Commit 2073b5e9 authored by Sergej Sawazki's avatar Sergej Sawazki Committed by Michael Turquette
Browse files

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: default avatarSergej Sawazki <ce3a@gmx.de>
Signed-off-by: default avatarMichael Turquette <mturquette@linaro.org>
parent 81573560

drivers/clk/clk-si5351.c

+17 −4
Original line number Diff line number Diff line
@@ -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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