[U-Boot] [PATCH] 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 andre@bluewatersys.com --- arch/arm/cpu/armv7/mx6/clock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c index bd65a08..7dd83ec 100644 --- a/arch/arm/cpu/armv7/mx6/clock.c +++ b/arch/arm/cpu/armv7/mx6/clock.c @@ -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;

On 09/06/2014 22:47, Andre Renaud wrote:
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 andre@bluewatersys.com
arch/arm/cpu/armv7/mx6/clock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c 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
participants (2)
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Andre Renaud
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Stefano Babic