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arm64: mvebu: a8k: autodetect RAM size

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Some Armada 8K boards like Macchiatobin and Clearfog GT-8K use RAM from
external DIMM. Hard coding the RAM size in the device-tree is not
convenient. Fortunately, the ATF that initializes the RAM knows the size
of RAM, and U-Boot can query the ATF using a SMC call.

The ATF maps the lower 3G of RAM starting at address 0. Higher RAM is
mapped at 4G. This leaves a 1G hole between 3G and 4G for IO
peripherals. Use a second bi_dram[] entry to describe the higher RAM
area. As a result, CONFIG_NR_DRAM_BANKS must be set to 2 to use more
than 3GB RAM.

This code in this commit is mostly taken from downstream Marvell U-Boot
code by Grzegorz Jaszczyk.

Cc: Grzegorz Jaszczyk <jaz@semihalf.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Baruch Siach 2018-11-11 12:31:04 +02:00 committed by Stefan Roese
parent b335e91bd1
commit 2b4d964718
1 changed files with 49 additions and 1 deletions
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50
arch/arm/mach-mvebu/arm64-common.c
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@ -7,6 +7,7 @@
#include <dm.h>
#include <fdtdec.h>
#include <linux/libfdt.h>
#include <linux/sizes.h>
#include <pci.h>
#include <asm/io.h>
#include <asm/system.h>
@ -45,15 +46,62 @@ const struct mbus_dram_target_info *mvebu_mbus_dram_info(void)
/* DRAM init code ... */
#define MV_SIP_DRAM_SIZE 0x82000010
static u64 a8k_dram_scan_ap_sz(void)
{
struct pt_regs pregs;
pregs.regs[0] = MV_SIP_DRAM_SIZE;
pregs.regs[1] = SOC_REGS_PHY_BASE;
smc_call(&pregs);
return pregs.regs[0];
}
static void a8k_dram_init_banksize(void)
{
/*
* The firmware (ATF) leaves a 1G whole above the 3G mark for IO
* devices. Higher RAM is mapped at 4G.
*
* Config 2 DRAM banks:
* Bank 0 - max size 4G - 1G
* Bank 1 - ram size - 4G + 1G
*/
phys_size_t max_bank0_size = SZ_4G - SZ_1G;
gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
if (gd->ram_size <= max_bank0_size) {
gd->bd->bi_dram[0].size = gd->ram_size;
return;
}
gd->bd->bi_dram[0].size = max_bank0_size;
if (CONFIG_NR_DRAM_BANKS > 1) {
gd->bd->bi_dram[1].start = SZ_4G;
gd->bd->bi_dram[1].size = gd->ram_size - max_bank0_size;
}
}
int dram_init_banksize(void)
{
fdtdec_setup_memory_banksize();
if (CONFIG_IS_ENABLED(ARMADA_8K))
a8k_dram_init_banksize();
else
fdtdec_setup_memory_banksize();
return 0;
}
int dram_init(void)
{
if (CONFIG_IS_ENABLED(ARMADA_8K)) {
gd->ram_size = a8k_dram_scan_ap_sz();
if (gd->ram_size != 0)
return 0;
}
if (fdtdec_setup_mem_size_base() != 0)
return -EINVAL;