linux-kernel - RE: [PATCH v2] iio: adc: add new lp8788 adc driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 16 Aug 2012 06:36:16 +0100
From:	Jonathan Cameron <jic23@...23.retrosnub.co.uk>
To:	"Kim, Milo" <Milo.Kim@...com>,
	Lars-Peter Clausen <lars@...afoo.de>,
	"jic23@....ac.uk" <jic23@....ac.uk>
CC:	"jic23@...nel.org" <jic23@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
	"sameo@...ux.intel.com" <sameo@...ux.intel.com>
Subject: RE: [PATCH v2] iio: adc: add new lp8788 adc driver



"Kim, Milo" <Milo.Kim@...com> wrote:

>> > +	switch (mask) {
>> > +	case IIO_CHAN_INFO_RAW:
>> > +		*val = result;
>> > +		return IIO_VAL_INT;
>> > +	case IIO_CHAN_INFO_SCALE:
>> > +		*val = adc_const[id] * ((result * 1000 + 500) / 1000);
>> 
>> This looks wrong. The IIO_CHAN_INFO_SCALE attribute is the factor by
>> which
>> IIO_CHAN_INFO_RAW needs to be multiplied to get the value in the
>proper
>> unit,
>> which is specified in the IIO ABI spec. E.g. milli volts for
>voltages.
>> 
>> What you return here seems to be the IIO_CHAN_INFO_PROCESSED
>attribute.
>> Which
>> basically is raw * scale.
>
>Thanks a lot for your review.
>
>Any way to get the result with offset value in the iio-consumer side?
>What I need is as below.
>
>  result = raw * scale + offset
>
>At this moment, there are two apis() for reading the iio channel
>- iio_read_channel_raw() and iio_read_channel_scale().
>
>Does it sound good if I add iio_read_channel_offset() consumer api
>using IIO_CHAN_INFO_OFFSET?

Yes. Please add that.
>
>Best Regards,
>Milo

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/