From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Lesiak Date: Fri, 29 May 2015 23:12:37 +0000 Subject: Re: [lm-sensors] [PATCH v2] hwmon: ntc: use iio_read_channel_processed if possible Message-Id: <5568F265.9020505@licor.com> List-Id: References: <1432821471-17373-1-git-send-email-chris.lesiak@licor.com> In-Reply-To: <1432821471-17373-1-git-send-email-chris.lesiak@licor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org On 05/29/2015 05:47 PM, Guenter Roeck wrote: > On 05/28/2015 06:57 AM, Chris Lesiak wrote: >> The function ntc_adc_iio_read (now ntc_adc_iio_read_raw) assumes >> both a 12 bit ADC and that pullup_uv is the same as the ADC reference >> voltage. If either assumption is false, then the result is incorrect. >> >> For iio channels supporting either IIO_CHAN_INFO_PROCESSED or >> IIO_CHAN_INFO_SCALE, the new ntc_adc_iio_read will be used. It gets >> microvolts directly with a call to iio_read_channel_processed. >> >> Signed-off-by: Chris Lesiak > > Looks ok to me. Applied to -next. > > Thanks, > Guenter > Guenter, I am sorry to say that I must ask you to please revert that patch. I had a mistaken belief that iio_read_channel_processed returned microvolts directly. But the standard voltage unit for the iio subsystem is in fact millivolts, just as in the hwmon subsystem. I was confused by a broken iio adc driver that in fact did scale results to microvolts. The combination resulted in tests that pased when they shouldn't have. Early next week I hope to submit a new patch that uses iio_read_channel_raw and converts the result to microvolts with iio_convert_raw_to_processed. That allows an additional scale actor of 1000. Thank you for your time and patience reviewing these patches. Chris _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors