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MX6: Correct calculation of PLL_SYS

PATCH New Andre Renaud 2 participants 2 messages Jun 9, 2014 – Jul 9, 2014 Arm (32-bit)

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Andre Renaud

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PATCH 1/1 MX6: Correct calculation of PLL_SYS

DIV_SELECT is used as Fout = Fin * div_select / 2.0, so we should do the shift after the multiply to avoid rounding errors

Signed-off-by Andre Renaud <[email protected]>
---
 arch/arm/cpu/armv7/mx6/clock.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/arm/cpu/armv7/mx6/clock.c +1 -1
index bd65a08..7dd83ec 100644
@@ -80,7 +80,7 @@ static u32 decode_pll(enum pll_clocks pll, u32 infreq)
 		div = __raw_readl(&imx_ccm->analog_pll_sys);
 		div &= BM_ANADIG_PLL_SYS_DIV_SELECT;
 
-		return infreq * (div >> 1);
+		return (infreq * div) >> 1;
 	case PLL_BUS:
 		div = __raw_readl(&imx_ccm->analog_pll_528);
 		div &= BM_ANADIG_PLL_528_DIV_SELECT;
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1.7.9.5
#1 lore raw

PATCH 1/1 MX6: Correct calculation of PLL_SYS

arch/arm/cpu/armv7/mx6/clock.c

Quoted 11 lines · Andre Renaud

DIV_SELECT is used as Fout = Fin * div_select / 2.0, so we should do the shift after the multiply to avoid rounding errors

Signed-off-by Andre Renaud <[email protected]>
---
 arch/arm/cpu/armv7/mx6/clock.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/arm/cpu/armv7/mx6/clock.c +0 -1
index bd65a08..7dd83ec 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c

Applied to u-boot-imx, as a fix, thanks !

Best regards,
Stefano Babic

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