On Tue, Sep 23, 2014 at 9:04 PM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
> We shouldn't be doing the unit conversion in kernel space. Just report the
> raw value for the property and the scale. Userspace can do the conversion if
> necessary.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> ---
> drivers/staging/iio/impedance-analyzer/ad5933.c | 17 ++++++++---------
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
> index b6bd609..ebff637 100644
> --- a/drivers/staging/iio/impedance-analyzer/ad5933.c
> +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
> @@ -113,7 +113,8 @@ static const struct iio_chan_spec ad5933_channels[] = {
> .type = IIO_TEMP,
> .indexed = 1,
> .channel = 0,
> - .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> .address = AD5933_REG_TEMP_DATA,
> .scan_index = -1,
> .scan_type = {
> @@ -522,10 +523,9 @@ static int ad5933_read_raw(struct iio_dev *indio_dev,
> __be16 dat;
> int ret = -EINVAL;
>
> - mutex_lock(&indio_dev->mlock);
> switch (m) {
> case IIO_CHAN_INFO_RAW:
> - case IIO_CHAN_INFO_PROCESSED:
> + mutex_lock(&indio_dev->mlock);
> if (iio_buffer_enabled(indio_dev)) {
> ret = -EBUSY;
> goto out;
> @@ -543,14 +543,13 @@ static int ad5933_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> goto out;
> mutex_unlock(&indio_dev->mlock);
> - ret = be16_to_cpu(dat);
> - /* Temp in Milli degrees Celsius */
> - if (ret < 8192)
> - *val = ret * 1000 / 32;
> - else
> - *val = (ret - 16384) * 1000 / 32;
> + *val = sign_extend32(be16_to_cpu(dat), 13);
>
> return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + *val = 1000;
> + *val2 = 5;
> + return IIO_VAL_FRACTIONAL_LOG2;
> }
>
> out:
Is it possible to reach this line with mutex not acquired?
out:
mutex_unlock(&indio_dev->mlock);
return ret;
Daniel.
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