Re: [PATCH] riscv: spacemit: k1: probe dram size during boot phase.

[Yixun Lan <dlan@gentoo.org>]

Hi Huan:

On 16:49 Wed 08 Jan     , Huan Zhou wrote:
> 
> 
..
> ---
remove above "---"? otherwise following commit message will be
dropped during patch application..

> This patch introduce improvement for get dram size on bananapi BPI-F3,
> retrieving the dram size dynamically.
> Have tested on bananapi BPIF3 4G and jupiter 8G.
> 
> Signed-off-by: Huan Zhou <me@per1cycle.org>
> ---
>  arch/riscv/cpu/k1/dram.c | 40 ++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 38 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/riscv/cpu/k1/dram.c b/arch/riscv/cpu/k1/dram.c
> index c477c15cbfb19f0e3a0ee72985b602f5bda352d7..095217f2a4c053f7477d62c0776bcb51e623db47 100644
> --- a/arch/riscv/cpu/k1/dram.c
> +++ b/arch/riscv/cpu/k1/dram.c
> @@ -4,17 +4,53 @@
>   */
>  
>  #include <asm/global_data.h>
> +#include <asm/io.h>
>  #include <config.h>
> +#include <bitfield.h>
>  #include <fdt_support.h>
>  #include <linux/sizes.h>
>  
> +#define DDR_BASE 0xC0000000
>  DECLARE_GLOBAL_DATA_PTR;
>  
> +static inline u32 map_format_size(u32 val)
> +{
> +	u32 tmp;
> +
> +	if (val & 0x1 == 0)
please add brackets explicitly, something like
	if ((val & 0x1) == 0)

> +		return 0;
> +
> +	tmp = bitfield_extract(val, 16, 5);
> +	switch (tmp) {
> +	case 0xd:
> +		return 512;
> +	case 0xe:
> +		return 1024;
> +	case 0xf:
> +		return 2048;
> +	case 0x10:
> +		return 4096;
> +	case 0x11:
> +		return 8192;
> +	default:
> +		pr_info("Invalid DRAM density %x\n", val);
> +		return 0;
> +	}
> +}
> +
> +u32 ddr_get_density(void)
> +{
> +	u32 cs0_size = map_format_size(readl((void *)DDR_BASE + 0x200));
> +	u32 cs1_size = map_format_size(readl((void *)DDR_BASE + 0x208));
> +	u32 ddr_size = cs0_size + cs1_size;
> +
> +	return ddr_size;
> +}
> +
>  int dram_init(void)
>  {
>  	gd->ram_base = CFG_SYS_SDRAM_BASE;
> -	/* TODO get ram size from ddr controller */
> -	gd->ram_size = SZ_4G;
> +	gd->ram_size = (u64)ddr_get_density() * SZ_1M;
while using cast, why not define ddr_get_density() return as same type?
also it's more reasonable to use phys_size_t as I checked gd_t

>  	return 0;
>  }
>  
> 
> ---
> base-commit: 19fc0b7f7d907119a13e9c207991899f0817f8fc
> change-id: 20250108-get-dram-size-65cf59a15201
> 
> Best regards,
> -- 
> Huan Zhou <me@per1cycle.org>
> 

-- 
Yixun Lan (dlan)
Gentoo Linux Developer
GPG Key ID AABEFD55