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 --- 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 reg_val &= ~CCM_PLL5_CTRL_VCO_GAIN; /* PLL VCO Gain off */ reg_val |= CCM_PLL5_CTRL_EN; /* PLL On */ writel(reg_val, &ccm->pll5_cfg); diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig index 66261fc..0331088 100644 --- a/board/sunxi/Kconfig +++ b/board/sunxi/Kconfig @@ -19,6 +19,13 @@ config SYS_SOC config FDTFILE string "Default fdtfile env setting for this board"
+config OLD_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 ""