200_init(struct vcnl4000_data *data)
> data->al_scale = 24000;
> break;
> case VCNL4040_PROD_ID:
> - /* Integration time is 80ms, add 10ms. */
> - data->vcnl4200_al.sampling_rate = ktime_set(0, 100000 * 1000);
> - data->vcnl4200_ps.sampling_rate = ktime_set(0, 100000 * 1000);
> + /* Default wait time is 80ms, add 20% tolerance. */
> + data->vcnl4200_al.sampling_rate = ktime_set(0, 96000 * 1000);
> + /* Default wait time is 5ms, add 20% tolerance. */
> + data->vcnl4200_ps.sampling_rate = ktime_set(0, 6000 * 1000);
I'm seeing the 80ms in VCNL4040 Application guide (Revision:
12-Nov-2019) but that one also says 6400us for the proximity so 8000
might be more on the safe side which (which i just tested, it's still
way better than the current 100000).
with that fixed
Reviewed-by: Guido Günther <agx@xxxxxxxxxxx>
Cheers,
-- Guido
> data->al_scale = 120000;
> break;
> }
> --
> 2.16.4
>
