Re: [PATCH v2 0/4] iio: light: fix scale in veml6030

Javier Carrasco
2025-01-25T20:13:02Z

On Sat Jan 25, 2025 at 1:33 PM CET, Jonathan Cameron wrote:
> On Sun, 19 Jan 2025 18:31:57 +0100
> Javier Carrasco <javier.carrasco.cruz@gmail.com> wrote:
>
> > This series follows a similar approach as recently used for the veml3235
> > by using iio-gts to manage the scale as stated in the ABI. In its
> > current form, the driver exposes the hardware gain instead of the
> > multiplier for the raw value to obtain a value in lux.
> >
> > Although this driver and the veml3235 have many similarities, there are
> > two main differences in this series compared to the one used to fix the
> > other driver:
> >
> > - The veml6030 has fractional gains, which are not supported by the
> > iio-gts helpers. My first attempt was adding support for them, but
> > that made the whole iio-gts implementation more complex, cumbersome,
> > and the risk of affecting existing clients was not negligible.
> > Instead, a x8 factor has been used for the hardware gain to present
> > the minimum value (x0.125) as x1, keeping linearity. The scales
> > iio-gts generates are therefore right without any extra conversion,
> > and they match the values provided in the different datasheets.
> >
> > - This driver included a processed value for the ambient light, maybe
> > because the scale did not follow the ABI and the conversion was not
> > direct. To avoid breaking userspace, the functionality has been kept,
> > but of course using the fixed scales. In order to ease the
> > calculations, iio_gts_get_total_gain() has been exported to avoid
> > working directly with the scale in NANO, that would require 64-bit
> > operations.
> >
> > To ease the usage of the iio-gts selectors, patches to support regfields
> > and caching has been included.
> >
> > This issue has been present since the original implementation, and it
> > affects all devices it supports.
> >
> > This series has been tested with a veml7700 (same gains as veml6030) and
> > a veml6035 with positive results.
> >
> > Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
> Whilst we might consider a backport eventually. This is a huge patch
> to do that with. Hence I'll take this the slow way for next merge window.
>
> For now I've applied patches 1 and 2 in the interest of nibbling away
> at what we will need to see again ;)
>
> Jonathan
>

Thanks, Jonathan.

Could you please tell me where you applied them, so I
can rebase onto that branch? I did not find them in linux-next/master,
iio/testing or iio/togreg. Or should they show up in one of those
within the next hours/days?

Best regards,
Javier Carrasco.