[U-Boot] [PATCH] mx6: clock: Fix the calculation of PLL_ENET frequency

[U-Boot] [PATCH] mx6: clock: Fix the calculation of PLL_ENET frequency

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam@freescale.com>

According to the mx6 quad reference manual, the DIV_SELECT field of register
CCM_ANALOG_PLL_ENETn has the following meaning:

"Controls the frequency of the ethernet reference clock.
- 00 - 25MHz
- 01 - 50MHz
- 10 - 100MHz
- 11 - 125MHz"

Current logic does not handle the 25MHz case correctly, so fix it.

Signed-off-by: Rabeeh Khoury <rabeeh@solid-run.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
 arch/arm/cpu/armv7/mx6/clock.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index 873d9d0..eab8596 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -94,7 +94,10 @@ static u32 decode_pll(enum pll_clocks pll, u32 infreq)
 		div = __raw_readl(&imx_ccm->analog_pll_enet);
 		div &= BM_ANADIG_PLL_ENET_DIV_SELECT;
 
-		return (div == 3 ? 125000000 : 25000000 * (div << 1));
+		if (div == 0)
+			return 25000000;
+		else
+			return (div == 3 ? 125000000 : 25000000 * (div << 1));
 	default:
 		return 0;
 	}
-- 
1.8.1.2

[U-Boot] [PATCH] mx6: clock: Fix the calculation of PLL_ENET frequency

[Troy Kisky]

On 12/3/2013 12:56 PM, Fabio Estevam wrote:
> From: Fabio Estevam <fabio.estevam@freescale.com>
>
> According to the mx6 quad reference manual, the DIV_SELECT field of register
> CCM_ANALOG_PLL_ENETn has the following meaning:
>
> "Controls the frequency of the ethernet reference clock.
> - 00 - 25MHz
> - 01 - 50MHz
> - 10 - 100MHz
> - 11 - 125MHz"
>
> Current logic does not handle the 25MHz case correctly, so fix it.
>
> Signed-off-by: Rabeeh Khoury <rabeeh@solid-run.com>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>   arch/arm/cpu/armv7/mx6/clock.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
> index 873d9d0..eab8596 100644
> --- a/arch/arm/cpu/armv7/mx6/clock.c
> +++ b/arch/arm/cpu/armv7/mx6/clock.c
> @@ -94,7 +94,10 @@ static u32 decode_pll(enum pll_clocks pll, u32 infreq)
>   		div = __raw_readl(&imx_ccm->analog_pll_enet);
>   		div &= BM_ANADIG_PLL_ENET_DIV_SELECT;
>   
> -		return (div == 3 ? 125000000 : 25000000 * (div << 1));
> +		if (div == 0)
> +			return 25000000;
> +		else
> +			return (div == 3 ? 125000000 : 25000000 * (div << 1));
>   	default:
>   		return 0;
>   	}
How about just

     return 25000000 * (div + (div >> 1) + 1);

[U-Boot] [PATCH] mx6: clock: Fix the calculation of PLL_ENET frequency

[Fabio Estevam]

Hi Troy,

On Tue, Dec 3, 2013 at 6:15 PM, Troy Kisky
<troy.kisky@boundarydevices.com> wrote:

> How about just
>
>     return 25000000 * (div + (div >> 1) + 1);

That looks much better, thanks!