linux/drivers/mtd/maps/uclinux.c
Mike Frysinger fa254ecbcc mtd: uclinux: allow systems to override map addr/size
Due to a processor anomaly (05000263 to be exact), most Blackfin parts
cannot keep the embedded filesystem image directly after the kernel in
RAM.  Instead, the filesystem needs to be relocated to the end of memory.
As such, we need to tweak the map addr/size during boot for Blackfin
systems.  This can be done in any early arch/board init code.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Paul Mundt <lethal@linux-sh.org>
CC: Greg Ungerer <gerg@uclinux.org>
CC: uclinux-dev@uclinux.org
CC: linux-mtd@lists.infradead.org
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-05 18:29:14 +01:00

122 lines
2.9 KiB
C

/****************************************************************************/
/*
* uclinux.c -- generic memory mapped MTD driver for uclinux
*
* (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
*/
/****************************************************************************/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/major.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <asm/io.h>
/****************************************************************************/
extern char _ebss;
struct map_info uclinux_ram_map = {
.name = "RAM",
.phys = (unsigned long)&_ebss,
.size = 0,
};
struct mtd_info *uclinux_ram_mtdinfo;
/****************************************************************************/
struct mtd_partition uclinux_romfs[] = {
{ .name = "ROMfs" }
};
#define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs)
/****************************************************************************/
int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, void **virt, resource_size_t *phys)
{
struct map_info *map = mtd->priv;
*virt = map->virt + from;
if (phys)
*phys = map->phys + from;
*retlen = len;
return(0);
}
/****************************************************************************/
static int __init uclinux_mtd_init(void)
{
struct mtd_info *mtd;
struct map_info *mapp;
mapp = &uclinux_ram_map;
if (!mapp->size)
mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
mapp->bankwidth = 4;
printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n",
(int) mapp->phys, (int) mapp->size);
mapp->virt = ioremap_nocache(mapp->phys, mapp->size);
if (mapp->virt == 0) {
printk("uclinux[mtd]: ioremap_nocache() failed\n");
return(-EIO);
}
simple_map_init(mapp);
mtd = do_map_probe("map_ram", mapp);
if (!mtd) {
printk("uclinux[mtd]: failed to find a mapping?\n");
iounmap(mapp->virt);
return(-ENXIO);
}
mtd->owner = THIS_MODULE;
mtd->point = uclinux_point;
mtd->priv = mapp;
uclinux_ram_mtdinfo = mtd;
add_mtd_partitions(mtd, uclinux_romfs, NUM_PARTITIONS);
return(0);
}
/****************************************************************************/
static void __exit uclinux_mtd_cleanup(void)
{
if (uclinux_ram_mtdinfo) {
del_mtd_partitions(uclinux_ram_mtdinfo);
map_destroy(uclinux_ram_mtdinfo);
uclinux_ram_mtdinfo = NULL;
}
if (uclinux_ram_map.virt) {
iounmap((void *) uclinux_ram_map.virt);
uclinux_ram_map.virt = 0;
}
}
/****************************************************************************/
module_init(uclinux_mtd_init);
module_exit(uclinux_mtd_cleanup);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
MODULE_DESCRIPTION("Generic RAM based MTD for uClinux");
/****************************************************************************/