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158 lines
3.7 KiB
158 lines
3.7 KiB
/* |
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* Common code to handle map devices which are simple RAM |
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* (C) 2000 Red Hat. GPL'd. |
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*/ |
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <asm/io.h> |
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#include <asm/byteorder.h> |
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#include <linux/errno.h> |
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#include <linux/slab.h> |
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#include <linux/init.h> |
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#include <linux/mtd/mtd.h> |
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#include <linux/mtd/map.h> |
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static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *); |
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static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *); |
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static int mapram_erase (struct mtd_info *, struct erase_info *); |
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static void mapram_nop (struct mtd_info *); |
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static struct mtd_info *map_ram_probe(struct map_info *map); |
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static int mapram_point (struct mtd_info *mtd, loff_t from, size_t len, |
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size_t *retlen, void **virt, resource_size_t *phys); |
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static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len); |
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static struct mtd_chip_driver mapram_chipdrv = { |
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.probe = map_ram_probe, |
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.name = "map_ram", |
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.module = THIS_MODULE |
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}; |
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static struct mtd_info *map_ram_probe(struct map_info *map) |
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{ |
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struct mtd_info *mtd; |
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/* Check the first byte is RAM */ |
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#if 0 |
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map_write8(map, 0x55, 0); |
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if (map_read8(map, 0) != 0x55) |
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return NULL; |
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map_write8(map, 0xAA, 0); |
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if (map_read8(map, 0) != 0xAA) |
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return NULL; |
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/* Check the last byte is RAM */ |
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map_write8(map, 0x55, map->size-1); |
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if (map_read8(map, map->size-1) != 0x55) |
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return NULL; |
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map_write8(map, 0xAA, map->size-1); |
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if (map_read8(map, map->size-1) != 0xAA) |
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return NULL; |
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#endif |
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/* OK. It seems to be RAM. */ |
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mtd = kzalloc(sizeof(*mtd), GFP_KERNEL); |
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if (!mtd) |
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return NULL; |
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map->fldrv = &mapram_chipdrv; |
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mtd->priv = map; |
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mtd->name = map->name; |
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mtd->type = MTD_RAM; |
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mtd->size = map->size; |
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mtd->_erase = mapram_erase; |
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mtd->_read = mapram_read; |
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mtd->_write = mapram_write; |
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mtd->_panic_write = mapram_write; |
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mtd->_point = mapram_point; |
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mtd->_sync = mapram_nop; |
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mtd->_unpoint = mapram_unpoint; |
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mtd->flags = MTD_CAP_RAM; |
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mtd->writesize = 1; |
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mtd->erasesize = PAGE_SIZE; |
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while(mtd->size & (mtd->erasesize - 1)) |
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mtd->erasesize >>= 1; |
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__module_get(THIS_MODULE); |
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return mtd; |
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} |
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static int mapram_point(struct mtd_info *mtd, loff_t from, size_t len, |
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size_t *retlen, void **virt, resource_size_t *phys) |
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{ |
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struct map_info *map = mtd->priv; |
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if (!map->virt) |
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return -EINVAL; |
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*virt = map->virt + from; |
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if (phys) |
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*phys = map->phys + from; |
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*retlen = len; |
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return 0; |
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} |
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static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) |
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{ |
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return 0; |
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} |
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static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) |
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{ |
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struct map_info *map = mtd->priv; |
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map_copy_from(map, buf, from, len); |
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*retlen = len; |
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return 0; |
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} |
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static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) |
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{ |
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struct map_info *map = mtd->priv; |
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map_copy_to(map, to, buf, len); |
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*retlen = len; |
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return 0; |
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} |
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static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr) |
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{ |
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/* Yeah, it's inefficient. Who cares? It's faster than a _real_ |
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flash erase. */ |
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struct map_info *map = mtd->priv; |
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map_word allff; |
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unsigned long i; |
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allff = map_word_ff(map); |
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for (i=0; i<instr->len; i += map_bankwidth(map)) |
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map_write(map, allff, instr->addr + i); |
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return 0; |
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} |
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static void mapram_nop(struct mtd_info *mtd) |
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{ |
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/* Nothing to see here */ |
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} |
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static int __init map_ram_init(void) |
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{ |
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register_mtd_chip_driver(&mapram_chipdrv); |
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return 0; |
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} |
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static void __exit map_ram_exit(void) |
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{ |
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unregister_mtd_chip_driver(&mapram_chipdrv); |
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} |
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module_init(map_ram_init); |
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module_exit(map_ram_exit); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("David Woodhouse <[email protected]>"); |
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MODULE_DESCRIPTION("MTD chip driver for RAM chips");
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