diff options
Diffstat (limited to 'drivers/mtd/chips/map_rom.c')
| -rw-r--r-- | drivers/mtd/chips/map_rom.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/mtd/chips/map_rom.c b/drivers/mtd/chips/map_rom.c new file mode 100644 index 0000000000..0823b15aaa --- /dev/null +++ b/drivers/mtd/chips/map_rom.c @@ -0,0 +1,133 @@ +// 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"); |