On Sat, Jul 30, 2022 at 3:32 PM Jakob Hauser <jahau@xxxxxxxxxxxxxx> wrote: > On 30.07.22 13:32, Andy Shevchenko wrote: > > On Sat, Jul 30, 2022 at 1:10 AM Jakob Hauser <jahau@xxxxxxxxxxxxxx> wrote: > >> On 29.07.22 19:24, Andy Shevchenko wrote: > >>> On Fri, Jul 29, 2022 at 1:13 AM Jakob Hauser <jahau@xxxxxxxxxxxxxx> wrote: ... > >>> To the 4100 denominator: > >>> https://github.com/XPerience-AOSP-Lollipop/android_kernel_wingtech_msm8916/blob/xpe-11.1/drivers/input/misc/yas_mag_drv-yas537.c#L235, > >>> seems you can find a lot by browsing someone's code and perhaps a Git > >>> history. > >> > >> I've seen that comment before but I don't understand its meaning. > > > > It points out that there is a SMPLTIM, which I decode as Sample Time, > > which is in 4.1 msec steps (up to 255 steps). > > Also thanks for this interpretation, that makes sense. Then the > denominator consists of factor 1000 to convert microseconds back to > milliseconds and a factor of 4.1 milliseconds per step. The value > "intrvl", which is written into the YAS537_MEASURE_INTERVAL register, > would then be the number of steps of the sample time. > > However, I wouldn't add anything of this into the driver as a comment or > as a name, because we're just guessing. Or we can precisely tell that this is guesswork. Up to you. ... > I think the define and the formula both look strange. Definition is available in units.h, for most of the SI prefixes. -- With Best Regards, Andy Shevchenko
