1 // SPDX-License-Identifier: GPL-2.0
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/map.h>
24 static int mapram_point (struct mtd_info *mtd, loff_t from, size_t len,
26 static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
31 	.name	= "map_ram",
37 	struct mtd_info *mtd;  in map_ram_probe()  local
50 	map_write8(map, 0x55, map->size-1);  in map_ram_probe()
51 	if (map_read8(map, map->size-1) != 0x55)  in map_ram_probe()
54 	map_write8(map, 0xAA, map->size-1);  in map_ram_probe()
55 	if (map_read8(map, map->size-1) != 0xAA)  in map_ram_probe()
60 	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);  in map_ram_probe()
61 	if (!mtd)  in map_ram_probe()
64 	map->fldrv = &mapram_chipdrv;  in map_ram_probe()
65 	mtd->priv = map;  in map_ram_probe()
66 	mtd->name = map->name;  in map_ram_probe()
67 	mtd->type = MTD_RAM;  in map_ram_probe()
68 	mtd->size = map->size;  in map_ram_probe()
69 	mtd->_erase = mapram_erase;  in map_ram_probe()
70 	mtd->_read = mapram_read;  in map_ram_probe()
71 	mtd->_write = mapram_write;  in map_ram_probe()
72 	mtd->_panic_write = mapram_write;  in map_ram_probe()
73 	mtd->_sync = mapram_nop;  in map_ram_probe()
74 	mtd->flags = MTD_CAP_RAM;  in map_ram_probe()
75 	mtd->writesize = 1;  in map_ram_probe()
78 	if (map->phys != NO_XIP) {  in map_ram_probe()
79 		mtd->_point = mapram_point;  in map_ram_probe()
80 		mtd->_unpoint = mapram_unpoint;  in map_ram_probe()
83 	mtd->erasesize = PAGE_SIZE;  in map_ram_probe()
84  	while(mtd->size & (mtd->erasesize - 1))  in map_ram_probe()
85 		mtd->erasesize >>= 1;  in map_ram_probe()
88 	return mtd;  in map_ram_probe()
91 static int mapram_point(struct mtd_info *mtd, loff_t from, size_t len,  in mapram_point()  argument
94 	struct map_info *map = mtd->priv;  in mapram_point()
96 	if (!map->virt)  in mapram_point()
97 		return -EINVAL;  in mapram_point()
98 	*virt = map->virt + from;  in mapram_point()
100 		*phys = map->phys + from;  in mapram_point()
105 static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)  in mapram_unpoint()  argument
110 static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)  in mapram_read()  argument
112 	struct map_info *map = mtd->priv;  in mapram_read()
119 static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char …  in mapram_write()  argument
121 	struct map_info *map = mtd->priv;  in mapram_write()
128 static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)  in mapram_erase()  argument
132 	struct map_info *map = mtd->priv;  in mapram_erase()
137 	for (i=0; i<instr->len; i += map_bankwidth(map))  in mapram_erase()
138 		map_write(map, allff, instr->addr + i);  in mapram_erase()
142 static void mapram_nop(struct mtd_info *mtd)  in mapram_nop()  argument
163 MODULE_DESCRIPTION("MTD chip driver for RAM chips");