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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 unsigned long mapram_unmapped_area(struct mtd_info *, unsigned long,
24 unsigned long, unsigned long);
25
26
27static struct mtd_chip_driver mapram_chipdrv = {
28 .probe = map_ram_probe,
29 .name = "map_ram",
30 .module = THIS_MODULE
31};
32
33static struct mtd_info *map_ram_probe(struct map_info *map)
34{
35 struct mtd_info *mtd;
36
37 /* Check the first byte is RAM */
38#if 0
39 map_write8(map, 0x55, 0);
40 if (map_read8(map, 0) != 0x55)
41 return NULL;
42
43 map_write8(map, 0xAA, 0);
44 if (map_read8(map, 0) != 0xAA)
45 return NULL;
46
47 /* Check the last byte is RAM */
48 map_write8(map, 0x55, map->size-1);
49 if (map_read8(map, map->size-1) != 0x55)
50 return NULL;
51
52 map_write8(map, 0xAA, map->size-1);
53 if (map_read8(map, map->size-1) != 0xAA)
54 return NULL;
55#endif
56 /* OK. It seems to be RAM. */
57
58 mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
59 if (!mtd)
60 return NULL;
61
62 map->fldrv = &mapram_chipdrv;
63 mtd->priv = map;
64 mtd->name = map->name;
65 mtd->type = MTD_RAM;
66 mtd->size = map->size;
67 mtd->erase = mapram_erase;
68 mtd->get_unmapped_area = mapram_unmapped_area;
69 mtd->read = mapram_read;
70 mtd->write = mapram_write;
71 mtd->sync = mapram_nop;
72 mtd->flags = MTD_CAP_RAM;
73 mtd->writesize = 1;
74
75 mtd->erasesize = PAGE_SIZE;
76 while(mtd->size & (mtd->erasesize - 1))
77 mtd->erasesize >>= 1;
78
79 __module_get(THIS_MODULE);
80 return mtd;
81}
82
83
84/*
85 * Allow NOMMU mmap() to directly map the device (if not NULL)
86 * - return the address to which the offset maps
87 * - return -ENOSYS to indicate refusal to do the mapping
88 */
89static unsigned long mapram_unmapped_area(struct mtd_info *mtd,
90 unsigned long len,
91 unsigned long offset,
92 unsigned long flags)
93{
94 struct map_info *map = mtd->priv;
95 return (unsigned long) map->virt + offset;
96}
97
98static int mapram_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
99{
100 struct map_info *map = mtd->priv;
101
102 map_copy_from(map, buf, from, len);
103 *retlen = len;
104 return 0;
105}
106
107static int mapram_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
108{
109 struct map_info *map = mtd->priv;
110
111 map_copy_to(map, to, buf, len);
112 *retlen = len;
113 return 0;
114}
115
116static int mapram_erase (struct mtd_info *mtd, struct erase_info *instr)
117{
118 /* Yeah, it's inefficient. Who cares? It's faster than a _real_
119 flash erase. */
120 struct map_info *map = mtd->priv;
121 map_word allff;
122 unsigned long i;
123
124 allff = map_word_ff(map);
125
126 for (i=0; i<instr->len; i += map_bankwidth(map))
127 map_write(map, allff, instr->addr + i);
128
129 instr->state = MTD_ERASE_DONE;
130
131 mtd_erase_callback(instr);
132
133 return 0;
134}
135
136static void mapram_nop(struct mtd_info *mtd)
137{
138 /* Nothing to see here */
139}
140
141static int __init map_ram_init(void)
142{
143 register_mtd_chip_driver(&mapram_chipdrv);
144 return 0;
145}
146
147static void __exit map_ram_exit(void)
148{
149 unregister_mtd_chip_driver(&mapram_chipdrv);
150}
151
152module_init(map_ram_init);
153module_exit(map_ram_exit);
154
155MODULE_LICENSE("GPL");
156MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
157MODULE_DESCRIPTION("MTD chip driver for RAM chips");