The DRAM PHY layer on PH1-LD20 is able to calibrate PHY parameters periodically. This compensates for the voltage and temperature deviation and improves the PHY parameter adjustment. Instead, it requires 64 byte scratch memory in each DRAM channel for the dynamic training. The memory regions must be reserved in DT before jumping to the kernel.
The scratch area can be anywhere in each DRAM channel, but the DRAM init code in SPL currently assigns it at the end of each channel. So, it makes sense to reserve the regions on run-time by U-Boot instead of statically embedding it in the DT in Linux. Anyway, a boot-loader should know much more about memory initialization than the kernel.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
arch/arm/Kconfig | 1 + arch/arm/mach-uniphier/Kconfig | 1 + arch/arm/mach-uniphier/dram_init.c | 40 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e75c4c0..5aaae96 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -801,6 +801,7 @@ config ARCH_UNIPHIER select SPL select OF_CONTROL select SPL_OF_CONTROL + select OF_LIBFDT select DM select SPL_DM select DM_GPIO diff --git a/arch/arm/mach-uniphier/Kconfig b/arch/arm/mach-uniphier/Kconfig index 89be0b3..e256eeb 100644 --- a/arch/arm/mach-uniphier/Kconfig +++ b/arch/arm/mach-uniphier/Kconfig @@ -40,6 +40,7 @@ config ARCH_UNIPHIER_LD11 config ARCH_UNIPHIER_LD20 bool "UniPhier PH1-LD20 SoC" select ARCH_UNIPHIER_64BIT + select OF_BOARD_SETUP
endchoice
diff --git a/arch/arm/mach-uniphier/dram_init.c b/arch/arm/mach-uniphier/dram_init.c index ef0e2e8..489366c 100644 --- a/arch/arm/mach-uniphier/dram_init.c +++ b/arch/arm/mach-uniphier/dram_init.c @@ -9,6 +9,9 @@ #include <fdtdec.h> #include <linux/err.h>
+#include "init.h" +#include "soc-info.h" + DECLARE_GLOBAL_DATA_PTR;
static const void *get_memory_reg_prop(const void *fdt, int *lenp) @@ -81,3 +84,40 @@ void dram_init_banksize(void) (unsigned long)gd->bd->bi_dram[i].size); } } + +#ifdef CONFIG_OF_BOARD_SETUP +/* + * The DRAM PHY requires 64 byte scratch area in each DRAM channel + * for its dynamic PHY training feature. + */ +int ft_board_setup(void *fdt, bd_t *bd) +{ + const struct uniphier_board_data *param; + unsigned long rsv_addr; + const unsigned long rsv_size = 64; + int ch, ret; + + if (uniphier_get_soc_type() != SOC_UNIPHIER_LD20) + return 0; + + param = uniphier_get_board_param(); + if (!param) { + printf("failed to get board parameter\n"); + return -ENODEV; + } + + for (ch = 0; ch < param->dram_nr_ch; ch++) { + rsv_addr = param->dram_ch[ch].base + param->dram_ch[ch].size; + rsv_addr -= rsv_size; + + ret = fdt_add_mem_rsv(fdt, rsv_addr, rsv_size); + if (ret) + return -ENOSPC; + + printf(" Reserved memory region for DRAM PHY training: addr=%lx size=%lx\n", + rsv_addr, rsv_size); + } + + return 0; +} +#endif