[U-Boot] [PATCH] Fix mx31_decode_pll

Benoît Thébaudeau benoit.thebaudeau at advansee.com
Tue Aug 14 20:43:47 CEST 2012


The MFN bit-field of the PLL registers represents a signed value. See the
reference manual.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
Cc: Stefano Babic <sbabic at denx.de>
---
 .../arch/arm/cpu/arm1136/mx31/generic.c            |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git u-boot-4d3c95f.orig/arch/arm/cpu/arm1136/mx31/generic.c u-boot-4d3c95f/arch/arm/cpu/arm1136/mx31/generic.c
index 8873fb7..3a35bfa 100644
--- u-boot-4d3c95f.orig/arch/arm/cpu/arm1136/mx31/generic.c
+++ u-boot-4d3c95f/arch/arm/cpu/arm1136/mx31/generic.c
@@ -22,6 +22,7 @@
  */
 
 #include <common.h>
+#include <div64.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/clock.h>
 #include <asm/io.h>
@@ -30,16 +31,17 @@
 static u32 mx31_decode_pll(u32 reg, u32 infreq)
 {
 	u32 mfi = GET_PLL_MFI(reg);
-	u32 mfn = GET_PLL_MFN(reg);
+	s32 mfn = GET_PLL_MFN(reg);
 	u32 mfd = GET_PLL_MFD(reg);
 	u32 pd =  GET_PLL_PD(reg);
 
 	mfi = mfi <= 5 ? 5 : mfi;
+	mfn = mfn >= 512 ? mfn - 1024 : mfn;
 	mfd += 1;
 	pd += 1;
 
-	return ((2 * (infreq >> 10) * (mfi * mfd + mfn)) /
-		(mfd * pd)) << 10;
+	return lldiv(2 * (u64)infreq * (mfi * mfd + mfn),
+		mfd * pd);
 }
 
 static u32 mx31_get_mpl_dpdgck_clk(void)


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