u-boot/arch/arm/cpu/arm926ejs/armada100/dram.c

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/*
* (C) Copyright 2010
* Marvell Semiconductor <www.marvell.com>
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>,
* Contributor: Mahavir Jain <mjain@marvell.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/armada100.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* ARMADA100 DRAM controller supports upto 8 banks
* for chip select 0 and 1
*/
/*
* DDR Memory Control Registers
* Refer Datasheet Appendix A.17
*/
struct armd1ddr_map_registers {
u32 cs; /* Memory Address Map Register -CS */
u32 pad[3];
};
struct armd1ddr_registers {
u8 pad[0x100 - 0x000];
struct armd1ddr_map_registers mmap[2];
};
/*
* armd1_sdram_base - reads SDRAM Base Address Register
*/
u32 armd1_sdram_base(int chip_sel)
{
struct armd1ddr_registers *ddr_regs =
(struct armd1ddr_registers *)ARMD1_DRAM_BASE;
u32 result = 0;
u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);
if (!CS_valid)
return 0;
result = readl(&ddr_regs->mmap[chip_sel].cs) & 0xFF800000;
return result;
}
/*
* armd1_sdram_size - reads SDRAM size
*/
u32 armd1_sdram_size(int chip_sel)
{
struct armd1ddr_registers *ddr_regs =
(struct armd1ddr_registers *)ARMD1_DRAM_BASE;
u32 result = 0;
u32 CS_valid = 0x01 & readl(&ddr_regs->mmap[chip_sel].cs);
if (!CS_valid)
return 0;
result = readl(&ddr_regs->mmap[chip_sel].cs);
result = (result >> 16) & 0xF;
if (result < 0x7) {
printf("Unknown DRAM Size\n");
return -1;
} else {
return ((0x8 << (result - 0x7)) * 1024 * 1024);
}
}
int dram_init(void)
{
int i;
gd->ram_size = 0;
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
gd->bd->bi_dram[i].start = armd1_sdram_base(i);
gd->bd->bi_dram[i].size = armd1_sdram_size(i);
/*
* It is assumed that all memory banks are consecutive
* and without gaps.
* If the gap is found, ram_size will be reported for
* consecutive memory only
*/
if (gd->bd->bi_dram[i].start != gd->ram_size)
break;
gd->ram_size += gd->bd->bi_dram[i].size;
}
for (; i < CONFIG_NR_DRAM_BANKS; i++) {
/* If above loop terminated prematurely, we need to set
* remaining banks' start address & size as 0. Otherwise other
* u-boot functions and Linux kernel gets wrong values which
* could result in crash */
gd->bd->bi_dram[i].start = 0;
gd->bd->bi_dram[i].size = 0;
}
return 0;
}
/*
* If this function is not defined here,
* board.c alters dram bank zero configuration defined above.
*/
void dram_init_banksize(void)
{
dram_init();
}