This is a note to let you know that I've just added the patch titled
iio: light: vcnl4000: update sampling periods for vcnl4040
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 2ca5a8792d617b4035aacd0a8be527f667fbf912 Mon Sep 17 00:00:00 2001
From: Tomas Novotny tomas@novotny.cz Date: Tue, 18 Feb 2020 16:44:51 +0100 Subject: iio: light: vcnl4000: update sampling periods for vcnl4040 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
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 --- 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); data->al_scale = 120000; break; }