[U-Boot] [U-Boot, 1/4] rockchip: rk322x: set the DDR region as non-secure in SPL

[Philipp Tomsich]

Kever,

On Wed, 26 Jul 2017, Kever Yang wrote:

> Lets set the all the DDR region as non secure in SPL, the
> trust like OPTEE should have the correct setting for it if
> there is one.
>
> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
> Acked-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
>
> arch/arm/mach-rockchip/rk322x-board-spl.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm/mach-rockchip/rk322x-board-spl.c b/arch/arm/mach-rockchip/rk322x-board-spl.c
> index 15216c7..aa8a742 100644
> --- a/arch/arm/mach-rockchip/rk322x-board-spl.c
> +++ b/arch/arm/mach-rockchip/rk322x-board-spl.c
> @@ -41,6 +41,8 @@ static struct rk322x_grf * const grf = (void *)GRF_BASE;
> 		     CON_IOMUX_UART2SEL_MASK,
> 		     CON_IOMUX_UART2SEL_21 << CON_IOMUX_UART2SEL_SHIFT);
> }
> +
> +#define SGRF_DDR_CON0 0x10150000

Please use a typed const-variable (e.g. 'const u32 *') in the function 
where this is needed.

> void board_init_f(ulong dummy)
> {
> 	struct udevice *dev;
> @@ -71,6 +73,7 @@ void board_init_f(ulong dummy)
> 		return;
> 	}
>
> +	rk_clrreg(SGRF_DDR_CON0, 0x4000);

Could you add a comment here that explains what is set and what the 
meanings of these bits are?  I think I've seen a comment somewhere (ATF?)
explaining that the '4' comes from enabling some sort of bypass, but it
would be great to be able to just look here and immediately understand 
what this line does...

Also (without any comment explaining what goes on), it feels a bit odd 
that 'set all to non-secure' does not simply zero all bits.

> #if defined(CONFIG_ROCKCHIP_SPL_BACK_TO_BROM) && !defined(CONFIG_SPL_BOARD_INIT)
> 	back_to_bootrom();
> #endif
>