iio: common: st_sensors: fix channel data parsing

Using realbits as i2c/spi read len, when that value is not byte aligned
(e.g 12 bits), lead to skip msb part of out data registers.
Fix this taking into account scan_type.shift in addition to
scan_type.realbits as read length:

read_len = DIV_ROUND_UP(realbits + shift, 8)

This fix has been tested on 8, 12, 16, 24 bit sensors

Fixes: e7385de529 ("iio:st_sensors: align on storagebits boundaries")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Lorenzo Bianconi 2016-11-16 22:15:28 +01:00 committed by Jonathan Cameron
parent b4e8a0eb71
commit 65c8aea07d
2 changed files with 6 additions and 2 deletions

View file

@ -30,7 +30,9 @@ static int st_sensors_get_buffer_element(struct iio_dev *indio_dev, u8 *buf)
for_each_set_bit(i, indio_dev->active_scan_mask, num_data_channels) {
const struct iio_chan_spec *channel = &indio_dev->channels[i];
unsigned int bytes_to_read = channel->scan_type.realbits >> 3;
unsigned int bytes_to_read =
DIV_ROUND_UP(channel->scan_type.realbits +
channel->scan_type.shift, 8);
unsigned int storage_bytes =
channel->scan_type.storagebits >> 3;

View file

@ -483,8 +483,10 @@ static int st_sensors_read_axis_data(struct iio_dev *indio_dev,
int err;
u8 *outdata;
struct st_sensor_data *sdata = iio_priv(indio_dev);
unsigned int byte_for_channel = ch->scan_type.realbits >> 3;
unsigned int byte_for_channel;
byte_for_channel = DIV_ROUND_UP(ch->scan_type.realbits +
ch->scan_type.shift, 8);
outdata = kmalloc(byte_for_channel, GFP_KERNEL);
if (!outdata)
return -ENOMEM;