^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Common code to handle map devices which are simple RAM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * (C) 2000 Red Hat. GPL'd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <asm/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/byteorder.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/mtd/mtd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/mtd/map.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) static int mapram_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) static int mapram_write (struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) static int mapram_erase (struct mtd_info *, struct erase_info *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static void mapram_nop (struct mtd_info *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static struct mtd_info *map_ram_probe(struct map_info *map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) static int mapram_point (struct mtd_info *mtd, loff_t from, size_t len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) size_t *retlen, void **virt, resource_size_t *phys);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static struct mtd_chip_driver mapram_chipdrv = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) .probe = map_ram_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) .name = "map_ram",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) .module = THIS_MODULE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) static struct mtd_info *map_ram_probe(struct map_info *map)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct mtd_info *mtd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /* Check the first byte is RAM */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) map_write8(map, 0x55, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) if (map_read8(map, 0) != 0x55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) map_write8(map, 0xAA, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (map_read8(map, 0) != 0xAA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /* Check the last byte is RAM */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) map_write8(map, 0x55, map->size-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (map_read8(map, map->size-1) != 0x55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) map_write8(map, 0xAA, map->size-1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) if (map_read8(map, map->size-1) != 0xAA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /* OK. It seems to be RAM. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) if (!mtd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) map->fldrv = &mapram_chipdrv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) mtd->priv = map;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) mtd->name = map->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) mtd->type = MTD_RAM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) mtd->size = map->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) mtd->_erase = mapram_erase;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) mtd->_read = mapram_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) mtd->_write = mapram_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) mtd->_panic_write = mapram_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) mtd->_point = mapram_point;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) mtd->_sync = mapram_nop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) mtd->_unpoint = mapram_unpoint;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) mtd->flags = MTD_CAP_RAM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) mtd->writesize = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) mtd->erasesize = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) while(mtd->size & (mtd->erasesize - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) mtd->erasesize >>= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) __module_get(THIS_MODULE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return mtd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) static int mapram_point(struct mtd_info *mtd, loff_t from, size_t len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) size_t *retlen, void **virt, resource_size_t *phys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) struct map_info *map = mtd->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) if (!map->virt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) *virt = map->virt + from;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) if (phys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) *phys = map->phys + from;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) *retlen = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) static int mapram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) struct map_info *map = mtd->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) map_copy_from(map, buf, from, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) *retlen = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) struct map_info *map = mtd->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) map_copy_to(map, to, buf, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) *retlen = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) /* Yeah, it's inefficient. Who cares? It's faster than a _real_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) flash erase. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) struct map_info *map = mtd->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) map_word allff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) unsigned long i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) allff = map_word_ff(map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) for (i=0; i<instr->len; i += map_bankwidth(map))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) map_write(map, allff, instr->addr + i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) static void mapram_nop(struct mtd_info *mtd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /* Nothing to see here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) static int __init map_ram_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) register_mtd_chip_driver(&mapram_chipdrv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) static void __exit map_ram_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) unregister_mtd_chip_driver(&mapram_chipdrv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) module_init(map_ram_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) module_exit(map_ram_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) MODULE_DESCRIPTION("MTD chip driver for RAM chips");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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