Hi Guenter, hi Anthony, On Thu, 19 Dec 2013 10:10:49 -0800, Guenter Roeck wrote: > On Thu, Dec 19, 2013 at 03:54:54PM +0100, Jean Delvare wrote: > > BTW, you (and we) probably shouldn't waste too much energy on this. > > ADCs are only accurate to some degree anyway. If you take the > > components connected to the input into consideration, the accuracy gets > > even worse. For example, if the input voltage must be scaled down to > > fit in the ADC's range, you need at least one resistor, which in best > > cases will have a 1% accurate value (known as tolerance.) That's ten > > times the LSB of your 10-bit ADC, at which point / 1023 or / 1024 > > really makes no practical difference. Sub-percent tolerant resistors are > > expensive and rare in consumer electronics in my experience. > > True, but on the other side (and after looking into the datasheet) > the driver already calculated the voltage on adc4..6 correctly, > so unless you disagree I would like to apply the hwmon patch to -next > for consistency. The datasheet isn't the best quality I've seen. The gain values mentioned to not even match the formulas in the same cell... But I can't object to implementing conversions the way the datasheet says, no matter how suspicious. I don't really know what tree the patch is based on. Anthony said linux-next but I can't see ichg_reg_to_mA there. If volt_reg_to_mv is updated then you certainly want to update vbbat_reg_to_mv the same way, as it diverges from the datasheet just the same. Also, please update Documentation/hwmon/da9052 so that the documentation matches the actual driver code. I really would like to hear what David Dajun Chen has to say about that. He must have had a reason to use different conversions formulas than the datasheet specifies. -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
