Re: [PATCH 1/3] iio:humidity:si7020: replaced bitmask on humidity values with range check

["Nicola Corna" <nicola@corna.info>]

August 20 2015 10:49 PM, "Hartmut Knaack" <knaack.h@gmx.de> wrote:
> Nicola Corna schrieb am 20.08.2015 um 16:11:
> 
>> The maximum possible value for the relative humidity is 55575 (100%RH).
>> This value, if shifted right by 2 bits, uses 14 bits and masking it with
>> a 12 bit mask removes 2 meaningful bits.
>> The masking has been replaced with a range check that sets the minimum
>> value at 3194 (0%RH) and the maximum at 55575 (100%RH).
> 
> Hmm, I guess the mask should have been applied for bits 13:2, but your
> solution confirms better to the data sheet. Just one essential detail:
> The raw sensor data has already been divided by 4 when you do the boundary
> check. So, you need to divide the boundaries, as well.
> Btw, you can make this a one-liner using clamp_val, check it out: [1]
> 
> [1]http://lxr.free-electrons.com/source/include/linux/kernel.h#L795
> 

Yes, you're right. Thanks.
Forgive me for my ignorance, but do I have now to upload the [PATCH v2] for
all the three patches?

>> Signed-off-by: Nicola Corna <nicola@corna.info>
>> ---
>> drivers/iio/humidity/si7020.c | 12 ++++++++++--
>> 1 file changed, 10 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c
>> index fa3b809..62fdbcf 100644
>> --- a/drivers/iio/humidity/si7020.c
>> +++ b/drivers/iio/humidity/si7020.c
>> @@ -57,8 +57,16 @@ static int si7020_read_raw(struct iio_dev *indio_dev,
>> if (ret < 0)
>> return ret;
>> *val = ret >> 2;
>> - if (chan->type == IIO_HUMIDITYRELATIVE)
>> - *val &= GENMASK(11, 0);
>> + /*
>> + * Humidity values can sligthly exceed the 0-100%RH
>> + * range and should be corrected by software
>> + */
>> + if (chan->type == IIO_HUMIDITYRELATIVE) {
>> + if (*val < 3194) /* 0%RH */
>> + *val = 3194;
>> + else if (*val > 55575) /* 100%RH */
>> + *val = 55575;
>> + }
>> return IIO_VAL_INT;
>> case IIO_CHAN_INFO_SCALE:
>> if (chan->type == IIO_TEMP)