From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from zone0.gcu-squad.org ([212.85.147.21]:34908 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714Ab1J0O4o (ORCPT ); Thu, 27 Oct 2011 10:56:44 -0400 Date: Thu, 27 Oct 2011 16:56:32 +0200 From: Jean Delvare To: Laurent Pinchart Cc: Jonathan Cameron , linux-media@vger.kernel.org, kernel@pengutronix.de Subject: Re: [PATCH] v4l: mt9p031/mt9t001: Use i2c_smbus_{read|write}_word_swapped() Message-ID: <20111027165632.57875cbb@endymion.delvare> In-Reply-To: <201110221057.54573.laurent.pinchart@ideasonboard.com> References: <20111021144652.6aa97c8f@endymion.delvare> <1319203825-23247-1-git-send-email-jic23@cam.ac.uk> <201110221057.54573.laurent.pinchart@ideasonboard.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On Sat, 22 Oct 2011 10:57:54 +0200, Laurent Pinchart wrote: > The MT9P031 and MT9T001 sensors transfer 16-bit data on the I2C bus in > swapped order. Let the I2C core handle byte order by using the > i2c_smbus_{read|write}_word_swapped() functions. > > Signed-off-by: Laurent Pinchart As far as I can tell, this fixes a bug too, the original code would not work on big-endian machines. Acked-by: Jean Delvare > --- > drivers/media/video/mt9p031.c | 5 ++--- > drivers/media/video/mt9t001.c | 5 ++--- > 2 files changed, 4 insertions(+), 6 deletions(-) > > diff --git a/drivers/media/video/mt9p031.c b/drivers/media/video/mt9p031.c > index 5cfa39f..aa01c4b 100644 > --- a/drivers/media/video/mt9p031.c > +++ b/drivers/media/video/mt9p031.c > @@ -131,13 +131,12 @@ static struct mt9p031 *to_mt9p031(struct v4l2_subdev *sd) > > static int mt9p031_read(struct i2c_client *client, u8 reg) > { > - s32 data = i2c_smbus_read_word_data(client, reg); > - return data < 0 ? data : be16_to_cpu(data); > + return i2c_smbus_read_word_swapped(client, reg); > } > > static int mt9p031_write(struct i2c_client *client, u8 reg, u16 data) > { > - return i2c_smbus_write_word_data(client, reg, cpu_to_be16(data)); > + return i2c_smbus_write_word_swapped(client, reg, data); > } > > static int mt9p031_set_output_control(struct mt9p031 *mt9p031, u16 clear, > diff --git a/drivers/media/video/mt9t001.c b/drivers/media/video/mt9t001.c > index cac1416..2ea6a08 100644 > --- a/drivers/media/video/mt9t001.c > +++ b/drivers/media/video/mt9t001.c > @@ -132,13 +132,12 @@ static inline struct mt9t001 *to_mt9t001(struct v4l2_subdev *sd) > > static int mt9t001_read(struct i2c_client *client, u8 reg) > { > - s32 data = i2c_smbus_read_word_data(client, reg); > - return data < 0 ? data : be16_to_cpu(data); > + return i2c_smbus_read_word_swapped(client, reg); > } > > static int mt9t001_write(struct i2c_client *client, u8 reg, u16 data) > { > - return i2c_smbus_write_word_data(client, reg, cpu_to_be16(data)); > + return i2c_smbus_write_word_swapped(client, reg, data); > } > > static int mt9t001_set_output_control(struct mt9t001 *mt9t001, u16 clear, -- Jean Delvare