Messages in this thread | | | Date | Sat, 4 Mar 2023 21:42:22 +0200 | From | Matti Vaittinen <> | Subject | Re: [PATCH v2 2/6] iio: light: Add gain-time-scale helpers |
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Hi Jonathan, all
On 3/4/23 20:35, Jonathan Cameron wrote: > On Thu, 2 Mar 2023 12:57:54 +0200 > Matti Vaittinen <mazziesaccount@gmail.com> wrote: > >> Some light sensors can adjust both the HW-gain and integration time. >> There are cases where adjusting the integration time has similar impact >> to the scale of the reported values as gain setting has. >> >> IIO users do typically expect to handle scale by a single writable 'scale' >> entry. Driver should then adjust the gain/time accordingly. >> >> It however is difficult for a driver to know whether it should change >> gain or integration time to meet the requested scale. Usually it is >> preferred to have longer integration time which usually improves >> accuracy, but there may be use-cases where long measurement times can be >> an issue. Thus it can be preferable to allow also changing the >> integration time - but mitigate the scale impact by also changing the gain >> underneath. Eg, if integration time change doubles the measured values, >> the driver can reduce the HW-gain to half. >> >> The theory of the computations of gain-time-scale is simple. However, >> some people (undersigned) got that implemented wrong for more than once. >> >> Add some gain-time-scale helpers in order to not dublicate errors in all >> drivers needing these computations. >> >> Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com> > > Probably makes sense to put the exports in their own namespace.
Andy asked for that as well. And, while I do not really see the usefulness of the namespaces when all symbols are properly prefixed (I only see added complexity there) - I agreed to use one.
> > I've been meaning to finish namespacing the rest of IIO but not > gotten around to it yet. > As this is a separate library probably makes sense to have a unique > namespace for it that the users opt in on. > Perhaps IIO_GTS makes sense?
Thanks. I think I'll use that. Although, as all of the symbols are prefixed with iio_gts - if I really saw a risk of symbol clash it would probably make more sense to use just about anything else ;) This because if someone else were prefixing symbols with iio_gts - he would likely be using the exactly same namespace.
> Otherwise, as Andy's done a detailed review of this version I'll let > you update it for those comments and take another look at v3.
This suits me fine. I have v3 almost prepared - but I'll be very much away from the computer next week so it may be the v3 will not be out until later. It may be I won't continue work with this until about after a week.
Yours, -- Matti
-- Matti Vaittinen Linux kernel developer at ROHM Semiconductors Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
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