linux/arch/mips/jz4740/setup.c

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/*
* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
* Copyright (C) 2011, Maarten ter Huurne <maarten@treewalker.org>
* JZ4740 setup code
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/kernel.h>
#include <linux/libfdt.h>
#include <linux/of_fdt.h>
#include <asm/bootinfo.h>
#include <asm/prom.h>
#include <asm/mach-jz4740/base.h>
#include "reset.h"
#define JZ4740_EMC_SDRAM_CTRL 0x80
static void __init jz4740_detect_mem(void)
{
void __iomem *jz_emc_base;
u32 ctrl, bus, bank, rows, cols;
phys_addr_t size;
jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
bus = 2 - ((ctrl >> 31) & 1);
bank = 1 + ((ctrl >> 19) & 1);
cols = 8 + ((ctrl >> 26) & 7);
rows = 11 + ((ctrl >> 20) & 3);
printk(KERN_DEBUG
"SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
bus, bank, rows, cols);
iounmap(jz_emc_base);
size = 1 << (bus + bank + cols + rows);
add_memory_region(0, size, BOOT_MEM_RAM);
}
void __init plat_mem_setup(void)
{
int offset;
jz4740_reset_init();
__dt_setup_arch(__dtb_start);
offset = fdt_path_offset(__dtb_start, "/memory");
if (offset < 0)
jz4740_detect_mem();
}
void __init device_tree_init(void)
{
if (!initial_boot_params)
return;
unflatten_and_copy_device_tree();
}
const char *get_system_type(void)
{
if (config_enabled(CONFIG_MACH_JZ4780))
return "JZ4780";
return "JZ4740";
}
void __init arch_init_irq(void)
{
irqchip_init();
}