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