Implement functionality to probe and calculate the DRAM size during the boot phase for the RISC-V spacemit K1 platform. The `map_format_size` function extracts the memory density from a given value, while `ddr_get_density` aggregates the sizes of the memory chips. The `dram_init` function initializes the global RAM base and size based on the detected DRAM density, ensuring proper memory configuration at boot.
Tested-by: Marcel Ziswiler marcel@ziswiler.com # BPI-F3 16G Signed-off-by: Huan Zhou me@per1cycle.org --- This patch introduce improvement for get dram size on spacemit k1 platform, retrieving the dram size dynamically. Have tested on Licheepi LPI3A 8G[1].
Links: [1] https://gist.github.com/per1cycle/e4eab66ebb6f83fe5118e823367fce28 .
Changes in v3: - Remove the inline attr in arch/riscv/cpu/k1/dram.c map_format_size(). - Add detailed commit message. - Link to v2: https://lore.kernel.org/r/20250114-get-dram-size-v2-1-aba5a281ea28@per1cycle...
Changes in v2: - Fix bracker and return type in map_format_size() function. - Add test log in the cover letter.. - Link to v1: https://lore.kernel.org/r/20250108-get-dram-size-v1-1-4bae32ecf756@per1cycle... --- 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..54d209ca277db7b304df04f81b12ae4efa400e45 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 phys_size_t map_format_size(u32 val) +{ + u32 tmp; + + if (!(val & 0x1)) + 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; + } +} + +phys_size_t ddr_get_density(void) +{ + phys_size_t cs0_size = map_format_size(readl((void *)DDR_BASE + 0x200)); + phys_size_t cs1_size = map_format_size(readl((void *)DDR_BASE + 0x208)); + phys_size_t 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 = ddr_get_density() * SZ_1M; return 0; }
--- base-commit: 19fc0b7f7d907119a13e9c207991899f0817f8fc change-id: 20250108-get-dram-size-65cf59a15201
Best regards,