[RFC 1/2] rockchip: sdram: Allow board/soc specific RAM bank logic

[Jonas Karlman]

Hi Chris,

On 2024-03-30 06:05, Chris Morgan wrote:
> From: Chris Morgan <macromorgan at hotmail.com>
> 
> Allow individual boards or SoCs to alter the RAM bank addition logic
> by defining a __weak function that these boards can then override
> if needed. In the event this function fails, fallback to the default
> detection logic.
> 
> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
> ---
>  arch/arm/mach-rockchip/sdram.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm/mach-rockchip/sdram.c b/arch/arm/mach-rockchip/sdram.c
> index 0d9a0aef6f..53aa19feca 100644
> --- a/arch/arm/mach-rockchip/sdram.c
> +++ b/arch/arm/mach-rockchip/sdram.c
> @@ -35,11 +35,18 @@ struct tos_parameter_t {
>  	s64 reserve[8];
>  };
>  
> +__weak int rk_get_ram_banks(void)

I would call this rockchip_dram_init_banksize()

> +{
> +	return -EINVAL;

and return 0 in default implementation,

> +}
> +
>  int dram_init_banksize(void)
>  {
>  	size_t ram_top = (unsigned long)(gd->ram_size + CFG_SYS_SDRAM_BASE);
>  	size_t top = min((unsigned long)ram_top, (unsigned long)(gd->ram_top));
>  
> +	if (!rk_get_ram_banks())
> +		return 0;

and something like:

ret = rockchip_dram_init_banksize();
if (ret)
	return ret;

is probably a better pattern when allowing board specific weak
implementations.

Regards,
Jonas

>  #ifdef CONFIG_ARM64
>  	/* Reserve 0x200000 for ATF bl31 */
>  	gd->bd->bi_dram[0].start = 0x200000;