On 07/28/11 09:08, Hennerich, Michael wrote: > Jonathan Cameron wrote on 2011-07-28: >> On 07/27/11 15:41, Michael Hennerich wrote: >>> On 07/26/2011 01:06 PM, Jonathan Cameron wrote: >>>> On 07/26/11 11:52, Michael Hennerich wrote: >>>>> On 07/26/2011 11:17 AM, Jonathan Cameron wrote: >>>>>> On 07/26/11 10:01, Hennerich, Michael wrote: >>>>>>> Jonathan Cameron wrote on 2011-07-25: >>>>>>>> Michael pointed out the issues that not having an explicit >>>>>>>> direction for channels was causing and the inconsistency of the >>>>>>>> inX and outX channel naming we got from hmwon. >>>>>>>> >>>>>>>> They are stuck with it, but we aren't, so lets fix this now. >>>>>>>> >>>>>>>> Interesting question is whether we reset the base units to be >>>>>>>> volts whilst we are at it? (for voltage channels obviously!) >>>>>>> What do you mean exactly volts versus milli volts? >>>>>> Make the in_voltage_scale correspond to conversion to volts instead >>>>>> of millivolts as now (I think). Err. Looking at it that isn't >>>>>> actually documented... oops. I wonder which drivers actually do >>>>>> that and which don't. >>>>> The ones I wrote provide the scale for millivolts. >>>>> With the recent introduction of IIO_VAL_INT_PLUS_NANO we got the >>>>> scale accurate enough for the precession 24-bit converters. >>>>> If we move to the SI base unit volt, we lose this accuracy again. >>>> Yup, that's the principal counter argument to the change. >>> If we decide to leave the milli scale for volts... Do we also want to >>> stay with milli degrees Celsius, etc.? If we do it for one, probably >>> best to do it for them all.. > > Hi Jonathan, > > So stick with the milli scale for all? Yes. > >>> >>> One other thing we should also address is the >>> byte-ordering/endianess of the scan elements stored in the ring buffers. >>> >>> Right now the scan_element type details signs, bits, storage bits and >>> shifts. However it lacks to tell the endianess within the storage bits. >>> Good point. I'd completely forgotten about that. >>> >>> How about le:s16/32>>0 or be:s16/32>>0 for example? >> Yup, that works for me. In cases where it doesn't matter they driver >> can pick one at random. > > > We need another case - Some drivers use the (be|le)(x)_to_cpu() helpers, > So in case these are used the endianess can be either or, depending on the host. > So maybe have le|be|cpu? I thought about that, but am inclined to say we just stop drivers doing the conversion. Better to leave it up to userspace? > > > Greetings, > Michael > > -- > Analog Devices GmbH Wilhelm-Wagenfeld-Str. 6 80807 Muenchen > Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368; Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin, Margaret Seif > > > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
