From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:38783 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932467Ab3AIUJH (ORCPT ); Wed, 9 Jan 2013 15:09:07 -0500 Message-ID: <50EDCE61.8000001@kernel.org> Date: Wed, 09 Jan 2013 20:09:05 +0000 From: Jonathan Cameron MIME-Version: 1.0 To: Lars-Peter Clausen CC: Jonathan Cameron , linux-iio@vger.kernel.org Subject: Re: [PATCH 1/7] staging:iio:adis16080: Perform sign extension References: <1357740079-12326-1-git-send-email-lars@metafoo.de> In-Reply-To: <1357740079-12326-1-git-send-email-lars@metafoo.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 01/09/2013 02:01 PM, Lars-Peter Clausen wrote: > The adis16080 reports sample values in twos complement. So we need to perform a > sign extension on the result, otherwise negative values will be reported > incorrectly as large positive values. > > Signed-off-by: Lars-Peter Clausen Added to fixes-togreg branch of iio.git > > --- > This one should go into 3.8 if possible, the rest of the series is for 3.9 > --- > drivers/staging/iio/gyro/adis16080_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/staging/iio/gyro/adis16080_core.c b/drivers/staging/iio/gyro/adis16080_core.c > index 3525a68..149ff99 100644 > --- a/drivers/staging/iio/gyro/adis16080_core.c > +++ b/drivers/staging/iio/gyro/adis16080_core.c > @@ -69,7 +69,7 @@ static int adis16080_spi_read(struct iio_dev *indio_dev, > ret = spi_read(st->us, st->buf, 2); > > if (ret == 0) > - *val = ((st->buf[0] & 0xF) << 8) | st->buf[1]; > + *val = sign_extend32(12, ((st->buf[0] & 0xF) << 8) | st->buf[1]); > mutex_unlock(&st->buf_lock); > > return ret; >