Re: [PATCH 1/7] staging:iio:adis16080: Perform sign extension

[Lars-Peter Clausen <lars@metafoo.de>]

On 01/09/2013 09:09 PM, Jonathan Cameron wrote:
> On 01/09/2013 02:01 PM, Lars-Peter Clausen wrote:
>> The adis16080 reports sample values in twos complement. So we need to perform a
>> sign extension on the result, otherwise negative values will be reported
>> incorrectly as large positive values.
>>
>> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> Added to fixes-togreg branch of iio.git
>>
>> ---
>> This one should go into 3.8 if possible, the rest of the series is for 3.9
>> ---
>>  drivers/staging/iio/gyro/adis16080_core.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/iio/gyro/adis16080_core.c b/drivers/staging/iio/gyro/adis16080_core.c
>> index 3525a68..149ff99 100644
>> --- a/drivers/staging/iio/gyro/adis16080_core.c
>> +++ b/drivers/staging/iio/gyro/adis16080_core.c
>> @@ -69,7 +69,7 @@ static int adis16080_spi_read(struct iio_dev *indio_dev,
>>  	ret = spi_read(st->us, st->buf, 2);
>>  
>>  	if (ret == 0)
>> -		*val = ((st->buf[0] & 0xF) << 8) | st->buf[1];
>> +		*val = sign_extend32(12, ((st->buf[0] & 0xF) << 8) | st->buf[1]);
>>  	mutex_unlock(&st->buf_lock);
>>  

Sorry, now that I look at it from a distance: This is completely wrong...
It needs to be,

sign_extend32((st->buf[0] & 0xF) << 8) | st->buf[1], 11);

Sorry again,
- Lars