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. > > > Or we can add a flag to the > > clk-fractional-divider code to handle this minor difference. > > This driver is used 2 register fields for numerator, denominator and > calculates both of them. > Do you think I can integrate this fractional scale into it ? > > Thanks > Hoan >
Hi Stephen, Do you have any comments ? Thanks Hoan > > > > > -- > > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > > a Linux Foundation Collaborative Project
