On Tue, Mar 14, 2023 at 6:22 PM Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Tue, Mar 14, 2023 at 2:12 PM Martin Kurbanov
> <mmkurbanov@xxxxxxxxxxxxxx> wrote:
> > On 2023-03-01 00:51, Andy Shevchenko wrote:
...
> > >> +static int aw200xx_set_imax(const struct aw200xx *const chip,
> > >> + u32 led_imax_microamp)
> > >> +{
> > >> + struct imax_global {
> > >> + u32 regval;
> > >> + u32 microamp;
> > >> + } imaxs[] = {
> > >> + { 8, 3300 },
> > >> + { 9, 6700 },
> > >> + { 0, 10000 },
> > >> + { 11, 13300 },
> > >> + { 1, 20000 },
> > >> + { 13, 26700 },
> > >> + { 2, 30000 },
> > >> + { 3, 40000 },
> > >> + { 15, 53300 },
> > >> + { 4, 60000 },
> > >> + { 5, 80000 },
> > >> + { 6, 120000 },
> > >> + { 7, 160000 },
> > >
> > > This looks a bit random. Is there any pattern on how value is
> > > connected to the register value?
> >
> > There is no ability to create any pattern here, because this table data
> > doesn’t have any regularity.
>
> There is a clear pattern.
>
> You have two tables, i.e. with multiplier 10000 and second one with
> multiplier 3333 (table in the datasheet seems bad from a math
> perspective). And it's even shown correctly in the datasheet.
>
> With this mix you missed 10.
>
> The coefficient table is 1,2,3,4,6,8,12,16 for both tables.
>
> Hence you need one table and two multipliers.
>
> Please, rewrite accordingly.
JFYI: You may see how I killed a table in one driver due to missing
understanding that there is a pattern.
9df461eca18f ("spi: pxa2xx: replace ugly table by approximation")
--
With Best Regards,
Andy Shevchenko
