linux-sg2042/drivers/mtd/maps/uclinux.c

144 lines
3.5 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>
#include <asm/sections.h>
/****************************************************************************/
#ifdef CONFIG_MTD_ROM
#define MAP_NAME "rom"
#else
#define MAP_NAME "ram"
#endif
/*
* Blackfin uses uclinux_ram_map during startup, so it must not be static.
* Provide a dummy declaration to make sparse happy.
*/
extern struct map_info uclinux_ram_map;
struct map_info uclinux_ram_map = {
.name = MAP_NAME,
.size = 0,
};
static unsigned long physaddr = -1;
module_param(physaddr, ulong, S_IRUGO);
static struct mtd_info *uclinux_ram_mtdinfo;
/****************************************************************************/
static struct mtd_partition uclinux_romfs[] = {
{ .name = "ROMfs" }
};
#define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs)
/****************************************************************************/
static 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 (physaddr == -1)
mapp->phys = (resource_size_t)__bss_stop;
else
mapp->phys = physaddr;
if (!mapp->size)
mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
mapp->bankwidth = 4;
printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
(int) mapp->phys, (int) mapp->size);
/*
* The filesystem is guaranteed to be in direct mapped memory. It is
* directly following the kernels own bss region. Following the same
* mechanism used by architectures setting up traditional initrds we
* use phys_to_virt to get the virtual address of its start.
*/
mapp->virt = phys_to_virt(mapp->phys);
if (mapp->virt == 0) {
printk("uclinux[mtd]: no virtual mapping?\n");
return(-EIO);
}
simple_map_init(mapp);
mtd = do_map_probe("map_" MAP_NAME, mapp);
if (!mtd) {
printk("uclinux[mtd]: failed to find a mapping?\n");
return(-ENXIO);
}
mtd->owner = THIS_MODULE;
mtd->_point = uclinux_point;
mtd->priv = mapp;
uclinux_ram_mtdinfo = mtd;
mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
return(0);
}
/****************************************************************************/
static void __exit uclinux_mtd_cleanup(void)
{
if (uclinux_ram_mtdinfo) {
mtd_device_unregister(uclinux_ram_mtdinfo);
map_destroy(uclinux_ram_mtdinfo);
uclinux_ram_mtdinfo = NULL;
}
if (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 MTD for uClinux");
/****************************************************************************/