u-boot/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c
Haavard Skinnemoen 1f36f73fe7 avr32: Add simple paging support
Use the MMU hardware to set up 1:1 mappings between physical and virtual
addresses. This allows us to bypass the cache when accessing the flash
without having to do any physical-to-virtual address mapping in the CFI
driver.

The virtual memory mappings are defined at compile time through a sorted
array of virtual memory range objects. When a TLB miss exception
happens, the exception handler does a binary search through the array
until it finds a matching entry and loads it into the TLB. The u-boot
image itself is covered by a fixed TLB entry which is never replaced.

This makes the 'saveenv' command work again on ATNGW100 and other boards
using the CFI driver, hopefully without breaking any rules.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2010-09-03 15:13:02 +02:00

109 lines
2.9 KiB
C

/*
* Copyright (C) 2008 Atmel Corporation
*
* See file CREDITS for list of people who contributed to this project.
*
* 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.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* 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., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <common.h>
#include <netdev.h>
#include <asm/io.h>
#include <asm/sdram.h>
#include <asm/arch/clk.h>
#include <asm/arch/hmatrix.h>
#include <asm/arch/mmu.h>
#include <asm/arch/portmux.h>
DECLARE_GLOBAL_DATA_PTR;
struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = {
{
.virt_pgno = CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT,
.nr_pages = CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT,
.phys = (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT)
| MMU_VMR_CACHE_NONE,
}, {
.virt_pgno = CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT,
.nr_pages = EBI_SDRAM_SIZE >> PAGE_SHIFT,
.phys = (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT)
| MMU_VMR_CACHE_WRBACK,
},
};
static const struct sdram_config sdram_config = {
/* MT48LC4M32B2P-6 (16 MB) */
.data_bits = SDRAM_DATA_32BIT,
.row_bits = 12,
.col_bits = 8,
.bank_bits = 2,
.cas = 3,
.twr = 2,
.trc = 7,
.trp = 2,
.trcd = 2,
.tras = 5,
.txsr = 5,
/* 15.6 us */
.refresh_period = (156 * (SDRAMC_BUS_HZ / 1000)) / 10000,
};
int board_early_init_f(void)
{
/* Enable SDRAM in the EBI mux */
hmatrix_slave_write(EBI, SFR, HMATRIX_BIT(EBI_SDRAM_ENABLE));
portmux_enable_ebi(32, 23, 0, PORTMUX_DRIVE_HIGH);
portmux_enable_usart3(PORTMUX_DRIVE_MIN);
#if defined(CONFIG_MACB)
portmux_enable_macb0(PORTMUX_MACB_MII, PORTMUX_DRIVE_HIGH);
#endif
#if defined(CONFIG_MMC)
portmux_enable_mmci(0, PORTMUX_MMCI_4BIT, PORTMUX_DRIVE_LOW);
#endif
return 0;
}
phys_size_t initdram(int board_type)
{
unsigned long expected_size;
unsigned long actual_size;
void *sdram_base;
sdram_base = uncached(EBI_SDRAM_BASE);
expected_size = sdram_init(sdram_base, &sdram_config);
actual_size = get_ram_size(sdram_base, expected_size);
if (expected_size != actual_size)
printf("Warning: Only %lu of %lu MiB SDRAM is working\n",
actual_size >> 20, expected_size >> 20);
return actual_size;
}
int board_early_init_r(void)
{
gd->bd->bi_phy_id[0] = 0x01;
return 0;
}
#if defined(CONFIG_MACB) && defined(CONFIG_CMD_NET)
int board_eth_init(bd_t *bi)
{
return macb_eth_initialize(0, (void *)MACB0_BASE, bi->bi_phy_id[0]);
}
#endif