On Mon, Aug 15, 2016 at 5:14 PM, Stephen Boyd <sb...@codeaurora.org> wrote: > Sorry I was away for some time. > > On 08/08, Hoan Tran wrote: >> On Wed, Jul 20, 2016 at 11:36 AM, Hoan Tran <hot...@apm.com> wrote: >> > On Fri, Jul 1, 2016 at 5:09 PM, Hoan Tran <hot...@apm.com> wrote: >> >> >> >> Hi Stephen, >> >> >> >> On Fri, Jul 1, 2016 at 11:38 AM, Stephen Boyd <sb...@codeaurora.org> >> >> wrote: >> >> > Sorry I replied offlist before. Pressed the wrong key. >> >> > >> >> > On 06/30, Hoan Tran wrote: >> >> >> On Thu, Jun 30, 2016 at 1:23 PM, Stephen Boyd <sb...@codeaurora.org> >> >> >> wrote: >> >> >> > >> >> >> > How is this different from clk-fractional-divider.c? >> >> >> > >> >> >> >> >> >> This is a driver which clock output is multiplied with a fixed >> >> >> fractional >> >> >> scale (denominator). >> >> >> A field inside a register is used to configure the multiplier. >> >> >> >> >> >> Example: With fractional scale is 1/8. >> >> >> Freq_out = Freq_parent * multiplier * (1/8) >> >> >> >> >> >> For fractional-divider, there are 2 fields of a register are used which >> >> >> - A field for numerator >> >> >> - A field for denominator >> >> >> Freq_out = Freq_parent * numerator / denominator >> >> >> >> >> > >> >> > Ok so the difference is that the denominator is a fixed value? >> >> >> >> The major difference is a fixed denominator. >> >> Another difference is: >> >> In case CLK_FRACTIONAL_SCALE_INVERTED=1, the freq_out is calculated as >> >> below >> >> >> >> Freq_out = Freq_parent * (fixed_denominator - multiplier) / >> >> fixed_denominator. >> >> >> >> > Perhaps that can be modeled as a clk-multiplier that is used as >> >> > the only parent of a fixed divider? >> >> >> >> Because of CLK_FRACTIONAL_SCALE_INVERTED flag, I don't know how to >> >> model as a clk-multiplier. And how to pass the fixed denominator into >> >> a clk-multiplier. > > Would it be possible to add a flag to clk-multiplier to handle > the inverted case? I haven't seen anyone else with hardware like > that though, so perhaps the implementation should just go into > the vendor specific clk driver instead of being written > as a "basic clk type".
Yes, I'll move it into our clk-xgene driver. Thanks Hoan > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project
