From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:49021 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753338AbcDCKRv (ORCPT ); Sun, 3 Apr 2016 06:17:51 -0400 Subject: Re: [PATCH v2 1/1] iio: accel: bmc150: fix endianness when reading axes To: Irina Tirdea , linux-iio@vger.kernel.org References: <1459254945-2012-1-git-send-email-irina.tirdea@intel.com> Cc: linux-kernel@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald From: Jonathan Cameron Message-ID: <5700EDCD.7030909@kernel.org> Date: Sun, 3 Apr 2016 11:17:49 +0100 MIME-Version: 1.0 In-Reply-To: <1459254945-2012-1-git-send-email-irina.tirdea@intel.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 29/03/16 13:35, Irina Tirdea wrote: > For big endian platforms, reading the axes will return > invalid values. > > The device stores each axis value in a 16 bit little > endian register. The driver uses regmap_read_bulk to get > the axis value, resulting in a 16 bit little endian value. > This needs to be converted to cpu endianness to work > on big endian platforms. > > Fix endianness for big endian platforms by converting > the values for the axes read from little endian to > cpu. > > This is also partially fixed in commit b6fb9b6d6552 ("iio: > accel: bmc150: optimize transfers in trigger handler"). > > Signed-off-by: Irina Tirdea Applied to the fixes-togreg-post-rc1 branch of iio.git and marked for stable. > --- > > Changes from v1: > - pass sizeof(raw_val) to regmap_bulk_read instead of > hardcoded value > > drivers/iio/accel/bmc150-accel-core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c > index c73331f7..2072a31 100644 > --- a/drivers/iio/accel/bmc150-accel-core.c > +++ b/drivers/iio/accel/bmc150-accel-core.c > @@ -547,7 +547,7 @@ static int bmc150_accel_get_axis(struct bmc150_accel_data *data, > { > int ret; > int axis = chan->scan_index; > - unsigned int raw_val; > + __le16 raw_val; > > mutex_lock(&data->mutex); > ret = bmc150_accel_set_power_state(data, true); > @@ -557,14 +557,14 @@ static int bmc150_accel_get_axis(struct bmc150_accel_data *data, > } > > ret = regmap_bulk_read(data->regmap, BMC150_ACCEL_AXIS_TO_REG(axis), > - &raw_val, 2); > + &raw_val, sizeof(raw_val)); > if (ret < 0) { > dev_err(data->dev, "Error reading axis %d\n", axis); > bmc150_accel_set_power_state(data, false); > mutex_unlock(&data->mutex); > return ret; > } > - *val = sign_extend32(raw_val >> chan->scan_type.shift, > + *val = sign_extend32(le16_to_cpu(raw_val) >> chan->scan_type.shift, > chan->scan_type.realbits - 1); > ret = bmc150_accel_set_power_state(data, false); > mutex_unlock(&data->mutex); > @@ -988,6 +988,7 @@ static const struct iio_event_spec bmc150_accel_event = { > .realbits = (bits), \ > .storagebits = 16, \ > .shift = 16 - (bits), \ > + .endianness = IIO_LE, \ > }, \ > .event_spec = &bmc150_accel_event, \ > .num_event_specs = 1 \ >