diff options
| author | Sergej Sawazki <ce3a@gmx.de> | 2015-05-11 10:44:50 +0200 |
|---|---|---|
| committer | Michael Turquette <mturquette@linaro.org> | 2015-05-13 11:52:05 -0700 |
| commit | 2073b5e909b96f8fbc9b8a40b89c1fa316fb092c (patch) | |
| tree | b203e773113113b7e031455cd203af93cb857cef | |
| parent | 81573560150d2f1a6d8433475a3660fcbcf08519 (diff) | |
clk: si5351: fix .round_rate for multisynth 6-7
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>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
| -rw-r--r-- | drivers/clk/clk-si5351.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c index 30335d3b99af..48c5298b6bb1 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; |