/* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform
*
* Copyright (C) 2001 Sysgo Real-Time Solutions GmbH
*
* 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
*
*
* The SC520CDP is an evaluation board for the Elan SC520 processor available
* from AMD. It has two banks of 32-bit Flash ROM, each 8 Megabytes in size,
* and up to 512 KiB of 8-bit DIL Flash ROM.
* For details see http://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/concat.h>
/*
** The Embedded Systems BIOS decodes the first FLASH starting at
** 0x8400000. This is a *terrible* place for it because accessing
** the flash at this location causes the A22 address line to be high
** (that's what 0x8400000 binary's ought to be). But this is the highest
** order address line on the raw flash devices themselves!!
** This causes the top HALF of the flash to be accessed first. Beyond
** the physical limits of the flash, the flash chip aliases over (to
** 0x880000 which causes the bottom half to be accessed. This splits the
** flash into two and inverts it! If you then try to access this from another
** program that does NOT do this insanity, then you *will* access the
** first half of the flash, but not find what you expect there. That
** stuff is in the *second* half! Similarly, the address used by the
** BIOS for the second FLASH bank is also quite a bad choice.
** If REPROGRAM_PAR is defined below (the default), then this driver will
** choose more useful addresses for the FLASH banks by reprogramming the
** responsible PARxx registers in the SC520's MMCR region. This will
** cause the settings to be incompatible with the BIOS's settings, which
** shouldn't be a problem since you are running Linux, (i.e. the BIOS is
** not much use anyway). However, if you need to be compatible with
** the BIOS for some reason, just undefine REPROGRAM_PAR.
*/
#define REPROGRAM_PAR
#ifdef REPROGRAM_PAR
/* These are the addresses we want.. */
#define WINDOW_ADDR_0 0x08800000
#define WINDOW_ADDR_1 0x09000000
#define WINDOW_ADDR_2 0x09800000
/* .. and these are the addresses the BIOS gives us */
#define WINDOW_ADDR_0_BIOS 0x08400000
#define WINDOW_ADDR_1_BIOS 0x08c00000
#define WINDOW_ADDR_2_BIOS 0x09400000
#else
#define WINDOW_ADDR_0 0x08400000
#define WINDOW_ADDR_1 0x08C00000
#define WINDOW_ADDR_2 0x09400000
#endif
#define WINDOW_SIZE_0 0x00800000
#define WINDOW_SIZE_1 0x00800000
#define WINDOW_SIZE_2 0x00080000
static struct map_info sc520cdp_map[] = {
{
.name = "SC520CDP Flash Bank #0",
.size = WINDOW_SIZE_0,
.bankwidth = 4,
.phys = WINDOW_ADDR_0
},
{
.name = "SC520CDP Flash Bank #1",
.size = WINDOW_SIZE_1,
.bankwidth = 4,
.phys = WINDOW_ADDR_1
},
{
.name = "SC520CDP DIL Flash",
.size = WINDOW_SIZE_2,
.bankwidth = 1,
.phys = WINDOW_ADDR_2
},
};
#define NUM_FLASH_BANKS ARRAY_SIZE(sc520cdp_map)
static struct mtd_info *mymtd[NUM_FLASH_BANKS];
static struct mtd_info *merged_mtd;
#ifdef REPROGRAM_PAR
/*
** The SC520 MMCR (memory mapped control register) region resides
** at 0xFFFEF000. The 16 Programmable Address Region (PAR) registers
** are at offset 0x88 in the MMCR:
*/
#define SC520_MMCR_BASE 0xFFFEF000
#define SC520_MMCR_EXTENT 0x1000
#define SC520_PAR(x) ((0x88/sizeof(unsigned long)) + (x))
#define NUM_SC520_PAR 16 /* total number of PAR registers */
/*
** The highest three bits in a PAR register determine what target
** device is controlled by this PAR. Here, only ROMCS? and BOOTCS
** devices are of interest.
*/
#define SC520_PAR_BOOTCS (0x4<<29)
#define SC520_PAR_ROMCS0 (0x5<<29)
#define SC520_PAR_ROMCS1 (0x6<<29)
#define SC520_PAR_TRGDEV (0x7<<29)
/*
** Bits 28 thru 26 determine some attributes for the
** region controlled by the PAR. (We only use non-cacheable)
*/
#define SC520_PAR_WRPROT (1<<26) /* write protected */
#define SC520_PAR_NOCACHE (1<<27) /* non-cacheable */
#define SC520_PAR_NOEXEC (1<<28) /* code execution denied */
/*
** Bit 25 determines the granularity: 4K or 64K
*/
#define SC520_PAR_PG_SIZ4 (0<<25)
#define SC520_PAR_PG_SIZ64 (1<<25)
/*
** Build a value to be written into a PAR register.
** We only need ROM entries, 64K page size:
*/
#define SC520_PAR_ENTRY(trgdev, address, size) \
((trgdev) | SC520_PAR_NOCACHE | SC520_PAR_PG_SIZ64 | \
(address) >> 16 | (((size) >> 16) - 1) << 14)
struct sc520_par_table
{
unsigned long trgdev;
unsigned long new_par;
unsigned long default_address;
};
static const struct sc520_par_table par_table[NUM_FLASH_BANKS] =
{
{ /* Flash Bank #0: selected by ROMCS0 */
SC520_PAR_ROMCS0,
SC520_PAR_ENTRY(SC520_PAR_ROMCS0, WINDOW_ADDR_0, WINDOW_SIZE_0),
WINDOW_ADDR_0_BIOS
},
{ /* Flash Bank #1: selected by ROMCS1 */
SC520_PAR_ROMCS1,
SC520_PAR_ENTRY(SC520_PAR_ROMCS1, WINDOW_ADDR_1, WINDOW_SIZE_1),
WINDOW_ADDR_1_BIOS
},
{ /* DIL (BIOS) Flash: selected by BOOTCS */
SC520_PAR_BOOTCS,
SC520_PAR_ENTRY(SC520_PAR_BOOTCS, WINDOW_ADDR_2, WINDOW_SIZE_2),
WINDOW_ADDR_2_BIOS
}
};
static void sc520cdp_setup_par(void)
{
volatile unsigned long __iomem *mmcr;
unsigned long mmcr_val;
int i, j;
/* map in SC520's MMCR area */
mmcr = ioremap_nocache(SC520_MMCR_BASE, SC520_MMCR_EXTENT);
if(!mmcr) { /* ioremap_nocache failed: skip the PAR reprogramming */
/* force physical address fields to BIOS defaults: */
for(i = 0; i < NUM_FLASH_BANKS; i++)
sc520cdp_map[i].phys = par_table[i].default_address;
return;
}
/*
** Find the PARxx registers that are reponsible for activating
** ROMCS0, ROMCS1 and BOOTCS. Reprogram each of these with a
** new value from the table.
*/
for(i = 0; i < NUM_FLASH_BANKS; i++) { /* for each par_table entry */
for(j = 0; j < NUM_SC520_PAR; j++) { /* for each PAR register */
mmcr_val = mmcr[SC520_PAR(j)];
/* if target device field matches, reprogram the PAR */
if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev)
{
mmcr[SC520_PAR(j)] = par_table[i].new_par;
break;
}
}
if(j == NUM_SC520_PAR)
{ /* no matching PAR found: try default BIOS address */
printk(KERN_NOTICE "Could not find PAR responsible for %s\n",
sc520cdp_map[i].name);
printk(KERN_NOTICE "Trying default address 0x%lx\n",
par_table[i].default_address);
sc520cdp_map[i].phys = par_table[i].default_address;
}
}
iounmap(mmcr);
}
#endif
static int __init init_sc520cdp(void)
{
int i, devices_found = 0;
#ifdef REPROGRAM_PAR
/* reprogram PAR registers so flash appears at the desired addresses */
sc520cdp_setup_par();
#endif
for (i = 0; i < NUM_FLASH_BANKS; i++) {
printk(KERN_NOTICE "SC520 CDP flash device: 0x%Lx at 0x%Lx\n",
(unsigned long long)sc520cdp_map[i].size,
(unsigned long long)sc520cdp_map[i].phys);
sc520cdp_map[i].virt = ioremap_nocache(sc520cdp_map[i].phys, sc520cdp_map[i].size);
if (!sc520cdp_map[i].virt) {
printk("Failed to ioremap_nocache\n");
return -EIO;
}
simple_map_init(&sc520cdp_map[i]);
mymtd[i] = do_map_probe("cfi_probe", &sc520cdp_map[i]);
if(!mymtd[i])
mymtd[i] = do_map_probe("jedec_probe", &sc520cdp_map[i]);
if(!mymtd[i])
mymtd[i] = do_map_probe("map_rom", &sc520cdp_map[i]);
if (mymtd[i]) {
mymtd[i]->owner = THIS_MODULE;
++devices_found;
}
else {
iounmap(sc520cdp_map[i].virt);
}
}
if(devices_found >= 2) {
/* Combine the two flash banks into a single MTD device & register it: */
merged_mtd = mtd_concat_create(mymtd, 2, "SC520CDP Flash Banks #0 and #1");
if(merged_mtd)
add_mtd_device(merged_mtd);
}
if(devices_found == 3) /* register the third (DIL-Flash) device */
add_mtd_device(mymtd[2]);
return(devices_found ? 0 : -ENXIO);
}
static void __exit cleanup_sc520cdp(void)
{
int i;
if (merged_mtd) {
del_mtd_device(merged_mtd);
mtd_concat_destroy(merged_mtd);
}
if (mymtd[2])
del_mtd_device(mymtd[2]);
for (i = 0; i < NUM_FLASH_BANKS; i++) {
if (mymtd[i])
map_destroy(mymtd[i]);
if (sc520cdp_map[i].virt) {
iounmap(sc520cdp_map[i].virt);
sc520cdp_map[i].virt = NULL;
}
}
}
module_init(init_sc520cdp);
module_exit(cleanup_sc520cdp);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sysgo Real-Time Solutions GmbH");
MODULE_DESCRIPTION("MTD map driver for AMD SC520 Customer Development Platform");
