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 <c...@gmx.de>
---
drivers/clk/clk-si5351.c | 37 ++++++++++++++++++++-----------------
1 file changed, 20 insertions(+), 17 deletions(-)
diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c
index 44ea107..1029bf7 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:
*
@@ -645,7 +646,7 @@ static long si5351_msynth_round_rate(struct clk_hw *hw,
unsigned long rate,
struct si5351_hw_data *hwdata =
container_of(hw, struct si5351_hw_data, hw);
unsigned long long lltmp;
- unsigned long a, b, c;
+ unsigned long a, b = 0, c = 1;
int divby4;
/* multisync6-7 can only handle freqencies < 150MHz */
@@ -675,9 +676,6 @@ static long si5351_msynth_round_rate(struct clk_hw *hw,
unsigned long rate,
} else
a = 4;
- b = 0;
- c = 1;
-
*parent_rate = a * rate;
} else {
unsigned long rfrac, denom;
@@ -698,18 +696,19 @@ static long si5351_msynth_round_rate(struct clk_hw *hw,
unsigned long rate,
a = SI5351_MULTISYNTH_A_MAX;
/* find best approximation for b/c = fVCO mod fOUT */
- denom = 1000 * 1000;
- lltmp = (*parent_rate) % rate;
- lltmp *= denom;
- do_div(lltmp, rate);
- rfrac = (unsigned long)lltmp;
-
- b = 0;
- c = 1;
- if (rfrac)
- rational_best_approximation(rfrac, denom,
- SI5351_MULTISYNTH_B_MAX, SI5351_MULTISYNTH_C_MAX,
- &b, &c);
+ if (hwdata->num <= 5) {
+ denom = 1000 * 1000;
+ lltmp = (*parent_rate) % rate;
+ lltmp *= denom;
+ do_div(lltmp, rate);
+ rfrac = (unsigned long)lltmp;
+
+ if (rfrac)
+ rational_best_approximation(rfrac, denom,
+ SI5351_MULTISYNTH_B_MAX,
+ SI5351_MULTISYNTH_C_MAX,
+ &b, &c);
+ }
}
/* recalculate rate by fOUT = fIN / (a + b/c) */
@@ -723,6 +722,10 @@ 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 = c;
+ hwdata->params.p2 = b;
+ hwdata->params.p1 = a;
} else {
hwdata->params.p3 = c;
hwdata->params.p2 = (128 * b) % c;
--
1.9.1
--
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