From patchwork Wed Jan 8 15:58:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tomas Novotny X-Patchwork-Id: 11323977 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 439D2109A for ; Wed, 8 Jan 2020 16:00:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C3DB2070E for ; Wed, 8 Jan 2020 16:00:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726281AbgAHQA1 (ORCPT ); Wed, 8 Jan 2020 11:00:27 -0500 Received: from hosting.pavoucek.net ([46.28.107.168]:46228 "EHLO hosting.pavoucek.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727135AbgAHQA1 (ORCPT ); Wed, 8 Jan 2020 11:00:27 -0500 Received: from 176-74-132-138.netdatacomm.cz (176-74-132-138.netdatacomm.cz [176.74.132.138]) (Authenticated sender: tomas@novotny.cz) by hosting.pavoucek.net (Postfix) with ESMTPSA id 3AE3D1048F2; Wed, 8 Jan 2020 17:00:25 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 hosting.pavoucek.net 3AE3D1048F2 From: Tomas Novotny To: linux-iio@vger.kernel.org Cc: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Tomas Novotny , Angus Ainslie , Marco Felsch , Thomas Gleixner , =?utf-8?q?Guido_G=C3=BCnther?= Subject: [PATCH 1/2] iio: light: vcnl4000: update sampling rates for vcnl4200 Date: Wed, 8 Jan 2020 16:58:51 +0100 Message-Id: <20200108155852.32702-2-tomas@novotny.cz> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200108155852.32702-1-tomas@novotny.cz> References: <20200108155852.32702-1-tomas@novotny.cz> Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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. This explains the drift seen during experiments. The proximity pulse width is also changed from 32us to 30us. According to the support, the tolerance also applies to ambient light. So update the sampling rates. As the reading is blocking, current users may notice slightly longer response time. Fixes: be38866fbb97 ("iio: vcnl4000: add support for VCNL4200") Signed-off-by: Tomas Novotny Reviewed-by: Guido Günther --- drivers/iio/light/vcnl4000.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c index b0e241aaefb4..98428bf430bd 100644 --- a/drivers/iio/light/vcnl4000.c +++ b/drivers/iio/light/vcnl4000.c @@ -167,10 +167,10 @@ static int vcnl4200_init(struct vcnl4000_data *data) data->vcnl4200_ps.reg = VCNL4200_PS_DATA; switch (id) { case VCNL4200_PROD_ID: - /* Integration time is 50ms, but the experiments */ - /* show 54ms in total. */ - data->vcnl4200_al.sampling_rate = ktime_set(0, 54000 * 1000); - data->vcnl4200_ps.sampling_rate = ktime_set(0, 4200 * 1000); + /* Default wait time is 50ms, add 20% tolerance. */ + data->vcnl4200_al.sampling_rate = ktime_set(0, 60000 * 1000); + /* Default wait time is 4.8ms, add 20% tolerance. */ + data->vcnl4200_ps.sampling_rate = ktime_set(0, 5760 * 1000); data->al_scale = 24000; break; case VCNL4040_PROD_ID: