On Wed, Mar 30, 2016 at 9:48 AM, Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx> wrote: >> >> + case IIO_CHAN_INFO_SCALE: >> >> + /* Returns raw lux value */ >> >> + *val = 1; >> > >> > not needed to scale by 1.0 >> > >> >> + *val2 = 0; >> >> + return IIO_VAL_INT; >> >> How do you mean? >> If I don't implement this (just let this function return negative) >> this happens: >> >> iio:device1 ls >> dev of_node >> in_illuminance_integration_time power >> in_illuminance_raw subsystem >> in_illuminance_scale uevent >> >> iio:device1 cat in_illuminance_scale >> cat: read error: Invalid argument >> >> Do you mean all userspace programs should assume scale by 1x >> if they get an error when they try to read the scale file, or is there >> a bug in IIO such that this file should return "1" if the callback asking for >> IIO_CHAN_INFO_SCALE returns negative? > > IIO_CHAN_INFO_SCALE is optional, if it is not given 1.0 is to be assumed > > you do not give _OFFSET as well and assume that offset is 0.0 when > interpreting _RAW I see what you mean, but the actual error I did was this: > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE) | > + BIT(IIO_CHAN_INFO_INT_TIME) If I drop IIO_CHAN_INFO_SCALE I don't get the file in sysfs even and then the userspace should assume scale by 1. I assume. OK changed it like so... Yours, Linus Walleij -- 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
