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/*
* MTD map driver for flash on the DC21285 (the StrongARM-110 companion chip)
*
* (C) 2000 Nicolas Pitre <nico@cam.org>
*
* This code is GPL
*
* $Id: dc21285.c,v 1.6 2001/10/02 15:05:14 dwmw2 Exp $
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
#include <asm/hardware/dec21285.h>
static struct mtd_info *mymtd;
__u8 dc21285_read8(struct map_info *map, unsigned long ofs)
{
return *(__u8*)(map->map_priv_1 + ofs);
}
__u16 dc21285_read16(struct map_info *map, unsigned long ofs)
{
return *(__u16*)(map->map_priv_1 + ofs);
}
__u32 dc21285_read32(struct map_info *map, unsigned long ofs)
{
return *(__u32*)(map->map_priv_1 + ofs);
}
void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
{
memcpy(to, (void*)(map->map_priv_1 + from), len);
}
void dc21285_write8(struct map_info *map, __u8 d, unsigned long adr)
{
*CSR_ROMWRITEREG = adr;
adr &= ~3;
*(__u8*)(map->map_priv_1 + adr) = d;
}
void dc21285_write16(struct map_info *map, __u16 d, unsigned long adr)
{
*CSR_ROMWRITEREG = adr;
adr &= ~1;
*(__u16*)(map->map_priv_1 + adr) = d;
}
void dc21285_write32(struct map_info *map, __u32 d, unsigned long adr)
{
*(__u32*)(map->map_priv_1 + adr) = d;
}
void dc21285_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
switch (map->buswidth) {
case 4:
while (len > 0) {
__u32 d = *((__u32*)from)++;
dc21285_write32(map, d, to);
to += 4;
len -= 4;
}
break;
case 2:
while (len > 0) {
__u16 d = *((__u16*)from)++;
dc21285_write16(map, d, to);
to += 2;
len -= 2;
}
break;
case 1:
while (len > 0) {
__u8 d = *((__u8*)from)++;
dc21285_write8(map, d, to);
to++;
len--;
}
break;
}
}
struct map_info dc21285_map = {
name: "DC21285 flash",
size: 16*1024*1024,
read8: dc21285_read8,
read16: dc21285_read16,
read32: dc21285_read32,
copy_from: dc21285_copy_from,
write8: dc21285_write8,
write16: dc21285_write16,
write32: dc21285_write32,
copy_to: dc21285_copy_to
};
/* Partition stuff */
static struct mtd_partition *dc21285_parts;
extern int parse_redboot_partitions(struct mtd_info *, struct mtd_partition **);
int __init init_dc21285(void)
{
/* Determine buswidth */
switch (*CSR_SA110_CNTL & (3<<14)) {
case SA110_CNTL_ROMWIDTH_8:
dc21285_map.buswidth = 1;
break;
case SA110_CNTL_ROMWIDTH_16:
dc21285_map.buswidth = 2;
break;
case SA110_CNTL_ROMWIDTH_32:
dc21285_map.buswidth = 4;
break;
default:
printk (KERN_ERR "DC21285 flash: undefined buswidth\n");
return -ENXIO;
}
printk (KERN_NOTICE "DC21285 flash support (%d-bit buswidth)\n",
dc21285_map.buswidth*8);
/* Let's map the flash area */
dc21285_map.map_priv_1 = (unsigned long)__ioremap(DC21285_FLASH, 16*1024*1024, 0);
if (!dc21285_map.map_priv_1) {
printk("Failed to ioremap\n");
return -EIO;
}
mymtd = do_map_probe("cfi_probe", &dc21285_map);
if (mymtd) {
int nrparts;
mymtd->module = THIS_MODULE;
/* partition fixup */
nrparts = parse_redboot_partitions(mymtd, &dc21285_parts);
if (nrparts <=0) {
printk(KERN_NOTICE "RedBoot partition table failed\n");
iounmap((void *)dc21285_map.map_priv_1);
return -ENXIO;
}
add_mtd_partitions(mymtd, dc21285_parts, nrparts);
/*
* Flash timing is determined with bits 19-16 of the
* CSR_SA110_CNTL. The value is the number of wait cycles, or
* 0 for 16 cycles (the default). Cycles are 20 ns.
* Here we use 7 for 140 ns flash chips.
*/
/* access time */
*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
/* burst time */
*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
/* tristate time */
*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
return 0;
}
iounmap((void *)dc21285_map.map_priv_1);
return -ENXIO;
}
static void __exit cleanup_dc21285(void)
{
if (mymtd) {
del_mtd_device(mymtd);
map_destroy(mymtd);
mymtd = NULL;
}
if (dc21285_map.map_priv_1) {
iounmap((void *)dc21285_map.map_priv_1);
dc21285_map.map_priv_1 = 0;
}
if(dc21285_parts)
kfree(dc21285_parts);
}
module_init(init_dc21285);
module_exit(cleanup_dc21285);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
MODULE_DESCRIPTION("MTD map driver for DC21285 boards");
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