- 根目录:
- drivers
- mtd
- maps
- sbc_gxx.c
/* sbc_gxx.c -- MTD map driver for Arcom Control Systems SBC-MediaGX,
SBC-GXm and SBC-GX1 series boards.
Copyright (C) 2001 Arcom Control System Ltd
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 SBC-MediaGX / SBC-GXx has up to 16 MiB of
Intel StrataFlash (28F320/28F640) in x8 mode.
This driver uses the CFI probe and Intel Extended Command Set drivers.
The flash is accessed as follows:
16 KiB memory window at 0xdc000-0xdffff
Two IO address locations for paging
0x258
bit 0-7: address bit 14-21
0x259
bit 0-1: address bit 22-23
bit 7: 0 - reset/powered down
1 - device enabled
The single flash device is divided into 3 partition which appear as
separate MTD devices.
25/04/2001 AJL (Arcom) Modified signon strings and partition sizes
(to support bzImages up to 638KiB-ish)
*/
// Includes
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
// Defines
// - Hardware specific
#define WINDOW_START 0xdc000
/* Number of bits in offset. */
#define WINDOW_SHIFT 14
#define WINDOW_LENGTH (1 << WINDOW_SHIFT)
/* The bits for the offset into the window. */
#define WINDOW_MASK (WINDOW_LENGTH-1)
#define PAGE_IO 0x258
#define PAGE_IO_SIZE 2
/* bit 7 of 0x259 must be 1 to enable device. */
#define DEVICE_ENABLE 0x8000
// - Flash / Partition sizing
#define MAX_SIZE_KiB 16384
#define BOOT_PARTITION_SIZE_KiB 768
#define DATA_PARTITION_SIZE_KiB 1280
#define APP_PARTITION_SIZE_KiB 6144
// Globals
static volatile int page_in_window = -1; // Current page in window.
static void __iomem *iomapadr;
static DEFINE_SPINLOCK(sbc_gxx_spin);
/* partition_info gives details on the logical partitions that the split the
* single flash device into. If the size if zero we use up to the end of the
* device. */
static struct mtd_partition partition_info[]={
{ .name = "SBC-GXx flash boot partition",
.offset = 0,
.size = BOOT_PARTITION_SIZE_KiB*1024 },
{ .name = "SBC-GXx flash data partition",
.offset = BOOT_PARTITION_SIZE_KiB*1024,
.size = (DATA_PARTITION_SIZE_KiB)*1024 },
{ .name = "SBC-GXx flash application partition",
.offset = (BOOT_PARTITION_SIZE_KiB+DATA_PARTITION_SIZE_KiB)*1024 }
};
#define NUM_PARTITIONS 3
static inline void sbc_gxx_page(struct map_info *map, unsigned long ofs)
{
unsigned long page = ofs >> WINDOW_SHIFT;
if( page!=page_in_window ) {
outw( page | DEVICE_ENABLE, PAGE_IO );
page_in_window = page;
}
}
static map_word sbc_gxx_read8(struct map_info *map, unsigned long ofs)
{
map_word ret;
spin_lock(&sbc_gxx_spin);
sbc_gxx_page(map, ofs);
ret.x[0] = readb(iomapadr + (ofs & WINDOW_MASK));
spin_unlock(&sbc_gxx_spin);
return ret;
}
static void sbc_gxx_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
{
while(len) {
unsigned long thislen = len;
if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
spin_lock(&sbc_gxx_spin);
sbc_gxx_page(map, from);
memcpy_fromio(to, iomapadr + (from & WINDOW_MASK), thislen);
spin_unlock(&sbc_gxx_spin);
to += thislen;
from += thislen;
len -= thislen;
}
}
static void sbc_gxx_write8(struct map_info *map, map_word d, unsigned long adr)
{
spin_lock(&sbc_gxx_spin);
sbc_gxx_page(map, adr);
writeb(d.x[0], iomapadr + (adr & WINDOW_MASK));
spin_unlock(&sbc_gxx_spin);
}
static void sbc_gxx_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
while(len) {
unsigned long thislen = len;
if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
spin_lock(&sbc_gxx_spin);
sbc_gxx_page(map, to);
memcpy_toio(iomapadr + (to & WINDOW_MASK), from, thislen);
spin_unlock(&sbc_gxx_spin);
to += thislen;
from += thislen;
len -= thislen;
}
}
static struct map_info sbc_gxx_map = {
.name = "SBC-GXx flash",
.phys = NO_XIP,
.size = MAX_SIZE_KiB*1024, /* this must be set to a maximum possible amount
of flash so the cfi probe routines find all
the chips */
.bankwidth = 1,
.read = sbc_gxx_read8,
.copy_from = sbc_gxx_copy_from,
.write = sbc_gxx_write8,
.copy_to = sbc_gxx_copy_to
};
/* MTD device for all of the flash. */
static struct mtd_info *all_mtd;
static void cleanup_sbc_gxx(void)
{
if( all_mtd ) {
mtd_device_unregister(all_mtd);
map_destroy( all_mtd );
}
iounmap(iomapadr);
release_region(PAGE_IO,PAGE_IO_SIZE);
}
static int __init init_sbc_gxx(void)
{
iomapadr = ioremap(WINDOW_START, WINDOW_LENGTH);
if (!iomapadr) {
printk( KERN_ERR"%s: failed to ioremap memory region\n",
sbc_gxx_map.name );
return -EIO;
}
if (!request_region( PAGE_IO, PAGE_IO_SIZE, "SBC-GXx flash")) {
printk( KERN_ERR"%s: IO ports 0x%x-0x%x in use\n",
sbc_gxx_map.name,
PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1 );
iounmap(iomapadr);
return -EAGAIN;
}
printk( KERN_INFO"%s: IO:0x%x-0x%x MEM:0x%x-0x%x\n",
sbc_gxx_map.name,
PAGE_IO, PAGE_IO+PAGE_IO_SIZE-1,
WINDOW_START, WINDOW_START+WINDOW_LENGTH-1 );
/* Probe for chip. */
all_mtd = do_map_probe( "cfi_probe", &sbc_gxx_map );
if( !all_mtd ) {
cleanup_sbc_gxx();
return -ENXIO;
}
all_mtd->owner = THIS_MODULE;
/* Create MTD devices for each partition. */
mtd_device_register(all_mtd, partition_info, NUM_PARTITIONS);
return 0;
}
module_init(init_sbc_gxx);
module_exit(cleanup_sbc_gxx);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arcom Control Systems Ltd.");
MODULE_DESCRIPTION("MTD map driver for SBC-GXm and SBC-GX1 series boards");