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. > > Move to IIO_VAL_INT_PLUS_PICO? Tricky as then we have holes (size of int on 32 bit machines isn't large enough...). That's probably not a problem, but would mean keeping a close eye on new drivers to make sure any computed values don't fall foul of the hole. When constants are used it will give a compile warning so that would be fine. >>> Or given the fact that we have some current converter currently as inX and outX - >> We do? Ouch. In the 'interesting' drivers or in the clean ones? > From top of my head I know the AD5446/AD5444 are current output DACs. > But the same driver also handles various other voltage output DACs. > I can make sure once we move this driver to channel spec and iio_info:write_raw > we get the units right. Good to know where this is happening. Clearly no driver is going out of staging until it uses chan_spec anyway so we'll get them sorted at the conversion stage as you suggest. Jonathan -- 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
