[PATCH v3] sunxi: extend R528/T113-s3/D1(s) DRAM initialisation

[Andre Przywara]

On Sun, 26 Oct 2025 12:41:17 +0100
Lukas Schmid <lukas.schmid at netcube.li> wrote:

Hi,

> The T113-s4 SoC is using the same die as the T113-s3, but comes with
> 256MiB of co-packaged DRAM. Besides the doubled size, the DRAM chip
> seems to be connected slightly differently, which requires to use a
> different pin remapping.
> 
> Extend the DRAM initialisation code to add support for the T113-S4 aka
> T113M4020DC0 by checking the SoC's CHIPID, which is stored in the first
> word of the SID efuses.
> 
> Signed-off-by: Lukas Schmid <lukas.schmid at netcube.li>
> Tested-by: John Watts <contact at jookia.org>
> Reviewed-by: John Watts <contact at jookia.org>
> Reviewed-by: Jernej Skrabec <jernej.skrabec at gmail.com>

Careful with those tags: those were given for quite a different version
of the patch, I wouldn't carry them over, since there were quite some
changes since then.

> ---
> Changes in v3:
>   - Move the Chip-ID list link to a comment in the header file
>   - Use andre's suggested commit message
>   - Drop out of remapping early for T113M4020DC0 instead of doing it in the
>     switch-case
> 
> Changes in v2:
>   - Use uint32_t instead of u32 for sid_read_soc_chipid return type
>   - Add descriptive comment about source of Chip-ID list and register
> 
>  drivers/ram/sunxi/dram_sun20i_d1.c | 10 ++++++++++
>  drivers/ram/sunxi/dram_sun20i_d1.h | 11 +++++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/ram/sunxi/dram_sun20i_d1.c b/drivers/ram/sunxi/dram_sun20i_d1.c
> index a1794032f3b..d851deac7a5 100644
> --- a/drivers/ram/sunxi/dram_sun20i_d1.c
> +++ b/drivers/ram/sunxi/dram_sun20i_d1.c
> @@ -54,6 +54,11 @@ static void sid_read_ldoB_cal(const dram_para_t *para)
>  	clrsetbits_le32(0x3000150, 0xff00, reg << 8);
>  }
>  
> +static uint32_t sid_read_soc_chipid(void)
> +{
> +	return readl(SUNXI_SID_BASE + 0x00) & 0xffff;
> +}
> +
>  static void dram_voltage_set(const dram_para_t *para)
>  {
>  	int vol;
> @@ -663,6 +668,11 @@ static void mctl_phy_ac_remapping(const dram_para_t *para,
>  
>  	fuse = (readl(SUNXI_SID_BASE + 0x28) & 0xf00) >> 8;
>  	debug("DDR efuse: 0x%x\n", fuse);
> +	debug("SoC Chip ID: 0x%08x\n", sid_read_soc_chipid());
> +
> +	if (sid_read_soc_chipid() == SUNXI_CHIPID_T113M4020DC0) {

You don't need braces for a single statement in the "if" branch (but I
can fix this up).

Other than that this looks quite good to me now. If someone with a
board (John?) could confirm that this works, I am happy to take it.

Thanks,
Andre


> +		return;
> +	}
>  
>  	if (para->dram_type == SUNXI_DRAM_TYPE_DDR2) {
>  		if (fuse == 15)
> diff --git a/drivers/ram/sunxi/dram_sun20i_d1.h b/drivers/ram/sunxi/dram_sun20i_d1.h
> index 91383f6cf10..83ae7eb36cd 100644
> --- a/drivers/ram/sunxi/dram_sun20i_d1.h
> +++ b/drivers/ram/sunxi/dram_sun20i_d1.h
> @@ -19,6 +19,17 @@ enum sunxi_dram_type {
>  	SUNXI_DRAM_TYPE_LPDDR3 = 7,
>  };
>  
> +/*
> + * Chip-IDs taken from
> + * https://github.com/ua1arn/hftrx/blob/25d8cb9e4cfe1d7d0e4a2f641025c88a9ec5e758/inc/clocks.h#L250
> + */
> +enum sunxi_soc_chipid {
> +	SUNXI_CHIPID_F133A = 0x5C00,
> +	SUNXI_CHIPID_D1S = 0x5E00,
> +	SUNXI_CHIPID_T113S3 = 0x6000,
> +	SUNXI_CHIPID_T113M4020DC0 = 0x7200,
> +};
> +
>  /*
>   * This structure contains a mixture of fixed configuration settings,
>   * variables that are used at runtime to communicate settings between