Messages in this thread |  | | Date | Sat, 11 Apr 2015 13:01:31 +0200 | From | Sebastian Hesselbarth <> | Subject | Re: [PATCH v3] clk: si5351: fix .round_rate for multisynth 6-7 |
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On 10.04.2015 21:14, Sergej Sawazki wrote: > The divider calculation for multisynth 6 and 7 differs from the > calculation for multisynth 0-5. > > For MS6 and MS7, set MSx_P1 directly, MSx_P1 = divide value > [AN619, p. 6]. > > Referenced document: > [AN619] Manually Generating an Si5351 Register Map, Rev. 0.4 > > Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
Looks good to me now,
Reviewed-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Thanks!
> --- > drivers/clk/clk-si5351.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c > index 44ea107..8e90bdd 100644 > --- a/drivers/clk/clk-si5351.c > +++ b/drivers/clk/clk-si5351.c > @@ -552,7 +552,8 @@ static const struct clk_ops si5351_pll_ops = { > * MSx_P2[19:0] = 128 * b - c * floor(128 * b/c) = (128*b) mod c > * MSx_P3[19:0] = c > * > - * MS[6,7] are integer (P1) divide only, P2 = 0, P3 = 0 > + * MS[6,7] are integer (P1) divide only, P1 = divide value, > + * P2 and P3 are not applicable > * > * for 150MHz < fOUT <= 160MHz: > * > @@ -679,6 +680,16 @@ static long si5351_msynth_round_rate(struct clk_hw *hw, unsigned long rate, > c = 1; > > *parent_rate = a * rate; > + } else if (hwdata->num >= 6) { > + /* determine the closest integer divider */ > + a = DIV_ROUND_CLOSEST(*parent_rate, rate); > + if (a < SI5351_MULTISYNTH_A_MIN) > + a = SI5351_MULTISYNTH_A_MIN; > + if (a > SI5351_MULTISYNTH67_A_MAX) > + a = SI5351_MULTISYNTH67_A_MAX; > + > + b = 0; > + c = 1; > } else { > unsigned long rfrac, denom; > > @@ -692,9 +703,7 @@ static long si5351_msynth_round_rate(struct clk_hw *hw, unsigned long rate, > a = *parent_rate / rate; > if (a < SI5351_MULTISYNTH_A_MIN) > a = SI5351_MULTISYNTH_A_MIN; > - if (hwdata->num >= 6 && a > SI5351_MULTISYNTH67_A_MAX) > - a = SI5351_MULTISYNTH67_A_MAX; > - else if (a > SI5351_MULTISYNTH_A_MAX) > + if (a > SI5351_MULTISYNTH_A_MAX) > a = SI5351_MULTISYNTH_A_MAX; > > /* find best approximation for b/c = fVCO mod fOUT */ > @@ -723,6 +732,10 @@ static long si5351_msynth_round_rate(struct clk_hw *hw, unsigned long rate, > hwdata->params.p3 = 1; > hwdata->params.p2 = 0; > hwdata->params.p1 = 0; > + } else if (hwdata->num >= 6) { > + hwdata->params.p3 = 0; > + hwdata->params.p2 = 0; > + hwdata->params.p1 = a; > } else { > hwdata->params.p3 = c; > hwdata->params.p2 = (128 * b) % c; >
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