[U-Boot] [PATCH 3/3] sunxi: Add CONFIG_OLD_KERNEL_COMPAT Kconfig option

[Ian Campbell]

On Wed, 2014-10-22 at 15:44 +0200, Hans de Goede wrote:
> Add a Kconfig option which users can select when they want to boot older
> kernels, e.g. the linux-sunxi 3.4 kernels. For now this just forces the pll5
> "p" value to 1 (divide by 2) as that is what those kernels are hardcoded too,
> in the future this may enable further workarounds.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  arch/arm/cpu/armv7/sunxi/dram.c | 4 ++++
>  board/sunxi/Kconfig             | 7 +++++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv7/sunxi/dram.c b/arch/arm/cpu/armv7/sunxi/dram.c
> index 0cbcf57..c0dc456 100644
> --- a/arch/arm/cpu/armv7/sunxi/dram.c
> +++ b/arch/arm/cpu/armv7/sunxi/dram.c
> @@ -293,6 +293,10 @@ static void mctl_setup_dram_clock(u32 clk, u32 mbus_clk)
>  		reg_val |= CCM_PLL5_CTRL_K(CCM_PLL5_CTRL_K_X(2));
>  		reg_val |= CCM_PLL5_CTRL_N(CCM_PLL5_CTRL_N_X(clk / 24));
>  	}
> +#ifdef CONFIG_OLD_KERNEL_COMPAT
> +	/* Old kernels are hardcoded to P=1 (divide by 2) */
> +	reg_val |= CCM_PLL5_CTRL_P(1);
> +#endif

I think this would be better placed above the if/else ladder, just next
to the:
    reg_val &= ~CCM_PLL5_CTRL_P_MASK;               /* set P to 0 (x1) */
i.e. keep the frobbings of P in the same place.

Ian.