From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 5.mo4.mail-out.ovh.net ([188.165.44.50]:55445 "EHLO 5.mo4.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136AbbHUA1M convert rfc822-to-8bit (ORCPT ); Thu, 20 Aug 2015 20:27:12 -0400 Received: from mail21.ha.ovh.net (b6.ovh.net [213.186.33.56]) by mo4.mail-out.ovh.net (Postfix) with SMTP id A1DC1FFB095 for ; Thu, 20 Aug 2015 23:58:03 +0200 (CEST) Mime-Version: 1.0 Date: Thu, 20 Aug 2015 21:57:55 +0000 Content-Type: text/plain; charset="utf-8" Message-ID: From: "Nicola Corna" Subject: Re: [PATCH 1/3] iio:humidity:si7020: replaced bitmask on humidity values with range check To: "Hartmut Knaack" , "Jonathan Cameron" , "Lars-Peter Clausen" , "Peter Meerwald" Cc: linux-iio@vger.kernel.org In-Reply-To: <55D63D5E.8050000@gmx.de> References: <55D63D5E.8050000@gmx.de> <1440079909-1337-1-git-send-email-nicola@corna.info> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org August 20 2015 10:49 PM, "Hartmut Knaack" wrote: > Nicola Corna schrieb am 20.08.2015 um 16:11: > >> The maximum possible value for the relative humidity is 55575 (100%RH). >> This value, if shifted right by 2 bits, uses 14 bits and masking it with >> a 12 bit mask removes 2 meaningful bits. >> The masking has been replaced with a range check that sets the minimum >> value at 3194 (0%RH) and the maximum at 55575 (100%RH). > > Hmm, I guess the mask should have been applied for bits 13:2, but your > solution confirms better to the data sheet. Just one essential detail: > The raw sensor data has already been divided by 4 when you do the boundary > check. So, you need to divide the boundaries, as well. > Btw, you can make this a one-liner using clamp_val, check it out: [1] > > [1]http://lxr.free-electrons.com/source/include/linux/kernel.h#L795 > Yes, you're right. Thanks. Forgive me for my ignorance, but do I have now to upload the [PATCH v2] for all the three patches? >> Signed-off-by: Nicola Corna >> --- >> drivers/iio/humidity/si7020.c | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c >> index fa3b809..62fdbcf 100644 >> --- a/drivers/iio/humidity/si7020.c >> +++ b/drivers/iio/humidity/si7020.c >> @@ -57,8 +57,16 @@ static int si7020_read_raw(struct iio_dev *indio_dev, >> if (ret < 0) >> return ret; >> *val = ret >> 2; >> - if (chan->type == IIO_HUMIDITYRELATIVE) >> - *val &= GENMASK(11, 0); >> + /* >> + * Humidity values can sligthly exceed the 0-100%RH >> + * range and should be corrected by software >> + */ >> + if (chan->type == IIO_HUMIDITYRELATIVE) { >> + if (*val < 3194) /* 0%RH */ >> + *val = 3194; >> + else if (*val > 55575) /* 100%RH */ >> + *val = 55575; >> + } >> return IIO_VAL_INT; >> case IIO_CHAN_INFO_SCALE: >> if (chan->type == IIO_TEMP)