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// SPDX-License-Identifier: GPL-2.0
/*
* Common code to handle map devices which are simple ROM
* (C) 2000 Red Hat.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
static int maprom_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
static int maprom_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
static void maprom_nop (struct mtd_info *);
static struct mtd_info *map_rom_probe(struct map_info *map);
static int maprom_erase (struct mtd_info *mtd, struct erase_info *info);
static int maprom_point (struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, void **virt, resource_size_t *phys);
static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
static struct mtd_chip_driver maprom_chipdrv = {
.probe = map_rom_probe,
.name = "map_rom",
.module = THIS_MODULE
};
static unsigned int default_erasesize(struct map_info *map)
{
const __be32 *erase_size = NULL;
erase_size = of_get_property(map->device_node, "erase-size", NULL);
return !erase_size ? map->size : be32_to_cpu(*erase_size);
}
static struct mtd_info *map_rom_probe(struct map_info *map)
{
struct mtd_info *mtd;
mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
if (!mtd)
return NULL;
map->fldrv = &maprom_chipdrv;
mtd->priv = map;
mtd->name = map->name;
mtd->type = MTD_ROM;
mtd->size = map->size;
mtd->_point = maprom_point;
mtd->_unpoint = maprom_unpoint;
mtd->_read = maprom_read;
mtd->_write = maprom_write;
mtd->_sync = maprom_nop;
mtd->_erase = maprom_erase;
mtd->flags = MTD_CAP_ROM;
mtd->erasesize = default_erasesize(map);
mtd->writesize = 1;
mtd->writebufsize = 1;
__module_get(THIS_MODULE);
return mtd;
}
static int maprom_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;
if (!map->virt)
return -EINVAL;
*virt = map->virt + from;
if (phys)
*phys = map->phys + from;
*retlen = len;
return 0;
}
static int maprom_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
return 0;
}
static int maprom_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
struct map_info *map = mtd->priv;
map_copy_from(map, buf, from, len);
*retlen = len;
return 0;
}
static void maprom_nop(struct mtd_info *mtd)
{
/* Nothing to see here */
}
static int maprom_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
{
return -EROFS;
}
static int maprom_erase (struct mtd_info *mtd, struct erase_info *info)
{
/* We do our best 8) */
return -EROFS;
}
static int __init map_rom_init(void)
{
register_mtd_chip_driver(&maprom_chipdrv);
return 0;
}
static void __exit map_rom_exit(void)
{
unregister_mtd_chip_driver(&maprom_chipdrv);
}
module_init(map_rom_init);
module_exit(map_rom_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("MTD chip driver for ROM chips");
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