[U-Boot] [RFC] ARM: rmobile: create DT memory nodes for R8A7795 3.0 and newer

[Marek Vasut]

On 06/15/2018 11:40 AM, Ulrich Hecht wrote:
> Uses an SMC call to the ATF to determine the memory configuration, then
> creates appropriate DT memory nodes.
> 
> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas at gmail.com>
> ---
> This is an attempt to avoid having to have a ton of different device trees
> for Renesas R8A7795 H3 SoCs from revision 3.0, which come in a number of
> different memory configurations.
> 
> The specific configuration is statically baked into the ARM Trusted Firmware
> binary, so this solution adds an SMC "SiP Service Call" to the ATF returning
> the memory configuration, and then has u-boot build appropriate memory nodes.
> 
> This has not been tested in the flesh successfully, as I only have a revision
> 1.0 board. I'd like to get some feedback on whether this approach is sound,
> though. Thanks.
> 
> Depends on "[RFC ATF] Add SMCCC_RENESAS_MEMCONF SMC call".
> 
> CU
> Uli
> 
> 
> 
>  board/renesas/salvator-x/salvator-x.c | 51 +++++++++++++++++++++++++++++++++++
>  configs/r8a7795_salvator-x_defconfig  |  2 ++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/board/renesas/salvator-x/salvator-x.c b/board/renesas/salvator-x/salvator-x.c
> index 651877c..307cb64 100644
> --- a/board/renesas/salvator-x/salvator-x.c
> +++ b/board/renesas/salvator-x/salvator-x.c
> @@ -24,6 +24,7 @@
>  #include <asm/arch/sh_sdhi.h>
>  #include <i2c.h>
>  #include <mmc.h>
> +#include <linux/arm-smccc.h>
>  
>  DECLARE_GLOBAL_DATA_PTR;
>  
> @@ -136,3 +137,53 @@ void reset_cpu(ulong addr)
>  	writel(RST_CODE, RST_CA57RESCNT);
>  #endif
>  }
> +
> +#define ARM_SMCCC_RENESAS_MEMCONF	0x82000000UL
> +int ft_board_setup(void *blob, bd_t *bd)
> +{
> +	if (rmobile_get_cpu_type() == RMOBILE_CPU_TYPE_R8A7795 &&
> +	    rmobile_get_cpu_rev_integer() >= 3) {
> +		u64 base[CONFIG_NR_DRAM_BANKS];
> +		u64 size[CONFIG_NR_DRAM_BANKS];
> +		struct arm_smccc_res res;
> +
> +		arm_smccc_smc(ARM_SMCCC_RENESAS_MEMCONF,
> +			      0, 0, 0, 0, 0, 0, 0, &res);

Will this call work on platforms without patched ATF ?
(I think not, don't you need to handle return value?)

> +		switch (res.a0) {
> +		case 1:
> +			base[0] = 0x048000000ULL;
> +			size[0] = 0x038000000ULL;
> +			base[1] = 0x500000000ULL;
> +			size[1] = 0x040000000ULL;
> +			base[2] = 0x600000000ULL;
> +			size[2] = 0x040000000ULL;
> +			base[3] = 0x700000000ULL;
> +			size[3] = 0x040000000ULL;
> +			fdt_fixup_memory_banks(blob, base, size, 4);
> +			break;
> +		case 2:
> +			base[0] = 0x048000000ULL;
> +			size[0] = 0x078000000ULL;
> +			base[1] = 0x500000000ULL;
> +			size[1] = 0x080000000ULL;
> +			fdt_fixup_memory_banks(blob, base, size, 2);
> +			break;
> +		case 3:
> +			base[0] = 0x048000000ULL;
> +			size[0] = 0x078000000ULL;
> +			base[1] = 0x500000000ULL;
> +			size[1] = 0x080000000ULL;
> +			base[2] = 0x600000000ULL;
> +			size[2] = 0x080000000ULL;
> +			base[3] = 0x700000000ULL;
> +			size[3] = 0x080000000ULL;
> +			fdt_fixup_memory_banks(blob, base, size, 4);
> +			break;

Obvious design question is -- since you're adding new SMC call anyway,
can't the call just return the memory layout table itself, so that it
won't be duplicated both in U-Boot and ATF ?

> +		default:
> +			break;
> +		}
> +	}
> +
> +	return 0;
> +}
> diff --git a/configs/r8a7795_salvator-x_defconfig b/configs/r8a7795_salvator-x_defconfig
> index fdfa41c..cd2bb59 100644
> --- a/configs/r8a7795_salvator-x_defconfig
> +++ b/configs/r8a7795_salvator-x_defconfig
> @@ -61,3 +61,5 @@ CONFIG_USB_EHCI_GENERIC=y
>  CONFIG_USB_STORAGE=y
>  CONFIG_OF_LIBFDT_OVERLAY=y
>  CONFIG_SMBIOS_MANUFACTURER=""
> +CONFIG_OF_BOARD_SETUP=y
> +CONFIG_ARM_SMCCC=y

Update the defconfig with make savedefconfig .

-- 
Best regards,
Marek Vasut