Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755264AbcC1RnA (ORCPT ); Mon, 28 Mar 2016 13:43:00 -0400 Received: from ns.pmeerw.net ([84.19.176.92]:41901 "EHLO pmeerw.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754046AbcC1Rm6 (ORCPT ); Mon, 28 Mar 2016 13:42:58 -0400 Date: Mon, 28 Mar 2016 19:42:56 +0200 (CEST) From: Peter Meerwald-Stadler To: Irina Tirdea cc: Jonathan Cameron , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Hartmut Knaack , Lars-Peter Clausen , Markus Pargmann Subject: Re: [PATCH 1/1] iio: accel: bmc150: fix endianness when reading axes In-Reply-To: <1459185141-18319-1-git-send-email-irina.tirdea@intel.com> Message-ID: References: <1459185141-18319-1-git-send-email-irina.tirdea@intel.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2147 Lines: 64 On Mon, 28 Mar 2016, 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"). looks good in bmc150_accel_get_axis() the call to regmap_bulk_read() could now pass sizeof(raw_val) instead of 2 > Signed-off-by: Irina Tirdea > --- > drivers/iio/accel/bmc150-accel-core.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c > index c73331f7..5b64c3e 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); > @@ -564,7 +564,7 @@ static int bmc150_accel_get_axis(struct bmc150_accel_data *data, > 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 \ > -- Peter Meerwald-Stadler +43-664-2444418 (mobile)