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@redhat.com -- Changes in v2: -s/CONFIG_OLD_KERNEL_COMPAT/CONFIG_OLD_SUNXI_KERNEL_COMPAT. -Move the code block setting P(1) for old kernels to where P gets cleared --- 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..3cf3cbf 100644 --- a/arch/arm/cpu/armv7/sunxi/dram.c +++ b/arch/arm/cpu/armv7/sunxi/dram.c @@ -262,6 +262,10 @@ static void mctl_setup_dram_clock(u32 clk, u32 mbus_clk) reg_val &= ~CCM_PLL5_CTRL_K_MASK; /* set K to 0 (x1) */ reg_val &= ~CCM_PLL5_CTRL_N_MASK; /* set N to 0 (x0) */ reg_val &= ~CCM_PLL5_CTRL_P_MASK; /* set P to 0 (x1) */ +#ifdef CONFIG_OLD_SUNXI_KERNEL_COMPAT + /* Old kernels are hardcoded to P=1 (divide by 2) */ + reg_val |= CCM_PLL5_CTRL_P(1); +#endif if (clk >= 540 && clk < 552) { /* dram = 540MHz */ reg_val |= CCM_PLL5_CTRL_M(CCM_PLL5_CTRL_M_X(2)); diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig index 121d7d0..fb650c0 100644 --- a/board/sunxi/Kconfig +++ b/board/sunxi/Kconfig @@ -20,6 +20,13 @@ config SYS_SOC config FDTFILE string "Default fdtfile env setting for this board"

+config OLD_SUNXI_KERNEL_COMPAT + boolean "Enable workarounds for booting old kernels" + default n + ---help--- + Set this to enable various workarounds for old kernels, this results in + sub-optimal settings for newer kernels, only enable if needed. + config MMC0_CD_PIN string "Card detect pin for mmc0" default ""