From: Tomas Novotny tomas@novotny.cz
commit 2ca5a8792d617b4035aacd0a8be527f667fbf912 upstream.
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 periods (and comment), including the correct sampling period for proximity. Both sampling periods 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") Reviewed-by: Guido Günther agx@sigxcpu.org Tested-by: Guido Günther agx@sigxcpu.org Signed-off-by: Tomas Novotny tomas@novotny.cz Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iio/light/vcnl4000.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/iio/light/vcnl4000.c +++ b/drivers/iio/light/vcnl4000.c @@ -174,9 +174,10 @@ static int vcnl4200_init(struct vcnl4000 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); data->al_scale = 120000; break; }