On Tuesday 01 September 2015 13:36:28 Geert Uytterhoeven wrote: > On Tue, Sep 1, 2015 at 12:59 PM, Magnus Damm <[email protected]> wrote: > >>> +/* > >>> + * MD EXTAL PLL0 PLL1 PLL2 PLL3 > >>> PLL4 > >>> + * 14 13 19 17 (MHz) *1 *1 *1 > >>> + *------------------------------------------------------------------- > >>> + * 0 0 0 0 16.66 x 1 x180/2 x192/2 x144/2 x192 > >>> x144 > >>> + * 0 0 0 1 16.66 x 1 x180/2 x192/2 x144/2 x128 > >>> x144 > >>> + * 0 0 1 0 Prohibited setting > >>> + * 0 0 1 1 16.66 x 1 x180/2 x192/2 x144/2 x192 > >>> x144 > >>> + * 0 1 0 0 20 x 1 x150/2 x156/2 x120/2 x156 > >>> x120 > >>> + * 0 1 0 1 20 x 1 x150/2 x156/2 x120/2 x106 > >>> x120 > >>> + * 0 1 1 0 Prohibited setting > >>> + * 0 1 1 1 20 x 1 x150/2 x156/2 x120/2 x156 > >>> x120 > >>> + * 1 0 0 0 25 x 1 x120/2 x128/2 x96/2 x128 > >>> x96 > >>> + * 1 0 0 1 25 x 1 x120/2 x128/2 x96/2 x84 > >>> x96 > >>> + * 1 0 1 0 Prohibited setting > >>> + * 1 0 1 1 25 x 1 x120/2 x128/2 x96/2 x128 > >>> x96 > >>> + * 1 1 0 0 33.33 / 2 x180/2 x192/2 x144/2 x192 > >>> x144 > >>> + * 1 1 0 1 33.33 / 2 x180/2 x192/2 x144/2 x128 > >>> x144 > >>> + * 1 1 1 0 Prohibited setting > >>> + * 1 1 1 1 33.33 / 2 x180/2 x192/2 x144/2 x192 > >>> x144 > >>> + * > >>> + * *1 : datasheet indicates VCO output (PLLx = VCO/2) > >> > >> As explained in a separate e-mail there's a few clocks on R8A7795 that > >> derive directly from PLL1 VCO. I thus wonder whether we shouldn't expose > >> the PLL1 clock as the VCO output and create VCO/2 using a fixed factor > >> clock in DT. > > > > Do you think that would reduce complexity or simplify the code? If so > > I think we should do it. Otherwise I think it makes sense to simply > > follow the data sheet. > > It would avoid having to apply a multiplier of two to the RPC clock.
And it would match the hardware clock tree topology. Applying a multiplier to the RPC clock is a hack I can live with though, so I'll let you decide which option is best, but in general matching the hardware seems a good idea to me. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
